Absorbable crystalline copolyester-based bioactive hydroforming luminal liner compositions

Abstract

Bioactive, hydroforming luminal liner compositions are formed of high molecular weight crystalline, absorbable copolyesters dissolved in a liquid derivative of a polyether glycol that undergoes transformation into a tissue-adhering, resilient interior cover or liner for the controlled release of its bioactive payload at clinically compromised conduits in humans as in the case of bacteria- and yeast-infected vaginal canals, esophagi, and arteries following angioplasty.

Claims

1. A composition comprising a. a crystalline absorbable copolyester; b. a water-soluble liquid polyalkylene glycol derivative; and c. a bioactive agent; where the copolyester is dissolved in the water-soluble liquid to provide an injectable or extrudable liquid composition; the bioactive agent is solubilized or microdispersed in the liquid composition; and the liquid composition is sterile.

2. The composition of claim 1 wherein the crystalline, absorbable copolyester has a heat of fusion of at least 10 J/g.

3. The composition of claim 1 wherein the crystalline, absorbable copolyester has a molecular weight of greater than of 20 kDa.

4. The composition of claim 1 wherein the copolyester comprises hydrophilic segments.

5. The composition of claim 1 wherein the polyalkylene glycol derivative is a polyalkylene glycol with ester end-groups.

6. The composition of claim 1 wherein the polyalkylene glycol derivatives is a polyalkylene glycol with ether end-groups.

7. The composition of claim 1 wherein the bioactive agent is an antimicrobial agent.

8. The composition of claim 1 wherein the bioactive agent is an antiviral agent.

9. The composition of claim 1 wherein the bioactive agent is an antiretroviral agent.

10. The composition of claim 1 wherein the bioactive agent is an antiinflammatory agent.

11. The composition of claim 1 wherein the bioactive agent is an antiproliferative agent.

12. The composition of claim 1 wherein the bioactive agent is an antineoplastic agent.

13. The composition of claim 1 wherein the bioactive agent is an immunosuppressing agent.

14. The composition of claim 1 wherein the bioactive agent is an anesthetic agent.

15. The composition of claim 1 wherein the bioactive agent is an antifungal agent.

16. The composition of claim 1 wherein the bioactive agent is an antibiotic agent.

17. The composition of claim 1 wherein the bioactive agent is an antibacterial agent.

Description

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(1) From a clinical perspective, the present invention in a major aspect is concerned with the treatment of vaginal and esophageal candidiasis. Vaginal Candidiasis (VC) is a common medical problem in women and is associated with discomfort, particularly due to a copious discharge, which is often accompanied by odor. Currently available treatments of yeast infection include (1) a systemic oral administration therapy; (2) use of topical creams; and (3) use of intravaginal suppositories which release the drug after melting or dissolving in the vagina. However, the systemic administration can lead to drug toxicity, while all other currently used forms for intravaginal administration are subject to uncontrolled leakage of the drug during the vaginal discharge, creating unsanitary conditions and discomfort while resulting in unpredictable bioavailability of the drug. Esophageal candidiasis (EC) is another form of fungal infection caused in most cases by a candida species and results in sore throat and difficulty in swallowing. This infection is becoming more serious with the growing number of HIV patients who are highly susceptible to yeast infection. The orally administered treatment options of EC using oral formulations are particularly effective in HIV patients. However, there have been concerns about the clinical relapse in these patients, which is dependent upon the degree of immunosuppression apart from the potential hepatotoxicity associated with high or prolonged doses of orally administered drugs. Clinical shortcomings of the current treatments of VC and EC evoked the need to explore the development of topically administered drug delivery systems that are not affected by the aqueous vaginal discharge in the vagina and food transport in the esophagus, in part because of its good adhesion to the vaginal and esophageal linings to provide predictably modulated release of the drug. The need for such a novel drug delivery system prompted the pursuit of the study, subject of the present invention.

(2) Compositions of the instant invention are designed to (1) be injectable or extrudable liquid formulations that contain a crystalline absorbable copolyester dissolved in a water-soluble liquid polyalkylene glycol with ester or ether end-groupsthis is to avoid reactions (causing reduction in molecular weight) with the crystalline copolyester during storage and hence, providing needed shelf-life stability; (2) be liquid formulations having at least one bioactive agent solubilized or microdispersed therein so as to provide the desired release profile when the formulations are applied to the biological sites to form flexible covers or liners on the wall of the application sites, which are typically conduits such as vaginal canals, esophagi, and blood vessels; (3) be formulations as described in item 1 which are capable of transforming into tissue adhering, resilient crystalline covers or linersthe transformation of the liquid to a resilient crystalline film, cover, or liner is achieved through the migration of the water-soluble liquid polyalkylene glycol derivative to the aqueous environment causing the crystalline polyester to hydroform (undergo phase transition in the presence of water) or simply to undergo phase transition to a crystalline film or liner; (4) undergo phase transition in the presence of water (hydroforming) into crystalline film or liner that adheres well to the surface of the luminal wall by virtue of having flexible polar polyester segments and preferably hydrophilic segments in the polymer chain as wellthe hydrophilic and polar flexible segments provide adequate adhesion to the biological lining and low frictional resistance towards adjacent fluids so as to prevent dislocation or migration of the liner from the application site in the presence of shear stresses caused by movement of biological fluids at the application site; (5) form in a timely manner a thin film or liner on the luminal wall that resists dislocation and migration from the application sitethe thickness of the film or liner can be controlled by varying the composition and/or thickness of the precursors liquid formulation which allows the modulation of the drug release profile; and (6) allow their use as carriers and precursors of liners that permit incorporating a broad range of bioactive agents without causing any drug-polymer chemical interactionthe bioactive agents include, among several types of drugs, those used for treating different forms of vaginal and esophageal infections (e.g., bacterial, yeast, and viral), those capable of preventing vascular restenosis following angioplasty (e.g., immunosuppressing, antineoplastic, and anti-inflammatory agents), and those used for treating periodontitis (e.g., antibacterial agents).

(3) Depending upon the site of the application, the present invention provides applicator kits capable of delivering, uniformly, an aliquot of the liquid formulation at the application site that undergoes a timely transformation (hydroformation) to a crystalline, drug-releasing film or liner at the site.

(4) Further illustrations of the present invention are provided by the following examples:

Example 1

Synthesis of a Typical Absorbable Crystalline Copolyester, P-1

(5) The polymer was prepared using the general procedure for the synthesis of crystalline, segmented, polyaxial copolyesters of U.S. Pat. No. 7,348,364 and U.S. patent application Ser. No. 11/598,427, both of which are incorporated herein by reference. An amorphous polymeric initiator comprising 35/14/9 (molar) -caprolactone/trimethylene carbonate/glycolide was made and end-grafted to form the crystalline end-grafts comprising 42/2 (molar) 1-lactide/glycolide to yield a copolyester made of 35/14/34/17 (molar) caprolactone/trimethylene carbonate/l-lactide/glycolide. The polymer was characterized for identity (IR, NMR), molecular weight (in terms of inherent viscosity), and thermal property (DSC). It was shown to have an inherent viscosity of 1.45 dL/g, melting temperature of 109 C., and heat of fusion of 7.4 J/g.

(6) Although the present invention has been described in connection with the preferred embodiments, it is to be understood that modifications and variations may be utilized without departing from the principles and scope of the invention, as those skilled in the art will readily understand. Accordingly, such modifications may be practiced within the scope of the following claims. Moreover, Applicant hereby discloses all subranges of all ranges disclosed herein. These subranges are also useful in carrying out the present invention.