CN113827562A

CN113827562A - Stable pharmaceutical compositions of clopidogrel free base for oral and parenteral administration

Info

Publication number: CN113827562A
Application number: CN202111171945.6A
Authority: CN
Inventors: 黄敬珺
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-02-06
Filing date: 2014-02-06
Publication date: 2021-12-24
Also published as: CN105188671A

Abstract

The present invention provides a ready-to-use oil/water emulsion composition having an average oil droplet size (average intensity, nm) of between 100 and 500nm, wherein the oil phase comprises clopidogrel free base dispersed in a pharmaceutically acceptable oil. The present emulsions use clopidogrel free base or a pre-mixture of clopidogrel free base in oil as the drug substance and may also contain one or more excipients, such as: surfactants and/or co-surfactants, osmotic agents, pH adjusters, antioxidants, preservatives, sweeteners, and/or suspending agents, and the like. Compared with other aqueous matrix formulas (for example, a cyclodextrin matrix formula and an emulsion which use a clopidogrel salt as a raw material drug), the formula and the preparation method of the emulsion obviously improve the stability of clopidogrel in the aspects of chiral conversion, hydrolysis and thermal degradation. The ready-to-use emulsion composition is administered parenterally or orally, with a single dose of up to 300mg of clopidogrel; it can be stored at ambient conditions for at least 19 weeks after preparation, or at refrigeration temperatures for at least 1 year. The composition can be used as an antiplatelet agent to play a rapid treatment role for patients who need emergency treatment, intensive care or can not swallow tablets.

Description

Stable pharmaceutical compositions of clopidogrel free base for oral and parenteral administration

The present application is a divisional application of chinese patent application 201480007796.1 entitled "stable clopidogrel free base pharmaceutical composition for oral and parenteral administration", filed 2/6/2014.

Priority

This application claims priority to U.S. provisional patent application No. 61/761,234, filed 2013, 2, 6, d.c., the content of which is incorporated herein by reference.

Technical Field

The invention relates to a clopidogrel oil/water emulsion composition, which obviously improves the stability of clopidogrel against chiral conversion, hydrolysis and thermal degradation by dispersing clopidogrel free alkali in an oil phase; methods of preparing and using clopidogrel compositions are described herein when a mammalian, and particularly a human subject, is in need of treatment with clopidogrel.

Background

Clopidogrel, its chemical name is: methyl (+) - (S) -alpha- (0-chlorophenyl) -6, 7-dihydrothieno [3,2-C ]) pyridine-5 (4H) -acetate, clopidogrel is an anticoagulant that inhibits platelet aggregation by selectively inhibiting the binding of Adenosine Diphosphate (ADP) to platelet receptors for ADP. It is widely used for preventing atherosclerotic events such as myocardial infarction, stroke, peripheral artery disease, acute coronary syndrome, cardiovascular death. The S-form enantiomer structure of clopidogrel is as follows:

clopidogrel (for example:

and other pharmaceuticals) has been marketed as a tablet formulation containing 75mg of clopidogrel free base, clopidogrel being present in the formulation as a sulfate. In the marketed products, no parenteral or oral liquid preparations have been presented.

Is an anti-platelet aggregation drug approved by the Food and Drug Administration (FDA) to reduce thrombotic events and acute coronary syndrome. For the average dose (300 mg)

Or clopidogrel) to achieve the desired therapeutic effect (e.g.: inhibiting platelet aggregation) requires between 2-5h, which can be attributed to delayed absorption, delayed availability of the system, poor bioavailability. If this treatment is required immediately (e.g. Percutaneous Coronary Intervention (PCI) is required in less than 2 to 3 hours), it is generally necessary to administer to the patient a greater than average dose of clopidogrel, in order to achieve a rapid onset of action, but this may cause potentially fatal side effects such as: bleeding and prolonged bleeding.

Therefore, there is an urgent need for a clopidogrel liquid preparation which can be administered parenterally or orally to achieve rapid onset and gradual controlled administration dosage. The key to the use of clopidogrel for the preparation of a intravenous parenteral or oral liquid formulation is the ability to place clopidogrel in a biocompatible solvent with low side effects and a suitable pharmacodynamic profile and to prepare it into a prescription; clopidogrel formulations present a serious challenge due to its lipid solubility, pH dependence and extremely low solubility at physiological pH, and extreme chemical instability at alkaline pH.

Clopidogrel is a weak base with pKa 4.5, which is almost insoluble in water at neutral pH, but is very soluble in solution at pH1, is very soluble in methanol, partially soluble in dichloromethane, and almost insoluble in diethyl ether. Its specific rotation is about +56 °. Clopidogrel free base is a semi-solid high viscosity oily substance which causes various problems during storage or handling thereof. In addition, clopidogrel free base is reported to be unsuitable for the preparation of pharmaceutical formulations because clopidogrel free base is unstable under an environment of increased humidity and temperature. Because of the proton instability of clopidogrel free base at the chiral center and the methyl ester group, clopidogrel free base is susceptible to racemization, oxidation, and hydrolysis of the methyl ester group. Antioxidants are reported to be unable to inhibit their degradation, and higher pH values exacerbate their instability. Literature reports so far indicate that clopidogrel can ensure the stability only by combining with acid to form a salt before being prepared into a preparation.

Clopidogrel hydrogen sulfate, currently applied to marketed oral tablet products

(SanofiAventis), which is an example of the clopidogrel salt form used in oral formulations, provides clopidogrel free base in a tablet dosage form having a specification of 75 mg. Like clopidogrel free base, clopidogrel bisulfate is relatively unstable under conditions of increased humidity, temperature, alkaline pH media due to its sensitivity to racemization, oxidation, hydrolysis of methyl ester groups. Clopidogrel is a chiral molecule with R, S enantiomers; the S enantiomer has biological activity, and the R enantiomer (impurity C) does not have any anticoagulation activity and has poor tolerance; animals can induce convulsions at high doses. Most of the clopidogrel entering the general circulation after administration is converted into an inactive carboxylic acid derivative, which is formed by the hydrolysis of ester functions catalyzed by a carboxylesterase. Carboxylic acid derivative (+) -S- (o-chlorophenyl) -6, 7-dihydrothiophene [3,2-c]Pyridine-5 (4H) -acetic acid (clopidogrel acid, impurity A)Obtainable by hydrolysis of an ester function; the carboxylic acid derivatives as hydrolysis products, whether catalytically produced by increasing humidity, pH, temperature in vitro or by carboxylesterase catalysis in vivo, are major degradation products with no pharmacological activity. This means that the clopidogrel drug substance or formulation product must have a fine control of the content of the R-enantiomer as well as the inactive carboxylic acid derivative. The main impurities of clopidogrel are recorded in the 32 th edition of the United states pharmacopoeia and the structure diagram of the European pharmacopoeia as follows:

clopidogrel has low solubility in an aqueous solution of neutral pH, making it difficult to develop a bioavailable and physico-chemically stable formulation product, particularly when patients require intravenous administration or oral solutions. The solubility of clopidogrel is highly pH-dependent, which makes it a great challenge to develop an aqueous parenteral preparation that is suitable for use, does not precipitate when it comes into contact with body fluids, and does not cause pain in the parenteral region, phlebitis, or vascular embolism. In addition, the chemical instability of clopidogrel, which is manifested by the instability of clopidogrel in wet, hot and alkaline pH environments, eliminates the use of aqueous solvents in the formulation, limits the product formulation to liquid formulations or freeze-dried solid formulations using organic solvents as a matrix, and strictly limits the storage conditions to lower storage temperatures, such as refrigeration or freezing.

A number of processes are available for preparing intravenous parenteral and oral liquid compositions of poorly soluble or poorly soluble drugs. These techniques mainly include: micellar solubilization or formation of nanoparticle suspensions of the drug by surfactants; forming a composition with cyclodextrin and its derivatives (hydroxypropyl β -cyclodextrin (HPBCD) and sulfobutyl ether- β -cyclodextrin (SBECD)); the use of multiple co-solvent systems; salt formation with strong acids in low pH solutions. However, for micellar systems, the surfactants used therein have a close correlation with adverse effects, such as: such as hemolytic and histamine reactions and severe allergic reactions; for nanosuspension systems, since nanoparticle size stability of the drug particles requires a certain amount of polymer and surfactant, catalytic degradation of the drug due to greater contact area of the drug with the aqueous medium and the peripherally surrounding surfactant has been reported; taste masking and parenteral pain are still a great problem faced by micellar/nanosuspension systems due to the higher concentration of free drug in the aqueous medium. It is well known that cosolvent systems cause precipitation, parenteral pain and phlebitis. Cyclodextrins and their derivatives can cause potential nephrotoxicity and bradycardia and blood pressure reduction; concerns have been raised about the association of cyclodextrins with co-administered lipophilic drugs. Formation of weakly basic salts such as clopidogrel hydrogen sulfate with strong acids in a low pH solution will cause problems in stability of the drug-excipient and the drug product and will cause problems in taste (clopidogrel has a bitter taste), and the drug, when present as a free base, will precipitate upon contact with blood at neutral pH, causing irritation and pain at the parenteral site. In summary, the above methods have their limitations, and it is difficult to prepare clopidogrel as an intravenous parenteral or oral solution with a suitable biocompatible solvent, minimal side effects, and a proper pharmacodynamic profile.

WO2008/060934 discloses an emulsion composition that stabilizes oil droplets of a prepared pure tetrahydropyridine antiplatelet drug by micronization and addition of a surfactant. The preparation does not use vegetable oil, and only uses pure antiplatelet drugs and surfactants. Although the patent mentions that the matrix can be applied to clopidogrel, the patent only discloses an emulsion composition using clopidogrel bisulfate as a raw material drug, and the preparation of an emulsion composition using clopidogrel free base as a raw material drug is not disclosed in the patent; the effect of the formulation on the product stability of clopidogrel free base or various salts of clopidogrel, particularly the effect of the composition on the distribution of impurities related to clopidogrel, is not disclosed in this patent.

CN102697724 discloses a method for preparing oil-in-water emulsion by using clopidogrel hydrogen sulfate and amino acid salt thereof as raw material medicines. However, this patent does not embrace a process for preparing an emulsion composition using clopidogrel free base as the drug substance, and clopidogrel is too low in concentration (< 0.15% w/v) in the formulation that ultimately forms the emulsion composition, which may require large amounts of emulsion to achieve a dosage requirement of 300 mg; and the influence of the dosage form on the stability of products caused by various salt forms of clopidogrel, particularly the influence of the combination on the related impurity distribution of clopidogrel is not disclosed in the patent.

Summary of The Invention

In order to solve the drawbacks and problems of the prior art, there is a need in the art to develop a clopidogrel liquid dosage form, particularly a parenteral formulation that is stable in quality, ready to use, can provide a single intravenous parenteral 300mg clopidogrel dose, is rapid in onset of action, and can be formulated and stored at room temperature or refrigerated temperature. The present patent provides compositions that can provide antiplatelet drugs to patients in emergency and intensive care situations, or in situations where oral administration is not available to the patient. The stability and purity of the product both meet the preparation requirements of the United states Food and Drug Administration (FDA) and GMP for pharmaceutical preparations.

In view of the above problems, the present invention provides a clopidogrel free base-containing oil/water parenteral or oral emulsion composition having an average particle size of 100-. Wherein the oil phase comprises clopidogrel free base dispersed in an oil containing a surfactant and/or co-surfactant at acceptable concentration limits, unexpectedly resulting in a product having good stability and an excellent profile of impurities when the oil phase is subjected to a pH of about 9 to 10, or to an autoclave with water or steam; the product still has excellent quality after long-term storage.

The present invention describes a method for controlling clopidogrel impurity content within a range conforming to the impurity content regulation of clopidogrel tablets formulated in the United States Pharmacopeia (USP)32 edition when clopidogrel is placed as an active substance in a pharmaceutical composition. Compared with other aqueous matrix formulas (such as cyclodextrin matrix formulas) and formulas using clopidogrel salt (such as clopidogrel hydrogen sulfate), the emulsion formula has the advantages that the stability of clopidogrel in chiral conversion, hydrolysis and thermal degradation is remarkably improved.

1. One aspect of the present invention is that the aqueous matrix emulsions prepared significantly reduce hydrolysis of the methyl ester groups (impurity a); although clopidogrel itself is very unstable in an alkaline pH environment, the emulsion formulation of the present invention is prepared in a pH9-10 environment while minimizing hydrolysis of clopidogrel during its shelf life, whereas clopidogrel not formulated is completely degraded in the same solution as the above conditions, which is formulated with NaOH, in only 5 minutes.

2. Another aspect of the present invention is that the prepared emulsion effectively inhibits thermal degradation of clopidogrel. It is reported in the literature that clopidogrel is easily oxidized due to unstable proton of the chiral center thereof, and degradation thereof cannot be inhibited even by adding an antioxidant. Contrary to literature conclusions, the emulsion formulation of the present invention effectively inhibits thermal degradation of clopidogrel without using an antioxidant.

3. Another aspect of the invention is that the emulsions prepared according to the invention effectively inhibit the chiral conversion of clopidogrel from the S-enantiomer (biologically active) to the R-enantiomer (in the absence of any anti-aggregation activity and poorly tolerated) (impurity C < 1.5%). In contrast, cyclodextrin inclusion compound solutions or emulsions using clopidogrel salt forms (e.g., clopidogrel bisulfate) as the drug substance form appreciable amounts of the R-enantiomer during preparation or storage.

4. Another aspect of the present invention is that pharmaceutical compositions prepared using the processes described herein minimize or reduce the levels of drug-related impurities, either during manufacture or during storage.

a) This is particularly true. The pharmaceutical composition described in the present invention uses clopidogrel as an effective active substance, and the content of impurities conforms to the impurities regulation for clopidogrel tablets in the United States Pharmacopeia (USP)32 edition.

b) More specifically, the pharmaceutical composition described herein uses clopidogrel as an active substance, and the pharmaceutical composition contains only clopidogrel-related substance a of not more than 1.2%, clopidogrel-related substance C of not more than 1.5%, none of the other single-drug-related impurities exceeds 0.2% (excluding clopidogrel-related substance B), and total impurities does not exceed 2.5% (excluding clopidogrel-related substance B).

5. In another aspect, the present invention is directed to a method of treating or alleviating a disease state in a subject in need of the formulation, comprising providing to the subject a pharmaceutical composition having clopidogrel free base as an effective active substance and containing an effective amount of less impurities or minimized impurities, the impurities not exceeding 2.5% of the total drug content (except for clopidogrel-related substance B). Any disease or condition such as those described herein can be treated with a medicament comprising clopidogrel, thereby preventing atherosclerotic events such as myocardial infarction, stroke, peripheral arterial disease, acute coronary syndrome, cardiovascular and cerebrovascular death and other cardiovascular diseases.

It is an object of the present invention to provide a stable, nano-sized oil droplet containing, oil/water emulsion composition for parenteral or oral use, which emulsion is composed of clopidogrel free base, surfactant, optionally co-surfactant, aqueous phase substantially free of clopidogrel, pH adjusting agent dispersed in oil phase.

It is another object of the present invention to provide a method for preparing a stable, parenteral or oral oil-in-water emulsion composition comprising nano-scale oil droplets, the method essentially comprising the steps of: a) dispersing clopidogrel free alkali in an oily carrier to prepare an oil phase; b) preparing an aqueous phase comprising water and a pH adjusting agent; c) adding a surfactant or optionally a co-surfactant to the aqueous or oil phase; d) dispersing the oil phase in the aqueous phase to form a crude emulsion, and if necessary adjusting the pH to-9; e) c, carrying out ultrasonic treatment or high-pressure homogenization treatment on the emulsion obtained in the step d to form a final emulsion, and adjusting the pH to be 5.5-10; f) filtering the final emulsion; g) the bioburden or sterility of the product is controlled by aseptic processing or terminal sterilization.

It is another object of the present invention to provide a method of treatment for a patient in need of a single high dose administration of clopidogrel, comprising: a) providing a liquid formulation of an oil/water emulsion composition by dispersing clopidogrel free base in an oily carrier; preparing water phase from water and a pH regulator; dispersing the oil phase into the water phase through ultrasonic treatment or high-pressure homogenization treatment to form oil drops with nanometer particle size, and finally preparing the oil drop; b) a single oral or parenteral dose of the composition comprising up to 300mg of clopidogrel free base.

Drawings

FIG. 1 illustrates the average droplet size (average intensity, nm) of emulsions prepared from clopidogrel free base (example 10) or clopidogrel bisulfate (example 8) after autoclaving, or freeze-thaw conditions, or exposure to refrigeration (-5 ℃) conditions for 1 year

FIG. 2 illustrates an HPLC chromatogram of a clopidogrel free base emulsion (example 10) after being subjected to refrigeration conditions (-5 ℃) for 1 year.

FIG. 3 compares the percentage of chiral conversion of clopidogrel from the S-enantiomer to the R-enantiomer after storage of the clopidogrel emulsion of the present invention (example 10) with clopidogrel-HPBCD and SBECD compositions at about pH8, all at 40 ℃.

FIG. 4 compares the percentage of chiral conversion of clopidogrel from the S-enantiomer to the R-enantiomer of clopidogrel (example 10) with clopidogrel-HPBCD and SBECD compositions at about pH8, all stored at 25 ℃.

FIG. 5 compares the percentage of chiral conversion of clopidogrel from the S-enantiomer to the R-enantiomer when both the clopidogrel emulsion of the present invention (example 10) and the clopidogrel salt type emulsion (example 8) are stored at 40 ℃.

FIG. 6 is a graph showing the droplet size distribution of a newly formulated emulsion sample, an emulsion sample stored at room temperature for 19 weeks, and an emulsion sample stored at 40 ℃ for 19 weeks, all superimposed on the emulsion described in example 6.

Detailed description of the invention

"clopidogrel drug substance" or "clopidogrel free base" is defined as: methyl (+) - (S) -alpha- (0-chlorophenyl) -6, 7-dihydrothieno [3,2-C ]) pyridine-5 (4H) -acetate.

"clopidogrel-related substance a" or "impurity a" is defined as: (+) -S- (o-chlorophenyl) -6, 7-dihydrothiophene [3,2-c ] pyridine-5 (4H) -acetic acid.

"clopidogrel-related substance B" or "impurity B" is defined as: methyl (±) - (o-chlorophenyl) -4, 5-dihydrothiophene [2,3-c ] pyridine-6 (7H) -acetate.

"clopidogrel-related substance C" or "impurity C" is defined as: methyl (-) - (R) - (o-chlorophenyl) -6, 7-dihydrothiophene [3,2-c ] pyridine-5 (4H) -acetate.

The invention provides an aqueous base oil/water emulsion formula composition with the average particle size of 100-500nm, which comprises clopidogrel free alkali, a surfactant and/or a cosurfactant and an aqueous liquid carrier in oil. The prescription of the invention comprises the following components:

a) clopidogrel free base;

b) an oil phase;

c) a surfactant and/or co-surfactant;

d) water and a pH regulator.

Optional ingredients for the emulsion formulation further include: chelating agent, antioxidant, penetrant, suspending agent, preservative and buffering agent.

In some embodiments, the formulation further comprises a solubilizing agent, a flavoring agent, a sweetener, a viscosity increasing agent, an electrolyte, another therapeutic agent, or a combination thereof.

Different combinations of clopidogrel with other ingredients within the allowed dosage ranges, as described in the claims of the present invention, can be used to provide different embodiments of the present invention. The invention also provides a method for administration of clopidogrel for immediate use, which comprises dissolving clopidogrel free base in an oil phase, and encapsulating the oil phase in an aqueous phase.

The emulsion of the invention has better stability and less side effect compared with other organic matrix or aqueous matrix preparations (such as cyclodextrin matrix preparation). The oil/water emulsion also inhibits the adhesion of lipophilic clopidogrel to the walls of plastic parenteral devices. The invention provides the clopidogrel emulsion which can be prepared at room temperature or under refrigeration condition and can keep stable, and the administration mode does not need to be diluted. In addition, the emulsion has the advantages of rapid release and rapid onset of action compared with other oral tablets.

In some embodiments, the formulation is administered to a patient without dilution. In other embodiments, the liquid formulation may be diluted and ensure that clopidogrel precipitation does not occur. The formulations of the present invention may be administered in a single dose or in multiple doses.

Modes of administration of the liquid formulation of some embodiments of the present invention include parenteral administration, oral administration, or enteral administration. The present invention provides a method of treatment which prevents or reduces the development of complications of platelet aggregation, or which is effective in treating conditions requiring clopidogrel therapy, which method includes administration to a subject as required by the present invention. The invention also provides a method for reducing the time to onset of therapeutic action or reducing the time to achieve a target therapeutic effect by administering the clopidogrel formulation of the invention to a subject in a parenteral, oral, enteral mode as desired. The formulations of the present invention may reduce the onset of therapeutic action or reduce the time required to achieve a target therapeutic effect compared to oral tablets. The formulation of the present invention allows administration of a low dose of clopidogrel to achieve a target therapeutic effect, for example, with respect to bleeding time or a platelet aggregation inhibition target, as compared to a solid oral formulation, administration of a low dose of clopidogrel using the formulation of the present invention to achieve the same target therapeutic effect.

According to one embodiment of the invention, the emulsion comprises

a) 0.01-10% w/w clopidogrel free base;

b) 1-30% w/w of an oil phase;

c) 0.5-5.4% w/w surfactant;

d) 0-0.5% of any co-surfactant; and

d) 60-99% w/w water with a pH adjusting agent, e.g. sodium hydroxide to adjust the pH

Clopidogrel free base uses its S-enantiomer as the bulk drug. The S-enantiomer is biologically active, the R enantiomer (impurity C) is free of any anticoagulant activity and poorly tolerated.

Clopidogrel bisulfate, an active pharmaceutical ingredient used in the marketed tablet product, is mainly the S-enantiomer according to the 32 th edition of the United States Pharmacopeia (USP), and contains not more than 0.2% of a clopidogrel-related substance a, not more than 0.3% of a first enantiomer of a clopidogrel-related substance B, not more than 1.0% of a clopidogrel-related substance C, not more than 0.1% of any other found drug-related impurities, and a total drug-related impurity content of not more than 1.5%.

According to the United States Pharmacopeia (USP)32 edition, as a tablet product on the market, the content of the clopidogrel-related substance a is not more than 1.2%, the content of the clopidogrel-related substance C is not more than 1.5%, the content of any single impurity is not more than 0.2% (except for the clopidogrel-related substance B), and the content of total impurities of the drug is not more than 2.5% (except for the clopidogrel-related substance B) after the preparation and during the storage.

Because the free base of the clopidogrel is unstable under the conditions of increased temperature and humidity, and the methyl ester group of the free base is easy to racemize, oxidize and hydrolyze; the free base of the clopidogrel can be stabilized only by being acidified into a salt before being prepared into a pharmaceutical preparation; it is therefore generally accepted that clopidogrel free base is not suitable for use in the preparation of pharmaceutical formulations. The present invention surprisingly found a new phenomenon, which, unlike the previous general opinion, shows better stability after emulsion made with clopidogrel free base than after emulsion made with clopidogrel salt. Because of its low solubility in the oils available for formulation, clopidogrel salt has a low partition ratio between the oil phase and the aqueous phase. Therefore, the encapsulation efficiency of the clopidogrel salt in the oil phase is low. Unless very high doses of surfactant or solvent are used, it is clearly not suitable to use clopidogrel salt as the drug substance to prepare emulsions and achieve higher drug loadings (> 0.15% clopidogrel free base loading) in the range of doses that can be tolerated by a single dose administered (e.g. 300mg in 100ml solvent or less by volume). Otherwise, the clopidogrel may be separated out from the oil phase, dissolved or precipitated in the water phase; this will cause problems of homogeneity of the product (there are two forms of dispersion, one in which the clopidogrel is dissolved in the oil phase and the other in which the free clopidogrel is suspended in the aqueous medium); as a result of direct exposure of clopidogrel to water, ionizing catalytic degradation reactions, clopidogrel will present stability problems; problems with parenteral irritation/pain, taste masking of oral formulations, physical stability (sedimentation) of intravenous parenteral administration, etc. will also occur. In one embodiment of the invention, clopidogrel free base is used as a drug substance, which is dissolved in oil that can be used in formulation formulations to make compositions; in another embodiment, the clopidogrel free base is obtained using a technique in which a clopidogrel salt is converted to the free base, and the counter ion is separated from the free base prior to the preparation of the formulation.

The preferred range for clopidogrel free base in the formulation is 0.15 to 10%, most preferably 0.2 to 3%.

The oil phase in the emulsion is a pharmaceutical grade oil, preferably triglycerides, such as, but not limited to, soybean oil, safflower oil, olive oil, cottonseed oil, sunflower oil, fish oil (including omega-3 fatty acids, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA)), castor oil, sesame oil, peanut oil, corn oil, medium chain triglycerides (e.g., Miglyol812or 810). The oil phase may contain surfactants and/or co-surfactants such as egg yolk lecithin, soy lecithin, other lecithins, propylene glycol diesters, oleic acid, or monoglycerides (e.g., acetyl monoglyceride). The oil phase may also be a mixed component.

Preferred oil phases are soybean oil, Medium Chain Triglycerides (MCT), olive oil, fish oil, either as individual ingredients or as a mixture with other ingredients.

The most preferred oil phase is soybean oil. The preferred range of oil carrier is 5-30%, the most preferred range of oil carrier is 10-20%.

The surfactant is any pharmaceutically acceptable surfactant, preferably phospholipid compounds extracted from egg yolk or soybean, synthetic phosphatidylcholine, and phosphatidylcholine purified from plants. It is also possible to use hydrogenated derivatives, such as: hydrogenated phosphatidylcholine (egg yolk) and hydrogenated phosphatidylcholine (soybean). The surfactant may also be a non-ionic surfactant, for example: poloxamers (e.g., poloxamer 188, poloxamer 407), losamide, polyoxyethylene stearate, polyoxyethylene sorbitan fatty acid esters or sorbitan fatty acid esters. Ionic surfactants may also be used, for example: cholic acid,

The preferred surfactant is egg yolk lecithin. A preferred range is 0.6-2.4%, and a most preferred range is 1.2-1.8%.

The cosurfactant is selected from oleic acid, sodium oleate, cholic acid, sodium cholate, deoxycholic acid, sodium deoxycholate, or mixture thereof; wherein the co-surfactant according to the invention is present in the composition in the range of 0-0.5 w/v%.

The preferred buffer has water in the range of 70-90%.

The emulsion may also contain co-solvents or other solubility enhancers, chelating agents, preservatives, antioxidants, stabilizers, pH adjusting agents or tonicity adjusting agents, such as: glycerin, polymers as suspending agents, sweeteners, and the like.

The ideal emulsion is a stable system with a mean droplet size of 100-1000nm, white to off-white. The preferred average droplet size is 100-500 nm; the most preferred mean droplet size is 100-300 nm.

Preferred emulsions have a pH range of 5.5 and above 5.5 after preparation and during storage. In one embodiment, the pH of the emulsion is controlled to be in the range of 5.5-7; in another embodiment, the pH of the emulsion is controlled to be in the range of 7 to 10. The pH range of the preferred emulsion is 6.5-9. The pH adjusting agent may be a buffer or sodium hydroxide or other pH adjusting agent, or a mixture of the above.

The emulsion of the present invention can be prepared by the following method: for the aqueous phase, the pharmaceutical grade water is dispersed in a vessel and heated to 40-80 deg.C, egg yolk lecithin and glycerol are added to the aqueous phase, and the pH is finally adjusted to 9-10. For the oil phase, the soybean oil should be dispersed in another container and heated to 40-80 deg.C; adding clopidogrel and any cosurfactant into soybean oil, and heating to 40-80 ℃; in addition, egg yolk lecithin may also be added to the oil phase. The aqueous phase was mixed with the oil phase using a high shear mixer to form a coarse emulsion. The coarse emulsion is prepared into emulsion with ideal microdroplet particle size by ultrasonic treatment, high-pressure homogenization treatment or microfluidization technology under the conditions of 5000-. The pH is adjusted to 5.5-10 by means of a pH adjusting agent, for example 1N sodium hydroxide solution. In one embodiment, the pH is adjusted to 9-10; in another embodiment, the pH is adjusted to 7-10; in yet another embodiment, the pH is adjusted to 8-10. The sample was filtered and dispersed in a clean grade bottle, the external environment was typically nitrogen blanketed, plugged with a siliconized rubber stopper, and finally sealed with an aluminum cap. The product should be prepared by aseptic processing or terminal sterilized. The preferred unit dose is a sterile and stable emulsion obtained by autoclaving techniques. In one embodiment, the emulsion should be autoclaved at 121 ℃ for 15-20 minutes. In another embodiment, the emulsion should be prepared in a sterile environment without the use of autoclaving techniques.

The invention will now be described by way of non-limiting examples. The invention consists of embodiments of the examples and detailed descriptions of various aspects of the invention. Accordingly, the invention includes single elements of the embodiments of the examples as well as different combinations of aspects of the invention as described herein. Furthermore, the present invention includes other features, advantages and embodiments that will be derived by those skilled in the art from the technical disclosure and related examples of the following sections. The disclosure herein includes all possible variations and modifications of the factors and methods. Furthermore, the embodiments are defined and illustrated for exemplary purposes, and are not intended to be exclusive or limited to what is described. The invention includes variations and modifications that would be recognized by those skilled in the art without departing from the spirit of the invention.

Example 1 comparison of drug partitioning ratio of clopidogrel hydrogen sulfate and clopidogrel free base between oil and aqueous phases

In order to determine the proportion of the clopidogrel in the oil phase and the water phase, the invention respectively determines the proportion of the clopidogrel hydrogen sulfate and the clopidogrel free alkali in the oil phase and the water phase, and 600mg of the drug is weighed and added into a beaker containing 20g of each of soybean oil and deionized water. The mixture was stirred at room temperature for 24 hours. Thereafter, the samples were separated from the two phases and tested using the HPLC chromatographic conditions described in example 14. And the pH of the aqueous phase was measured.

Table 1 shows that about 50% of clopidogrel will enter the aqueous phase when experiments are carried out with clopidogrel hydrogen sulfate. In contrast, when the experiment was carried out using clopidogrel free base, only a very small amount of clopidogrel entered the aqueous phase. This indicates that clopidogrel free base is more suitable than clopidogrel hydrogen sulfate as a drug substance in an emulsion if we wish to minimize the amount of clopidogrel entering the aqueous phase. Otherwise, the formulation will have problems of homogenization and stability.

TABLE 1 partitioning of drugs between oil and aqueous phases

Example 2 preparation of an emulsion Using Clopyrrolidine free base obtained from a supplier

Formulation of	Quantity:
			keke (Chinese character of 'Keke')
Clopidogrel free base	0.20
		Soybean oil	10.0
Egg yolk lecithin	1.2
		Glycerol	2.25
Sodium hydroxide	Adjusting pH to 9-10
		Water for parenteral use	To 100g

All preparation processes were carried out under nitrogen protection.

The sterile aqueous oil-in-water emulsion for parenteral administration is prepared as follows:

1. the aqueous phase was prepared using glycerol and parenteral water. The pH of the aqueous phase was adjusted to 9-10 using 1N sodium hydroxide solution. Mixing was continued with stirring and heating to 60 ℃.

2. The aqueous phase was filtered using a 0.22 micron filter and charged to a mixing vessel.

3. Meanwhile, the soybean oil filtered by a 0.22 micron filter, the clopidogrel free alkali and the egg yolk lecithin are put into a mixing container to prepare an oil phase. Mixing with stirring was continued and heating to 60 ℃ was continued until all ingredients had dissolved.

4. And adding the mixed oil phase into the water phase.

5. The mixture was stirred using a high shear mixer (Polytron PT3100) at 10,000rpm for 5 minutes to give a crude emulsion. Adjusting the pH of the emulsion to 9-10.

6. The crude emulsion was sonicated for 30 minutes using a sonicator (Fisher Scientific Sonic Dismembator, Model 500). And the product temperature was controlled at 45 ℃.

7. Cooling the resulting oil-in-water emulsion; if necessary, adjusting the pH to 9-10; finally the emulsion was transferred to a filling container.

8. The emulsion was filtered under nitrogen using a 0.45 micron filter and filled into containers, for example. Finally autoclaving at 121 ℃ for 20 minutes.

9. The final product had a pH of 8.

Example 3 preparation of an emulsion Using Clopyrrolidine free base obtained from the supplier

Formulation of	Quantity:
			keke (Chinese character of 'Keke')
Clopidogrel free base	0.6
		Soybean oil	10.0
Egg yolk lecithin	1.8
		Glycerol	2.25
Sodium hydroxide	Adjusting pH to 9-10
		Water for parenteral use	To 100g

All preparation processes were carried out under nitrogen protection.

1. the aqueous phase was prepared using egg yolk lecithin, glycerol and parenteral water. The pH of the aqueous phase was adjusted to 9-10 using 1N sodium hydroxide solution. Mixing was continued with stirring and heating to 60 ℃.

3. Meanwhile, the soybean oil filtered by a 0.22 micron filter and the clopidogrel free alkali are placed in a mixing container to prepare an oil phase. Mixing with stirring was continued and heating to 60 ℃ was continued until all ingredients had dissolved.

4. And adding the mixed oil phase into the water phase.

6. The crude emulsion was homogenized using a high pressure homogenizer (APV2000) at a pressure of 10,000psi for 10 cycles. And the product temperature was controlled at 45 ℃.

9. The final product had a pH of 8.

Example 4 preparation of an emulsion Using Clopyrrolidine free base obtained from the supplier

Formulation of	Quantity:
			keke (Chinese character of 'Keke')
Clopidogrel free base	3.0
		Soybean oil	10.0
Egg yolk lecithin	1.2
		Glycerol	2.25
Sodium hydroxide	Adjusting pH to 9-10
		Water for parenteral use	To 100g

All preparation processes were carried out under nitrogen protection.

3. Meanwhile, the soybean oil filtered by a 0.22 micron filter, lecithin and clopidogrel free alkali are placed in a mixing container to prepare an oil phase. Mixing with stirring was continued and heating to 60 ℃ was continued until all ingredients had dissolved.

4. And adding the mixed oil phase into the water phase which is continuously stirred at high speed.

9. The final product had a pH of 8.

Example 5 preparation of an emulsion by aseptic technique Using clopidogrel free base obtained from the supplier

Preparation of emulsions Using Clopyrrolidine free base obtained from the supplier as drug substance

Formulation of	Quantity:
			keke (Chinese character of 'Keke')
Clopidogrel free base	3.0
		Soybean oil	10.0
Egg yolk lecithin	1.8
		Glycerol	2.25
Vitamin E	0.06
		Sodium hydroxide	Adjusting pH to 8-10
Water for parenteral use	To 100g

All preparation processes were carried out under nitrogen protection.

4. And adding the mixed oil phase into the water phase.

7. Cooling the resulting oil-in-water emulsion; if necessary, adjusting the pH value to 8-10; finally the emulsion was transferred to a filling container.

8. The emulsion was filtered under nitrogen using a 0.45 micron filter and filled into containers, for example.

9. The final product had a pH of 8.

Example 6 preparation of an emulsion by aseptic Process Using Clopyrrolidine free base obtained from the supplier

Formulation of	Quantity:
			keke (Chinese character of 'Keke')
Clopidogrel free base	3.0
		Soybean oil	10.0
Egg yolk lecithin	1.2
		Glycerol	2.25
Sodium hydroxide	Adjusting pH to 8-10
		Water for parenteral use	To 100g

All preparation processes were carried out under nitrogen protection.

5. The mixture was stirred using a high shear mixer (polytron pt3100) at 6,000rpm for 5 minutes to give a crude emulsion. Adjusting the pH of the emulsion to 9-10.

9. The pH of the final product was about 8.

Example 7 preparation of an emulsion Using clopidogrel free base obtained from a supplier

Emulsion is prepared by using clopidogrel free alkali as a raw material medicine, lecithin as a surfactant and oleic acid as a cosurfactant

Formulation of	Quantity:
			keke (Chinese character of 'Keke')
Clopidogrel free base	0.2
		Soybean oil	10.0
Egg yolk lecithin	1.2
		Oleic acid	0.03
Glycerol	2.25
		Sodium hydroxide	Adjusting pH to 9-10
Water for parenteral use	To 100g

All preparation processes were carried out under nitrogen protection.

1. the aqueous phase was prepared using glycerol, egg yolk lecithin and parenteral water. The pH of the aqueous phase was adjusted to 9-10 using 1N sodium hydroxide solution. Mixing was continued with stirring and heating to 60 ℃.

3. Meanwhile, the soybean oil filtered by a 0.22 micron filter, oleic acid and clopidogrel free alkali are placed in a mixing container to prepare an oil phase. Mixing with stirring was continued and heating to 60 ℃ was continued until all ingredients had dissolved.

6. The crude emulsion was sonicated for 30 minutes using a sonicator (FisherScientific sonic Dismembator, Model 500). And the product temperature was controlled at 45 ℃.

7. Cooling the resulting oil-in-water emulsion; adjusting the pH value to 9-10; finally the emulsion was transferred to a filling container.

9. The pH of the final product was about 8.

EXAMPLE 8 preparation of an emulsion using clopidogrel hydrogen sulfate (reference preparation)

This example is prepared by the same procedure as described in example 2 without autoclaving. The final product pH was 7.4.

Example 9 preparation of an emulsion Using clopidogrel free base

Formulation of	Quantity:
			keke (Chinese character of 'Keke')
Clopidogrel free base	2.0
		Soybean oil	10.0
Egg yolk lecithin	1.2
		Glycerol	2.25
Sodium hydroxide	Adjusting pH to 9-10
		Water for parenteral use	To 100g

The procedure for this example was as described in example 2. The final product had a pH of 8.

Example 10 an emulsion was prepared using clopidogrel free base premixed in soybean oil;

the clopidogrel hydrogen sulfate is converted into clopidogrel free base before the emulsion is prepared, and sulfate ions are separated from the clopidogrel free base.

All preparation processes were carried out under nitrogen protection.

A preparation method of premixing free base of clopidogrel in soybean oil.

Dissolving clopidogrel bisulfate in sufficient water. While stirring continuously, the desired soybean oil is dispersed in the aqueous phase, and a 1N sodium hydroxide solution is gradually dropped, for example, into the aqueous phase mixture until the pH of the aqueous phase reaches 6.5 or more. Separating an oil phase containing clopidogrel free base from an aqueous phase containing sulfate ions and sodium ions; if necessary, the oil phase is washed with water.

1. the drug-oil premix was stirred at 60 ℃, the oil phase filtered through a 0.22 micron filter, and charged to a mixing vessel.

2. The aqueous phase was prepared using glycerol, egg yolk lecithin and parenteral water. The pH of the aqueous phase was adjusted to 9-10 using 1N sodium hydroxide solution. Mixing was continued with stirring and heating to 60 ℃.

3. The aqueous phase was filtered using a 0.22 micron filter and charged to a mixing vessel.

5. The mixture was stirred using a high shear mixer (polytron pt3100) at 10,000rpm for 5 minutes to give a crude emulsion.

6. The crude emulsion was homogenized using a high pressure homogenizer at a pressure of 10,000psi for 5 cycles. And the product temperature was controlled at 45 ℃.

8. The emulsion was filtered under nitrogen using a 0.45 micron filter and filled into containers. Finally autoclaving at 121 ℃ for 20 minutes.

9. The final product had a pH of 8.

Example 11 preparation of an emulsion Using clopidogrel free base

Formulation of	Quantity:
			keke (Chinese character of 'Keke')
Clopidogrel free base	0.20
		Soybean oil	10.0
Egg yolk lecithin	1.8
		Glycerol	2.25
Vitamin E	0.06
		Sodium hydroxide	Adjusting pH to 9-10
Water for parenteral use	To 100g

The procedure for this example was as described in example 3. The final product had a pH of 8.

Example 12 preparation of an emulsion Using clopidogrel free base

Formulation of	Quantity:
			keke (Chinese character of 'Keke')
Clopidogrel free base	2.8
		Soybean oil	0.17
Egg yolk lecithin	0.54
		Glycerol	2.25
Sodium hydroxide	Adjusting pH to 9-10
		Water for parenteral use	To 100g

Example 13 comparison of the differences in droplet size distribution characteristics of emulsions prepared using clopidogrel free base and clopidogrel hydrogen sulfate by a NanoZetasizer

Particle size distribution testing was performed using the emulsions prepared in examples 8 and 10. The emulsion was tested for droplet size distribution using a Malvern Zetasizer Nano-ZSSEN 3600. FIG. 1 shows the average droplet size (average intensity, nm) of emulsions prepared using clopidogrel free base (example 10) and clopidogrel hydrogen sulfate (example 8), respectively. Emulsions prepared using clopidogrel free base are very stable after storage for 1 year under autoclaving, freeze-thawing and refrigeration conditions, whereas emulsions prepared using clopidogrel hydrogen sulfate show drastic changes in particle size after autoclaving, freeze-thawing.

Example 14 comparison of the chemical stability of compositions Using emulsions of the invention with SB-E-CD and HP-B-CD

HPLC chromatographic conditions

Chiral liquid chromatography was used to detect impurity and enantiomer contents. The stationary phase used ULTRONES-OVM column, 5um (4.6 mm. times.150 mm. i.d.). The composition of the mobile phase was: phase A, adding 1.36g sodium dihydrogen phosphate (NaH2PO4.H2O) into 1L pure water; phase B, acetonitrile; isoconcentrate elution was performed at a constant flow rate of 1.0mL/min for 18 min run time; the sample injection volume is 5-10 ul; the UV detection wavelength was 220 nm.

The main degradation impurity of the clopidogrel emulsion prepared by the invention is impurity C (R-enantiomer); according to observations, hydrolysate impurity a (< 1.2%) in the emulsion product appeared less and did not change significantly. Thus, the indicator monitored for chemical stability of the emulsion of the invention is impurity C (fig. 2). The emulsions prepared using clopidogrel free base had better stability data than the cyclodextrin based clopidogrel solutions (fig. 3, fig. 4).

FIG. 3 shows the percentage conversion of the chiral structure of clopidogrel from the S enantiomer to the R enantiomer after storage of the clopidogrel emulsion prepared according to the invention (example 10) with a composition of clopidogrel-HPBCD, clopidogrel-SBECD (US20100292268) having a pH of about 8 at 40 ℃.

FIG. 4 shows the percentage conversion of the chiral structure of clopidogrel from the S enantiomer to the R enantiomer after storage of the clopidogrel emulsion prepared according to the invention (example 10) with a composition of clopidogrel-HPBCD, clopidogrel-SBECD (US20100292268) having a pH of about 8 at 25 ℃.

Example 15 comparison of the differences in chemical stability of emulsions prepared using clopidogrel free base (example 10) and clopidogrel sulfate (example 8)

The HPLC chromatographic conditions were the same as described in example 14.

The emulsion prepared using clopidogrel free base had better stability data than the emulsion prepared using clopidogrel hydrogen sulfate (figure 5).

FIG. 5 shows the percentage conversion of the chiral structure of clopidogrel from the S enantiomer to the R enantiomer after storage at 40 ℃ of an emulsion prepared with clopidogrel free base (example 10) and an emulsion prepared with clopidogrel hydrogen sulfate (example 8).

Example 16 summary of emulsion stability data for example 10

Table 2 shows stability data for the emulsions of example 10 stored under refrigerated conditions for at least 52 weeks

TABLE 2 stability data of the emulsions of example 10 stored under refrigerated conditions

Example 17 summary of emulsion stability data for example 6

Table 3, Table 4 show stability data for the emulsions of example 6 stored under refrigerated (-5 ℃) and room temperature (-25 ℃) conditions for at least 19 weeks

TABLE 3 stability of example 6 (25 ℃ C.)

TABLE 4 stability of example 6 (5 degree C)

Claims

1. A stable pharmaceutical oil/water emulsion composition containing nano-sized oil droplets for parenteral or oral administration comprising the following ingredients:

clopidogrel free base dispersed in the oil phase;

a surfactant and optionally a co-surfactant;

an aqueous phase substantially free of clopidogrel; and

a pH regulator.

Preferably, wherein the composition further comprises one or more ingredients selected from the group consisting of chelating agents, antioxidants, osmotic agents, preservatives, suspending agents and buffering agents.

Preferably, wherein the average oil droplet size (average intensity, nm) is 100-500 nm.

More preferably, wherein the average oil droplet particle diameter (average intensity, nm) is 100-300 nm.

2. The composition of claim 1, wherein the composition comprises no more than 1.2% impurity a, no more than 1.5% impurity C, and wherein the pH of the composition is above 5.5.

Preferably wherein the pH of the composition is from 5.5 to 10.

Preferably wherein the oil phase is present in the composition in a proportion of about 5 to 30% (w/v).

Preferably, wherein the oily phase is selected from the group of pharmaceutically acceptable oils comprising: triglycerides, such as: soybean oil, safflower seed oil, olive oil, sunflower seed oil, fish oil, castor oil, sesame oil, peanut oil and corn oil; medium chain triglycerides; or a mixture of the above ingredients.

More preferably wherein the oil is selected from soybean oil, fish oil, medium chain triglycerides, olive oil, or mixtures thereof.

Still more preferably, wherein the oil is soybean oil.

Preferably wherein the composition comprises 0.1-10% (w/v) clopidogrel free base.

3. The composition of claim 1 or 2, wherein the composition comprises 0.15-3% (w/v) clopidogrel free base.

Preferably wherein the total weight of the surfactant and optional co-surfactant is 0.5-6% (w/v) of the composition.

Preferably, the composition comprises 0.5-5.5% (w/v) surfactant with 0-0.5% (w/v) optional co-surfactant:

wherein said surfactant is selected from the group consisting of pharmaceutically acceptable surfactants including phospholipids extracted from egg yolk or soy, synthetic phosphatidylcholines or plant-purified phosphatidylcholines, hydrogenated phospholipid derivatives; nonionic surfactants include poloxamers (e.g., poloxamer 188, poloxamer 407), losamide, polyoxyethylene stearate, polyoxyethylene sorbitan fatty acid esters or sorbitan fatty acid esters; the ionic surfactant comprises cholic acid, deoxycholic acid or surface active derivatives and salts thereof; the optional co-surfactant is selected from oleic acid, sodium oleate, cholic acid, sodium cholate, deoxycholic acid, sodium deoxycholate, or a mixture thereof.

Preferably, the composition comprises 0.6-2.4% (w/v) surfactant and 0.0-0.5% (w/v) optional co-surfactant; wherein the surfactant is egg yolk lecithin and the co-surfactant is oleic acid or sodium oleate.

4. The composition of any one of claims 1-3, wherein the composition comprises 0.15-3% (w/v) clopidogrel free base, 10-20% (w/v) soybean oil, 1.2-1.8% (w/v) egg yolk lecithin, 2.25% (w/v) glycerin, sodium hydroxide, and water.

5. A process for preparing a stable pharmaceutical oil/water emulsion composition containing nano-sized oil droplets for parenteral or oral administration, said process comprising the steps of:

a) preparing an oil phase by dispersing clopidogrel free base in an oil carrier;

b) preparing an aqueous phase comprising water and a pH adjusting agent;

c) adding a surfactant or optionally a co-surfactant to the oil or water phase;

d) dispersing the oil phase in the aqueous phase to form a coarse emulsion and adjusting the pH to 9-10;

e) preparing the crude emulsion prepared in step d into a final emulsion by ultrasonic or high-pressure homogenization, and adjusting the pH to 5.5-10;

f) filtering the final emulsion; and

g) the bioburden or sterility of the product is controlled by the aseptic process or terminal sterilization.

Preferably, wherein the clopidogrel free base is obtained by converting clopidogrel hydrogen sulfate into clopidogrel free base and separating sulfate ions from the clopidogrel free base.

Preferably, wherein the clopidogrel free base is provided as a free base-oil carrier premix.

6. The method of claim 5, wherein the oil carrier is soybean oil, fish oil, medium chain triglycerides, olive oil, or mixtures thereof, and the surfactant is egg yolk lecithin.

7. The process of claim 5 or 6, wherein the product of step e is adjusted to a pH of 7-10.

8. A method of treatment for administering to a patient in need of a single high dose of clopidogrel, the method comprising:

a) providing a pharmaceutical oil/water emulsion composition in liquid form; the composition is prepared by the following method: dispersing clopidogrel free alkali in an oil carrier to prepare an oil phase, preparing a water phase by using water and a pH regulator, dispersing the oil phase in the water phase, and finally forming oil drops with nano particle sizes by using ultrasonic or high-pressure homogenization treatment; and

b) by oral or parenteral administration containing a single dose of the composition, the single dose should contain up to 300mg of clopidogrel free base.

9. The method according to claim 8, wherein a single dose of the composition should contain no more than 1.2% of impurity a and no more than 1.5% of impurity C.

10. The method of claim 8, wherein the composition is adjusted to a pH of 7-10 in step a.