title: Microencapsulation of superoxide dismutase into biodegradable microparticles by spray-drying.
abstract: The aim of this work was to encapsulate superoxide dismutase (SOD) into biodegradable microparticles by spray-drying technique. The nature of the organic solvent to dissolve the polymer, the method of incorporation of the drug in the organic phase (with or without a surfactant, namely sucrose ester of HLB = 6), the surfactant/polymer ratio, and the nature of the biodegradable polyesters were investigated as formulation variables. The polyesters investigated as matrix were poly(epsilon-caprolactone) (PCL), poly(d, l, lactide-co-glycolide) (PLG-RG756), and poly(d, l-lactide) (PLA-R207) of respective molecular weight 78.2 kDa, 84.8 kDa, and 199.8 kDa. At surfactant/polymer ratio of 1/10, the SOD-retained enzymatic activities were higher (> 95%) for PLG-RG756 and PLA-R207 but relatively lower for the PCL (approximately 85%) probably due to the PCL relatively higher hydrophobicity. The obtained microparticles exhibited average volume mean diameter of 4-10 microm, the smaller for PCL and the larger for PLG-RG756 polymeric matrix. The in vitro release profile showed that SOD was completely (100%) released from PLA-R207 in 48 hr and from PLG-RG756 and PCL within 72 hr. These results showed that spray-drying with incorporation of surfactant such as sucrose ester may efficiently encapsulate SOD into biodegradable microparticles. Such formulations may improve the bioavailability of SOD and similar biopharmaceuticals.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, Texas 79106, USA. bcyouan@ama.ttuhsc.edu
authors.forename: Bi-Botti Célestin
authors.initials: BB
authors.lastname: Youan
mesh_terms: D000465:Algorithms; D002214:Capsules; D003890:Desiccation; D004339:Drug Compounding; D004952:Esters; D016166:Free Radical Scavengers / Q000008:administration & dosage*; D010316:Particle Size; D011091:Polyesters; D012995:Solubility; D012997:Solvents; D013395:Sucrose; D013482:Superoxide Dismutase / Q000008:administration & dosage*; D013501:Surface-Active Agents
chemical_list: D002214:Capsules; D004952:Esters; D016166:Free Radical Scavengers; D011091:Polyesters; D012997:Solvents; D013501:Surface-Active Agents; D013395:Sucrose; D013482:Superoxide Dismutase