Journal of Pharmaceutical Research

Amara O. Onuegbu ¹, Ikhuoria M. Arhewoh ¹, Augustine O. Okhamafe ¹

Affiliations
1 Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, University of Benin, Benin City 300001, NG

Abstract

A widely used approach for the microencapsulation of drugs especially for controlled drug delivery is emulsion polymerization. The purpose of this study was to comparatively evaluate chitosan-alginate microcapsules for oral delivery of ibuprofen using two techniques. Alginate-based microcapsules were prepared using the emulsion/internal gelation and electrostatic droplet generator/counter-ion coacervation methods. The effect of production parameters on the size of the microcapsules and in vitro ibuprofen release at pH 1.2 and 7.4 was determined. For emulsion/internal gelation method, the results showed that increase in stirring rate, volume of dispersion medium and viscosity of the coating materials did not significantly (p > 0.05) affect the size of the microcapsules. Microcapsules produced by the electrostatic droplets generator method had a narrower size distribution compared to the emulsion method. Drug release at pH 7.4 was considerably more than at pH 1.2, especially for uncoated microcapsules, microcapsules coated with high-viscosity (undigested) chitosan, and microcapsules prepared by the emulsion method. The encapsulation efficiencies of the two methods were similar as over 90% of ibuprofen was entrapped in each case. The two microencapsulation techniques can be applied in the microencapsulation of ibuprofen for oral delivery.

Keywords

Droplet Generator, Emulsion Method, Ibuprofen, Microcapsules, Oral Delivery.

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Edith I. Ahonkhai ¹, Ikhuoria M. Arhewoh ¹, Augustine O. Okhamafe ¹

Affiliations
1 Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, University of Benin, Benin City 300001, NG

Abstract

The protein retention characteristics of chitosan-alginate microcapsules modified with selected excipients were evaluated in vitro for oral protein delivery using Bovine serum albumin (BSA) as the 'model' protein. The microcapsules were prepared by extruding alginate solution containing BSA and either talc, Eudragit L100, Eudragit RSPM, microcrystalline cellulose (MCC) or HPMCAS, into chitosan/calcium chloride solution. Protein retention in microcapsules at different pH of the elution medium was determined spectrophotometrically at e_max of 280 nm. Microcapsules containing MCC and talc had the highest protein retention capacity, with 68% and 60%, respectively, of protein still available in the core of the microcapsules after 9 h at pH 1.2, while HPMCAS failed to retain any protein after 9 h at the same pH. Protein retention in microcapsules modified with other additives was intermediate. At higher pH values, microcapsules containing talc still exerted the highest protein retention of 77% (pH 3) and 85% (pH 6), followed by microcapsules containing Eudragit RS PM, 65% (pH 3) and 80% (pH 6), after 9 h. This work has demonstrated that blending the core with suitable excipient enhanced protein retention capacity of chitosanalginate microcapsules. This technology can be employed in oral delivery of protein/vaccines to human and aquaculture.

Keywords

Chitosan-Alginate, Excipients, Microcapsules, Protein Retention, Oral Delivery.

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