Aims & Objectives: The present work deals with the modification of controlled release dosage form of poorly water soluble drug (Metoclopramide hydrochloride) in order to improve the bioavailability and to control drug release for a longer period of time by the aid of solid dispersion.
Methods: Various binary combination of MET-solid dispersion was prepared with different carriers such as HPβCD, PVP K30 and PLX-188 by solvent evaporation technique and then the aqueous solubility, dissolution study and phase solubility study was performed. DSC analysis is performed to carry out for metoclopramide loaded solid dispersion, physical mixture & also for pure drug to analyze the crystalline and amorphous nature of compounds.
Results and Discussion: The saturation solubility of Metoclopramide with various carriers at different pH was performed and found that in pH 5.5 (solubility is 5553.2µg/ml), pH 6.8 (3363.3µ/ml), pH 7.4 (1367.3µg/ml) at 37oC. In dissolution study of solid dispersion (5:1) of different carriers in DDW, the Cumulative % dissolution is found in the order of PVP K30>PLX-Met>HPβCD-Met & in pH 7.4, in the order of PLX-Met>PVP K30>HPβCD-Met. DSC thermogram of Metoclopramide base showed a sharp endothermic peak at its melting point (147oC) which exhibits in crystalline form complying with that of Metoclopramide hydrochloride form, melting point was found to be 850C. In the ex-vivo study of several transdermal patches, patch C [SD of MET: HPβCD (1:5)] showed the controlled release and permeation of drug.
Conclusion: Poor solubility of new chemical entities being a well known problem for past few decades despite the imbalance between significant research efforts & few successful marketed formulations, the solid dispersion proves to hold a key position among all the various formulation strategies to enhance the aqueous solubility & dissolution rate and thereby the bioavailability of poorly aqueous solubility of drug.
Keywords: Bioavailability,DSC, Metoclopramide hydrochloride, solid dispersion, HPβCD,
Application of the solid dispersion method to controlled release of medicine. I. Controlled release of water soluble medicine by using solid dispersion.