An assessment of the antimicrobial activity of the encapsulated seed extract of Chrysophyllum albidum

Abstract

This study was aimed at formulating the seed (cotyledon) extract of Chrysophyllum albidum into capsule dosage form and evaluating its antibacterial property on Gram +ve and Gram -ve bacteria. The therapeutic use of herbal medicines has been gaining considerable acceptance within the past decade. World Health Organization (1) estimates that herbal medicine is still the main hope of about 75 - 80% of the World population especially in the developing nations for primary health care due to its affordability, availability and accessibility. The maceration method was adopted to extract the seed (cotyledon), which was then filtered, and concentrated to dryness on a water bath at controlled temperature of 500 ± 0.5⁰C for 72 h. A weighed amount (400 mg/capsule) of the milled powdered extract was granulated with appropriate amounts of excipients and dried in an oven at 450 ± 0.5⁰C for 6 h and subjected to physicochemical characterization. The flow properties of the granules were: flow rate (5 g/sec), angle of repose (230), bulk density (0.6 g/cm³), tapped density (0.7 g/cm³), Hausner’s ratio (1.180) and Carr’s index (15); indicating good flow properties of the granules. Granules (400 mg) of both ethanol and aqueous extracts respectively were accurately weighed with electronic balance and hand filled into empty hard gelatin shells. The seeded plate method was used to determine the antibacterial activity of the encapsulated C. albidum seed extracts. Dissolution profile for both capsules using 800 ml of 0.1N HCl at 370 ± 0.5⁰C as dissolution medium, was determined and at time intervals of 5, 15, 30, 45 and 60 min, 5 ml aliquots were taken and used to determine its antibacterial activity on both Gram +ve and Gram -ve bacteria. The results showed that the encapsulated extracts inhibited the growth of the Gram +ve (Staphylococcus aureus, Bacillus subtilis) and Gram -ve (Klebsiella pneumonia, Escherichia coli) bacteria. This was evidenced by a clear zone of inhibition which was concentration dependent. The mean disintegration time of the capsules was within the pharmacopoeia standard and when exposed to room temperature and relative humidity for 14 days, the capsules gained relative increase in weight of about 1.5 ± 0.5%.

Keywords: Antimicrobial, encapsulation, seed, Chrysophyllum albidum, extract