Utilization of ionotropic gelation technique for bioavailability enhancement of cinnarizine: in-vitro optimization and in-vivo performance in human.

ABSTRACT

Gastro retentive drug delivery system techniques were adopted to deliver drugs having narrow absorption window from a particular site in the GIT. Therefore, gastro retentive dosage forms were retained in the stomach, thus improving absorption and bioavailability would be improved consequently. In this study, cinnarizine (CNZ) was employed as the model drug. CNZ is a poorly soluble basic drug, suffering from low and erratic bioavailability. This is attributed to its pH-dependant solubility (highly soluble at pH < 4). CNZ is characterized by short half-life (3-6 h). Accordingly, floating CNZ emulsion gel calcium pectinate beads were developed. A mixture design was employed to study the effect of the percent of LM pectin (A), the percent of GMO (B) and the percent of Labrafac Lipophile (C) simultaneously on the percent of drug released and loaded. The optimized floating CNZ emulsion gel calcium pectinate beads and Stugeron® (the marketed reference product) were compared through a pharmacokinetic study carried on healthy human volunteers. Fortunately, simple floating CNZ emulsion gel calcium pectinate beads were prepared with zero-order release profile for 12 h. A promising in-vivo CNZ controlled release dosage form with higher bioavailability, when compared to once daily administration of Stugeron® tablets was achieved.