DEVELOPMENT OF CASHEW GUM AND ITS DERIVATIVES FOR SUSTAINED RELEASED DRUG DELIVERY SYSTEM: BY RESPONSE SURFACE METHODOLOGY

The aim of the present study was to investigate the Cashew gum (CG) and its modifications for formulating the sustained release delivery system using theophylline (TH) as a model drug by varying the gum to drug ratio (1:1 and 3:1). Different formulations were designed, prepared and evaluated by employing response surface, optimal design of experimental technique using Design Expert® ver 8.0.1 software. The optimized formulation was identified and validated for its performance by using the numerical optimization technique. The matrix tablets were prepared by direct compression using CG, cross linked CG (CCG), carboxymethylated cashew gum (CMCG) and carboxymethylated cross linked CG (CMCCG). The modifications in CG were confirmed using FT-IR and C[13] NMR. SEM was used to study the surface morphology of formulations. In vitro drug release, gum erosion and hydration studies were carried out using a dissolution apparatus (USP 1) for 12 h using specified buffer solutions (pH 1.2 and pH 6.8). The kinetic analysis of dissolution data showed a good fit in Peppas equation which confirmed anomalous non-fickian release mechanism for CCG (epichlorhydrin/ gum ratio (E/Gb = 0.15)) with TH. The physiochemical changes, solubility, metallic remains after purification, stability of crude and purified CG and the effects of crosslinking density on swelling were also accessed. The stability of the optimized formulation indicated that it was stable. Thus, it can be concluded that CG crosslinking (E/Gb = 0.15) can be effectively employed to formulate sustained release systems