Gum Cordia: A Novel Matrix Forming Material for Enteric resistant and Sustained Drug Delivery—A Technical Note

Abstract

Sustained drug delivery systems can improve patient compliance and provide extended periods of effective blood levels. In an approach, polymers and their blend are used in various formulations to achieve sustained drug release. The authors investigated various natural, semisynthetic and synthetic polymeric materials. Most thoroughly investigated and used synthetic polymers for sustained release drug delivery are methylcellulose, ethylcellulose, methacrylic acid copolymers (Eudragit; 1), hydroxypropylmethylcellulose (2,3,4), polyoxyethyleneglycol (macrogol; 5), sodium carboxymethylcellulose and carboxypolymethylene (carbopol-934; 6). Some natural gums such as gum karaya (7), chitosan (8), gum copal and gum dammar (9) were also investigated as hydrophilic matrices for sustained drug delivery. However the gums were found to be unable to sustain the drug release for a longer period of time even at higher concentration beyond 12 h. Therefore the study of new materials for retarding drug release is the motive of research even after the advent of synthetic, semi-synthetic and natural polymers. The past research acknowledged the use of gum cordia as a potential non-toxic and safe pharmaceutical excipient (binding agent) in tablet (10). These particulars explicate the rationale, why proposed article concerns the evaluation of natural gums for sustained drug delivery. In the present study, an effort has been made to evaluate the efficacy of gum cordia (obtained from Cordia Obliqua, Willed., Fam.: Boraginaceae) as a novel sustained release matrix forming material in tablet formulations using diclofenac. Diclofenac is used for long-term treatment of various arthritic conditions (11). However the drug has a short biological half-life (11) which needs multiple dosing regimens of immediate-release formulations and requires sustained release formulation for patient compliance. Therefore, it was chosen as a model drug for the present study.