Effect of sodium chloride as channeling agent on release profile of diclofenac tablets formulated using <i>Grewia mollis</i> and acacia gums

Abstract

Sustained release formulations are designed to modify and improve the bioavailability of drugs, by increasing the duration of action and reducing frequency of dosing of the drug. The study was carried out to investigate the effect of a channeling agent, (sodium chloride) on the release profiles  of diclofenac potassium-matrix tablets formulated with natural gums. Diclofenac potassium-matrix granules were prepared by wet granulation technique using acacia and grewia gums (10% w/w). Sodium chloride (channeling agent) at varying concentrations (50, 100, 150 and 200 mg) was incorporated and the granules compressed into tablets. The granules were evaluated for micromeritic properties, while the formulated tablets were  analyzed for hardness, friability and in vitro dissolution profiles. Drug-excipient compatibility studies were carried out using Fourier Transform  Infrared (FTIR) spectroscopy. The release data were subjected to different release kinetics and their release mechanism determined. All granules were free flowing with angle of repose ≤31.0°. The dissolution rate increased generally with increase in concentration of the channeling agent. For  instance, the dissolution rate (m∞/t∞) without channeling agents and with channeling agents at same concentration (200 mg) were 43.5%h-1 and  92.3%h-1 respectively. The mechanism of drug release from these formulations followed anomalous transport, often termed first-order release  since the diffusional release exponent (n) for all the formulations was between 0.45 and 0.89. FTIR studies showed that the active ingredient and excipients were compatible.

Keywords: Channeling agent, sodium chloride, grewia gum, diclofenac potassium.