Physicochemical, compressional, mechanical, and dissolution properties of metronidazole tablets prepared with cocoa pod gum.

Abstract

Background: Natural gums offer environmentally friendly, biodegradable and non-toxic alternatives to synthetic binders in pharmaceutical formulations. Cocoa pod gum (CPG), derived from cocoa pod husk (CPH), presents a sustainable and underexplored source for pharmaceutical application.

Objectives: This study investigates the potential of CPG as a natural binder in metronidazole tablet formulations, evaluating its physicochemical and compressional properties, mechanical strength, drug release behavior, and compatibility with the active pharmaceutical ingredient.

Material and methods: The CPG was extracted from CPH and characterized alongside xanthan gum (XNG), a standard natural binder. Physicochemical analyses included pH, flow properties, viscosity, particle size, crystallinity, and thermal behavior. Compaction behavior was assessed using Heckel and Kawakita equations. Metronidazole tablets were formulated with varying concentrations (10-20% w/w) of both gums and evaluated for hardness, friability, disintegration time, and in vitro drug release. Compatibility was examined using Fourier transform infrared spectroscopy (FTIR).

Results: Cocoa pod gum demonstrated better flow properties and swelling capacity, while XNG showed higher viscosity and plastic deformation, yield pressure (Py) and PK values. Tablets formulated with XNG had greater hardness and slower disintegration, resulting in more delayed drug release. Cocoa pod gum-based tablets disintegrated faster and showed rapid drug release, making them more suitable for immediate release formulations. Fourier transform infrared spectroscopy confirmed no drug-excipient incompatibilities.

Conclusions: Cocoa pod gum exhibits promising binder properties comparable to XNG and may serve as a cost-effective, sustainable and biocompatible alternative to conventional excipients in tablet formulations.