1: Pharmazie. 2008 Mar;63(3):235-40. Spontaneously self-assembled micelles from poly(ethylene glycol)-b-poly(epsilon-caprolactone-co-trimethylene carbonate) for drug solubilization. Latere DJ, Rouxhet L, Brewster ME, Préat V, Ariën A. Cordis Corp., Welsh and McKean Roads, Spring House, PA, USA. Di-block copolymers composed of polyethylene glycol (PEG) and a second block of (co)polyesters of epsilon-caprolactone (CL) and/or trimethylene carbonate (TMC) were synthesized and characterized. Tin octoate was used as catalyst and polymerization were completed over a period of 24 h with high conversion (> 95%). Self-assembling properties in water were evaluated. All di-block copolymers behave similarly except when PCL served as the second block. Stable crew-cut micelles of about 20 nm were obtained by direct dissolution of the liquid di-block copolymers in water at room temperature. When PCL was present as the second block, no solubilization occurred. Drug encapsulation of poorly water-soluble drugs belonging to biopharmaceutics classification system (BCS) class II (ketoprofen and furosemide) was evaluated. Experimental solubility for these two drugs shows a significant enhancement such that a maximum value of 23.4 mg/ml was obtained for ketoprofen in a 10% w/v micellar solution as compared to 0.14 mg in water. In the case of furosemide, the solubility increased from 0.04 mg/ml in water to about 3.2 mg/ml in a 10% w/v micellar solution. Enzymatic degradation of diblock copolymers was also studied in the presence of Pseudomonas lipase in a phosphate buffer solution (pH 7.4). Results indicated rapid degradation of copolymers containing relatively higher amounts of CL compared to TMC suggesting the potential in vivo degradation. PMID: 18444514 [PubMed - indexed for MEDLINE] Related Links Enzymatic degradation of block copolymers prepared from epsilon-caprolactone and poly(ethylene glycol). [Biomacromolecules. 2002] PMID:12005524 Prediction of drug solubility in amphiphilic di-block copolymer micelles: the role of polymer-drug compatibility. [Pharmazie. 2007] PMID:17718189 Synthesis and micellar characterization of short block length methoxy poly(ethylene glycol)-block-poly(caprolactone) diblock copolymers. [Colloids Surf B Biointerfaces. 2004] PMID:15261040 Synthesis and characterization of star poly(epsilon-caprolactone)-b-poly(ethylene glycol) and poly(L-lactide)-b-poly(ethylene glycol) copolymers: evaluation as drug delivery carriers. [Bioconjug Chem. 2008] PMID:18564869 New biodegradable amphiphilic block copolymers of epsilon-caprolactone and delta-valerolactone catalyzed by novel aluminum metal complexes. II. Micellization and solution to gel transition. [Macromol Biosci. 2005] PMID:16134088