title: Design of methylprednisolone biodegradable microspheres intended for intra-articular administration.
abstract: This study aimed to design methyprednisolone (MP)-loaded poly(D,L lactide-co-glycolide) (PLGA) microspheres (MS) intended for intra-articular administration. MP was encapsulated in four different types of PLGA by using an S/O/W technique. The effects of beta-irradiation at the dose of 25 kGy were evaluated on the chemical and physicochemical properties of MS and the drug release profiles. The S/O/W technique with hydroxypropylmethylcellulose (HPMC) as surfactant allowed obtaining MS in the tolerability size (7-50 microm) for intra-articular administration. The MP encapsulation efficiency ranged 56-60%. HPMC traces were evidenced in the loaded and placebo MS by attenuated total reflectance Fourier transform infrared spectroscopy. MS made of the capped PLGA DL5050 2M (MS 2M) and uncapped PLGA DL5050 3A (MS 3A) prolonged the release of MP over a 2- to 3-month period with a triphasic (burst release-dormant period-second release pulse) and biphasic release pattern, respectively. The beta-irradiation did not significantly alter the morphology, chemical, and physicochemical properties of MS. The only variation was evidenced in the drug release for MS 2M in term of shorting of the dormant period. The minimal variations in the properties of irradiated PLGA MS, which are in disagreement with literature data, may be attributed to a radioprotecting effect exerted by HPMC.
authors.affiliation: Istituto di Chimica Farmaceutica e Tossicologica "P. Pratesi", Università degli Studi di Milano, Via Mangiagalli 14, 20133 Milan, Italy. francesco.cilurzo@unimi.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Cilurzo
authors.forename: Francesca
authors.initials: F
authors.lastname: Selmin
authors.forename: Paola
authors.initials: P
authors.lastname: Minghetti
authors.forename: Luisa
authors.initials: L
authors.lastname: Montanari
mesh_terms: D002152:Calorimetry, Differential Scanning; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D015195:Drug Design; D065347:Hypromellose Derivatives; D007596:Joints; D019344:Lactic Acid / Q000737:chemistry; D008747:Methylcellulose / Q000031:analogs & derivatives / Q000737:chemistry; D008775:Methylprednisolone / Q000008:administration & dosage* / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size; D010919:Placebos; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D010919:Placebos; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D065347:Hypromellose Derivatives; D008747:Methylcellulose; D008775:Methylprednisolone