title: Study on in vitro release patterns of fentanyl-loaded PLGA microspheres.
abstract: In order to study the development of the delivery device of long-acting local anaesthetics for post-operative analgesia and control of chronic pain of cancer patient, fentanyl loaded poly(l-lactide-co-glycolide) (PLGA, molecular weight; 5000, 8000, 20,000, and 33,000 g/mole) microspheres (FMS) were studied. FMS were prepared by an emulsion solvent-evaporation method. The influence of several preparation parameters such as initial drug loading, PLGA concentrations, emulsifier concentrations, oil phase volume and mole ratio and molecular weight has been investigated on the fentanyl release patterns. Generally, the drug showed the biphasic release patterns, with an initial diffusion followed by a lag period before the onset of the degradation phase, but there were no lag times in the device. Fentanyl was slowly released from FMS over 10 days in vitro, with a quasi-zero order property. The release rate increased with increasing drug loading as well as increasing polymer concentration with a relatively small initial burst effect. From the results, FMS may be a good formulation to deliver the anaesthesia for the treatment of chronic pain.
authors.affiliation: Department of Polymer Science and Technology, Chonbuk National University, Chonju, Korea.
authors.forename: S-A
authors.initials: SA
authors.lastname: Seo
authors.forename: G
authors.initials: G
authors.lastname: Khang
authors.forename: J M
authors.initials: JM
authors.lastname: Rhee
authors.forename: J
authors.initials: J
authors.lastname: Kim
authors.forename: H B
authors.initials: HB
authors.lastname: Lee
mesh_terms: D000700:Analgesics; D001672:Biocompatible Materials; D001673:Biodegradation, Environmental; D003692:Delayed-Action Preparations; D004339:Drug Compounding / Q000379:methods; D005079:Excipients; D005283:Fentanyl / Q000032:analysis / Q000737:chemistry; D019344:Lactic Acid; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008863:Microspheres; D008970:Molecular Weight; D010316:Particle Size; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D012997:Solvents; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D000700:Analgesics; D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D005079:Excipients; D011108:Polymers; D012997:Solvents; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D005283:Fentanyl