title: Development and evaluation of pH-sensitive sodium alginate/chitosan microparticles containing the antituberculosis drug rifampicin.
abstract: This paper describes the encapsulation of a high molecular weight molecule rifampicin (RIF) in sodium alginate/chitosan microparticles, which provided controlled-release when evaluated in vitro. The microparticles were prepared by the coacervation technique. To evaluate and select the best encapsulation method two approaches were applied: coacervation (MCP method 1) and impregnation (MCP method 2). The microparticles obtained were analyzed by DSC, DRIFT, XRD and SEM and also the loading efficiency, swelling degree (SD) and in vitro release were determined. The results obtained showed that the alginate/chitosan microparticles represent an efficient system for the controlled-release of RIF. At acidic pH, the release of 20% of the drug occurred in 2h, and at pH6.8 a rapid increase in the release rate was observed up to 100%. The mechanism involved in the release was Super Case II kinetics since n>1 (n=1.09 and 1.13 for microparticles produced by methods 1 and 2, respectively), indicating that the release was related to diffusion, swelling, relaxation and erosion processes. The dissolution efficiencies were similar for both formulations, and the f2 values of ≥50 indicated the similarity between the two profiles, under the assumption of a maximum allowable difference of 10%.
authors.affiliation: Laboratório Quitech, Departamento de Química, Universidade Federal de Santa Catarina, Brazil.
authors.forename: Loreana
authors.initials: L
authors.lastname: Lacerda
authors.affiliation: Universidade de Brasília, Campus Planaltina, Vila Nossa Sra de Fátima, 73000-970 Planaltina, DF, Brazil.
authors.forename: Alexandre Luis
authors.initials: AL
authors.lastname: Parize
authors.affiliation: Laboratório Quitech, Departamento de Química, Universidade Federal de Santa Catarina, Brazil.
authors.forename: Valfredo
authors.initials: V
authors.lastname: Fávere
authors.affiliation: Laboratório Quitech, Departamento de Química, Universidade Federal de Santa Catarina, Brazil.
authors.forename: Mauro Cesar Marghetti
authors.initials: MC
authors.lastname: Laranjeira
authors.affiliation: Laboratório de Controle de Qualidade, Departamento de Ciências Farmacêuticas, Universidade Federal de Santa Catarina, Brazil. Electronic address: hellen.stulzer@gmail.com.
authors.forename: Hellen Karine
authors.initials: HK
authors.lastname: Stulzer
mesh_terms: D000464:Alginates / Q000737:chemistry*; D000904:Antibiotics, Antitubercular / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical; D048271:Chitosan / Q000737:chemistry*; D003692:Delayed-Action Preparations; D004337:Drug Carriers / Q000737:chemistry; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry; D010316:Particle Size; D012293:Rifampin / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D000464:Alginates; D000904:Antibiotics, Antitubercular; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D048271:Chitosan; D012293:Rifampin
keywords: Chitosan; Controlled release; Microparticles; Rifampicin; Sodium alginate