Use of Opadry® CA-A cellulose acetate/polyethylene glycol system for rate-controlled osmotic drug delivery of highly soluble antispastic agent Eperisone HCl

The study was aimed to prolong the antispastic effect of a highly soluble drug Eperisone HCl by osmotic drug delivery technology. Oral osmotically controlled release formulations of Eperisone HCl were designed and optimized to acquire desired zero-order release kinetics. Drug cores were prepared by direct compression followed with a semipermeable coating of Opadry((R)) CA. Delivering orifice of variable size was created on Opadry((R)) CA film using different size bits ranging from 0.2 to 0.8 mm, fitted into Proxxon MF70 microdrill. Drug release was determined initially at pH 1.2 for 2 hr then at pH 6.8 up to 24 hr in USP dissolution apparatus-II. Fourier transform infrared spectroscopy was conducted, and no interaction was found. Eperisone HCl release in the presence of osmagent showed inverse relationship. Drug release was independent of pore size at 5%-10% osmagent concentration, although this behavior was reversed with the increased osmagent amount (15%). The release was unaffected by dissolution medium pH and agitation rate but significantly altered by changing osmolality of dissolution medium. Release kinetic was shifted from first-order to zero-order with the increased osmagent amount. SEM indicated the formation of pores on the surface of Opadry((R)) CA after dissolution. Formulation of controlled release osmotic pumps of Eperisone HCl using Opadry((R)) CA can be used to establish a system for extended release of highly soluble drugs.