Description

Evaluation of the Properties of Rifampicin-Loaded Solid Lipid Microparticles Based on Moringa oleifera oil and Phospholipon 90G Admixtures
Evaluation of the Properties of Rifampicin-Loaded Solid Lipid Microparticles Based on Moringa oleifera oil and Phospholipon 90G Admixtures

*Salome A. Chime, Echezona O. Ogudiegwu and Ikechukwu V. Onyishi
Department of Pharmaceutical Technology and Industrial Pharmacy, University of Nigeria, Nsukka 410001, Nigeria
*Corresponding author: Tel.: +2348061329790
Fax: +234-42-771709
E-mail address: salome.chime@unn.edu.ng
Abstract
Context: Rifampicin is one of the most effective antitubercular agents, however, it suffers from many drawbacks such as, short half-life, adverse effects, pH-dependent degradation, and bioavailability problems. The degradation of the Rifampicin in acidic pH of the stomach depends on the initial amount of drug released in the stomach. Hence formulations designed as sustained release systems are of immense benefit in order to release the drug in intestinal pH and hence, circumvent degradation in gastric pH of 1.2.
Aim: The aim of the work was to formulate sustained release rifampicin-loaded solid lipid microparticles (SLMs) using structured lipid matrices based on Moringa oil (MO) and Phospholipon 90G (P90G) for effective treatment of tuberculosis.                              
Materials and Methods: Rifampicin-loaded and unloaded SLMs were formulated by melt homogenization and characterized for particle morphology and size, encapsulation efficiency (EE%), pH stability, stability in simulated gastric fluid (SGF, pH 1.2), minimum inhibitory concentration (MIC) and in vitro release. In vivo release was studied in Wistar rats.                
 Results: Rifampicin-loaded SLMs had particle size range of 32.50 ± 2.10 to 34.0 ± 8.40 μm, highest EE% of 87.6 % and showed stable pH. SLMs had good sustained release properties with about 77.1 % release at 12 h in phosphate buffer (pH 6.8) and 80.3 % drug release at 12 h in simulated intestinal fluid (SIF, pH 7.4). SLMs exhibited 48.51 % degradation of rifampicin in SGF at 3 h, while rifampicin pure sample had 95.5 % degradation. Formulations exhibited MIC range of 0.781 to 1.562, 31.25 to 62.5 and 6.25 to 12.5 μg/ml against Salmonella typhi, Escherichia coli, and Bacillus subtilis respectively and had higher in vivo absorption than the reference rifampicin (p < 0.05).                                                                                                                       
Conclusion: Rifampicin-loaded SLMs exhibited good in vitro stability in SGF and showed drug release profiles which indicated that they could be used once daily for the treatment tuberculosis.

Keywords: Moringa oil; tuberculosis; in vivo release; lipid absorption, rifampicin degradation.