CN115887420A - Slow-release film agent for mucous membrane and preparation method thereof - Google Patents

Abstract

The invention provides a slow-release film agent for mucous membranes and a preparation method thereof. The invention uses polyacrylic acid (Polyacrylic acid, PAA) and hydroxypropyl methyl cellulose (Hydroxypropyl methyl cellulose, HPMC) to form polymer hydrogen bonds IPC (interpolymer complexe, IPC) is used as the film-forming material of the sustained-release layer, coated on the waterproof backing layer, dried and cut to prepare the film. The obtained film of the present invention has a thickness of less than 0.1mm, has good comfort, adhesion, stability and slow-release effect, and its preparation method is simple, and can be used as a good slow-release carrier for drugs such as small molecules, polypeptides, proteins, etc. Drug action time, improve drug bioavailability.

Description

A sustained-release film preparation for mucosa and preparation method thereof

technical field

The invention belongs to the technical field of film preparations, and in particular relates to a slow-release film preparation for mucous membranes and a preparation method thereof.

Background technique

Films are defined in the Pharmacopoeia of the People's Republic of China as film-like preparations processed from raw materials and suitable film-forming materials. Film formulations have a wide range of administration routes, including oral administration, sublingual administration, intraocular conjunctival sac and intravaginal administration, etc. Oral films have several advantages over other oral formulations, including ease of transport and storage; and ease of swallowing without additional fluids, especially for patients with dysphagia, vomiting, dyskinesias, and mental disorders. However, there are still some defects in the oral film that hinder its wide clinical application, mainly including: poor adhesion of the preparation, easy to fall off and translocate, disintegrate too fast and cannot maintain effective therapeutic blood concentration for a long time, etc. Therefore, increasing the adhesion and sustained release properties of oral films is a key element to improve the compliance, drug delivery efficiency, bioavailability and efficacy of oral films.

In recent years, many research reports have focused on microcrystalline cellulose (MCC), hydroxypropylmethylcellulose (HPMC), low-substituted hydroxypropylcellulose (L-HPC), polyethylene glycol (PEG), etc. Substrate, prepared oral film. This type of film dissolves quickly in the oral cavity, making it difficult to achieve sustained release administration. In addition, studies have reported that some multi-component mixed film formulations can achieve the purpose of sustained-release drug delivery, but due to the complexity of the preparation process of such film formulations, it increases the difficulty of large-scale industrial production.

Drug carriers for mucosa have received more and more attention in the field of sustained release. The drug carrier for mucosa can be attached to the surface of the mucosa, which can not only release the drug slowly, but also increase the absorption of the drug, so as to produce a sustained and good therapeutic effect. Common bioadhesive materials include polyacrylic acid (PAA), carboxymethylcellulose (CMC), chitosan (Chitosan, CS) and so on. However, these single-component polymer materials often have some limitations, which affect their applications. For example, PAA has high water solubility, which may lead to sudden drug release due to material dissolution.

Contents of the invention

Purpose of the invention: In order to solve the problems in the prior art, the present invention adopts the polymer hydrogen bond complex (interpolymer complexe, IPC) formed by the proton donor polymer PAA and the non-ionic proton acceptor polymer HPMC as the sustained-release layer component. The film material is coated on the waterproof backing layer, dried and cut to prepare a slow-release film for mucous membrane.

Technical solution: the invention discloses a slow-release film preparation for mucous membranes and a preparation method thereof. Specifically, PAA is used as a proton donor to form IPC with non-ionic proton acceptor polymer HPMC through hydrogen bonding. IPC is used as a film-forming material, coated on the waterproof backing layer, and cut to a suitable size to prepare a film. The film prepared by the invention has a thickness of less than 0.1 mm, has good comfort, adhesion and slow-release effect, and can be used as a good carrier for drugs such as small molecules, polypeptides and proteins. Concretely comprise following preparation steps:

(1) Take PAA and add water to stand still, after fully swelling, stir and dissolve to obtain solution I;

(2) Take HPMC and add water to stand still, after fully swelling, stir and dissolve to obtain solution II;

(3) Slowly add solution II to solution I to form a polymer hydrogen bond complex (IPC) solution, and then add additives and drugs to prepare a sustained-release layer solution;

(4) Take the water-insoluble film-forming material and dissolve it in the organic solvent, add additives, stir evenly, form a film, and prepare a waterproof backing layer;

(5) Spread the slow-release layer solution obtained in step (3) on the waterproof backing layer to prepare a slow-release layer, dry and cut to obtain a film.

Preferably, in step (1), the molecular weight of the proton donor polymer PAA is 5-3000 kDa; more preferably, the molecular weight of PAA is 3000 kDa.

Preferably, in step (3), the drug includes small molecules, polypeptides, protein drugs, etc., such as insulin, etc.

Preferably, in step (3), the additive includes propylene glycol (Propylene glycol, PG), castor oil (Castor oil, CO), triethyl citrate (Triethyl citrate, TEC), silicone oil (Silicone oil, SO) , glycerol (Glycerol, GL), diethyl phthalate (Diethyl phthalate, DEP) or one or more of dibutyl phthalate (Dibutyl phthalate, DBP); more preferably TEC.

Preferably, in step (3), the mass ratio of PAA in solution I to HPMC in solution II is 9:1˜1:9 (w/w); more preferably 3:2 (w/w).

Preferably, in step (3), slowly add solution II to solution I, adjust the pH to 3-9 (more preferably pH=3), and form polymer hydrogen at 40-80°C (more preferably 80°C) bond complex solution.

Preferably, in step (3), the additive also includes an inorganic salt, and the amount of the inorganic salt is: after mixing the solution I, solution II, the additive and the drug, adjust the salt ion concentration of the solution to 0.0125-0.075 mol/L; more preferably the ion concentration is 0.025mol/L.

Preferably, in step (4), the water-insoluble film-forming material is selected from ethyl cellulose (Ethyl cellulose, EC), cellulose acetate (Cellulose acetate, CA), ethylene-vinylacetate copolymer (Ethylene-vinylacetate copolymer , EVA), hydroxypropyl methylcellulose phthalate (HPMCP), phthalate cellulose acetate (Cellulose phthalate acetate, CAP) and other materials; more preferably EC .

Preferably, in step (4), the organic solvent is one or more of solvents such as isopropanol, methylene chloride, acetone or ethanol; more preferably ethanol.

Preferably, in step (4), the additive includes propylene glycol (Propylene glycol, PG), castor oil (Castor oil, CO), triethyl citrate (Triethyl citrate, TEC), silicone oil (Silicone oil, SO) , glycerol (Glycerol, GL), diethyl phthalate (Diethyl phthalate, DEP) or one or more of dibutyl phthalate (Dibutyl phthalate, DBP); more preferably TEC and CO.

Preferably, in step (4) and step (5), the film-forming method of the waterproof backing layer or the slow-release layer is a coating method, and the preparation process parameters of the waterproof backing layer and the slow-release layer include: the thickness of the coating is 0.3- 1.5mm, the drying temperature is 30-60°C, and the drying time is 5-120min; the preferred coating thickness of the slow-release layer is 1.0mm, the drying temperature is 40°C, and the drying time is 90min; more preferably, the waterproof backing layer coating The thickness is 0.5mm, the drying temperature is 40°C, and the drying time is 5min.

Finally, the present invention also provides a slow-release film preparation for mucosa, which includes a waterproof backing layer and a slow-release layer coated on the waterproof backing layer. Acrylic acid and hydroxypropyl methylcellulose form a high molecular hydrogen bond complex and drug. Further, the sustained-release film preparation for mucosa is the sustained-release film preparation for mucosa prepared by the above preparation method.

The present invention forms IPC by using proton donor polymer material PAA and non-ionic cellulose polymer material HPMC under the action of hydrogen bonds, and uses IPC as a slow-release layer film-forming material to prepare a waterproof back Sustained-release film for the lining of the mucous membrane. Traditional film-forming materials may have limitations in application such as large thickness, poor adhesion, and poor sustained-release effect; some studies have also reported that some multi-component mixed film formulations can achieve the purpose of sustained-release drug delivery, but due to the The complexity of the preparation process of the film-like agent increases the difficulty of industrialized mass production. For example, proton donor polymers (such as PAA) can be used as a single film-forming material, which has the characteristics of good spreadability, good adhesion, and no irritation to the skin and mucous membranes, and is an excellent matrix for mucosal drug delivery. However, PAA has high water solubility, which will lead to sudden drug release due to the dissolution of the material. Non-ionic proton acceptor polymers (such as HPMC) are also often used as a single film-forming material, but due to the high viscosity of its aqueous solution, it is difficult to coat; and its adhesion is poor, and it is easy to fall off when used. In order to solve the above problems, the applicant innovatively mixed two kinds of high molecular polymers, and under certain conditions, the hydrogen bonding between polymer macromolecules was used to form IPC. The prepared IPC exhibits completely different properties and characteristics from single-component polymers, and has obvious advantages after being laid into a film: the thickness is less than 0.1mm, and it has good comfort; the adhesion to the mucous membrane is good, and it is not easy to Shedding; the release rate of the drug can be slowed down to achieve the effect of sustained release; the preparation process only involves mixing and film laying, the process is simple, and it is easy for industrial production.

The inventors investigated the influence of the above factors on the formation of IPC formed between PAA and HPMC by detecting the turbidity and viscosity changes of the solution under different conditions, and further proved the formation of IPC by FTIR detection. The IPC is used to prepare a sustained-release layer, which is coated on a waterproof backing layer prepared by a water-insoluble film-forming material to prepare a sustained-release film for mucous membranes. By examining the mechanical strength, appearance, and adhesion of the film, it is proved that the film prepared by IPC as the sustained-release layer has good mechanical strength, film-forming property, bioadhesion and tissue permeability. The applicant took insulin (Insulin, INS) as a model drug, and by investigating the in vitro release behavior of different formulations, it proved that the film loaded with INS has better sustained release ability. In addition, after subcutaneous injection or oral mucosal administration, the drug-time curve of INS in type Ⅰ diabetic rats was drawn. The results showed that, compared with subcutaneous injection, sustained-release mucosal formulations can sustainably lower blood sugar.

Beneficial effects: The present invention utilizes PAA and HPMC to form IPC as a film-forming material for the slow-release layer, which is coated on the waterproof backing layer, dried and cut to prepare a slow-release film for mucous membranes. The thickness of the film is about 0.1 mm, it has good comfort and adhesion, and shows good slow-release performance. It can be used as a carrier of oral administration route to prolong the drug action time and improve the curative effect; the preparation of the film The method is simple and easy for industrialized mass production.

Description of drawings

Figure 1 is a schematic diagram of the improved disintegration instrument used in the adhesion test of the present invention.

Fig. 2 is the screening result of the film-forming material of the present invention.

Fig. 3 is the investigation result of the influencing factors of IPC of the present invention.

Fig. 4 is an infrared result map of the IPC of the present invention.

Fig. 5 is a schematic diagram of the slow-release film preparation for mucosa of the present invention.

Fig. 6 is the DSC and SEM results of the sustained-release film formulation for mucosa of the present invention.

Fig. 7 is the investigation results of in vitro release degree, adhesion and permeability of the sustained-release film preparation for mucosa of the present invention.

Fig. 8 is the hypoglycemic effect and drug-time curve of the slow-release film agent for mucosa of the present invention acting on type I diabetic rats through oral mucosal administration.

Fig. 9 shows the safety evaluation (histological evaluation) of the sustained-release film preparation for mucosa of the present invention after administration through the oral mucosa.

Detailed ways

The present invention can be better understood from the following examples. However, the contents described in the embodiments are only for illustrating the present invention, and should not and will not limit the invention described in detail in the claims.

Embodiment 1 film-forming material screening

Using HPMC, polyvinyl alcohol (PVA), PEG as proton acceptor polymers and PAA, CMC, CS and other proton donor polymers as film-forming materials, the film-forming properties of different film-forming materials were investigated for oral cavity For mucosal administration, the prescriptions of the examples are shown in Table 1. Disperse the HPMC, PVA and PEG of recipe quantity respectively in deionized water, stir and make it dissolve, and configure the concentration to be 8% (w/v); v) gel solution. Dissolve CS in 2% (w/v) acetic acid solution to form a 5% (w/v) gel solution. Add the corresponding proton acceptor polymers (HPMC, PVA, PEG) and plasticizers to the above PAA, CMC and CS solutions according to the prescription, stir evenly, and add fluorescein isothiocyanate (FITC) with a concentration of 5mg/mL ) marked INS (FITC-INS) solution, let it stand to remove the bubbles in the solution, and evenly coat it on the dried backing layer, set the process parameters: the coating thickness is 1.0mm, the drying temperature is 40°C, and the drying time is 120min. Heat and dry to form a film, cut into suitable shape and size. The appearance, spreadability, and viscosity of the film-forming material are used as the sensory evaluation index when screening the film prescription, as shown in Table 2. The full score of each index is 10 points, and the sum of the scores of the above three indexes is taken as The comprehensive sensory score of the film-forming material is 30 points. The appearance, quantity (mg) and thickness (mm) of different prescription films were observed with a balance and a thickness gauge to characterize the films.

Table 1. Film formulation

Table 2. Score Form for Film Prescription Screening

Experimental results: From Table 3 and Table 4, it can be seen that the formulations RX-I, RX-II, RX-III and RX-VII in the films prepared in Example 1 have higher scores, the appearance of the films is uniform and smooth, and the spreadability of the solution is relatively high. Moderate viscosity and good film-forming property. The thicknesses are all within 50-1000 μm of the ideal thickness of the film. Both the folding endurance and the weight difference meet the requirements.

Table 3. Scoring results of film-forming material prescription screening

Table 4. Characterization results of film-forming agents for film-forming materials

Note: aFolding endurance refers to the number of times of folding along the same crease 180° until it breaks or reaches the maximum number of times of folding (300 times).

bAccording to the "Chinese Pharmacopoeia" 2020 edition of the four general rules <0125 film> in the weight difference, the weight is within the range of "0.02g and below 0.02g", and the weight difference limit should be within 15%.

The in vitro release, adhesion and permeability investigation of embodiment 2 embodiment 1 membrane

Experimental method: The in vitro release of RX-I, RX-II, RX-III and RX-VII prepared in Example 1 was studied by the small cup net dish method. Each film was placed in 500 mL of artificial saliva (phosphate buffered saline, pH=6.8), samples were taken out at specific time points, and their contents were measured using a fluorescence spectrophotometer. The adhesion time of the film to the porcine oral mucosa was measured by a modified disintegration instrument (Fig. 1). Fix the buccal membrane of the pig's mouth on a glass slide and place it in 900mL of artificial saliva, observe and record the adhesion time of the film during the movement of the disintegrator, so as to simulate the state of the film in the oral cavity. The present invention adopts a vertical Franz diffusion cell as an in vitro permeation research device, adopts artificial saliva as a receiving cell medium, and adopts magnetic stirring at a rotational speed of 100 rpm, and controls the temperature of a water bath at 37±0.5°C to investigate the tissue permeability of drugs through the oral mucosa of pigs . Take the medium in the receiver pool at different time points and replenish the same volume of medium. After sampling, the buccal tissue was cut and collected, and washed with PBS buffer. Cut the obtained buccal tissue into small pieces with scissors, soak in PBS solution and use a homogenizer to crush the tissue at a speed of 10,000 rpm, centrifuge for 5 minutes to obtain a tissue homogenate, collect the supernatant, and perform quantitative analysis of FITC-INS in the entire tissue .

Experimental results: Fig. 2A shows the in vitro release test results of prescriptions RX-Ⅰ, RX-Ⅱ, RX-Ⅲ and RX-Ⅶ. RX-Ⅱ and RX-Ⅲ reached 85% drug release in about 5 hours, and RX-Ⅰ reached 85% in about 5 hours. The release rate reached 86% in about 6 hours, and the release rate of RX-Ⅶ reached 88% in 8 hours, which was slower than the above three prescriptions. Figure 2B shows that the prescriptions RX-I, RX-II, and RX-III fell off at 315min, 308min, and 295min, respectively, while RX-VII fell off at 424min, showing better adhesion. Figure 2C shows that the cumulative penetration rates of prescriptions RX-Ⅰ, RX-Ⅱ, RX-Ⅲ and RX-Ⅶ are 0.18%, 0.19%, 0.20% and 0.23% respectively at about 8 hours, and the content of FITC-INS in RX-Ⅲ prescription tissues was 0.4406 μg (Fig. 2D). From the above results, it can be seen that RX-Ⅶ has good film-forming properties, sustained-release properties, mucoadhesion and tissue permeability. The present invention uses HPMC and PAA as film-forming materials to prepare film agents for follow-up investigation.

Embodiment 3 investigates the impact of PAA and HPMC ratio on the formation of IPC

Experimental method: Nonionic proton acceptor polymers (such as HPMC) contain hydroxyl and ether groups in their repeating units, and can act as proton acceptors to form IPC with proton donor polymers (such as PAA) through hydrogen bonding. Mix different concentrations of HPMC solutions (2.5mL, 0-0.02%) with different concentrations of PAA solutions (molecular weight is 3000kDa, 2.5mL, 0-0.02%) at room temperature, so that the total concentration of the polymer in the sample is fixed at 0.02 %, adjust the solution pH=3. After thorough mixing, use an ultraviolet spectrophotometer and a viscometer to measure the turbidity and viscosity of the above mixed solution. Calculate the relative viscosity of the solution according to formula (1). To screen out the dosage of each component when forming a stable IPC, the ratio is followed up for investigation.

ηr represents the relative viscosity value; t is the time used for the polymer solution to flow; _t0 is the time used for the flow of deionized water.

Experimental results: Figure 3A shows the turbidity and viscosity changes of IPC at different ratios of HPMC and PAA. The results showed that with the increase of the ratio of HPMC, the turbidity of HPMC and PAA solution first increased and then decreased, and the turbidity of the solution was the highest when the ratio of PAA:HPMC was 3:2 (w/w). With the increase of the proportion of HPMC, the viscosity of the mixed solution of HPMC and PAA decreased first and then increased, and the solution viscosity was the lowest when PAA:HPMC=3:2(w/w). The changes in viscosity and turbidity during the formation of IPC indicate that the polymer has undergone a conformational change, and the polymer has changed from a stretched state to a coiled state, resulting in a dense IPC structure and increased hydrophobicity, so the viscosity of the solution decreases and the turbidity increases. Therefore, PAA:HPMC=3:2 (w/w) in the mixed component of the present invention.

Embodiment 4 investigates the influence that PAA molecular weight forms on IPC

Experimental method: In order to investigate the influence of the molecular weight of PAA on the formation of IPC, HPMC was dissolved in deionized water and mixed with PAA (5, 25, 90, 450, 3000kDa) of different molecular weights, where PAA:HPMC=3:2(w/w ), the total concentration of the polymer in the sample was fixed at 0.02%, and the pH of the solution was adjusted to 3 to examine the turbidity and viscosity of the solution. To screen out the PAA that can form IPC with HPMC, and carry out subsequent experiments under this condition.

Experimental results: Figure 3B shows the investigation results of the molecular weight of PAA on the formation of IPC. The results showed that PAA with molecular weight below 25kDa could not form IPC with HPMC. When the molecular weight of PAA was 90kDa, the solution of HPMC and PAA had smaller turbidity and higher viscosity, but IPC could not be effectively formed between HPMC and PAA. With the increase of PAA molecular weight, the turbidity of the solution increases and the viscosity decreases, but when the molecular weight of PAA is 3000kDa, the turbidity and viscosity of the solution change significantly. Therefore, based on the experimental results, the molecular weight of PAA in the mixed component of the present invention is 3000kDa.

Embodiment 5 investigates the impact of solution pH on the formation of IPC

Experimental method: In order to investigate the effect of solution pH on the formation of IPC, HPMC and PAA (molecular weight 3000kDa) were dissolved in deionized water respectively, and mixed according to PAA:HPMC=3:2 (w/w), so that the polymer in the sample The total concentration was fixed at 0.02%. And use HCl and NaOH to adjust the pH of the solution to 3, 5, 6, 7, 9, observe the turbidity and viscosity of the mixed solution at different pH, and analyze the influence of the solution pH on the formation of IPC. Screen out the optimal pH value of the solution.

Experimental results: Fig. 3C shows the changes of turbidity and viscosity of the solution at different pH. The results showed that when the pH of the polymer solution was 3, the viscosity of the HPMC and PAA polymer solutions was low, the turbidity was high, and a relatively dense complex was formed between the two; with the increase of the solution pH, the solution viscosity increased, the turbidity decreased, and the possible formation of IPC was destroyed. Therefore, based on the experimental results, the pH value of the selected solution of the present invention is 3.

Embodiment 6 investigates the impact of temperature on the formation of IPC

Experimental method: In order to investigate the influence of temperature on IPC, HPMC and PAA (molecular weight 3000kDa) were dissolved in deionized water respectively, and mixed according to PAA:HPMC=3:2 (w/w), so that the total concentration of polymer in the sample Fixed at 0.02%. Adjust the pH of the solution to 3, observe the turbidity and viscosity of IPC at different temperatures, and analyze the influence of temperature on IPC.

Experimental results: Figure 3D shows the results of the investigation of the influence of temperature IPC. When the temperature increased, the turbidity of the solution increased significantly at around 80 °C, and the viscosity decreased, which may be attributed to the increase in hydrophobicity caused by the spatial change of IPC. The results indicated that a more stable IPC was formed between the two polymers. Based on the experimental results, in the present invention, the temperature for forming stable IPC is 80°C.

Embodiment 7 investigates the impact of ionic strength on the formation of IPC

Experimental method: In order to investigate the influence of ionic strength on the formation of IPC, HPMC and PAA (molecular weight 3000kDa) were dissolved in deionized water respectively, and mixed according to PAA:HPMC=3:2 (w/w), so that the polymer in the sample The total concentration is fixed at 0.02%, and the pH of the solution is adjusted to 9 to exclude the influence of low pH value on the results. Add NaCl solution to adjust the ion concentration to 0, 0.0125, 0.025, 0.05, 0.075mol/L, and observe the obtained solutions under different ion concentrations. The turbidity and viscosity changes of different solutions were analyzed to analyze the influence of different solution ionic strengths on the formation of IPC.

Experimental results: Fig. 3E is the investigation result of the effect of ionic strength on the formation of IPC. The ionic strength in aqueous solution plays a crucial role in the formation of complexes and affects the performance of IPCs. At pH 9, the addition of different concentrations of NaCl to the mixed solution of HPMC and PAA resulted in an increase in the turbidity of the solution, indicating the formation of IPC. A certain concentration of NaCl is beneficial to the interaction between HPMC and PAA. Based on the experimental results, the selected ion concentration in the experiment of the present invention is 0.025mol/L.

The infrared analysis of embodiment 8IPC

Experimental method: Add HPMC and PAA (molecular weight 3000kDa) into water according to PAA:HPMC=3:2 (w/w), adjust pH=3, then take the solution for freeze-drying, use ATR-FTIR to analyze the structure of IPC freeze-dried powder for analysis.

Experimental results: Figure 4 is the infrared spectrum of IPC. The results showed that the spectrum of PAA showed a typical peak of carboxyl vibration at 1712cm ^-1 . The spectrum of HPMC has a characteristic peak at 783cm ^-1 . Absorption bands at 3000–2800 ^cm as CH bond stretching vibrations belong to saturated methyl and methylene groups. The broad peaks around 3500–3300 ^cm might be related to NH and OH stretching. Compared with HPMC or PAA, IPC not only retains the typical characteristic peaks at 1712 and 783 cm ^-1 . Moreover, the intensity of the absorption peaks at 1710 and 3500-3300cm ^-1 changed, presumably because the hydrogen bond between HPMC and PAA changed the electron cloud distribution density of the conjugate.

Embodiment 9 Sustained-release layer prescription screening and optimization

Experimental method: The slow-release layer is prepared by mixing the optimized IPC and plasticizer under certain process conditions by using the coating method. This example takes the thickness, folding resistance, appearance, quality difference and adhesion time of the slow-release layer as investigation indicators, and screens out the prescription composition (ratio of film-forming material and plasticizer) and preparation process (ratio of film-forming material and plasticizer) for preparing the slow-release layer. Coating thickness, drying temperature, drying time).

① Investigation of the amount of plasticizer in the sustained-release layer: IPC solution was prepared according to the optimized conditions. According to Table 5, PAA, HPMC and TEC were mixed evenly, and the slow-release layer was prepared by coating method, and the process parameters were set: the coating thickness was 1.0mm, the drying temperature was 40°C, and the drying time was 120min. The slow-release layer was characterized by examining the thickness, folding resistance, appearance, weight difference and adhesion of the slow-release layer, and the amount of plasticizer used to prepare the slow-release layer was screened. Adhesion of the films was evaluated by a modified disintegrator. The results are shown in Table 5. When the slow-release layer was spread, the amount of plasticizer was less, resulting in poor mechanical strength of the slow-release layer and overall brittleness of the film. When the amount of plasticizer is too high, the film is soft but has poor adhesion. Based on the comprehensive analysis of various factors, it is determined that when the slow-release layer is laid, the amount of plasticizer used is PAA:HPMC:TEC=24:16:5 (w/w).

Table 5. Investigation of the amount of plasticizer in the slow-release layer

②Inspection of the coating thickness of the slow-release layer: Prepare the IPC solution according to the optimized conditions, mix it with the plasticizer uniformly according to PAA:HPMC:TEC=24:16:5 (w/w), and use the coating method for slow-release For the preparation of the layer, set the process parameters: the coating thickness is 0.5, 1.0, 1.5mm, the drying temperature is 40°C, and the drying time is 120min. Characterize the slow-release layer, and screen out the coating thickness when the slow-release layer is prepared. The results are shown in Table 6. The thinner slow-release layer makes it difficult to release the film after drying. Laying too thick will lead to uneven heating, thickening of the edge of the film, and even chapping, which will affect the appearance and performance of the film. Based on the comprehensive analysis of various factors, the thickness of the slow-release layer coating is 1.0 mm, which is more appropriate.

Table 6. Coating Thickness Inspection of Sustained Release Layer

③Inspection of drying temperature of slow-release layer: Prepare IPC solution according to optimized conditions, mix with plasticizer uniformly according to PAA:HPMC:TEC=24:16:5 (w/w), and use coating method to form slow-release layer For the preparation, set the process parameters: the coating thickness is 1.0mm, the drying temperature is 30, 40, 60°C, and the drying time is 120min. Characterize the sustained-release layer, and screen out the drying temperature for the preparation of the sustained-release layer. The results are shown in Table 7. When the slow-release layer was spread, the drying temperature was lower and it was more difficult to dry. When the temperature is too high, the solvent evaporates during the drying process, resulting in the formation of air bubbles and affecting the appearance and performance of the film. Based on the comprehensive analysis of various factors, the drying temperature of the slow-release layer is 40°C, which is more suitable.

Table 7. The drying temperature investigation of the sustained release layer

④ Investigation of the drying time in the preparation process of the sustained-release layer: prepare the IPC solution according to the optimized conditions, mix it with the plasticizer uniformly according to PAA:HPMC:TEC=24:16:5 (w/w), and use the coating method to prepare The sustained-release layer was prepared, and the process parameters were set: the coating thickness was 1.0 mm, the drying temperature was 40° C., and the drying time was 60, 90, and 120 minutes. Characterize the slow-release layer and screen out the drying time of the slow-release layer. The results are shown in Table 8. When the slow-release layer was spread, the slow-release layer was more difficult to dry when the drying time was shorter. When the time is too long, the excessive evaporation of water will make the whole body harder and the mechanical strength will be poor, which will affect the comfort of use. Based on the comprehensive analysis of various factors, the drying time of the slow-release layer is 90 minutes, which is more appropriate.

Table 8. Drying Time Investigation of Sustained Release Layer

The prescription screening and optimization of embodiment 10 waterproof backing layer

Experimental method: The waterproof backing layer is prepared by mixing the water-insoluble film-forming material EC and the plasticizer TEC and CO in an organic solvent in a certain proportion, and then using the coating method. In this example, the thickness, folding resistance, appearance and quality differences of the waterproof backing layer are used as the investigation indicators, and the prescription composition (concentration of the film-forming material EC, and the ratio of the plasticizer) and the preparation of the waterproof backing layer are screened out. Process (coating thickness, drying temperature, drying time).

① Investigation of the amount of EC in the waterproof backing layer: Dissolve EC in ethanol solution at concentrations of 0.05, 0.07, and 0.10 g/mL, respectively, according to EC:CO:TEC=7.5:1:1 (w/w) and plasticizing Mix the agent evenly, use the coating method to prepare the waterproof backing layer, set the process parameters: the coating thickness is 0.5mm, the drying temperature is 40°C, and the drying time is 15min. The waterproof backing layer was characterized by examining the thickness, folding resistance, appearance and quality differences of the waterproof backing layer, and the EC concentration for preparing the waterproof backing layer was screened out. The results are shown in Table 9. Under the same preparation process, with the increase of EC concentration, the film thickness of the waterproof backing layer increases, and the folding resistance is better. Considering all factors, the concentration of EC is 0.10g/mL is more appropriate.

Table 9. Investigation of the amount of EC in the waterproof backing layer

② Investigation of the amount of plasticizer in the waterproof backing layer: Dissolve EC in an ethanol solution at a concentration of 0.10g/mL, mix it evenly with the plasticizer, use the coating method to prepare the waterproof backing layer, and set the process parameters: The coating thickness is 0.5mm, the drying temperature is 40°C, and the drying time is 15min. Characterize the waterproof backing layer, and screen out the amount of plasticizer used to prepare the waterproof backing layer. The investigation results are shown in Table 10. The amount of plasticizer affects the release properties and mechanical strength of the waterproof backing layer. Based on the analysis of various factors, the dosage of plasticizer is EC:TEC:CO=7.5:1:1 (w/w) is more appropriate.

Table 10. Investigation of the amount of plasticizer in the waterproof backing layer

③Inspection of coating thickness of waterproof backing layer: Dissolve EC in ethanol solution at a concentration of 0.10g/mL, mix evenly with plasticizer, use coating method to prepare waterproof backing layer, set process parameters: coating The thicknesses are 0.3, 0.5, 1.0 mm respectively, the drying temperature is 40°C, and the drying time is 15 minutes. Characterize the waterproof backing layer and screen out the coating thickness of the waterproof backing layer. The results are shown in Table 11. The coating thickness of the waterproof backing layer affects the final dry thickness of the waterproof backing layer, and at the same time affects the mechanical strength, release property and appearance of the waterproof backing layer. Based on the analysis of various factors, the coating thickness of 0.5 mm is more appropriate in the preparation process of the waterproof backing layer.

Table 11. Coating thickness inspection of waterproof backing layer

④Drying temperature investigation of waterproof backing layer: Dissolve EC in ethanol solution at a concentration of 0.10g/mL, mix evenly with plasticizer, use coating method to prepare waterproof backing layer, set process parameters: coating thickness 0.5mm, the drying temperature is 30, 40, 60°C, and the drying time is 15min. By characterizing the waterproof backing layer, the drying temperature for preparing the waterproof backing layer is screened out. The results are shown in Table 12. The drying temperature during laying of the waterproof backing layer has a great influence on the appearance. When the temperature is low, the drying process is slow and the drying time is longer. When the temperature is too high, due to the rapid volatilization of the surface solvent, more air bubbles will be generated during the drying process, which will affect the appearance and performance of the waterproof backing layer. Based on the analysis of various factors, the drying temperature in the preparation process of the waterproof backing layer is 40°C, which is more appropriate.

Table 12. Drying temperature investigation of waterproof backing layer

⑤Drying time investigation of waterproof backing layer: Dissolve EC in ethanol solution at a concentration of 0.10g/mL, mix with plasticizer evenly, use coating method to prepare waterproof backing layer, set process parameters: coating thickness 0.5mm, the drying temperature is 40°C, and the drying time is 5, 15, and 30 minutes respectively. Characterize the waterproof backing layer and screen out the drying time to prepare the waterproof backing layer. The results are shown in Table 13. The drying time mainly affects the solvent evaporation of the waterproof backing layer. The waterproof backing layer can be completely dried within 5 minutes, and the mechanical strength of the film is poorer if the drying time is longer. Considering various factors, the drying time of the waterproof backing layer is 5 minutes is more appropriate.

Table 13. Drying time investigation of waterproof backing layer

The preparation of embodiment 11 mucous membrane sustained-release film preparation

Experimental method: the film is a double-layer film composed of a waterproof backing layer and a slow-release layer, as shown in Figure 5 for a schematic diagram. The solution containing medicine, additive and film-forming material (IPC) is spread on the waterproof backing layer, and dried to prepare a drug-containing sustained-release layer; after cutting, a sustained-release film for mucous membranes is obtained. The prescription of the sustained-release layer is shown in Table 14, and the prescription of the waterproof backing layer is shown in Table 15.

Prepare the waterproof backing layer according to the optimized conditions. The preparation process is as follows: dissolve EC in ethanol solution at a concentration of 0.10g/mL, and mix EC:CO:TEC=7.5:1:1 (w/w) with plasticizer Mix evenly, use the coating method to prepare the waterproof backing layer, set the process parameters: the coating thickness is 0.5mm, the drying temperature is 40°C, and the drying time is 5min.

Prepare the sustained-release layer according to optimized conditions, and the preparation process is as follows: the film-forming material is dissolved in deionized water, the molecular weight of PAA is 3000kDa, the film-forming material, plasticizer (PAA:HPMC:TEC=24:16:5 , w/w) and mix evenly, adjust the pH to 3, the temperature is 80°C, and the ion concentration is 0.025mol/L, and finally add the model drug-insulin (Insulin, INS) and mix evenly, and use the coating method to prepare the sustained-release layer , set the process parameters: the thickness is 1.0mm, the drying temperature is 40°C, and the drying time is 90min. The slow-release layer is spread on the dried waterproof backing layer, and after the slow-release layer is dried, it is cut to obtain the slow-release film preparation for mucous membranes.

Through the above prescription and process, the applicant prepared the target film INS@EC/H+P film. At the same time, three groups of contrast films were prepared: ① use HPMC alone as the film-forming material of the drug-containing layer, and spread it on the waterproof backing layer to obtain INS@EC/H film; ② use PAA alone as the film-forming material of the drug-containing layer, lay Made on the waterproof backing layer to obtain INS@EC/P film; ③Pave the drug-free HPMC on the waterproof backing layer after drying, and then spread the drug-containing PAA layer to obtain INS@EC/H film/ P film three-layer film agent. The appearance, weight (mg), thickness (mm), folding endurance and surface pH of different prescription films were observed by balance, thickness gauge and pH meter to characterize the films.

Table 14. Sustained release layer formulation

Table 15. Waterproof Backing Layer Recipe

Experimental results: The results are shown in Table 16. INS@EC/H film, INS@EC/H film/P film and INS@EC/H+P film all have a relatively suitable weight and thickness, which ensures the use of the film comfort. Among them, INS@EC/H film and INS@EC/H+P film are flat and uniform in appearance, and INS@EC/H film/P film and INS@EC/H+P film have better folding endurance.

Table 16. Film formulation characterization

The thermal analysis research of embodiment 12 mucous membrane sustained-release film

Experimental method: prepare blank film (Blank film) and INS@EC/H+P film, use differential scanning calorimetry (Differential scanning calorimetry, DSC) to investigate the properties of Blank film, INS and INS@EC/H+P film thermal curve. The surface morphology of Blank film and INS@EC/H+P film was studied by SEM.

Experimental results: Figure 6A shows the thermal analysis results of the film. INS and INS@EC/H+P film have a broad endothermic peak around 318.75°C, which corresponds to the disappearance of water from INS and the degradation of INS. The surface morphology of Blank film (see Figure 6B) and INS@EC/H+P film (see Figure 6B) was studied by SEM. The surface of Blank film is smoother, which may be due to the addition of INS, which makes the surface of the film appear frosted glass.

Example 13 Release, Adhesion and Permeability Investigation of Sustained-release Membrane for Mucosa

Experimental method: FITC-INS was used as a model drug to prepare FITC-INS@EC/H film, FITC-INS@EC/P film, FITC-INS@EC/H film/P film and FITC-INS@EC/ H+P film film agent. The release of FITC-INS in vitro was studied by the small cup net dish method. And use disintegration instrument and Franz diffusion cell to investigate its adhesion and permeability.

Experimental results: As can be seen from Figure 7A, the drug release in FITC-INS@EC/H film, FITC-INS@EC/P film and FITC-INS@EC/H film/P film is close to 85% in about 8 hours, and The release plateau was reached at 1 h. Compared with the above three films, the release of FITC-INS@EC/H+P film was slower, and only 47.5% was released in 1 hour. The possible reason is that IPC has strong hydrophobicity and slow swelling. The drug is mainly released in the form of diffusion in the early stage, and the drug is gradually released in the later stage as the gel skeleton gradually erodes. It can be seen from Figure 7B that FITC-INS@EC/H film, FITC-INS@EC/P film and FITC-INS@EC/H film/P film fell off after 111min, 204min and 221min respectively, while FITC-INS@EC/P film The H+P film peeled off at 487min, showing good adhesion. Figures 7C and 7D are the results of the investigation of the permeability of the film in the isolated porcine buccal membrane tissue, compared with FITC-INS@EC/H film, FITC-INS@EC/P film and FITC-INS@EC/H film/P The film has better tissue permeability than FITC-INS@EC/H+P film. From the above results, it can be seen that FITC-INS@EC/H+P film has good sustained-release effect, mucosal adhesion and tissue permeability.

Example 14 The hypoglycemic effect of INS-loaded mucosal slow-release film preparations on type I diabetic rats

Experimental method: SD rats with type I diabetes induced by streptozocin (STZ) were divided into 4 groups: Model group (oral saline group), S.C group (subcutaneous injection of INS, 1IU/kg), Blank film group group and the INS@EC/H+P film group containing INS (30IU/kg) were used as the experimental group (n=6), and the Control group in which healthy rats were orally given normal saline was used as a negative control. Before the experiment, the rats were fasted for 12 hours (with free access to drinking water), and the rats were anesthetized and placed on a warm pad. Rats were orally given physiological saline, subcutaneously injected with INS or placed on the buccal membrane of rats. Collect 0.5mL blood samples from the tail vein at predetermined time points and measure the blood glucose level of rats with a blood glucose meter, and calculate the change level of blood glucose according to formula (2).

Where G ₁ and G ₂ represent the blood glucose value at the time point measured and the initial blood glucose value, respectively.

Experimental results: The applicant evaluated the hypoglycemic effect of oral mucosa administration and subcutaneous injection of INS solution in type Ⅰ diabetic rats. It can be seen from Fig. 8A that after the mice were subcutaneously injected with INS, the blood glucose decreased rapidly. It reached the lowest value at 2 hours, which was 55.4% of the initial blood glucose level, and then recovered rapidly, and recovered to 82.1% of the initial blood glucose level at 8 hours. Compared with the subcutaneous injection group, the blood glucose level of the INS@EC/H+P film group decreased more slowly and persistently. This is mainly due to the good sustained release effect of INS@EC/H+P film.

Example 15 Pharmacokinetic study of INS-loaded mucosal sustained-release film preparation on type I diabetic rats

Experimental method: After administration, the blood of rats at different time points was placed in collection tubes, and the supernatant serum was collected by centrifugation after coagulation. The insulin ELISA kit was used to measure the concentration of INS in serum, and the curve of serum INS concentration over time was drawn for pharmacokinetic investigation.

Experimental results: after subcutaneous injection of INS or oral mucosal administration, and administration of different preparations to type 1 diabetic rats, the curves of serum INS concentration over time are shown in Figure 8B. After subcutaneous injection of INS solution, the concentration of INS in rat serum increased sharply and reached the peak at 0.5h. However, after INS@EC/H+P film was administered through the oral mucosa, the serum INS levels of rats increased slowly and peaked at 2h and 4h, respectively. It is speculated that part of the drug diffused from the film and was absorbed to form the first absorption peak, and then the gel matrix gradually eroded, and the remaining drug continued to be released and absorbed to form the second absorption peak.

Example 16 Safety Evaluation of INS-loaded Mucosa Sustained Release Film (Histological Evaluation)

Experimental method: After the experiment, the mucosal tissue was obtained from the rat oral cavity for histological staining to evaluate the safety of the preparation. Specifically, tissue samples were fixed in 10% buffered formalin at room temperature for 24 hours, embedded in paraffin, and sectioned with a thickness of 4 μm. Then, the sections were stained with HE and photographed under a microscope.

Experimental results: Fig. 9 The mucosal basal epithelial cells in each treatment group are arranged regularly and closely connected. In the tissue samples after administration of the film, it can be seen that the morphology of the buccal epithelial cells has no obvious change, and there is no inflammation or damage. The results showed that the sustained-release film preparation for mucosa was safe.

Claims (10)

1. a preparation method for mucosal slow-release film preparation, is characterized in that, comprises the following steps: (1) Take polyacrylic acid (Polyacrylic acid, PAA) and add water to stand still, after fully swelling, stir and dissolve to obtain solution Ⅰ; (2) Take hydroxypropyl methylcellulose (HPMC) and add water to stand still, after fully swelling, stir and dissolve to obtain solution II; (3) Slowly add solution II to solution I to form a polymer hydrogen bond complex (interpolymer complexe, IPC) solution, and then add additives and drugs to prepare a sustained-release layer solution; (4) Take the water-insoluble film-forming material and dissolve it in the organic solvent, add additives, stir evenly, form a film, and prepare a waterproof backing layer; (5) Spread the slow-release layer solution obtained in step (3) on the waterproof backing layer to prepare a slow-release layer, dry and cut to obtain a film. 2. The preparation method of the sustained-release film for mucosa according to claim 1, characterized in that, in step (1), the molecular weight of the PAA is 5-3000 kDa. 3. The preparation method of sustained-release film for mucosa according to claim 1, characterized in that, in step (3), the drug includes small molecule, polypeptide or protein drugs. 4. the preparation method of mucosa sustained-release film preparation according to claim 1, is characterized in that, in step (3), described additive comprises propylene glycol (Propylene glycol, PG), castor oil (Castor oil, CO) , triethyl citrate (Triethyl citrate, TEC), silicone oil (Silicone oil, SO), glycerin (Glycerol, GL), diethyl phthalate (Diethyl phthalate, DEP) or dibutyl phthalate ( One or more of Dibutyl phthalate, DBP). 5. the preparation method of mucosa sustained-release film preparation according to claim 1, is characterized in that, in step (3), the mass ratio of PAA in described solution I and HPMC in solution II is 9:1～1: 9(w/w). 6. The preparation method of sustained-release film for mucosa according to claim 1, characterized in that, in step (3), slowly add solution II to solution I, adjust the pH to 3-9, and adjust the pH between 40-80 Under the condition of ℃, a polymer hydrogen bond complex solution is formed. 7. The preparation method of the sustained-release film preparation for mucosa according to claim 1, characterized in that, in step (3), the additive also includes inorganic salts, and the amount of the inorganic salts is: the solution I , Solution II, additives and drugs are mixed, and the concentration of salt ions in the solution is adjusted to 0.0125-0.0750 mol/L. 8. the preparation method of mucosa sustained-release film agent according to claim 1, is characterized in that, in step (4), described film-forming material is selected from ethyl cellulose (Ethyl cellulose, EC), cellulose acetate (Cellulose acetate, CA), ethylene-vinyl acetate copolymer (EVA), hypromellose phthalate (HPMCP), cellulose acetate phthalate One or more in (Cellulose phthalate acetate, CPA); Described organic solvent is one or more in Virahol, dichloromethane, acetone or ethanol solvent; Described additive comprises propylene glycol (Propylene glycol, PG), castor oil (Castor oil, CO), triethyl citrate (Triethyl citrate, TEC), silicone oil (Silicone oil, SO), glycerin (Glycerol, GL), diethyl phthalate (Diethyl phthalate, DEP) or one or more of dibutyl phthalate (DBP). 9. the preparation method of mucosa slow-release film agent according to claim 1, is characterized in that, in step (4) and step (5), the film-forming method of waterproof backing layer or slow-release layer is coating method The preparation process parameters include: the coating thickness is 0.3-1.5mm, the drying temperature is 30-60°C, and the drying time is 5-120min. 10. A slow-release film for mucosa, characterized in that, the slow-release film for mucosa comprises a waterproof backing layer and a slow-release layer coated on the waterproof backing layer, and the slow-release layer comprises Acrylic acid and hydroxypropyl methylcellulose form a high molecular hydrogen bond complex and drug.

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