Formulation of non-effervescent floating matrix tablets of metronidazole using <I>Abelmoschus esculentus</I> gum as binder and 2-camphanone as sublimating agent.

Abstract

The aim of this study was to formulate non-effervescent floating drug delivery system of metronidazole tablets using Abelmoschus esculentus (Okra) (AE) gum as a binder and 2-camphanone (camphor®) as the sublimating agent. Granules were prepared by wet granulation technique using varying concentrations of AE gum (2, 4, 6 and 8% w/w) admixed with 1%w/w acrylate methacrylate copolymer. A 30 %w/w of 2-camphanone was used as the sublimating agent. The granules were characterized for micromeritic properties. And thereafter, compressed at a compression pressure of 25 N/m2 using a Manesty single punch tableting machine. The metronidazole tablet was then sintered at 70oC for 12 h. Drug-excipient compatibility study was done using Fourier Transform Infra-red Spectroscopy (FTIR). Tablets were evaluated for floating lag time, in-vitro buoyancy and release kinetics. FTIR studies showed that the excipients and the active pharmaceutical ingredient (API) i.e. metronidazole, were compatible. All the granules were free flowing, with Carr’s index ≤ 15 %, Hausner ratio ≤ 1.18 and angle of repose of ≤ 33.5o. The tablets had hardness and friability values of 5.0-9.5 N and 0.4-0.8% respectively. The floating lag time was 0 s showing that the tablets floated immediately after immersion in the simulated gastric fluid. The maximum % release (m∞) and time to achieve it (t∞) were ≥ 88 % and ≥ 10 h, respectively. Release exponent (n) for all the formulations had values >0.45, hence their release was by non-Fickian diffusion. Non-effervescent floating matrix tablets of metronidazole were formulated using AE gum as the binder and 2-camphanone as the sublimating agent. The formulated floating tablets had increased in-vitro retention time, which indicated potential for sustained release of the drug. If well developed, this may help reduce the oral dosing frequency and encourage patient adherence to the drug therapy.

Keywords: Non-effervescent, Abelmoschus esculentus, 2-camphanone, floating