EP0179904A1 - Oral insulin and a method of making the same - Google Patents

Abstract

A composition is useful as an oral dosage form of insulin based on a two-phase aqueous liquid system in which the insulin component (s) are incorporated. The invention also describes a method for preparing the oral dosage form of insulin as well as another method for producing oral sustained release dosage forms of insulin. The oral form of insulin eliminates or reduces the need to use the injection to deliver insulin.

Description

ORAL INSULIN AND A METHOD OF MAKING THE SAME

This invention concerns an improved form of insulin which is orally administered, and methods of preparation.

Review of the scientific literature indicates that despite intensive research, the problems obstructing the development of an oral dosage form of insulin remain unsolved. The published research includes no report of a delivery system that will make it possible to admin¬ ister insulin orally. (Reference: Chemical Abstracts 1970-1984)

The investigations of Dapergolas and Gregoriadis suggest that a moderately effective hypoglycemic effect may be achieved through the intragatric use of liposome entrapped insulin. Examination of the data of these experiments indicate that the rate of insulin absorption was erratic and further, that it was not possible to determine the quantity of insulin that was absorbed. (Reference: Dapergolas, G. and Gregoriadis, G. Hyper- glycemic Effect of Liposome Entrapped Insulin Administered Intragastrically Into Rats; Lancet, Oct. 16, 1976, pp. 824-827)

The use of liposomes to prepare an oral form of insulin is based upon a concept and a method manu¬ facture that differs fundamentally from the concept and method of the herein disclosed invention. A two phase coacervate system comprises the basis of this invention; it bears no relationship to liposomes. Moreover, given the known difficulties in the manufacture and use of liposomes, such compositions do not appear to be the basis on which, a useful oral insulin may be developed. (.Reference: Ostro, Marc, Lipsomes, Marcel Dekker, New York, 1983)

The advantages of an oral dosage form of insulin are readily apparent. An oral form of insulin will elim¬ inate or reduce the need to use injection as the mode of administering insulin. Further, it appears that an oral form of insulin could be used to advantage in the treat¬ ment of adult onset diabetes mellitus. The sulfonylureas are now prescribed for the treatment of this form of diabetes despite the adverse effects associated with the use of this class of drugs. The sulfonylureas are not considered to be an acceptable substitute for insulin nor are they considered to be oral forms of insulin.

It is important to note that no known oral dosage form of insulin has been developed since the discovery of insulin more than sixty years, ago.

The present invention discloses an oral dosage form of insulin and a method by which said insulin can be prepared. However, it should be noted that the herein disclosed invention constitutes a safe, effective oral dosage form not only for insulin but for non-polar drugs and other medical compositions known to be subject to degradation in the digestive system.

Examples of the applicants¹ discovery of coacervate systems by means of which drugs, enzymes, nutr_ients and hemoglobin may be introduced into and transported in the circulatory system are disclosed in U. S. Patent Nos. 4,343,797 and 4,439,424. In the pres¬ ent disclosure, the concepts of the inventions referred to above have been modified and utilized in a manner that yields an oral as opposed to an intravenous prepara¬ tion- Moreover, the specific use of the coacervate system of this invention distinguishes- the claimed composition and its method of prepara ion* from the known microencapsulated biologicals and drug products and the methods used to produce them. At this point, the state of the art does not include an., oral composition which will protect drugs, biologicals and other medical preparations vulnerable to degradation by enzymes, pH, acid-base balance and other conditions and processes o _.the gastrointestinal tract.

It is an object of this invention to provide a delivery system that enables the safe, effective oral administration of the known forms of insulin. When insulin is incorporated in the herein disclosed delivery system it retains all of its known pharmacologic and physiological properties. Furthermore, this invention provides a convenient method of preparation of the claimed oral dosage forms.

The invention provides a composition of matter useful as an oral dosage form of insulin; said preparation comprising a non-toxic two phase liquid system, both phases being aqueous; a) one of said phases being a relatively non- polar coacervate phase; b) The other of said phases being a relatively polar liquid aqueous phase; c) said relatively non-polar coacervate phase being insoluble in and in equilibrium with said relatively polar liquid aqueous phase; d) said two phase system, when prepared to contain an insulin component or components in the co¬ acervate phase of the coacervate system, yields a delivery system for the oral administration of insulin.

Moreover, the invention provides for a method of preparing a composition useful as an oral dosage form of insulin, said method based upon the two phase liquid system. A preferred method is characterized by the steps of (a) combining albumin and lecithin in equal propor¬ tions in sterile water; (b) thoroughly mixing the com¬ ponents; (c) storing said mixture undisturbed until the composition of step (a) separates into two layers, one above the other, the lower phase being a substantially non-polar coacervate ^"phase, the upper phase being an equilibrium water phase; (d) continuing the separation process until no increase in the volume of the coacervate system can be observed; (e) centrifuging the composition until inspection reveals a clear demarcation of the two phases and (f) separating the two phases.

Given that no oral dosage form of insulin now exists, the herein disclosed invention represents a significant scientific and medical advance. By using any one of a number of appropriate non-toxic coacervate systems as a beginning step in the manufacture of this invention, it becomes possible, through a subsequent sequence of relatively simple processing steps to produce a delivery system for the oral administration of insulin. The said system can be produced as a liquid or as an encapsulated composition-

In this disclosure, the term particle refers to encapsulated or emulsion droplet entities. In the claimed invention, the size of the particles which will contain the hemoglobin component may range from nanometer size to micron -size; from 10^~8 microns to 10 microns. Particles in this range of sizes are known to pass through the wall of the small intestine and, it follows, into the cir¬ culatory system. There is reason to believe that in the finished product of this invention, the coacervated micro and sub-micro encapsulated particles will tend to adhere to the membrane of the gastrointestinal tract, thereby facilitating passage through the wall of the small in¬ testine.

Another singularly important feature of this invention is the protection afforded the insulin component Q£ this composition from enzymatic degradation in the digestive tract. This is accomplished by incorporating the insulin in the coacervate phase of the coacervate system. In the process of this incorporation, a film of coacervate phase water surrounds and coats each insulin molecule. This feature is of fundamental importance since coacervate phase water differs in physical chemical structure from the bulk water present in the stomach. The digestiveenzymes whichdegrade insulin readily diffuse in the aforementioned bulk water, however, since these en¬ zymes diffuse only minimally, if at all, in the water of the coacervate phase. The rate of interaction between the insulin component and the digestive enzyme is extremely slow. Since the rate of interaction is so slow, physio¬ logically useful quantities of insulin escape destruction, pass through the wall of the small intestine and into the circulation. Moreover, in this invention, the insulin component is protected from the degradation effects of pH, acid-base balance and other conditions and processes of the gastrointestinal tract.

In the manufacture of the claimed composition, any of the known forms of insulin, i.e., regular insulin, globin zinc insulin, insulin zinc suspension, prompt insulin zinc suspension, extended insulin zinc suspension, or combinations thereof may be used. The insulins used in this invention may be of U.S.P. standard, if desired. Non U.S.P. insulins may be used provided they are accept¬ able in other fundamental respects.

If preferred, the insulin component may be comprised of recrystallized insulin obtained from animal, recombinant genetic, synthetic or other sources. Since the claimed compositions are intended only for oral use, the insulin used in this invention need not be subjected to the rigorous manufacturing steps required for U.S.P. injectable insulin. However, if desired, insulin pre¬ pared for injection may be used in this invention.

The claimed composition may be prepared to any of several specifications. Thus, it may consist of insulin dispersed in the disclosed coacervate system and dispensed as a liquid preparation. The method of this invention also provides for additional steps in which the previously described preparation is further processed to yield a product which is comprised of particles of encapsulated insulin. The particles are within the size range referred to previously. The final product can be placed in conventional gelatin capsules and dispensed as such, or alternatively, the particles containing insulin can be dispensed in any suitable liquid vehicle, i.e., a vehicle based on coacervate phase water and dispensed for use in that form. The invention provides for sus¬ tained release dosage forms and for emulsion and suspen¬ sion preparations.

Any appropriate non-toxic coacervate system can be used in the manufacture of the product of this invention. Further, any endogenous biological surface active agent or derivatives thereof, e.g., albumin, lecithin, gelatin, etc., can be used to make a coacervate system appropriate for the product and process of this invention. Alternatively, suitable non-toxic exogenous components can also be used to prepare the coacervate system, for example, acacia when combined with gelatin. Many other surface active agents and/or combinations thereof that can form multiple coacervate phase systems can also be used. However, it is fundamental to the claims of this invention that regardless of the constituent ingredients used, the first manufacturing step involves this preparation of an appropriate coacervate system. Upon completion of this step, the coacervate system will consist of two phases: (1) an internal suspension, re¬ latively non-polar phase, commonly referred to as the coacervate phase, and (2) an associated, relatively polar, external suspension or equilibrium phase. These phases are insoluble in and in equilibrium with each other. The coacervate phase of the disclosed coacervate system can comprise from 0.5 to 99.5% by volume of the system; correspondingly, the associated equilibrium phase can _, comprise from 0.5 to 99.5% by volume of the herein described coacervate system.

In order to explain the claimed composition and method of this invention, the following is a descrip¬ tion of the preferred method of manufacture of said composition and the composition itself. Specific examples which follow will explain and illustrate the variety of formulations that are possible within the parameters of this disclosure.

As noted previously, preparation of an appropriate coacervate system comprises the first step in the manufacuture of the claimed composition of matter. The said coacervate system may be formulated using any acceptable non-toxic biological, non-biological surface active agent, derivatives or mixtures thereof. Sources of the surface active agent component may be either of natural or synthetic origin. Any of the following are examples of acceptable surface active agents: albumin, suitable phospholipids, gelatin_., modified fluid gelatin, acacia gel and other surface active compositions known to those skilled in the art. In this invention, appro¬ priate combinations of these agents are preferred.

In the method of this invention, the combination- of albumin and a phospholipid, preferably lecithin is preferred. Other phospholipids such as cephalin, iso- lecithin, sphingomyelin, phosphatidyl serine, phosphatidic acid, phosphatidyl inositol and phosphatidyl choline may be used in place of the preferred lecithin.

In the preferred method of this invention, equal weight to volume proportions of albumin and lecithin are added to a quantity of sterile water that will yield 100 mis of aqueous solution. Any quantity of albumin and lecithin can be used, provided that the proportions given above are observed and the quantity of water is adjusted accordingly. Three per cent weight to volume of lecithin and three per cent weight tc volume of albumin is preferred. Unequal proportions of these compositions may be used to produce a coacervate system; however, while such systems may have useful character¬ istics, unequal proportions are not believed to be pre¬ ferable i.e.; drug transport, etc., for this invention. In the method of this invention, other com¬ binations of surface active agents may be used. These combinations would include the following: acacia gel and gelatin or modified gelatin, two gelatins of the same or differing isoelectric points, two modified fluid gelatins of the same or differing isoelectric points and other combinations of surface active agents known to those skilled in the art.

Following the step in which albumin and lecithin are added to sterile water, the solution is thoroughly mixed and stored, undisturbed in suitable containers. The storage step takes place at a temper¬ ature which can range from the freezing point to 4° C to room temperature. In the disclosed preferred method storage takes place at any temperature within the range of 4° to 15° C.

During the period of storage, the solution described above will separate into two phases. The upper phase (layer) is referred to as the equilibrium water phase. The lower phase (layer) is referred to as the coacervate phase. The period of storage is continueduntil the maximum yield of the coacervate phase of the coacervate system has been achieved. Maximum yield is the point in the manufacturing process at which no significant increase in the volume of the coacervate phase can be observed. This determination may be made by visual inspection or other suitable means. As is known to those skilled in theart, longer periods of storage will produce greater yields of the coacervate phase.

When it is determined that the maximum yield of the coacervate phase has been achieved, the coacervate system is centrifuged until observation indicates that a clear division exists at the interface of the two phases of the coacervate system. At this point, the two phases are separated from each other by means of a separatory funnel. The desired amount and type of insulin is then added to the coacervate phase and mixed thoroughly.

Any of the known forms and dosages of insulin, i.e., regular insulin, globin zinc insulin, insulin zinc suspension, prompt insulin zinc suspension, extended insulin zinc suspension, protamine zinc insulin or com¬ bination thereof may be used. The insulin(s) used may be of U.S. . standard. If preferred, the insulin component may be one directly derived from recrystallization of insulin from animal, recombinant genetic or other sources. The invention contemplates the manufacutre of a variety of oral insulin preparations, compositions and dosages in order to meet specific medical requirements. Accordingly, no single insulin specification can be described as pre¬ ferred. For purposes of this disclosure, the individual dose can be 100 standard units and/or fractions and/or multiples thereof.

After the step in which the insulin component is dispersed in the coacervate phase and thoroughly mixed, the preparation may be dispensed as an oral dosage form of insulin. Preferably, the manufacturing process is continued. In that case, the next procedure involves the recombination of the equilibrium water phase and the coacervate phase which now contains the insulin component.

Following the recombination of the phases, the preparation is emulsified using a colloid mill, sonifier or other emulsifying technique known to those skilled in the art. The particles of the emulsion may range in size from 10 —8 microns to 10 microns. It is preferred that the particle size be within the nanometer and millimicron range.

The product resulting from the emulsifying step comprises a prompt release form of insulin and may be used as such or stored under refrigeration until needed. The emulsified composition is, if desired, processed further to produce time release, i.e., sustained release forms of insulin(s). To produce these forms of insulin, the preparation is subjected to a heating step, i.e., the preparation is heated for from 30 seconds to 15 minutes at a temperature which may range from 20° to 70° C. Since this step will harden the surface film surrounding each particle, the variables of time and temperature may be varied to produce a spectrum of particle surface film hardnesses. This method comprises the preferred method. Other processes may be used to prepare sustained release forms of the claimed compo¬ sition. Thus, a cross linking agent, such as a non-toxic entity within the aldehyde group, i.e., gluteraldehyde may be used in a chemical process which harden the film surface of the particles containing the insulin component.

As a result of the heating step, the claimed oral insulin composition is comprised of particles which are characterized by differing degrees of surface film hard¬ ness and thus, differing rates of time release. After the heating step is completed, the composition is filtered through a filter pad. The product remaining in the filter bed constitutes the particles of oral insulin. These are removed from the filter bed by a washing step and then dried by any acceptable drying process. Upon completion of the drying step, the preparation of particles containing oral insulin is completed. The composition may now be placed in an appropriate oral dosage form. Thus the desired dose of the composition may be re- suspended in a suitable non-toxic liquid vehicle, or placed in other conventional oral dosage forms and dis¬ pensed or stored, preferably under refrigeration until needed. If it is desired, an appropriate dose of the prompt release particles may be mixed with an appropriate dose of the previously described time release oral insulin(s) formulation. This mixture is then placed in any acceptable, non-toxic oral dosage form and dispensed or stored, preferably under refrigeration until needed.

Previously, in his disclosure it was stated that a number of entities may be used to prepare the required coacervate system. An example of an alternative acceptable coacervate system for preparing oral insulin is based on the use of gelatin. In this alternative, the following steps are used to produce the coacervate system. Five per cent gelatin solution is dispersed in distilled water and heated to 40°C. 0.9% sodium chloride solution is slowly added to the preparation until the solution separates into two layers. The lower layer comprises the colloid rich liquid gelatin or coacervate phase. The upper layer consists of the equilibrium water phase.

The two phases are separated by means of a separatory funnel. The desired quantity and type of insulin or combinations thereof, as described above, are then added and mixed into the coacervate phase, and may, if desired, be dispensed as oral liquid insulin. If pre¬ ferred, the manufacturing process proceeds and the two previously separated phases, one of which now contains insulin, are recombined. Through the use of any acceptable emulsifying technique, an emulsion consisting of nanometer, millimicron and micron size particles inside of which insulin is contained is prepared. The emulsion is simultaneously rapidly cooled^* and stirred at a temperature of from 0 to 10°C for from 15 to 60 minutes by means of a refrigerated stirring unit. After this stirring step, the composition is forced through a filtering system. The product remaining in the filter bed is removed through a washing step. Upon completion of this step the particles are dried in an air drying system. When the encapsulated particles of insulin are completely dried, the quantity and type of insulin necessary for a specific dose is placed in any appropriate oral drug delivery system. The conventional gelatin capsule is preferred. SPECIFIC EXAMPLES

Examples of how the claimed composition(s) of matter may be prepared follow:

Example 1_ 5% weight to volume proportions of albumin and lecithin are added to an amount of distilled water that will yield 100 mis of aqueous solution. The mixture is then thoroughly mixed by a vortex mixer. Following the mixing step, the solution is stored undisturbed until the max¬ imum yield of the coacervate phase of the coacervate system has been achieved. The storage step takes place at 4°C. When it is observed that the maximum yield of the coacervate phase has been achieved, the coacervate..system is centrifuged until observation indicates that a clear division exists at the interface of the two phases of the coacervate system. The two phases are then separated by means of a separatory funnel. The equilibrium water phase resulting from this separation step is set aside for sub¬ sequent recombination with the coacervate phase. Next, 100 standard units of regular insulin U.S. . is thoroughly mixed into the coacervate phase. Following this step, the two phases are recombined and subjected to an emulsifying procedure to produce an emulsion, the particles of which will range from the nanometer to the millimicron size. The emulsified product comprises a prompt release form of insulin and may be used as such or stored, preferably under refrigeration,until needed.

Example 2_ The method-of Example 1 is followed except that Extended Insulin Zinc Suspension U.S.P. is used in place of regular insulin and the particles removed from the filtration bed are placed in gelatin capsules in doses that are medically appropriate. Example 3_ The method of Example 1 is followed except that Prompt Insulin Zinc Suspension U.S.P. is used in place of regular insulin.

Example 4_ The method of Example 1 is used except that _Glo_bin Zinc Insulin Suspension U.S,P. is; used in place of regular insulin. A mixture of the produce of the emulsification step and the product subjected to the heat¬ ing step is prepared and dispensed in an appropriate liquid dosage form.

Example 5_ The method of Example 1 is used except that Protamine Zinc Insulin is used in place of regular insulin.

Example 6_ The method of Example 1 is used except that a mixture of regular insulin U.S.P. and Insulin Zinc Sus¬ pension U.S.P. are used in place of regular insulin.

Example 7_ 200 mis of 5% solution of albumin is added to 200 is of 3% solution of lecithin and mixed thoroughly. The remaining steps of the procedure follow those of Example 1, except that Protamine Zinc Insulin are used in place of regular insulin.

Example 8_ 200 is of a 5% solution of albumin is added to 200 mis of a 7% solution of lecithin and mixed thoroughly. The remaining steps of the procedure follow Example 1, except that Globulin Zinc Insulin Suspension U.S.P. is used in place of Regular Zinc Insulin. Example 9_ 200 mis of a 3% solution of albumin is thoroughly mixed with 200 mis of a 3% solution of isolecithin. The solution is then stored undisturbed at 4°C for 24 hours. The remaining steps of the procedure follow Example 1.

Example 10 Disperse 6% gelatin solution in distilled water and heat to 40°C. Next, slowly add that amount of sodium chloride to the solution as will result in a two phase system. The. lower layer comprises the colloid rich liquid gelatin phase, the upper layer constitutes the coacervate phase. The two phases are separated and 100 units of regular insulin U.S.P. is added to the coacervate phase. Recombine the two phases, mix thoroughly and through the use of a colloid mill prepare an emulsion of the recombined phases wherein the size of the particles of said emulsion are in the range of 10 microns • Following the emulsify¬ ing step, the emulsion is simultaneously rapidly cooled and stirred at a temperature of 5°C for 30 minutes. The resulting particles are thoroughly rinsed with distilled water following which they are completely dried. The quantity of the composition placed in gelatin capsules is a function of the medically indicated dosage of insulin or combinations thereof. The particles are then placed in gelatin capsules in the dosages and types of insulin desired.

Example 11 The method of Example 9 is followed except that Isophane Insulin Suspension U.S.P. is used in place of regular insulin U.S.P.

Example 12 The method of Example 1 is followed except that ExtendedInsulin Zinc Suspension U.S.P. is used in place of Regular Insulin U.S.P. Example 13 The method of Example 1 is followed except that Lente Insulin is used in place of regular insulin.

Example 14 The method of Example 1 is followed except that recrystallized insulin directly derived from animal sources is used in place of Regular Insulin U.S.P.

Example 15 The method of Example 1 is used except that a combination of regular and globin zinc insulin are used in place of regular insulin.

Example 16 200 mis of a 3% solution of albumin is thoroughly mixed with 200 mis of a 3% solution of iso- lecithin. The solution is then stored undisturbed at 4°C for 24 hours. The remaining steps of the. procedure follow Example 1, except that Prompt Insulin Zinc Suspension U.S.P. is used in place of regular insulin U.S.P.

Example 17 The method of Example 1 is used except that a combination of Regular Insulin U.S.P., Prompt Zinc Suspension and Extended Insulin Zinc Suspension is used in place of regular insulin.

Example 18 The method of Example 1 is used except that after the two phases of the coacervate system are separated, 10 units of regular insulin are dispersed into the coacervate phase and mixed thoroughly. The composi¬ tion is then dispensed as oral liquid insulin or placed in refrigerated storage until it is to be dispensed. Example 19 The method of Example 10 is followed except that after two phases of the system are separated 20 units of insulin are dispersed in the coacervate phase and mixed thoroughly. The preparation can either be dispensed as an oral liquid insulin preparation or stored until needed.

Example 20 Example 1 is followed except that the final product of said example is heated for 20 seconds at a temperature of 40°C. Following the heating step, the composition is forced through a filter bed. The product remaining in the filter bed is removed through a washing procedure andthen dried. Upon completing of the drying step, the composition may be placed in any acceptable oral dosage vehicle in the indicated dose.

Example 21 Example 1 is followed except that the heating step is carried out for 10 seconds at 35° C.

Example 22 Example 1 is followed except that 0.5% weight to volume of gluteraldehyde is added to the final product of said example. The composition is mixed thoroughly and then subjected to a filtering step. The particulate matter remaining in the filter bed is removed and placed in refrigerated storage for three to five hours, after which the composition is washed with distilled water until no trace of the gluteraldehyde is found in the wash water. This step is followed by a period of drying, after which the product of the drying step may be placed in any suitable dose in any conventional oral dosage vehicle.

Claims

1. A composition of matter useful as an oral dosage form of insulin; said preparation comprising a non-toxic two phase liquid system, both phases being aqueous; a), one of said phases being a relatively non- polar coacervate phase; b) the other of said phases being a relatively polar liquid aqueous phase; c). said relatively non-polar coacervate phase being insoluble in and in equilibrium with said relatively polar liquid aqueous phase; d) said two phase system, when prepared to con¬ tain an insulin component or components in the coacervate phase of the coacervate system, yields a delivery system for the oral administration of insulin.

2. A composition according to claim 1, wherein the relatively non-polar coacervate phase comprises from 0.5% to 99.5% by volume, and the relatively polar liquid aqueous phase comprises from 0.5 to 99.5% by volume, of the two phase liquid system.

3. A composition according to claim 1 wherein the two liquid phases comprise any non-toxic surface active agent or mixtures thereof including albumin, gelatin, phospholipid, acacia gel; two gelatins of the same or different isoelectric points or two modified fluid gelatins of the same or different isoelectric points.

4. A composition according to claim 3 wherein the phospholipid is selected from lecithin, cephalin, isolecithin, sphingomyelin, phosphatidyl serine, phospha¬ tidyl inositol, phosphatidic acid, phosphatidyl choline or mixtures thereof.

5. A composition according to claims 3 or 4 wherein the two phase liquid system comprises albumin and lecithin, and wherein the concentration of albumin in said two phase system is equal to or less than the concentra¬ tion of lecithin.

6. The composition according to claim 5 wherein the concentration of albumin is greater than the concentra¬ tion of lecithin.

7. A composition according to claim 1 wherein the insulin component is selected from regular insulin, globin zinc insulin, isophane insulin suspension, insulin zinc suspension, protamine zinc insulin, prompt insulin zinc suspension, extended insulin zinc suspension and/or mixtures thereof, or insulin directly recrystallized from animal, genetic recombinant, synthetic or mixtures thereof.

8. A composition according to claim 1 wherein, the insulin component is comprised of either prompt, or sustained release forms of insulin or mixtures thereof.

9. A composition according to claim 8 wherein, the dose of said insulin component is 100 standard units or fractions or multiples thereof as is medically indicated.

10. A composition according to any of claims 1 to 9 wherein the relatively non-polar coacervate phase is separated from the relatively polar liquid aqueous phase and 10.0. units of the insulin component or fractions or multiples thereof are added to said coacervate phase, said coacervate phase comprising a useful oral, liquid dosage form of insulin.

11. A composition according to claim 10 wherein (a) the two liquid phases are recombined and emulsified; and (b) the preparation is heated from 1 minute to 15 minutes at a temperature of 20 C to 70 C in order to harden the surface film of the particles comprising the composition.

12. A composition according to claim 11 wherein the product resulting from step (b) is filtered and the particles from the filter bed are removed and resuspended in an appropriate non-toxic liquid vehicle or placed in the appropriate dose in gelatin capsules or any appropriate oral dosage forms.

13. A composition according to claim 12 wherein the size of the particles of the final product range from about 10~ microns to 10 microns.

14. A composition as defined in any of claims 1 to 9 or 11 to 13 wherein the particles of the composition are in prompt release or time release form or any combina¬ tion thereof.

15. A composition as defined according to claims 1 to 9 or 11 to 13 or 10 to 14 or any medically indicated mixtures thereof useful as a form of oral insulin.

16. A composition as defined in any of claims 1 to 9 or 11 to 15 useful as a form of oral insulin.

17. A composition according to claims 1 to 9 or 13 to 16 wherein the composition may be dispensed in appropriate doses for immediate use or stored, preferably under refrigeration, until needed.

18. A method of preparing a composition of matter which is useful as an oral dosage form of insulin, said method based upon a non-toxic two phase liquid system, both phases being aqueous; a) one of said phases being a relatively non- polar coacervate phase; b) the other of said phases being a relatively polar liquid aqueous phase; c) said relatively non-polar coacervate phase being insoluble in and in equilibrium with said relatively polar liquid aqueous phase. d) said two phase system prepared to contain an insulin component or components in the coacervate phase of the coacervate system.

19. The method of claim 18 wherein the relatively non-polar coacervate phase comprises from 0-.5% to 99.5% by volume and the relatively polar liquid aqueous phase comprises from 0.5% to 99.5% by volume, of the two phase liquid system.

20. The method of claims 18 or 19 wherein the two phase liquid system comprises any appropriate non-toxic surface active agent or mixtures thereof including: albumin, gelatin, a phospholipid, acacia gel; two gelatins of the same or differing isoelectric points or two modified fluid gelatins of the same or differing isoelectric points,

21. The method of claim 20. wherein the phospho¬ lipid is selected from cephalin, lecithin, isolecithin, sphingomyelin, phosphatidyl serine, phosphatidyl choline, phosphatidyl inositol, phosphatidic acid or mixtures thereof,

22. The method of claims 18, 20L or 21 wherein albumin and lecithin are combined and the concentration of albumin in said two phase liquid system is equal to or less than the concentration of lecithin.

23. The method of claim 22 wherein the concentra¬ tion of albumin is greater than the concentration of lecithin

24. The method of claim 22 which steps comprise (a) combining albumin and lecithin in equal proportions in sterile water, (b) thoroughly mixing the components (c) storing said mixture undisturbed until the composition of step (a) separates into two layers one above the other, the lower phase being a substantially non-polar coacervate phase, the upper phase being an equilibrium water phase; (d) continuing the separation process until no increase in the volume of the coacervate phase can be observed; (e) centrifuging the composition until inspection reveals a clear demarcation of the two phases; and (.f) separating the two phases.

25. The method of claim 24 wherein the insulin cumponent is mixed into the coacervate phase.

26. The method of claim 5 wnerein the insulin component is selected from regular insulin, globin insulin with zinc, isophane insulin suspension, insulin zinc suspen¬ sion, protamine zinc insulin, prompt insulin zinc suspen¬ sion, extended insulin zinc suspension or mixtures thereof.

27. The method of claim 26 wherein the insulin is derived from animal, recombinant genetics or other sources or mixtures thereof.

28. The method of claim 27 wherein the insulin component may or may not be of U.S.P. standard.

29. The method of claims 26, 27 or 28 wherein the quantity of insulin added to the coacervate phase is 100. standard units, or fractions thereof or multiples thereof.

30.. The method as defined, according to any of claims 18 to 29 which yields an oral dosage form of insulin.

31. The method of any of claims 18 to 29 which additional steps comprise (gj rccombining the relatively polar liquid aqueous phase with the relatively non-polar coacervate phase, said coacervate phase now containing the insulin component and (h) emulsifying the product of step (g) to produce either an emulsion or a suspension of the composition.

32. The method of claim 31 whereir, the encapsu- lated particles of said emulsion range from 10 —8 microns to 10 microns.

33. The method of claims; 31 or 32 wherein the emulsified composition is subjected to a process to harden the surface films of the particles of the composition.

34. The method of claim 33, wherein the harden¬ ing process is based upon either a physical or chemical procedure.

35. The method of claim 33, wherein the physical process comprises a heating step.

36. The method of claim 33, wherein the chemical process comprises the addition of a non-toxic cross-linking agent, such as a non-toxic entity of the aldehyde group.

37. The method of claim 35 wherein the emulsion is heated at a temperature between 20 C and 70 C for any interval of time ranging from 15 seconds to 15 minutes.

38. The method of claim 37 which yields time release particles containing the insulin component; ranging from relatively prompt release to sustained release particles.

39. The method of any of claims 31 to 38 which additional steps comprise: (.i). filtering the composition; (.j) removing from the filter bed by means of a washing step the encapsulated particles containing the insulin component and (Jc) drying the particles.

40.. The method of any of claims 18 to 29 or claims 31 to 39 wherein the insulin component contained within the encapsulating particle comprises one type of insulin, or mixtures thereof.

41. The method of any of claims 18 to 29 or claims 31 to 40. wherein the claimed composition is comprised of prompt release particles or sustained release particles or combinations thereof.

42. The method of any of claims 18 to 29 or 31 to 41 wherein the prompt release particles, or sustained release particles or combinations thereof in medically appropriate doses may be placed in any suitable oral dosage form such as gelatin capsules or liquid vehicles based upon a coacervate phase, and dispensed as oral insulin or stored, preferably under refrigeration, until needed.