WO1995016465A1

WO1995016465A1 - Pharmaceutical compositions containing alkyl polyoxyalkylene carboxylates

Info

Publication number: WO1995016465A1
Application number: PCT/EP1994/004128
Authority: WO
Inventors: Stacley Y. Au; Werner K. Baumann; Josephine P. Nazareno; John W. Sharkey
Original assignee: Sandoz Ltd.; Sandoz-Patent-Gmbh; Sandoz-Erfindungen Verwaltungsgesellschaft Mbh
Priority date: 1993-12-14
Filing date: 1994-12-13
Publication date: 1995-06-22
Also published as: AU1313695A

Abstract

Pharmaceutical compositions comprising one or more pharmaceutically active agent(s) and an alkyl polyoxyalkylene carboxylate ester or mixtures thereof provide enhancement and improvement in solubility and bioavailability of the pharmaceutically active agent(s).

Description

PHARMACEUTICAL COMPOSITIONS CONTAINING ALKYL POLYOXYALKYLENE CARBOXYLATES

Pharmaceutical compositions typically comprise a variety of additives, such as surfactants, solvents, emollients and other excipients to affect performance and efficacy characteristics. Additives are also incorporated into many cosmetic formulations to provide useful benefits. Means for improving and enhancing the solubility, bioavaUability and other properties of pharmaceutically active agents are constantly being researched and are the focus of the present invention.

U.S. patent No. 4,766,153 describes alkyl polyoxyalkylene carboxylate esters and their use as surface active agents and emollients in skin care compositions such as hand and body lotion or cream. European Patent Application publication No. 0455185 A 2 describes cosmetic compositions in the form of microemulsions for shampoos, conditioners, mousses, fixatives, lotions, hair sprays, gels and other hair-styling and hair-treating products. These products can contain esters such as isopropyl C₁₂.₁₅ pareth-9-carboxylate for durable conditioning properties. PCT patent publication number WO 91/16040 describes a liposome composition which is obtained by using as a constituent component of the liposome membrane a polyoxyethylene derivative represented by the formula X-O-(CH₂CH₂O)„-Y, wherein X is an alkyl or alkanoyl group, Y is a residue of a compound having a negative charge, and n is an integer of 2-50.

VELSAN product bulletin No. 7-231/90 (1990) from Sandoz Chemicals Corp., Charlotte, N.C. describes the use of alkyl polyoxyalkylene carboxylate esters in a variety of cosmetic compositions, such as skin care lotions, sunscreen lotions, hair shampoo and conditioners, antiperspirants and bath products.

None of the prior art references teach or suggest pharmaceutical compositions comprising a pharmaceutically active agent and an alkyl polyoxyalkylene carboxylate ester in accordance with the present invention, nor the resultant enhancement and improvement in solubility and bioavaUability of the pharmaceutically active agent. Thus, it is an object of the present invention to provide pharmaceutical compositions comprising one or more pharmaceutically active agents and an alkyl polyoxyalkylene carboxylate ester described herein or a mixture of said esters. It is a further object of this invention to provide pharmaceutical compositions comprising one or more pharmaceutically active agent(s) and an alkyl polyoxyalkylene carboxylate ester or a mixture thereof which exhibit substantially enhanced bioavaUability of the pharmaceutically active agents. It is an even further object of the present invention to provide a process for solubilizing pharmaceutically active agents, particularly water-insoluble agents, by admixing the agent with an effective amount of the described alkyl polyoxyalkylene carboxylate ester or a mixture thereof.

SUMMARY OF THE INVENTION

This invention relates to pharmaceutical compositions comprising one or more pharmaceutically active agent(s) and an alkyl polyoxyalkylene carboxylate ester of the formula I or a mixture thereof:

O It

RO-(C₃H₆O)_m -(C₂H₄O)_n-(CH₂)₀-C-O-(C₂H₄O)_p-R. I

where

R is C₈-C₂₂ straight or branched chain alkyl;

R, is C,-C₂₂ straight or branched chain alkyl; m is O or an integer from 1 to 4, inclusive; n is an integer from 3 to 20, inclusive; o is an integer from 1 to 4, inclusive; and p is O or an integer from 1 to 20, inclusive, with the provisos that: 1) when R, isC,-C₃ alkyl, then p is O; and (2) when m is , n is an integer from 6 to 20, inclusive.

Preferred pharmaceutically active agents are those which are substantially water-insoluble, such as, for example, cyclosporins and terbinafine. Preferred alkyl polyoxyalkylene carboxylate esters are isopropyl C_I2-C₁₅-pareth-9-carboxylate and isopropyl polypropylene glycol-2-isodeceth-7-carboxylate or mixtures thereof. The alkyl polyoxyalkylene carboxylate esters are preferably present in an amount of about 5% to about 20% by weight based on total weight of the composition. The pharmaceutical compositions of this invention provide an enhancement and improvement in solubility and bioavaUability of the pharmaceutically active agent(s).

BRIEF DESCRIPTION OF THE DRAWING

Figure I shows the bioavaUability through in vitro skin permeation of terbinafine at 8 mg/ml in water containing 10% by weight isopropyl C,₂.-₅-pareth-9-carboxylate in comparison to a similar concentration of terbinafine in water containing 10% by weight polysorbate(20) polyoxyet hylene (20) sorbitan monolaurate (TWEEN 20).

The present invention involves pharmaceutical compositions exhibiting enhanced bioavaUability, for example for systemic administration through the skin into the blood, and solubility of a pharmaceutically active agent. The compositions of this invention comprise a pharmaceutically active agent and an alkyl polyoxyalkylene carboxylate ester of the formula I:

O RO-(C₃H₆O)_m -(C₂H₄O)_n-(CH₂)₀-C-O-(C₂H₄O)_p-R. I where

R is C₈-C₂₂ straight or branched chain alkyl;

R, is C,-C₂₂ straight or branched chain alkyl; m is O or an integer from 1 to 4, inclusive; n is an integer from 3 to 20, inclusive; o is an integer from 1 to 4, inclusive; and p is O or an integer from 1 to 20, inclusive, with the provisos that: (1) when R- is C--C₃ alkyl, then p is O; and (2) when m is O, n is an integer from 6 to 20, inclusive. Any pharmaceutically active agent can be used in accordance with the present invention. Suitable pharmaceutically active agents include, for example:

a) local anesthetics such as:

Ambucaine, Amolanone, Amylocaine Hydrochloride, Benoxinate, Bethoxycaine, Biphenamine, Bupivacaine, Butacaine, Butamben, Butanilicaine, Butethamine, Butoxycaine, Carticaine, 2-Chloroprocaine Hydrochloride, Cocaethylene, Cocaine, Cyclomethycaine, Dibucaine Hydrochloride, Dimethisoquin, Dimethocaine, Diperodon Hydrochloride, Dyclonine, Ecgonidine, Ecgonine, Ethyl Aminobenzoate, Ethyl Chloride, Etidocaine, β-Eucaine, Euprocin, Fenalcomine, Fomocaine, Hexylcaine Hydrochloride, Hydroxyprocaine, Hydroxytetracaine, Isobutyl p-Aminobenzoate, Leucinocaine Mesylate, Levoxadrol, Lidocaine, Mepivacaine, Meprylcaine Hydrochloride, Metabutoxycaine Hydrochloride, Methyl Chloride, Myrtecaine, Naepaine, Octacaine, Orthocaine, Oxethazaine, Parethoxycaine, Phenacaine Hydrochloride, Phenol, Piperocaine, Piridocaine, Polidocanol, Pramoxine, prilocaine, Procaine, Propanocaine, Proparacaine, Propipocaine, Propoxycaine Hydrochloride, pseudococaine, Pyrrocaine, Quinine Urea Hydrochloride, Risocaine, Salicyl Alcohol, Tetracaine Hydrochloride, Tolycaine, Trimecaine, and Zolamine;

b) narcotic analgesics such as: Alfentanil, Allylprodine, Alphaprodine, Anileridine, benzylmo hine, Bezitramide, Buprenorphine, Butoφhanol, Clonitazene, Codeine, Codeine Methyl Bromide, Codeine Phosphate, Codeine Sulfate, Desomorphine, Dextromoramide, Dezocine, Diampromide, Dihydrocodeine, Dihydrocodeinone Enol Acetate, Dihydromorphine, Dimenoxadol, Dimepheptanol, Dimethylthiambutene, Dioxaphetyl Butyrate, Dipipanone, Eptazocine, Ethoheptazine, Ethylmethylthiambutene, Ethylmorephine, Etonitazene, Fentanyl, Hydrocodone, Hydromorphone, Hydroxypethidine, Isomethadone, Ketobemidone, Levorphanol, Lofentanil, Meperidine, Meptazinol, Metazocine, Methadone Hydrochloride, Metopon, Morphine, Morphine Derivatives, Myrophine, Nalbuphine, Narceine, Nicomorphine, Norlevorphanol, Normethadone, Normorphine, Norpipanone, Opium, Oxycodone, Oxymorphone, Papaveretum, pentazocine, Phenadoxone, Phenazocine, Phenoperidirie, Piminodine, Piritramide, Proheptazine, Promedol, Properidine, Propiram, propoxyphene, Sufentanil and Tilidine;

non-narcotic analgesics such as:

Acetaminophen, Acetaminosalol, Acetanilide, Acetylsalicylsalicylic Acid, Alconfenac, Alminoprofen, Aloxiprin, Aluminum Bis (acetylsalicylate), Aminochlorthenoxazin, 2-amino-4-picoline, Aminopropylon, Aminopyrine, Ammonium Salicylate, Antipyrine, Antipyrine Salicylate, Antrafenine, Apazone, Aspirin, Benorylate, Benoxaprofen, Benziperylon, benzydamine, p-Bromoacetanilide,

5-Bromosalicylic Acid Acetate, Bucetin, Bufexamac,

Bumadizon, Butacetin, Calcium Acetylsalicylate,

Carbamazepine, Carbetidine, Carbiphene, Carsalam,

Chloralantipyrine, Chlorthenoxazin(e), Choline

Salicylate, Cinchophen, Ciramadol, Clometacin,

Cropropamide, Crotethamide, Dexoxadrol, Difenamizole, Diflunisal,

Dihydroxy aluminum Acetylsalicylate,

Dipyrocetyl, Dipyrone, Emorfazone, Enfenamic Acid,

Epirizole, Ethenzamide, Ethoxazene Etodolac,

Felbinac, Fenoprofen, Floctafenine, Flufenamic Acid,

Fluoresone, Flupirtine, Fluproquazone, Flurbiprofen,

Fosfosal, Gentisic Acid, Glafenine, Ibufenac,

Imidazole Salicylate, Indomethacin, Indoprofen,

Isofezolac, Isoladol, Isonixin, Ketoprofen,

Ketorolac, -Lactophenetide, Lefetamine, Loxoprofen,

Lysine Acetylsalicylate, Magnesium Acetylsalicylate,

Metergoline, Methotrimeprazine, Metofoline,

Miroprofen, Morazone, Morpholine Salicylate,

Naproxen, Nefopam, Nifenazone,

5'-Nitro-2'-propoxyacetanilide, Parsalmide, Perisoxal,

Phenacetin, Phenazopyridine Hydrochloride, Phenocoll,

Phenopyrazone, Phenyl Acetylsalicylate, Phenyl

Salicylate, Phenyramidol, Pipebuzone, Piperylone,

Prodilidine, Propacetamol, Propyphenazone, Proxazole,

Quinine Salicylate, Ramifenazone, Rimazolium

Metilsulfate, Salacetamide, Salicin, Salicylamide,

Salicylamide O-Acetic Acid, Salicylsulfuric Acid,

Salsalate, Salverine, Simetride, Sodium Salicylate,

Sulfamipyrine, Suprofen, Talniflumate, Tenoxicam,

Terofenmate, Tetrandrine, Tinoridine, Tolfenamic Acid, Tolpronine, Tramadol, Viminol, Xenbucin, and Zomepirac;

d) antibacterials and antibiotics such as:

Aminoglycosides (i.e. Amikacin, Neomycin, Streptomycin and the like), Amphenicols, Ansamycins, β-lactams (i.e. Carbapenems, Cephalosporins, Cephamycins, Monobactams, Oxacephems and Penicillins), Linosamides, Macrolides, Polypeptides, Tetracyclines, Nitrofurans, Quinolones, Sulfonamides, Sulfones, Hexedines, 2,4-Diaminopyrimidines and the like;

e) Antifungals, such as Polyenes (i.e. Amphotericin B, Dermostatin, Fungichromin,Perimycin and the like), Allylamines (i.e. Naftifine, Terbinafine and the like), Imidazoles (i.e. Bifonazole, Butoconazole, Chlordantoin, Chlormidazole, Ketoconazole, Econazole Miconazole, Omoco nazole, Sulconazole, Tioconazole and the like), triazoles (i.e. Fluconazole, Itraconazole, Terconazole and the like), Acrisorcin, Amorolfine, Biphenamine, Bromosalicylchloranilide, Buclosamide, Calcium Propionate, Chlorphenesin, Ciclopirox, Cloxiquin, Coparaffinate, Diamthazole Dihydrochloride, Exalamide, Flucytosine, Halethazole, Hexetidine, Loflucarban, Nifuratel, Potassium Iodide, Propionic Acid, Pyrithione, Salicylanilide, Sodium Propionate, Sulbentine, Tenonitrozole, Tolciclate, Tolindate, Tolnftate, Triacetin, Ujothion, Undecylenic Acid, and Zinc Propionate; anti-inflammatory agents such as:

Acemetacin, Isonixin, and Ketorolac, Aminoarylcarboxylic Acid Derivatives (i.e. Enfenamic Acid, Etofenamate, Flufenamic Acid, Meclofenamic Acid, Mefenamic Acid, Niflumic Acid, Talniflumate, Terofenamate, Tolfenamic Acid and the like),

Aryl-group-containing Acetic Acid and Derivatives thereof i.e., Alclofenac, Amfenac, Bufexamac, Cinmetacin, Clopirac, Diclofenac Sodium, Etodolac, Felbinac, Fenclofenac, Fenclorac, Fenclozic Acid, Fentiazac, Glucametacin,

Ibufenac, Indomethacin, Isofezolac, Isoxepac, Lonazolac, Metiazinic Acid, oxametacine, Proglumetacin, Sulindac, Tiaramide, Tolmetin, Zomepirac and the like),

Arylbutyric Acids and Derivatives (i.e Bumadizon, Butibufen, Fenbufen, Xenbucin and the like),

Aryl-group-containing Carboxylic Acids (i.e. Clidanac, Tinoridine and the like),

Pyrazolones (i.e. Apazone, Benziperylon, Feprazone, Mofebutazone, Morazone, oxyphenbutazone, Phenylbutazone, Pipebuzone, Propyphenazone, Ramifenazone, Suxibuzone, Thiazolinobutazone and the like),

Salicylic Acid Derivatives, Thiazinecarboxamides (i.e Droxicam, Isoxicam Piroxicam Tenoxicam and the like), Arylpropionic Acid Derivatives (i.e. Alminoprofen, Benoxaprofen, Bucloxic Acid, Carprofen, Fenoprofen, Flunoxaprofen, Flurbiprofen, Ibuprofen, Ibuproxam, Indoprofen, Ketoprofen, Loxoprofen, Miroprofen, Naproxen, oxaprozin, Piketoprofen, Piroprofen, Pranoprofen, protizinic Acid, Suprofen, Tiaprofenic, and the like), Pyrazoles, Amixetrine, Bendazac, Benzydamine, Bucolome, difenpiramide, Ditazol, Emorfazone, Guaiazulene, Nabumetone, Nimesulide, Orgotein, Oxaceprol, Paranyline, Perisoxal, Pifoxamine, Proquazone, Proxazole, Tenidap, and steroidal anti-inflammatory agents such as hydrocortisones, methylprednisolones, dexamethasone and other glucocorticoids; and any of their pharmaceutically acceptable salts.

Some preferred pharmaceutically active agents for use in this invention are polypeptides (such as the cyclosporins) and antifungals (such as miconazole, econazole, naftifine and terbinafine and pharmaceutically acceptable salts thereof).

This invention is especially useful and beneficial with pharmaceutically active agents which are substantially insoluble (i.e., less than 0.01 % by weight) in water at 22°C.

The alkyl polyoxyalkylene carboxylate esters of this invention are those of formula I and are further described in U.S. patent no. 4,766,153 (the disclosure of which is herein incoφorated by reference). The alkyl polyoxyalkyl carboxylate esters preferably have an hydrophilic-lipophilic balance (HLB) number ranging from 12 to 20; more preferably 14 to 18, inclusive.

The most preferred alkyl polyoxyalkylene carboxylate esters are the mixture of esters isopropyl C₁₂-₁₅pareth-9-carboxylate (also referred to as isodecyl-dipropoxy-hexa- ethoxymethyl carboxylic acid isopropyl ester as prepared in Ex. 1 of U.S. Pat. No. 4,766,153) and the mixture isopropyl polypropylene glycol-2-isodeceth-7-carboxylates (as prepared in Example 7(b) of U.S. Pat. No. 4,766,153). These esters have the following typical physical properties:

The pharmaceutical compositions of the present invention can contain any amount of said alkyl polyoxyalkylene carboxylate ester(s), but preferably present in an amount from 5% to 20% by weight based on the total weight of said composition.

The pharmaceutical compositions of the invention can contain any amount of the pharmaceutically active agent(s). Preferably the amount of the pharmaceutically active agent(s) range(s) from 0.01% to 50% by weight of the total composition. Preferably, the compositions additionally comprise a pharmaceutically acceptable hydrophilic solvent, such as water, an alcohol or mixtures thereof. The most preferred solvents are water, ethanol and mixtures of water and ethanol. The compositions can also comprise excipients and other optional ingredients which are conventionally used in pharmaceutical compositions. The pharmaceutical compositions preferably are in a dosage form suitable for oral ingestion, topical application, and transdermal (passive and iontophoretic) delivery.

According to a further feature of this invention, there is provided a process for solubilizing pharmaceutically active agent(s) to form pharmaceutical compositons comprising admixing at least one pharmaceutically active agent with an effective amount (preferably 5-20% by weight of total composition) of said alkyl polyoxyalkylene carboxylate ester of formula I defined earlier in the specification, or a mixture thereof.

The present invention also involves a process for increasing the bioavaUability of pharmaceutically active agent(s) in pharmaceutical composition(s) comprising admixing at least one pharmaceutically active agent with an effective amount (preferably 5-20% by weight of total composition) of an alkyl polyoxyalkylene carboxylate ester of formula I or mixture thereof.

The following examples are presented to further demonstrate this invention. The examples are intended in an illustrative and not in a limitative sense. EXAMPLE 1 :

The effect of the alkyl polyoxyalkylene carboxylate ester of the present invention on the solubility of Cyclosporin A and terbinafine were determined at various concentrations in water, ethanol and water/ethanol mixtures.

The equilibrium solubility of Cyclosporin A was determined by continual addition of the drug in a small amount to the solvent until the drug was completely dissolved and reached an equilibrium (i.e. more than 24 hours) at 22°C. The actual solubility was then determined by HPLC. The equilibrium solubility of terbinafine was determined by putting an excess of drug in a vial with the appropriate solvent or cosolvent system. The vials were agitated at 22°C for approximately 24 hours and the supernatants were filtered through 0.45 μm membrane filters. The quantity of dissolved drug in the clear filtrate was determined by HPLC after dilution with the mobile phase.

The concentrations of Cyclosporin A and terbinafine were determined by HPLC. The method for Cyclosporin A utilized a BROWNLEE SPHERI-5^R RP-18 reversed phase column with a mobile phase consisting of tetrahydrofuran water: in a ratio of 40/60 (v/v). The flow rate rate was 1.0 ml/min and detection was made by UV at 220 nm. For terbinafine, the HPLC method uses a E. Merck LICHROSORB^R RP-18 reversed phase column with a mobile phase containing acetonitrile/tetrahydrofuran/0.016 M tetramethyl- ammonium hydroxide pentahydrate buffer (adjusted to pH 7.8 with phosphoric acid) in a ratio of 70/8.5/21.5(v/v/v). The flow rate was 2.0 ml/min and detection was by UV at 220 nm.

The results for Cyclosporin A are presented in Table I TABLE I

Isopropyl C₁₂.₁₅. Pareth-9-carboxylates (% by wt. of total Ethanol/Water Cyclosporin A Solubility composition) % (w/w) (mg/gm of solvent)

0 0/100 0.04

20 0/100 0.22

10 20/80 5.2

20 50/50 230.7

5 80/20 1.6

10 80/20 7.6

20 80/20 363.9

0 100/0 180

The results for terbinafine are presented in Table II below:

TABLE π

Isopropyl C₁₂.₁₅- Pareth-9-carboxylates (% by wt. of total Ethanol/Water Terbinafine HC1 Solubility composition) % (w/w) (mg/ml, equivalent to base)

0 0/100 5.3

10 0/100 15.9

20 0/100 20.3

5 80/20 11.2

10 80/20 23.6

20 80/20 231.4

0 100/0 >70

The above results demonstrate that isopropyl C₁₂.₁₅-pareth-9-carboxylate significantly improves the solubility of Cyclosporin A and terbinafine in water and water/ethanol solvent systems. For comparison, the solubility of terbinafine in water with 10% (w/w) polysorbate(20)polyoxyethylene(20) sorbitan monolaurate was found to be 12.2 mg/ml.

EXAMPLE II;

The solubility of Cyclosporin A in ethanol was determined visually by dissolving Cyclosporin A to saturation in ethanol containing 10% (w/w) isopropyl polyρropylene-2- isodeceth-7-carboxylate. The solubility of Cyclosporin A in this solvent system was found to be greater than 1 gram per gram of solvent.

EXAMPLE III;

The effect of the alkyl polyoxyalkylene carboxylate esters of the present invention on the bioavaUability of pharmaceutically active agent, such as terbinafine, was determined through an in vitro skin permeation study.

Hairless guinea pig skin obtained from 30 to 90 day old hairless guinea pig (Charles River) was used. After the animal was sacrificed by carbon dioxide asphyxiation, abdominal and dorsal skin sections were excised with surgical scissors. The skin was then sectioned (Padgett Dermatome) to about 130 μm thick to remove the underlying subcutaneous fat and part of the dermis. Appropriate size specimens were cut into squares to fit the diffusion cells.

Teflon flow-through Bronaugh diffusion cells (Crown Glass) held in a temperature controlled aluminum block were used in the skin permeation experiments. Prepared skin was mounted, stratum corneum side up, in the cells. A 400 μl sample of the donor solution was applied on the surface of the skin and capped with a plastic stopper. A 10% by weight isopropyl C₁₂.₁₅-pareth-9-carboxylate in water solution containing 8 mg/ml terbinafine was used. Comparative experiments were conducted using 10% by weight polysorbate (20) polyoxyethylene(20) sorbitan monolaurate (TWEEN-20) in water containing 8 mg/ml terbinafine. For the cells used in this study, the diffusional cross-section area was 0.35 cm² and the volume of the receptor was 0.13 ml. The temperature in the diffusion cells was maintained at 35 to 37°C by pumping water from a water bath through the aluminum block. The receptor solution was 0.01 M sodium chloride in water (pH about 7). A multichannel cassette pump delivered the receptor fluid to each cell at a rate of either 0.5 to 1 ml hr. The effluent was collected in HPLC vials in a fraction collector for about 24 to 30 hours. The amount of drug permeated was determined by injecting the collected effluent into a HPLC.

The results are presented in Figure I.

Figure I shows that compositions of the present invention containing isopropyl C₁₂.₁₅-pareth-9-carboxylate and terbinafine significantly improved the skin permeability and bioavaUability of the terbinafine.

Claims

CLAIMS:

1. A pharmaceutical composition comprising one or more pharmaceutically active agent(s) and an alkyl polyoxyalkylene carboxylate ester of formula I, ora mixture thereof,

O

//

RO-(C₃H₆O)_m -(C₂H₄O)_n-(CH₂)₀-C-O-(C₂H₄O)_p-R. I

R is C₈.C₂₂ straight or branched chain alkyl;

R, is C_rC₂₂ straight or branched chain alkyl;

m is O or an integer from 1 to 4, inclusive;

n is an is an integer from 3 to 20, inclusive;

o is an integer from 1 to 4, inclusive, and

p is O or an integer from 1 to 20, inclusive, with the provisos that: (1 ) when R, is C,-C₃ alkyl, then p is O; and (2) when m is O, n is an integer from 6 to 20, inclusive.

2. A pharmaceutical composition of claim 1 wherein the alkyl polyoxyalkylene carboxylate esters are a mixture of isopropyl C₁₂-C₁₅ pareth-9-carboxylates.

3. A pharmaceutical composition of claim 1 wherein the alkyl polyoxyalkylene carboxylate esters are a mixture of isopropyl polypropylene glycol-2-isodeceth-7-

' carboxylates.

4. A pharmaceutical composition of claim 1 wherein the alkyl polyoxyalkylene carboxylate esters have an hydrophilic-lipophilic-balance number ranging from 12 to 20.

5. A pharmaceutical composition of claim 1 wherein the alkyl polyoxyalkylene carboxylate esters have an hydrophilic-lipophilic-balance number ranging from 14 to 18.

6. A pharmaceutical composition of claim 1 wherein said alkyl polyoxyalkylene carboxylate ester is present in an amount from 5% to 20% by weight based on total weight of said composition.

7. A pharmaceutical composition of claim 1 additionally comprising a hydrophilic solvent.

8. A pharmaceutical composition of claim 7 wherein said solvent is selected from the group consisting of water, pharmaceutically acceptable alcohols, and mixtures thereof.

9. A pharmaceutical composition of claim 8 wherein said alcohol is ethanol.

10. A pharmaceutical composition of claim 1 wherein said active agent is substantially insoluble in water at 22°C.

11. A composition of claim 1 wherein said active agent is terbinafine or a pharmaceutically acceptable salt thereof.

12. A composition of claim 1 wherein said active agent is a cyclosporin.

13. The composition of claim 1 wherein said composition is in a dosage form for oral ingestion.

14. The composition of claim 1 wherein said composition is in a form suitable for topical application.

15. The composition of claim 1 wherein said composition is in a form suitable for transdermal delivery.

16. A process for solubilizing a pharmaceutically active agent to form a pharmaceutical composition comprising admixing one or more pharmaceutically active agent(s) with an effective amount of an alkyl polyoxyalkylene carboxylate ester of formula 1, or a mixture thereof,

O ti

RO-(C₃H₆O)_m -(C₂H₄O)_n-(CH₂)₀-C-O-(C₂H₄O)_p-R- I

where

R is C₈-C₂₂ straight or branched chain alkyl;

R, is C,-C₂₂ straight or branched chain alkyl; m is O or an integer from 1 to 4; inclusive n is an integer from 3 to 20; inclusive o is an integer from 1 to 4; inclusive, and p is O or an integer from 1 to 20, with the provisos that: (1) when R, is C--C₃ alkyl, then p is O; and (2) when m is O, n is an integer from 6 to 20, inclusive.

17. A process of claim 16 wherein the alkyl polyoxyalkylene carboxylate esters are a mixture of isopropyl C₁₂.₁₅pareth-9-carboxylates.

18. A process of claim 16 wherein the alkyl polyoxyalkylene carboxylate esters are a mixture of isopropyl polypropylene glycol-2-isodeceth-7-carboxylates.

19. A process of claim 16 wherein said effective amount of alkyl polyoxyalkylene carboxylate ester or a mixture thereof is 5% to 20% by weight based on the total weight of said pharmaceutical composition.

20. A process of claim 16 wherein the pharmaceutically active agent(s) are substantially water-insoluble at 22°C.

21. A process of claim 16 wherein the pharmaceutically active agent is selected from the group consisting of Cyclosporin A and terbinafine.

22. A process for increasing the bioavaUability of pharmaceutically active agents in a pharmaceutical composition comprising admixing one or more pharmaceutically active agent(s) with an effective amount of an alkyl polyoxyalkylene carboxylate ester of formula I or a mixture thereof,

O (I

RO-(C₃H₆O)_m -(C₂H₄O)_n-(CH₂)₍ -C-O-(C₂H₄O)_p R, I

where

R is C₈-C₂₂ straight or branched chain alkyl;

R, is C_rC₂₂ straight or branched chain alkyl; m is O or an integer from 1 to 4 inclusive; n is an integer from 3 to 20 inclusive; o is an integer from to 4 inclusive; and p is O or an integer from 1 to 20 inclusive, with the provisos that: (1) when R, is

C_rC₃ alkyl, then p is O; and (2) when m is O, n is an integer from 6 to 20, inclusive.

23. The process of claim 22 wherein the alkyl polyoxyalkylene carboxylate esters are a mixture of isopropyl C₁₂.₁₅ pareth-9-carboxylates.

24. The process of claim 22 wherein the alkyl polyoxyalkylene carboxylate esters are a mixture of isopropyl polypropylene glycol-2-isodeceth-7-carboxylates.

25. The process of claim 22 wherein the effective amount of alkyl polyoxyalkylene carboxylate esters is 5% to 20% by weight based on the total weight of said pharmaceutical composition.

26. The process of claim 22 wherein the pharmaceutically active agent(s) are substantially water-insoluble at 22°C.

27. The process of claim 22 wherein the pharmaceutically active agent is selected from the group consisting of Cyclosporin A and terbinafine.

28. The process of claim 22 wherein the pharmaceutical composition is in a dosage form for oral ingestion.

29. The process of claim 22 wherein the pharmaceutical composition is in a form suitable for topical application.

30. The process of claim 22 wherein the pharmaceutical composition is in a form suitable for transdermal delivery.