Kinetics And Stability Studies Of Formulated Micro/Nano Suspension Of Metronidazole

Abstract

Kinetic models describe the overall release of drugs from dosage form because qualitative and quantitative changes do occur in a formulation. These changes may alter drug release and in vivo performance hence the application of methods that facilitates product development and thereby reducing the necessity of bio studies, this leads to the adoption of in vitro drug dissolution analysis that involves the use of dialysis membrane and adopting a diffusion method. Stability studies revealed that the formulated nano/micro suspension was more stable at refrigerated condition (4 O C) showing no significant change in particle size distribution, %EE and release characteristics after 3months of study. The in vitro drug release analysis shows drug release from the various formulations (S, Y and W) to follow zero order release kinetics and this was confirmed after determination of line of best fit and from the correlation coefficients values obtained following the consideration of various kinetic models such as: first order, zero order, Korsmeyer- Peppas and Higuchi models. The stability studies and shelf life determinations of the formulations show formulation S, having a shelf life of 4.598 months, while that of formulation Y and W,   are 4.808 months and 3.085 months respectively. These values could be related to the size of the particles formed using the various polymers which might influence their film forming and protective ability over the particles. The protective ability of tragacanth when used alone seem not to be sustained over a long period of time and this reduced stability effect could lead to short shelf life as a result of the tendency of Ostwald ripening and agglomeration of particles after a short period of storage but when compared to the formulation involving C.olitorious gum used alone or that consisting of C.olitorious and Tragacanth, stability was sustained signifying better protective ability of the polymer.