title: Preparation and characterization of melittin-loaded poly (DL-lactic acid) or poly (DL-lactic-co-glycolic acid) microspheres made by the double emulsion method.
abstract: The water soluble peptide, melittin, isolated from bee venom and composed of twenty-six amino acids, was encapsulated in poly (DL-lactic acid, PLA) and poly (DL-lactic-co-glycolic acid, PLGA) microspheres prepared by a multiple emulsion [(W1/O)W2] solvent evaporation method. The aim of this work was to develop a controlled release injection that would deliver the melittin over a period of about one month. The influence of various preparation parameters, such as the type of polymer, its concentration, stabilizer PVA concentration, volume of internal water phase and level of drug loading on the characteristics of the microspheres and drug release was investigated. It was found that the microspheres of about 5 microm in size can be produced in high encapsulation (up to 90%), and the melittin content in the microspheres was up to 10% (w/w). The drug release profiles in vitro exhibited a significant burst release, followed by a lag phase of little or no release and then a phase of constant melittin release. The type of polymer used was a critical factor in controlling the release of melittin from the microspheres. In this study, the rate of peptide release from the microspheres correlated well with the rate of polymer degradation. Moreover, melittin was released completely during the study period of 30 days, which agreed well with the polymer degradation rate.
authors.affiliation: Department of Pharmaceutics, School of Pharmaceutical Science, Shenyang Pharmaceutical University, No. 103, Wenhua Road, Shenyang 110016, China.
authors.forename: Fude
authors.initials: F
authors.lastname: Cui
authors.forename: Dongmei
authors.initials: D
authors.lastname: Cun
authors.forename: Anjin
authors.initials: A
authors.lastname: Tao
authors.forename: Mingshi
authors.initials: M
authors.lastname: Yang
authors.forename: Kai
authors.initials: K
authors.lastname: Shi
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
authors.forename: Ying
authors.initials: Y
authors.lastname: Guan
mesh_terms: D004337:Drug Carriers; D004339:Drug Compounding; D004655:Emulsions; D019344:Lactic Acid / Q000737:chemistry*; D008555:Melitten / Q000008:administration & dosage* / Q000737:chemistry; D008863:Microspheres; D010316:Particle Size; D011091:Polyesters; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry*; D011142:Polyvinyl Alcohol; D013499:Surface Properties
chemical_list: D004337:Drug Carriers; D004655:Emulsions; D011091:Polyesters; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D008555:Melitten; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide); D011142:Polyvinyl Alcohol