ABSTRACT
OBJECTIVES: To formulate sustained release rifampicin-loaded solid lipid microparticles (SLMs) using structured lipid matrices based on Moringa oil (MO) and Phospholipon 90G (P90G). METHODS: Rifampicin-loaded and unloaded SLMs were formulated by melt homogenization and characterized in terms of particle morphology and size, percentage drug content (PDC), 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 PDC 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 could be used once daily for the treatment tuberculosis.
Subject(s)
Antibiotics, Antitubercular/administration & dosage , Delayed-Action Preparations/chemistry , Lipids/chemistry , Moringa oleifera/chemistry , Plant Oils/chemistry , Rifampin/administration & dosage , Animals , Antibiotics, Antitubercular/pharmacokinetics , Antibiotics, Antitubercular/pharmacology , Male , Particle Size , Rats, Wistar , Rifampin/pharmacokinetics , Rifampin/pharmacology , Tuberculosis/drug therapyABSTRACT
CONTEXT: Gongronema latifolium Benth Hook, (Asclepiadaceae) is a tropical rainforest plant primarily used in traditional folk medicine in the treatment of malaria, diabetes, hypertension, and as laxative. OBJECTIVE: To study the antidiabetic properties of Gongronema latifolium-loaded solid lipid microparticles (SLMs). MATERIALS AND METHODS: The methanolic extract of Gongronema latifolium leaves were obtained and formulated into SLMs using lipid matrix comprising of fat from Capra hircus and Phospholipon® 90H. The SLMs were characterized in vitro by determining the particle size and morphology, pH stability studies, and encapsulation efficiency EE%. Also, the antidiabetic properties of the Gongronema latifolium-loaded SLMs were studied in alloxan-induced diabetic rats. RESULTS AND DISCUSSION: The results show that the particle size of G. latifolium-loaded SLMs was within an acceptable range for SLMs. Highest EE% of 68% was obtained for SLMs containing 5% G. latifolium (batch F3). The formulations remained stable with insignificant pH reduction over time (p < 0.05). Gongronema latifolium-loaded SLMs had mean percentage reduction in blood glucose of 76% at 2 h, 42.3% at 8 h, and 24.4% at 12 h, while the group that received the reference-glibenclamide had 82.6, 61.7, and 46.7% at 2, 8, and 12 h, respectively, after oral administration of all samples. Gongronema latifolium-loaded SLMs had blood glucose reduction significantly higher than the pure extract and the glibenclamide (p < 0.05) at the concentrations used. CONCLUSIONS: Gongronema latifolium-loaded SLMs exhibited a good hypoglycemic effect and could be used for the treatment of diabetes.
