title: Evaluation of rate of swelling and erosion of verapamil (VRP) sustained-release matrix tablets.
abstract: Tablets manufactured in-house were compared to a marketed sustained-release product of verapamil to investigate the rate of hydration, erosion, and drug-release mechanism by measuring the wet and subsequent dry weights of the products. Swelling and erosion rates depended on the polymer and granulating fluid used, which ultimately pointed to their permeability characteristics. Erosion rate of the marketed product was highest, which suggests that the gel layer that formed around these tablets was weak as opposed to the robust and resistant layers of test products. Anomalous and near zero-order transport mechanisms were dominant in tests and commercial product, respectively.
authors.affiliation: Faculty of Pharmacy, Rhodes University, Grahamstown, South Africa.
authors.forename: Sandile M
authors.initials: SM
authors.lastname: Khamanga
authors.forename: Roderick B
authors.initials: RB
authors.lastname: Walker
mesh_terms: D002121:Calcium Channel Blockers / Q000008:administration & dosage; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004339:Drug Compounding; D066298:In Vitro Techniques; D011108:Polymers; D013607:Tablets; D014700:Verapamil / Q000008:administration & dosage*; D014867:Water
chemical_list: D002121:Calcium Channel Blockers; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D011108:Polymers; D013607:Tablets; D014867:Water; D014700:Verapamil