title: Preparation and in vitro dissolution profile of dual polymer (Eudragit RS100 and RL100) microparticles of diltiazem hydrochloride.
abstract: A microparticulate dosage form for a highly soluble drug, diltiazem hydrochloride, was formulated with Eudragit RS100 and RL100 using a novel dual polymer technique. A mixture of diltiazem with Eudragit RS100 (low water permeability) in acetone was coacervated into soft polymer microdrops, following which a mixture of diltiazem and RL100 (high water permeability) was added to produce microparticles consisting of both polymers with diltiazem dispersed in the matrix. A second formulation was developed using the same method except using Eudragit RS100 for both steps. For a comparative study, diltiazem, Eudragit RS100 and RL100 were combined together in a single matrix and formulated into microparticles. In vitro drug release profiles using USP paddle dissolution apparatus 2 revealed that dual polymer matrix microparticles containing Eudragit RS100 in the inner and Eudragit RL100 in the outer core exhibit a suitable release profile with an initial release of the drug followed by a plateau level for the test period of 5 h. Differential scanning calorimetric analysis showed no interaction of the drug with the polymers.
authors.affiliation: Nova Southeastern University, College of Pharmacy, Ft. Lauderdale, FL 33328, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Das
authors.forename: N G
authors.initials: NG
authors.lastname: Das
mesh_terms: D000180:Acrylic Resins; D002121:Calcium Channel Blockers / Q000008:administration & dosage* / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D004110:Diltiazem / Q000008:administration & dosage* / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008863:Microspheres; D011109:Polymethacrylic Acids; D012995:Solubility
chemical_list: D000180:Acrylic Resins; D002121:Calcium Channel Blockers; D011109:Polymethacrylic Acids; C038300:methylmethacrylate-methacrylic acid copolymer; C050528:Eudragit RS; D004110:Diltiazem