LIPID DEPOT FORMULATIONS

Abstract

The present invention relates to pre-formulations comprising low viscosity, non-liquid crystalline, mixtures of: a) at least one neutral diacyl lipid and/or at least one tocopherol; b) at least one phospholipid; c) at least one biocompatible, oxygen containing, low viscosity organic solvent;
wherein at least one bioactive agent is dissolved or dispersed in the low viscosity mixture and wherein the pre-formulation forms, or is capable of forming, at least one liquid crystalline phase structure upon contact with an aqueous fluid. The preformulations are suitable for generating parenteral, non-parenteral and topical depot compositions for sustained release of active agents. The invention additionally relates to a method of delivery of an active agent comprising administration of a preformulation of the invention, a method of treatment comprising administration of a preformulation of the invention and the use of a preformulation of the invention in a method for the manufacture of a medicament.

Claims

1. A pre-formulation comprising a low viscosity, non-liquid crystalline, mixture of: a) at least one neutral diacyl lipid and/or at least one tocopherol; b) at least one phospholipid; c) at least one biocompatible, oxygen containing, low viscosity organic solvent; wherein at least one bioactive agent is dissolved or dispersed in the low viscosity mixture and wherein the pre-formulation forms, or is capable of forming, at least one liquid crystalline phase structure upon contact with an aqueous fluid.

2. (canceled)

3. A pre-formulation as claimed in claim 1 wherein component a) consists essentially of diacyl glycerols, especially glycerol dioleate; or wherein component a) consists essentially of at least one tocopherol; or wherein component a) consists essentially of a mixture of GDO and tocopherol.

4-5. (canceled)

6. A pre-formulation as claimed in claim 1 wherein component b) is selected from phosphatidylcholines, phosphatidylethanolamines, phosphatidylserines, phosphatidylinositols and mixtures thereof.

7. A preformulation as claimed in claim 1 having a viscosity of 0.1 to 5000 mPas.

8. (canceled)

9. A preformulation as claimed in claim 1 having a ratio of a) to b) of between 95:5 and 5:95 by weight.

10. A preformulation as claimed in claim 1 having 0.5 to 50% component c) by weight of components a)+b)+c) and/or wherein component c) is selected from alcohols, ketones, esters, ethers, amides, sulphoxides and mixtures thereof.

11-12. (canceled)

13. A preformulation as claimed claim 1 wherein said active agent is selected from drugs, antigens, nutrients, cosmetics, fragrances, flavourings, diagnostic agents, vitamins, dietary supplements and mixtures thereof.

14. A preformulation as claimed in claim 13 wherein said drug is selected from hydrophilic small molecule drugs, lipophilic small molecule drugs, amphiphilic small molecule drugs, peptides, proteins, oligonucleotides and mixtures thereof; or wherein said drug is selected from somatostatin related peptides, interferons, glucagon-like peptides 1 and 2, GnRH agonists, GnRH antagonists, bisphosponates, chlorhexidine and mixtures thereof.

15. (canceled)

16. A preformulation as claimed in claim 1 which is administrable by injection or which is administrable by spraying, dipping, rinsing, application from a pad or ball roller, painting, dropping, aerosol spraying or pump spraying.

17. (canceled)

18. An injectable preformulation as claimed in claim 1 which forms a depot providing continuous release of active agent for at least two weeks, wherein said active agent comprises at least one selected from i. octreotide ii. human growth hormone iii. interferon alpha iv. leuprolide; or wherein said active agent comprises at least one selected from i. risperidone ii. olanzapine iii. testosterone undecanoate

19. (canceled)

20. A topical formulation as claimed in claim 1 for intraoral administration which forms a bioadhesive, controlled release product, wherein said active agent comprises at least one selected from i. benzydamine ii. tramadol

21. (canceled)

22. A non-parenteral formulation as claimed claim 1 for intranasal spray administration which forms a bioadhesive, controlled release product, wherein said active agent comprises at least one selected from i. fentanyl ii. diazepam

23. A topical formulation as claimed in claim 1 suitable for ocular administration, wherein said active agent comprises at least one selected from diclofenac, pilocarpine, levocabastine hydrochloride, ketotifen fumarate, timolol, betaxolol, carteolol, levobunolol, dorzolamide, brinzolamide, epinephrine, dipivefrin, clonidine, apraclonidine, brimonidine, pilocarpine, atanoprost, travoprost, bimatoprost, unoprostone, pilocarpine hydrochloride, dexamethasone, chloramphenicol, and indomethacin.

24. A non-parenteral formulation as claimed in claim 1 for dermatological administration which forms a bioadhesive, controlled release product, wherein the active agent is selected from; i. acyclovir ii. testosterone undecanoate.

25. (canceled)

26. A method of delivery of a bioactive agent to a human or non-human animal (preferably mammalian) body, this method comprising administering a pre-formulation comprising a non-liquid crystalline, low viscosity mixture of: a) at least one neutral diacyl lipid and/or at least one tocopherol; b) at least one phospholipid; c) at least one biocompatible, oxygen containing, low viscosity organic solvent; and at least one bioactive agent is dissolved or dispersed in the low viscosity mixture, whereby to form at least one liquid crystalline phase structure upon contact with an aqueous fluid in vivo following administration.

27. A method as claimed in claim 26 wherein said pre-formulation is administered by a method selected from subcutaneous injection, intramuscular injection, intra-cavity injection through tissue, intra-cavity injection into an open cavity without tissue penetration, spraying, rolling, wiping, dabbing, painting, rinsing, or dropping.

28-30. (canceled)

31. A process for the formation of a pre-formulation suitable for the administration of a bioactive agent to a (preferably mammalian) subject, said process comprising forming a non-liquid crystalline, low viscosity mixture of a) at least one neutral diacyl lipid and/or at least one tocopherol; b) at least one phospholipid; c) at least one biocompatible, oxygen containing low viscosity, organic solvent; and dissolving or dispersing at least one bioactive agent in the low viscosity mixture, or in at least one of components a, b or c prior to forming the low viscosity mixture.

32. A process as claimed in claim 31 wherein said preformulation comprises a low viscosity, non-liquid crystalline, mixture of: a) at least one neutral diacyl lipid and/or at least one tocopherol; b) at least one phospholipid; c) at least one biocompatible, oxygen containing, low viscosity organic solvent; wherein at least one bioactive agent is dissolved or dispersed in the low viscosity mixture and wherein the pre-formulation forms, or is capable of forming, at least one liquid crystalline phase structure upon contact with an aqueous fluid.

33-34. (canceled)

35. A method of treatment or prophylaxis of a human or non-human animal subject comprising administration of a preformulation as claimed in claim 1.

36. The method of claim 35 for the treatment of a condition selected from bacterial infection, fungal infection, skin soreness, eye conditions, genital soreness, infections and conditions for the finger and/or toe nails, travel sickness, addiction including nicotine addiction, periodontal infection, conjunctivitis, glaucoma and hormone deficiency or imbalance; or for prophylaxis against at least one condition selected from infection during surgery, infection during implantation, sunburn, infection at the site of burns, cuts or abrasions, oral infections, genital infections and infections resulting from activities resulting in exposure to infective agents.

37. (canceled)

Description

[0144] The Invention will now be further illustrated by reference to the following non-limiting Examples and the attached Figures, in which;

[0145] FIG. 1 shows the cumulative release of methylene blue (MB) from a depot formulation comprising PC/GDO/EtOH (45/45/10 wt %) when injected into excess water;

[0146] FIG. 2 demonstrates the non-linear decrease of pre-formulation viscosity upon addition of N-methyl pyrolidinone (NMP) and EtOH;

[0147] FIG. 3 shows the plasma concentration (in rats) of salmon calcitonin (sCT) after subcutaneous injection of various PC/GDO/EtOH depot precursors containing 500 μg sCT/g of formulation;

[0148] FIG. 4 shows the initial in vivo release (up to 48 hours) to plasma (in rats) of sCT from two different depot formulations following subcutaneous injection;

[0149] FIG. 5 shows the plasma concentration (in rats) of octreotide (OCT) following subcutaneous injection of a depot formulation comprising PC/GDO/EtOH (36/54/10 wt %) containing 5 mg OCT/g formulation, corresponding to 0.5% drug load.

[0150] FIG. 6 shows the plasma concentration (in rats) of octreotide (OCT) following subcutaneous injection of a depot formulation comprising PC/GDO/EtOH (47.5/47.5/5.0 wt %) containing 30 mg OCT/g formulation, corresponding to 3% drug load.

[0151] FIG. 7 displays the in vitro release in excess aqueous phase of chlorhexidine from a depot formulation comprising PC/GDO/EtOH (36/54/10 wt %) containing 50 mg chlorhexidine/g of formulation, corresponding to 5% drug load.

EXAMPLES

Example 1

[0152] Availability of Various Liquid Crystalline Phases in the Depot by Choice of Composition

[0153] Injectable formulations containing different proportions of phosphatidyl choline (“PC”—Epikuron 200) and glycerol dioleate (GDO) and with EtOH as solvent were prepared to illustrate that various liquid crystalline phases can be accessed after equilibrating the depot precursor formulation with excess water.

[0154] Appropriate amounts of PC and EtOH were weighed in glass vials and the mixture was placed on a shaker until the PC completely dissolved to form a clear liquid solution. GDO was then added to form an injectable homogenous solution.

[0155] Each formulation was injected in a vial and equilibrated with excess water. The phase behaviour was evaluated visually and between crossed polarizes at 25° C. Results are presented in Table 1.

TABLE-US-00001 TABLE 1 PC GDO EtOH Phase in Formulation (wt %) (wt %) (wt %) H.sub.2O A 22.5 67.5 10.0 L.sub.2 B 28.8 61.2 10.0 I.sub.2 C 45.0 45.0 10.0 H.sub.II D 63.0 27.0 10.0 H.sub.II/L.sub.α L.sub.2 = reversed micellar phase I.sub.2 = reversed cubic liquid crystalline phase H.sub.II = reversed hexagonal liquid crystalline phase L.sub.α = lamellar phase

Example 2

[0156] In Vitro Release of a Water-Soluble Substance

[0157] A water-soluble colorant, methylene blue (MB) was dispersed in formulation C (see Example 1) to a concentration of 11 mg/g formulation. When 0.5 g of the formulation was injected in 100 ml water a stiff reversed hexagonal H.sub.∥ phase was formed. The absorbency of MB released to the aqueous phase was followed at 664 nm over a period of 10 days. The release study was performed in an Erlenmeyer flask at 37° C. and with low magnetic stirring.

[0158] The release profile of MB (see FIG. 1) from the hexagonal phase indicates that this (and similar) formulations are promising depot systems. Furthermore, the formulation seems to give a low initial burst, and the release profile indicates that the substance can be released for several weeks; only about 50% of MB is released after 10 days.

Example 3

[0159] Viscosity in PC/GDO (6:4) or PC/GDO (3:7) on Addition of Solvent (EtOH, PG and NMP)

[0160] A mixture of PC/GDO/EtOH was manufactured according to the method in Example 1. All, or nearly all, of the EtOH was removed from the mixture with a rotary evaporator (vacuum, 40° C., 1 h) and the resulting solid mixture were weighed in glass vial after which 2, 5, 10 or 20% of a solvent (EtOH, propylene glycol (PG) or n-methyl pyrrolidone (NMP)) was added. The samples were allowed to equilibrate several days before the viscosity was measured at a shear rate of 0.1 s.sup.−1 with a Physica UDS 200 rheometer at 25° C.

[0161] This example clearly illustrates the need for solvent with certain depot precursors in order to obtain an injectable formulation (see FIG. 2). The viscosity of solvent-free PC/GDO mixtures increases with increasing ratio of PC. Systems with low PC/GDO ratio (more GDO) are injectable with a lower concentration of solvent.

Example 4

[0162] Composition and In Vitro Phase Study

[0163] The formulations were manufactured according to the method described in Example 1 with compositions according to Table 2. An active substance (peptide), salmon calcitonin (sCT), was added to each formulation to a concentration of 500 μg sCT/g formulation. The formulations were designed as homogenous suspensions for parenteral administration (mixing required shortly prior to use since the drug is not completely dissolved in the PC/GDO/EtOH system).

[0164] The phase study in this example is performed in excess of rat serum at 37° C. in order to simulate an in vivo situation. Table 2 shows that the same phases as those in water are formed (compare Table 1).

TABLE-US-00002 TABLE 2 PC GDO OA EtOH Phase in Formulation (wt %) (wt %) (wt %) (wt %) rat serum E 18 72 — 10 L.sub.2 F 36 54 — 10 I.sub.2 G 34 51 5 10 I.sub.2 H 54 36 — 10 H.sub.II I 72 18 — 10 H.sub.II/L.sub.α OA = Oleic Acid

Example 5

[0165] Sterile Filtration of Formulations with Reduced Viscosity

[0166] To lower the viscosity with various solvents is sometimes necessary in order to obtain an injectable formulation and to be able to administrate the system with a regular syringe (see Example 3). Another important effect from the viscosity-lowering solvent is that the formulations can be sterile filtrated.

[0167] Formulations E to I in Example 4 were studied in a sterile filtration test by using a 0.22 μm filter (before addition of the active substance). Formulations E to H were successfully filtrated, but formulation I failed since the viscosity was too high. An aseptic manufacturing procedure was therefore needed for this formulation.

Example 6

[0168] In Vivo Release Study from Depot Formulations Subcutaneously Administered

[0169] Formulations E to I in Example 4 were used in an in vivo drug release study in rat. The formulations were administrated subcutaneously between the scapulae by using a syringe (21G, 0.6 mm×30 mm) and the dose of sCT was 500 μg/kg body weight. The release profile was monitored for a period of 13 days. The sCT concentration in the rat plasma samples was analysed with sandwich-type immunoassay using a commercial kit from DSLabs.

[0170] FIG. 3 shows the results (n=4). A pure triglyceride vehicle based on sesame oil was selected as a lipid reference system.

Example 7

[0171] In Vivo Release Study in the Initial Phase

[0172] Formulations F and G as in Example 6 were used in an in vivo study in rat designed to investigate the initial “burst effect”. From FIG. 4 (n=8) it appears that none of the investigated formulations has a severe burst effect.

Example 8: Preparation of Depot Precursor Compositions with Various Solvents

[0173] Depending on composition of the formulation and the nature and concentration of active substance certain solvents may be preferable.

[0174] Depot precursor formulations (PC/GDO/solvent (36/54/10)) were prepared by with various solvents; NMP, PG, PEG400, glycerol/EtOH (90/10) by the method of Example 1. All depot precursor compositions were homogeneous one phase solutions with a viscosity that enabled injection through a syringe (23G—i.e. 23 gauge needle; 0.6 mm×30 mm). After injecting formulation precursors into excess water a liquid crystalline phase in the form of a high viscous monolith rapidly formed with NMP and PG containing precursors. The liquid crystalline phase had a reversed cubic micellar (I.sub.2) structure. With PEG400, glycerol/EtOH (90/10) the viscosification/solidification process was much slower and initially the liquid precursor transformed to a soft somewhat sticky piece. The difference in appearance probably reflects the slower dissolution of PEG400 and glycerol towards the excess aqueous phase as compared to that of EtOH, NMP and PG.

Example 9: Preparation of Depot Composition Containing Human Growth Hormone (HGH)

[0175] Human growth hormone (hGH) plays a critical role in stimulating body growth and development, and is involved in the production of muscle protein and in the breakdown of fats. A deficiency of the hormone adversely affects numerous body processes such as lipid profile, insulin status, physical performance, bone-mineral density and quality of life. A targeted dose every 2 weeks is estimated at 0.10 to 0.24 mg/kg of body weight.

[0176] 1 ml of a 2 weeks depot formulation precursor was formed by sequentially mixing 10 mg hGH and 360 mg PC in 0.1 ml NMP. 540 mg GDO was added to the mixture to obtain a low viscosity depot formulation precursor. Injecting the formulation precursor into excess water (syringe 23G; 0.6 mm×30 mm) resulted in a monolithic liquid crystalline phase (12 structure).

Example 10: Preparation of Depot Composition Containing a Sparingly Soluble Active Substance

[0177] Risperidone is an antipsychotic medication agent belonging to the chemical class of benzisoxazole derivatives. It is a very strong dopamine blocker (antagonist); ie, it inhibits functioning of dopamine receptors, it is practically insoluble in water, and it has log(P)=3.49.

[0178] 1 g of a depot formulation containing 50 mg of risperidone was prepared by dissolving the active substance in 0.7 g of a mixture 95% wt in EtOH (99.5%) and 5% wt in acetic acid. 0.34 g PC and 0.51 g GDO were subsequently dissolved in this solution followed by solvent reduction to remaining 0.15 g solvent (0.55 g was evaporated under vacuum). The composition of the final homogenous and clear depot formulation with 50 mg risperidone was PC/GDO/solvent/risperidone (32/49/14/5). Injecting the formulation precursor into excess water (syringe 23G; 0.6 mm×30 mm) resulted in a monolithic liquid crystalline phase (12 structure). I.e. the amount of active substance (5%) did not change monolith formation and phase behavior after exposure to an aqueous environment.

Example 11: Alternate Preparation of Depot Composition Containing Risperidone

[0179] A risperidone depot precursor formulation could also be prepared by using a solvent mixture composed of 90% wt EtOH (99.5%) and 10% wt in acetic acid.

[0180] 50 mg of risperidone was dissolved in 0.7 g of the solvent mixture, after which 0.36 g PC and 0.54 g GDO were subsequently dissolved in this solution. 0.60 g of the solvent mixture was evaporated under vacuum to a homogenous and clear depot formulation precursor with 50 mg risperidone (PC/GDO/solvent/risperidone (34/51/10/5)). Injecting the formulation precursor into excess water (syringe 23G; 0.6 mm×30 mm) resulted in a monolithic liquid crystalline phase (12 structure). I.e. the amount of active substance (5%) did not change monolith formation and phase behavior after exposure to an aqueous environment.

Example 12: Temperature Stability of Depot Composition Containing a Sparingly Soluble Active Substance

[0181] The risperdone depot precursor formulations in examples 10 and 11 were tested for stability against crystallization during storage. Each formulation was stable at 25° C. for at least two weeks and at +8° C. for at least one week.

Example 13: Preparation of Depot Composition Containing Benzydamine

[0182] Benzydamine is a non-steroidal antiinflammatory drug and is extensively used as a topical drug in inflammatory conditions.

[0183] 1 g of a depot formulation containing 1.5 mg benzydamine was prepared by dissolving the active substance in a mixture of PC/GDO/EtOH (36/54/10) prepared as described in Example 1. The depot composition was stable against crystallization during storage at 25° C. for at least two weeks. Equilibration of the formulation precursor with excess water resulted in a high viscous monolithic liquid crystalline phase (I.sub.2 structure).

Example 14: Robustness of the Behaviour of the Formulation Against Variations in the Excipient Quality

[0184] Depot precursor formulations were prepared with several different GDO qualities (supplied by Danisco, Dk), Table 3, using the method of Example 1. The final depot precursors contained 36% wt PC, 54% wt GDO, and 10% wt EtOH. The appearance of the depot precursors was insensitive to variation in the quality used, and after contact with excess water a monolith was formed with a reversed micellar cubic phase behaviour (12 structure).

TABLE-US-00003 TABLE 3 Tested qualities of GDO. GDO Monoglyceride Diglyceride Triglyceride quality (% wt) (% wt) (% wt) A 10.9 87.5 1.6 B 4.8 93.6 1.6 C 1.0 97.3 1.7 D 10.1 80.8 10.1 E 2.9 88.9 8.2 F 0.9 89.0 10.1

Example 15: Preparation of Depot Composition Containing Saturated PC (Epikuron 200SH)

[0185] Depot precursor formulations were prepared with various amounts PC comprising saturated hydrocarbon chains by addition of Epikuron 200SH directly to a mixture of PC/GDO/EtOH, prepared as for Example 1. The formulations are shown in Table 4. All precursor formulations were homogenous one phase samples in RT, while they became more viscous with increasing amount Epikuron 200SH. Injecting the depot precursor into excess water gave a monolith comprising a reversed miceller cubic (I.sub.2) structure. Monoliths formed from samples containing higher amounts of Epikuron 200SH became turbid, possibly indicating segregation between Epikuron 200SH and the other components upon exposure to water and formation of the 12 phase.

TABLE-US-00004 TABLE 4 Depot composition containing saturated PC Saturated PC, Epikuron 200SH PC GDO EtOH Formulation (% wt) (% wt) (% wt) (% wt) G1 3.9 34.6 51.9 9.6 G2 7.0 33.5 50.2 9.3 G3 14.3 30.8 46.3 8.6

Example 16: Preparation of Depot Precursor being a Dispersion or Solution of the Peptide Salmon Calcitonin

[0186] By adding 500 μg sCT/g formulation to a solution of PC/GDO/EtOH (36/54/10), obtained as in Example 1, a dispersion of sCT was formed.

[0187] In an alternative method, 500 μg sCT was dissolved in excess of EtOH followed by addition of PC and GDO. The solvent concentration was then reduced (EtOH evaporation) to form a homogenous (active drug in solution) formulation. This latter technique can be used to obtain higher drug loads. Precursor compositions corresponding to at least 1500 μg dissolved sCT per gram of the final depot precursor composition could be obtained by this method.

Example 17: In Vivo Release Study from Depot Formulation Subcutaneously Administered

[0188] The two sCT compositions described in Example 16 were administered in an in vivo rat model by subcutaneous injection (between the scapulae). The first depot precursor having dispersed sCT was found to give somewhat unstable initial plasma concentrations, while the second depot precursor, having sCT dissolved therein, gave much more stable initial plasma levels (see Table 5).

TABLE-US-00005 TABLE 5 Coefficient of Formulations variation (% CV) Dispersed: 500 μg sCT/g 32-127 PC/GDO/EtOH (36/54/10) Dissolved: 500 μg sCT/g 20-37  PC/GDO/EtOH (36/54/10)

Example 18: Preparation of Depot Composition Containing the Peptide Octreotide

[0189] Octreotide is an acetate salt of a synthetic octa-peptide and is similar to the hormone somatostatin. Octreotide decreases production of substances such as growth hormone, insulin and glucagons. It is used in treatment of acromegaly, and to reduce flushing and watery diarrhoea caused by metastatic cancerous tumors (carcinoid syndrome) or tumors called vasoactive intestinal peptide tumors (VIPomas).

[0190] 24 mg or 60 mg octreotide was dissolved in 0.1 g EtOH. 0.36 g PC and 0.54 g GDO were subsequently dissolved in this solution and a depot formulation precursor was obtained. Injecting the formulation precursor into excess aqueous phase (syringe 23G; 0.6 mm×30 mm) resulted in a monolithic liquid crystalline phase (12 structure). I.e. octreotide (2.4% or 6.0%) did not change monolith formation and phase behaviour after exposure to an aqueous environment.

[0191] The octreotide depot precursor formulations in this Example were tested for stability against crystallization during storage. Each formulation was stable at 4-8° C. for at least two weeks.

Example 19: In Vivo Release Study from Depot Formulation Containing Octreotide Subcutaneously Administered

[0192] In an in vivo rat model the drug release of octreotide was followed during 28 days. The formulations were administered subcutaneously between the scapulae by using a syringe (23G, 0.6 mm×25 mm). The octreotide concentration in the rat plasma was followed for a period of 28 days (see FIG. 5). The dose was 5 mg/kg and volume 1 ml/kg corresponding to a drug load of 0.5% octreotide in the depot formulation precursor (PC/GDO/EtOH (36/54/10)).

[0193] From FIG. 5 (n=3) it appears that the investigated formulation gives a release profile essentially without a burst effect.

[0194] FIG. 5 shows Octreotide plasma levels in the rat model following administration of octreotide formulation precursor (0.5% in octreotide).

Example 20: Degradation of Depot Formulation in the Rat

[0195] Various volumes (1, 2, 6 ml/kg) of the depot precursor (36% wt PC, 54% wt GDO, and 10% wt EtOH) were injected in the rat and were removed again after a period of 14 days. It was found that substantial amounts of the formulations were still present subcutaneously in the rat after this time, see Table 6.

TABLE-US-00006 TABLE 6 Mean diameter of depot monolith. Mean diameter Mean diameter Dose (ml/kg) day 3 (mm) day 14 (mm) 1 (n = 3) 15.8 12.5 2 (n = 3) 18.5 15.3 6 (n = 3) 23.3 19.3

Example 21: In Vitro Study of Formation of Depot Monolith after Injection of Depot Formulation Precursor Between the Bone and Periostium

[0196] A precursor (36% wt PC, 54% wt GDO, and 10% wt EtOH prepared as described in Example 1) was injected by syringe between the bone and periostium. The composition was observed to spread to fill voids and after uptake of aqueous fluids formed a monolith that was bioadhesive to both the bone and periostium.

Example 22: Bioadhesive Spray of Depot Precursor Formulation

[0197] A pump spray bottle was found to be a convenient way to apply the formulation topically, e.g. to the skin or the oral mucosa.

[0198] A depot precursor formulation prepared as in Example 1 (36% wt PC, 54% wt GDO, and 10% wt EtOH) was sprayed with a pump spray bottle onto the skin and oral mucosa. A film with solid mechanical properties formed shortly after application.

Example 23: Robustness of a Topical Film

[0199] After applying the depot precursor formulation, as described in Example 22, (36% wt PC, 54% wt GDO, and 10% wt EtOH) to the skin, the applied formulation was exposed to flushing water (10 L/min) for 10 minutes. The formulation showed excellent bioadhesive properties and resistance against rinsing and no loss of the formulation could be discerned.

Example 24: Formation of Cubic Phase with Solid Properties after Exposure of Depot Precursor Formulation to Air

[0200] After exposing a depot precursor formulation prepared as described in Example 1 (36% wt PC, 54% wt GDO, and 10% wt EtOH) to air (RT, relative humidity 40%) for at least 3 hours, a solid cubic phase was formed. This formation of a cubic phase structure demonstrates that a topical film will acquire bulk non-lamellar depot properties after application without the need for direct exposure to excess aqueous fluid.

Example 25: Formulation to Treat Periodontitis or Perimplantitis

[0201] In order to treat periodontitis or perimplantitis an antibacterial formulation is injected in the periodontal pocket, and a prolonged effect of the formulation is normally desired. 100 μL of a formulation as prepared in Example 1, with the addition of the antibiotic chlorohexidine (PC/GDO/EtOH/chlorhexidine (35/53/10/2)), is injected via a syringe into a rat peridontal pocket. The injected composition is observed to transform from the low viscous formulation, and which initially spreads out to fill voids, to form a solid mass by uptake of gingival fluids. An antibacterial depot system is thus provided.

[0202] Chlorhexidine remains at clinically effective levels (MIC 125 μg/ml) in the GCF of the periodontal pockets for over 1 week. The depot system is completely degraded by enzymes within 7 to 10 days and does not need to be removed.

Example 26: Alternate Antibacterial Formulation to Treat Periodontitis or Perimplantitis

[0203] An alternate antibacterial formulation was provided by a formulation prepared as described in Example 1 and containing the antibacterial detergent Gardol (Glycine, N-methyl-N-(1-oxododecyl)-, sodium salt) (PC/GDO/EtOH/Gardol (34/51/10/5)). This formulation is injected into the rat periodontal pocket.

[0204] Gardol is observed to remain at clinically effective levels in the GCF of the periodontal pockets for a prolonged period (several days). The depot system is completely degraded by enzymes within 7 to 10 days and did not need to be removed.

Example 27: Adhesion of the Formulation to High Energy Surfaces

[0205] In order to treat perimplantitis, adhesion not only to biological surfaces but also to high energy surfaces such as a gold or titanium implant is important. It is also important that the formulation adheres to ceramic and plastic surfaces.

[0206] A formulation (PC/GDO/EtOH (36/54/10)) as prepared in Example 1 was applied to various surfaces in the oral cavity. The composition showed excellent adhesion to ceramic, plastic, gold, as well as to a normal tooth surface and could not be rinsed away by excess aqueous fluid. The depot resulting from the composition stayed at the site in the oral cavity where it was applied for at least 6 h.

Example 28: Bioadhesive Sustained Release Formulation of Sodium Fluoride for Use on the Teeth

[0207] Fluoride containing compounds are often needed to oppose caries attack and a bioadhesive formulation precursor with depot effect was prepared as indicated in Example 1 from a mixture of PC/GDO/EtOH/sodium fluoride (35/53/10/2). The formulation was a dispersion of sodium fluoride since it could not be dissolved in the precursor. The liquid formulation was applied to the teeth with the aid of a brush. By uptake of saliva the formulation solidified and formed a depot providing sustained release of sodium fluoride for an extended period (several hours).

Example 29: Oral Cavity Spray Depot Composition

[0208] To be suitable as a topical depot system in the oral cavity the mechanical properties of the system was adjusted by decreasing the PC/GDO ratio.

[0209] A mixture containing PC/GDO/EtOH (27/63/10) was prepared according to Example 1. A drop of patent blue was added to visualize the formulation after application. About 300 μl of the formulation was sprayed into the oral cavity with pump spray bottle. Shortly after application the formulation viscosified/solidified since it underwent a phase transformation by uptake of aqueous fluid (saliva) and loss of solvent (EtOH). The formulation had excellent bioadhesion to keritinized surfaces such as the hard palate and the gum. Here the film lasted for several hours despite saliva secretion and mechanical wear by the tongue. At soft mucosal surfaces the duration was much shorter (minutes).

Example 30: Oral Cavity Liquid Depot Composition

[0210] To be suitable for application with a pipette to the oral cavity the solidification/viscosification of the formulation has to be delayed relative to the spray formulation.

[0211] This is to allow the formulation to be conveniently distributed with the tongue to a thin film in the oral cavity after application.

[0212] Propylene glycol (PG) and EtOH were added to a formulation prepared as in Example 1, to the final composition PC/GDO/EtOH/PG (24/56/10/10). 300 μl of the formulation was conveniently applied with a pipette to the oral cavity and distributed with the tongue to a thin film in the oral cavity. After about 20 seconds the viscosification of the formulation started since it underwent a phase transformation by uptake of aqueous fluid (saliva) and loss of solvent (EtOH and PG). After about one minute the solidification/viscosification appeared to be finished. The formulation had excellent bioadhesion to keritinized surfaces such as the hard palate and the gum. Here the film lasted for several hours despite saliva secretion and mechanical wear by the tongue. At soft mucosal surfaces the duration was much shorter (minutes).

Example 31—Bioadhesive Depot for Nails

[0213] The mixture in Example 29 was sprayed to the nail bed and in between the toes. The formulation solidifies/viscosifies slowly by uptake of aqueous fluids (cf. sweat). The solidification can be speeded up by adding water after spray application. The formulation had excellent bioadhesive properties and had a duration for several hours.

Example 32: Loading Capacity of the Bioactive Agent Benzydamine in the Formulation Precursors

[0214] Formulations with compositions as specified in Table 7 were prepared using the method in Example 1. An excess amount of benzydamine (50 mg) was added to 0.5 g of the formulations. The vials were placed on a shaker at 15° C. for three days after which the solutions were filtered through a filter (0.45 μm) to get rid of crystals of undissolved benzydamine. The benzydamine concentration in each formulation was determined with reversed phase gradient HPLC and UV detection at 306 nm and the results are given in Table 7.

TABLE-US-00007 TABLE 7 Benzydamine Composition GDO/ concentration PC(Lipoid S100)/EtOH in formulation 67.5/22.5/10 3.4% 63/27/10 3.2% 58.5/31.5/10 3.3% 60/20/20 4.0% 56/24/20 4.5% 52/28/20 4.3%

Example 33: Compositions Containing PC and Tocopherol

[0215] Depot precursor formulations were prepared with several different PC/α-tocopherol compositions using the method of Example 1 (PC was first dissolved in the appropriate amount of EtOH and thereafter α-tocopherol was added to give clear homogenous solutions).

[0216] Each formulation was injected in a vial and equilibrated with excess water. The phase behaviour was evaluated visually and between crossed polarizes at 25° C. Results are presented in Table 8.

TABLE-US-00008 TABLE 8 α- Phase in tocopherol PC Ethanol excess H.sub.2O 2.25 g 2.25 g 0.5 g H.sub.II 2.7 g 1.8 g 0.5 g H.sub.II/I.sub.2 3.15 g 1.35 g 0.5 g I.sub.2 3.6 g 0.9 g 0.5 g I.sub.2/L.sub.2

Example 34: Composition Containing Octreotide

[0217] 60 mg octreotide was dissolved in 0.1 g EtOH. 0.25 g PC and 0.59 g α-tocopherol were subsequently dissolved in this solution and a depot formulation precursor was obtained. Injecting the formulation precursor into excess aqueous solution (phosphate buffered saline—PBS) resulted in a monolithic liquid crystalline phase (12 structure) i.e. octreotide (6.0%) did not change monolith formation and phase behaviour after exposure to an aqueous environment.

[0218] The octreotide depot precursor formulation in this Example was tested for stability against crystallization during storage. The formulation was stable at 4-8° C. for at least two weeks.

Example 35: In Vitro Release of Water-Soluble Disodium Fluorescein

[0219] A water-soluble colorant, disodium fluorescein (Fluo), was dissolved in a formulation containing PC/α-tocopherol/Ethanol (27/63/10 wt %) to a concentration of 5 mg Fluo/g formulation. When 0.1 g of the formulation was injected in 2 ml of phosphate buffered saline (PBS) a reversed micellar (I.sub.2) phase was formed. The absorbency of Fluo released to the aqueous phase was followed at 490 nm over a period of 3 days. The release study was performed in a 3 mL vial capped with an aluminium fully tear off cap at 37° C. The vial was placed on a shaking table at 150 rpm.

[0220] The release of Fluo from the PC/α-tocopherol formulation (see Table 9) indicates that this (and similar) formulations are promising depot systems. Furthermore, the absence of a burst effect is noteworthy, and the release indicates that the substance can be released for several weeks to months; only about 0.4% of Fluo is released after 3 days.

TABLE-US-00009 TABLE 9 % release (37° C.) Formulation 24 h 72 h PC/α-tocopherol/EtOH: 27/63/10 wt % <0.1* 0.43 *Release below detection limit of the absorbance assay

Example 36: Formulations of the Analgesic/Antiinflammatory Benzydamine

[0221] Formulations were prepared as in Example 1 by mixing benzydamine with a mixture of GDO, PC, ethanol and optionally PG/AP in the following proportions.

TABLE-US-00010 Formulation BZD GDO PC EtOH PG AP 1 3.0 53.3 28.7 10.0 5.0 0.01 2 3.0 53.3 28.7 15.0 0 0.01 3 3.0 57.4 24.6 10.0 5.0 0.01 4 3.0 49.2 32.8 10.0 5.0 0.01 where BZD is benzydamine, EtOH is ethanol, PC is LIPOID S100 soybean phosphatidylcholine, GDO is glycerol dioleate, PG is propylene glycol, and AP is ascorbyl palmitate.

[0222] All formulations are low viscosity liquids which generate liquid crystalline phase compositions upon exposure to aqueous conditions.

Example 37: Fentanyl Nasal Formulation

[0223] Formulations were prepared as in Example 1 by mixing the narcotic analgesic fentanyl with a mixture of GDO, PC, ethanol and optionally PG in the following proportions.

TABLE-US-00011 Formulation Fentanyl PC GDO EtOH PG 1 0.05 34 51 10 5 2 0.05 36 54 10 — 3 0.05 42 43 10 5 4 0.05 45 45 10 — 5 0.15 34 51 10 5 6 0.15 36 54 10 — 7 0.05 30 45 15 10  8 0.15 30 45 15 10  where EtOH is ethanol, PC is LIPOID S100 soybean phosphatidylcholine, GDO is glycerol dioleate, and PG is propylene glycol

[0224] All formulations are low viscosity liquids suitable for administration by nasal spray, which generate liquid crystalline phase compositions upon exposure to aqueous conditions.

Example 38: Diazepam Nasal Formulation

[0225] Formulations were prepared as in previous examples by mixing the benzodiazepine antianxiety agent diazepam with a mixture of GDO, PC, ethanol and optionally PG in the following proportions.

TABLE-US-00012 Formulation Diazepam PC GDO EtOH PG 1 5 32 48 10 5 2 5 34 51 10 — 3 10 37 38 10 5 4 10 40 40 10 — 5 10 30 45 10 5 6 10 32 48 10 — 7 10 26 39 15 10  8 10 30 45 15 — where EtOH is ethanol, PC is LIPOID S100 soybean phosphatidylcholine, GDO is glycerol dioleate, and PG is propylene glycol

[0226] All formulations are low viscosity liquids suitable for administration by nasal spray, which generate liquid crystalline phase compositions upon exposure to aqueous conditions.

Example 39: Interferon Alpha-2a

[0227] Interferons (IFNs) are used as a treatment for many types of systemic cancer, often in combination with chemotherapy or radiation. Recent data suggest that IFN Alpha is a multifunctional immunomodulatory cytokine with profound effects on the cytokine cascade including several anti-inflammatory properties. These newly identified immunoregulatory and anti-inflammatory functions may also be of importance in treatment of diseases such as chronic viral hepatitis and help to explain some of the IFN mechanisms.

[0228] A non-aqueous precursor formulation was formed by dissolving PC (360 mg) and GDO (540 mg) in EtOH (100 mg). Interferon Alpha-2a (4 mg) was dissolved in water (76 mg) and this solution was thereafter added to the non-aqueous precursor formulation to form a depot formulation precursor of low viscosity.

[0229] Injecting the depot precursor into excess water (syringe 23 G; 0.6 mm×30 mm) resulted in a monolithic liquid crystalline phase (12 structure).

Example 40 Leuprorelin (Leuprolide)

[0230] Leuprorelin acetate (or leuprolide acetate) is a synthetic nonapeptide analogue of naturally occurring gonadotropin releasing hormone (GnRH or LH-RH) that, when given continuously (e.g. as a depot formulation), inhibits pituitary gonadotropin secretion and suppresses testicular and ovarion steroidogenesis. Leuprorelin is used for the treatment of advanced prostate cancer.

[0231] A depot formulation precursor was formed by sequentially dissolving 22.5 mg leuprorelin acetate and 360 mg PC in 100 mg of NMP. 540 mg of GDO was added to the mixture yielding a molecular solution depot formulation precursor of low viscosity. Injecting the formulation precursor into excess water (syringe 23 G; 0.6 mm×30 mm) resulted in a monolithic liquid crystalline phase (12 structure).

Example 41: Alendronate

[0232] Bisphosphonates are structural analogues of pyrophosphates and have pharmacologic activity specific for bone due to the strong affinity of bisphosphonates for hydroxyapatite, a major inorganic component of bone. The compounds are used to treat postmenopausal osteoporosis, hypercalcemia of malignancy and metastatic bone disease (MBD).

[0233] A non-aqueous precursor formulation was formed by dissolving PC (360 mg) and GDO (540 mg) in EtOH (100 mg). Alendronate (12 mg) was dissolved in water (80 mg) and this solution was thereafter added to the non-aqueous precursor formulation to form a depot formulation precursor of low viscosity. Injecting the depot precursor into excess water (syringe 23 G; 0.6 mm×30 mm) resulted in a monolithic liquid crystalline phase (12 structure).

Example 42: Olanzapine

[0234] Olanzapine is a low molecular weight drug used for the treatment of patients with schizophrenia.

[0235] A depot formulation precursor was formed by sequentially mixing 50 mg olanzapine, 360 mg PC and 100 mg of EtOH. 540 mg of GDO was added to the mixture resulting in the final depot formulation precursor.

[0236] Injecting the formulation precursor into excess water (syringe 23 G; 0.6 mm×30 mm) resulted in a monolithic liquid crystalline phase (12 structure).

Example 43: Acne Formulations with Clindamycin

[0237] Formulations were prepared as in previous examples by mixing the semisynthetic antibiotic clindamycin (free base or salt) with a mixture of GDO, PC, ethanol and PG in the following proportions (by weight).

TABLE-US-00013 Formulation Clindamycin HCl PC GDO EtOH PG 1 1 30 54 10 5 2 2 29 54 10 5 3 1 34 50 10 5 4 2 33 50 10 5 Formulation Clindamycin base PC GDO EtOH PG 5 1 30 54 10 5 6 2 29 54 10 5 7 1 33 54 2 10 8 2 32 54 2 10

[0238] The resulting preformulations are low viscosity liquids which, after application resistant to water, sweat, etc. The formulation are applied locally on the skin as a gel or by spraying and are bioadhesive with good film-forming properties.

Example 44: Further Examples of Viscosity in PC/GDO Mixtures on Addition of Co-Solvent

[0239] Mixtures of PC/GDO and co-solvent were prepared according to the methods of Example 1 and Example 3 in the proportions indicated in the table below. The samples were allowed to equilibrate for several days before viscosity measurements were performed using a Physica UDS 200 rheometer at 25° C.

TABLE-US-00014 PC/GDO EtOH/ Glycerol/ H.sub.2O/ Viscosity/ Sample (wt/wt) wt % wt % wt % mPas 1 50/50 3 — — 1900 2 50/50 5 — — 780 3 50/50 7 — — 430 4 50/50 8 — — 300 5 50/50 10 — — 210 6 50/50 15 — — 100 7 45/55 3 — — 1350 8 45/55 5 — — 540 9 45/55 7 — — 320 10 45/55 8 — — 250 11 45/55 10 — — 150 12 45/55 15 — — 85 13 40/60 3 — — 740 14 40/60 5 — — 400 15 40/60 7 — — 240 16 40/60 8 — — 200 17 40/60 10 — — 130 18 40/60 15 — — 57 19 40/60 — 10 — 8*10.sup.6 20 40/60 — — 3 2.5*10.sup.8   21 40/60 — — 5 4*10.sup.7

[0240] This example further illustrates the need for a solvent with viscosity lowering properties in order to obtain injectable formulations. The mixtures containing glycerol (sample 19) or water (samples 20 and 21) are too viscous to be injectable at solvent concentrations equivalent to the samples containing EtOH (compare with samples 13, 14 and 17).

Example 45: Occtreotide Formulation Compositions

[0241] Formulations were prepared as in Example 1 by mixing the peptide active octreotide with a mixture of GDO (at one of several purity levels) or tocopherol, PC, ethanol and optionally dioleoyl PG in the following proportions (by weight)

TABLE-US-00015 For- mula- tion OCT EtOH PC GDO1 GDO2 GDO3 TP DOPG E 2 10 35.2 — — 52.8 — — F 2 10 35.2 52.8 — — — — G 2 10 35.2 — 52.8 — — — H 2 10 26.4 — — — 61.6 — I 1 10 35.6 53.4 — — — — J 2 5 37.2 — — 55.8 — — K 3 5 36.8 — — 55.2 — — L 6 5 35.6 — — 53.5 — — M 3 5 35.8 — — 55.2 — 1 N 3 5 33.8 — — 55.2 — 3 O 3 5 30.8 — — 55.2 — 6 P 3 5 46 — — 46 — — Q 3 10 43.5 — — 43.5 — — R 6 10 42 — — 42 — — S 3 7 45 — — 45 — — T 6 7 43.5 — — 43.5 — — where OCT is octreotide, EtOH is ethanol, PC is LIPOID S100 soybean phosphatidylcholine, GDO is glycerol dioleate, TP is α-tocopherol, DOPG is dioleoyl phosphatidylglycerol

TABLE-US-00016 GDO quality (according to AC) Monoglycerides Diglycerides Triglycerides GDO1 10.9% 87.5% 1.4% GDO2 4.2% 92.1% 3.5% GDO3 0.5% 95.3% 4.0%

[0242] Formulation P (for composition see above) was administered by s.c. injection in the rat at a level of 1 ml formulation per kg body weight, corresponding to 30 mg/kg of octreotide.

[0243] Octreotide plasma levels after administration were monitored for 5 days to examine any burst profile. It was observed that the highest plasma concentration was less than three fold greater than the average plasa concentration over the first 5 days.

[0244] The results of the study are shown in FIG. 6

Example 46: Sunscreen Formulations

[0245] Formulations were prepared as in Example 1 by mixing each of several UV absorbing/scattering agents with a mixture of GDO, PC, and ethanol in the following proportions (by weight)

TABLE-US-00017 Tioveil Formu- Tioveil Spectraveil Solaveil 50 lation PC GDO EtOH CM FIN CT-100 MOTG 1 38 42 5 — — — 15 2 38 42 5 — — 15 — 3 37 38 5 15 5 — — Where TIOVEIL CM (Uniqema) comprises Cyclomethicone (and) Titanium Dioxide (and) Dimethicone Copolyol (and) Aluminium Stearate (and) Alumina, SPECTRAVEIL FIN (Uniqema) comprises Zinc Oxide (and) C12-15 Alkyl Benzoate (and) Polyhydroxystearic Acid, SOLAVEIL CT-100 (Uniqema) comprises C12-15 Alkyl Benzoate (and) Titanium Dioxide (and) Polyhydroxystearic Acid (and) Aluminum Stearate (and) Alumina, and TIOVEIL 50 MOTG (Uniqema) comprises Titanium Dioxide (and) Caprylic/Capric Triglyceride (and) Mineral Oil (and) Polyhydroxystearic Acid (and) Aluminum Stearate (and) Alumina.

[0246] The resulting formulation precursors show low viscosity upon formulation and are readily applied by pump spray. Upon contact with body surfaces a resilient UV protective layer is formed.

Example 47: Chlorhexidine Periodontal Depots

[0247] Formulations were prepared as in Example 1 by mixing the antiinfective agent chlorhexidine digluconate with a mixture of GDO, PC, and ethanol in the following proportions (by weight)

TABLE-US-00018 TABLE Chlorhexidine digluconate depot formulation compositions. Chlorhexidine Formulation digluconate PC GDO EtOH A 5 34 51 10 B 5 36 54 5 C 7 33 50 10 D 10 32 48 10 E 15 30 45 10

[0248] The chlorhexidine depot preformulations have low viscosity and are easily administered to the periodontal pocket. The compositions provide better distribution and spreading of the active substance throughout the periodontal pocket when compared to current products, such as Periochip®.

[0249] The depot formed after application gives protection against re-infection of the pocket. The depot also has excellent bioadhesive properties and sticks to mucosal, teeth and bone surfaces.

[0250] Release of chlorhexidine digluconate from 250 mg Formulation A (see above) in 0.9% aqueous NaCl (500 ml) was studied. The formulation was held in a cylindrical metal cup which was placed in a teflon holder at the bottom of a standard USP release bath. The contact area between the formulation and surrounding saline solution was 2.4 cm.sup.2, and the solution was stirred by paddle at 100 rpm.

[0251] The release curve shown in FIG. 7 demonstrates the sustained and essentially uniform release of chlorhexidine from the formulation over a period of 24 hours.