Antimicrobial activity of Ficus exasperata (Vahl) leaf extract in clinical isolates and its development into herbal tablet dosage form

Abstract

Background: Ficus exasperata (Vahl) from the family Moraceae is a herb of ethnobotanical importance with antimicrobial properties. The past studies have been on the phytochemistry and pharmacological activities of the plant, but there is a need to formulate this valuable herb into tablet dosage form to offer standardisation.

Aim: The aim of this study was to assess the antimicrobial activity of F. exasperata leaf extract (extract) and formulate it into herbal tablet dosage form.

Setting: The experiments were performed at the laboratories of the Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria.

Methods: The extract was obtained by maceration and assessed for antimicrobial activity using agar cup diffusion method. Tablets were prepared by direct compression using Avicel^®, Lactose and Emcompress^® at a drug–diluent ratio of 1:4 and 1:9. The flow properties of the powder mixtures were determined using compressibility index, Hausner’s ratio, angle of repose and density measurements. The mechanical properties of the tablets were assessed using crushing strength (CS), friability (FR) and the crushing strength–friability ratio (CSFR) and release properties with disintegration times (DT), disintegration efficiency ratio and dissolution times. Analyses were carried out using two-way analysis of variance on Prism 5.0.

Results: The results showed that the extract had concentration-dependent antimicrobial activity. The flow properties of the powder mixtures were in the rank order of Avicel^® > Lactose > Emcompress^®. Tablet CS and CSFR increased, whilst FR decreased with increase in compression force and diluent concentration. All tablets passed the DT test. The ranking of dissolution times was Avicel^® < Lactose < Emcompress^® < no diluent.

Conclusion: Ficus exasperata extract demonstrated antimicrobial properties dependent on type of organism and extract concentration. The herbal tablets have acceptable mechanical and release parameters, which varied with diluent type, drug–diluent ratio and compression pressure.