Natural Polymer from Sesamum radiatum as an Emulsifier and Stabilizer in Fabrication of Macroemulsions
Ndidi C. Ngwuluka *
Biomaterials and Drug Delivery Unit, Faculty of Pharmaceutical Sciences, University of Jos, Jos, Nigeria.
Edith O. Ugwuagbo
Biomaterials and Drug Delivery Unit, Faculty of Pharmaceutical Sciences, University of Jos, Jos, Nigeria.
Elijah I. Nep
Biomaterials and Drug Delivery Unit, Faculty of Pharmaceutical Sciences, University of Jos, Jos, Nigeria.
Patrick O. Olorunfemi
Biomaterials and Drug Delivery Unit, Faculty of Pharmaceutical Sciences, University of Jos, Jos, Nigeria.
Patricia O. Odumosu
Biomaterials and Drug Delivery Unit, Faculty of Pharmaceutical Sciences, University of Jos, Jos, Nigeria.
Nelson A. Ochekpe
Biomaterials and Drug Delivery Unit, Faculty of Pharmaceutical Sciences, University of Jos, Jos, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Aim: Sesamum gum was extracted from the leaves of Sesamum radiatum and evaluated as emulsifier or stabilizer in coarse emulsions.
Methods: The emulsion systems were assessed by monitoring of emulsion density, viscosity, globule size, and by evaluating the effects of temperature and salt over a four week period.
Results: It was observed that the known 4:2:1 ratio did not form emulsions when sesamum was used but other ratios such as 2:4:1, 2:4:0.5, 2:4:0.25 and 2:4:0.125 formed emulsions. The emulsions were however, unstable. When sesamum gum was used as a stabilizing agent (0.4%w/v – 2.0%w/v), and acacia (7.5%w/v) as an emulsifying agent, stable emulsions were formed. At the end of four weeks, the emulsion systems exhibited lower globule sizes (1.68-1.95 µm) than the emulsion systems containing acacia alone (3.95 µm) as emulsifier. The emulsions creamed or cracked when exposed to temperatures of about 40°C over 4 weeks. They were however stable even in the presence of salt of 1.0%w/v concentration.
Conclusion: The presence of sesamum as a stabilizer influenced the globule size and size distribution, the viscosity and consequently the stability of the emulsions. The study suggests that sesamum gum possesses the desirable properties of emulsifier/stabilizer in emulsions.
Keywords: Dosage forms, drug delivery, emulsions, macroemulsions, natural polymers, naturapolyceutics, Sesamum radiatum, stability.