FORMULATION AND IN-VITRO RELEASE STUDY OF SPARINGLY SOLUBLE DRUG NIFEDIPINE USING SOLID DISPERSION METHOD

Abstract

Since the drug Nifedipine is insoluble in water, it was selected to formulate in the form of the solid dispersion in order to increase its dissolution. Also the carrier was selected because they are freely soluble in water. The standard curve of Nifedipine was prepared with the concentration of the solution ranging from 2 – 14 $\mu$ g/ml. The absorbance was measured at 350nm using spectrophotometer. The solid dispersion of Nifedipine was formulated by using melting or fusion method. The drug and carrier was weighed and heated in a china dish in a water bath upto melting of both materials. The different formulations of Nifedipine – Mannitol (1:1, 1:2, 1:3) and Nifedipine – Urea (1:1, 1:2, 1:3) were formulated and was subjected to the dissolution rate studies in pH 7.4 buffer solution. The in-vitro release studies and the drug content for the formulated solid dispersion were carried out. On the basis of dissolution studies, we found that 1:1 (drug:mannitol) solid dispersion showed a marked increase in the dissolution rates when compared to the pure drug. The increase dissolution rates observed in all the cases of the solid dispersion could be mainly due to reduction in particle size.