Abstract

Verapamil HCl is a calcium channel blocker administered on thrice a day dosage regimen. In the present study resinates of verapamil HCl were formulated using Indion resins. Drug loading process was optimized with respect to drug:resin ratio, pH of loading solution, and particle size of resin. Resinates were characterized using XRPD. In vitro drug release rates from resinate was not adequately sustained. Hence resinates were incorporated in pellets using extrusion spheronization to achieve desired release pattern. Optimum drug loading was seen at pH of 3.5 in drug resin ratio of 1:1 and was seen to increase with temperature. XRPD studies revealed verapamil to be present in amorphous form in resinates. Drug release from resinates was complete in four hours. Resinates were pelletized using hydroxypropylmethylcellulose. Resinate of Indion 254 with 5% hydroxypropylmethylcellulose fulfilled USP criteria for extended release verapamil preparation.