Evaluation of Novel Solid Lipid Microparticles Drug Delivery Systems for Oral Delivery of a Herbal Antidiabetic Extract

Aim: The aim of the present study was to prepare and evaluate a novel multiparticulate pharmaceutical formulation of Vernonia amygdalina extract suitable for oral administration.

Study Design: Solid lipid microparticles (SLMs) of Vernonia amygdalina aqueous extract and evaluate in vivo

Place and Duration of Study: Drug Delivery Research Unit, Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, University of Nigeria Nsukka, between October 2011-2013.

Methods: Phospholipon® 90H and Homolipid (HLP) from Capra hircus were used to prepare solid lipid microparticles (SLMs) of Vernonia amygdalina (VA). The SLMs were characterization based on size, morphology, stability and encapsulation efficiency (EE%). In vitro release was performed in phosphate buffer while the antidiabetic properties of the SLMs were evaluated in alloxan- induced diabetic rats.

Results: There was a dose dependent increase in EE% irrespective of the type of matrixing agents used. Generally, the batches containing 400 mg VA (A1-A3) had higher EE (79.24, 81.42 and 89.16%) than those containing 200 mg VA (B1-B3; 72.19, 73.09 and 84.21%). The ratio of Phospholipon® 90H and Homolipid determined the EE% of the formulation. The formulations are stable, the particle size range 38.1 µm to 81.1. The release of VA in phosphate buffer varied widely with the lipid contents. Moreover, significant antidiabetic (p<0.05) properties were observed in all the VA-loaded SLM formulations.

Conclusion: The SLMs-based formulations would likely offer a more effective means of delivering Vernonia amygdalina, a natural extract with good antidiabetic activities as compared to the traditional way of taking the extract orally.