title: In vitro performance of carbamazepine loaded to various molecular weights of poly (D,L-lactide-co-glycolide).
abstract: The purpose of this study was to develop and assess the in vitro characteristics of carbamazepine-loaded microspheres. A solvent evaporation method was used to incorporate carbamazepine (CBZ) into poly (D,L-lactide-co-glycolide) (PLGA) with different molecular weights. The optimum conditions for CBZ-PLGA microspheres preparation were considered and the in vitro release of CBZ of PLGA microspheres were followed up to 24 hr in USP dissolution medium. The effect of using different ratios of PLGA microspheres, prepared with different molecular weights, for optimizing CBZ release also was investigated. CBZ encapsulation efficiency was 68 to 82% for all prepared formulations. Thermograms of CBZ-PLGA microspheres suggest that CBZ was totally entrapped with the PLGA polymer. The presence of Pluronic F-68 has improved the encapsulation of CBZ, resulted in better and smoother microspheres surfaces and enhanced its release pattern. CBZ release profiles were biphasic patterns; after an initial burst, a constant CBZ release rate was observed up to 24 hr. The release from these PLGA-based spherical matrices was consistent with the diffusion mechanism. CBZ dissolution T(50%) was significantly affected (> 3-fold) by increasing the lactide percent from 33.3 to 66.6% from different microspheres mixtures. The present study provides evidence that the encapsulation of CBZ to PLGA microspheres, either as a single polymer or mixture of two, was a successful attempt to control the release of CBZ.
authors.affiliation: Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Nahla S
authors.initials: NS
authors.lastname: Barakat
authors.forename: Mahasen A
authors.initials: MA
authors.lastname: Radwan
mesh_terms: D000927:Anticonvulsants / Q000008:administration & dosage*; D002220:Carbamazepine / Q000008:administration & dosage*; D004055:Differential Thermal Analysis; D004339:Drug Compounding; D019344:Lactic Acid; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D008970:Molecular Weight; D010316:Particle Size; D020442:Poloxamer; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D012995:Solubility; D013055:Spectrophotometry, Infrared
chemical_list: D000927:Anticonvulsants; D011108:Polymers; D020442:Poloxamer; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D002220:Carbamazepine; D019344:Lactic Acid