title: Release characteristics of pectin microspheres prepared by an emulsification technique.
abstract: The potential application of pectin as a matrix polymer for making microspheres by an emulsification technique was explored, and the drug release property of these pectinate microspheres containing drug cores of varying aqueous solubilities: sulphanilamide, sulphaguanidine and sulphathiazole, was investigated using different dissolution media. The size and size distribution, specific surface area, drug content and drug release property of the pectinate microspheres were determined. The solubility and solution pH of drugs and their propensity to interact with pectin were characterized. Pectinate microspheres were successfully prepared by external gelation, using a modified emulsification technique. The kinetics of drug release from the microspheres best fitted Higuchi's model. Interestingly, the lowest percentage of drug released was produced by microspheres which were smallest in size and, therefore, largest in specific surface area, and containing sulphanilamide, the most aqueous soluble and the lowest molecular weight drug. Mathematical correlation study indicated that the drug release profile of pectinate microspheres was notably affected by the drug content and the extent of drug-pectin interaction in the microspheres. Generally, a higher percentage of drug was released from the microspheres with a higher drug content and/or lower extent of drug-pectin interaction. The extent of drug-pectin interaction was highest in microspheres containing sulphanilamide, followed by sulphaguanidine and sulphathiazole, opposite to that of drug content.
authors.affiliation: Department of Pharmacy, Faculty of Science, National University of Singapore, 18 Science Drive 4, 117543, Singapore.
authors.forename: T W
authors.initials: TW
authors.lastname: Wong
authors.forename: L W
authors.initials: LW
authors.lastname: Chan
authors.forename: H Y
authors.initials: HY
authors.lastname: Lee
authors.forename: P W S
authors.initials: PW
authors.lastname: Heng
mesh_terms: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004339:Drug Compounding / Q000379:methods*; D004655:Emulsions; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008863:Microspheres; D008954:Models, Biological; D010316:Particle Size; D010368:Pectins; D012995:Solubility; D013414:Sulfaguanidine / Q000008:administration & dosage / Q000493:pharmacokinetics; D000077145:Sulfanilamide; D013424:Sulfanilamides / Q000008:administration & dosage / Q000493:pharmacokinetics; D000077589:Sulfathiazole; D013432:Sulfathiazoles / Q000008:administration & dosage / Q000493:pharmacokinetics
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004655:Emulsions; D013424:Sulfanilamides; D013432:Sulfathiazoles; D013414:Sulfaguanidine; D000077145:Sulfanilamide; D010368:Pectins; D000077589:Sulfathiazole