title: Development and in-vitro evaluation of modified release tablets including ethylcellulose microspheres loaded with diltiazem hydrochloride.
abstract: In this study, development of modified release tablet formulations containing diltiazem hydrochloride-loaded microspheres to be taken once rather than two or three times a day was attempted. For this purpose, ethylcellulose microspheres were prepared by emulsion-solvent evaporation technique. The influence of emulsifier type and drug/polymer ratio on production yield, encapsulation efficiency, particle size, surface morphology and in-vitro release characteristics of the microspheres was evaluated. Suitable microspheres were selected and tabletted using different tabletting agents, Ludipress, Cellactose80, Flow-Lac100 and excipients Compritol888 ATO, KollidonSR. Tablets were evaluated from the perspective of physical and in-vitro drug release characteristics. It was seen that type and ratio of the excipients played an important role in the tabletting of the microspheres. As a result, two tablet formulations containing 180 mg diltiazem hydrochloride and using either Compritol888 ATO or KollidonSR were designed successfully and maintained drug release for 24 h with zero order and Higuchi kinetics, respectively.
authors.affiliation: Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Ankara, Tandogan, Ankara, Turkey.
authors.forename: Ceyda T
authors.initials: CT
authors.lastname: Sengel
authors.forename: Canan
authors.initials: C
authors.lastname: Hasçiçek
authors.forename: Nurşin
authors.initials: N
authors.lastname: Gönül
mesh_terms: D002021:Buffers; D002121:Calcium Channel Blockers / Q000737:chemistry / Q000493:pharmacokinetics*; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics / Q000648:ultrastructure; D003692:Delayed-Action Preparations; D004110:Diltiazem / Q000737:chemistry / Q000493:pharmacokinetics*; D004339:Drug Compounding / Q000379:methods; D005069:Evaluation Studies as Topic; D005079:Excipients; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008863:Microspheres; D010316:Particle Size; D012597:Sclerosing Solutions / Q000737:chemistry / Q000493:pharmacokinetics*; D012995:Solubility; D013607:Tablets; D014867:Water / Q000737:chemistry
chemical_list: D002021:Buffers; D002121:Calcium Channel Blockers; D003692:Delayed-Action Preparations; D005079:Excipients; D012597:Sclerosing Solutions; D013607:Tablets; D014867:Water; C013517:ethyl cellulose; D002482:Cellulose; D004110:Diltiazem