Background and the purpose of the study: Multiparticulates by liquid layering process has advantages of producing homogenous small drug loaded units, high reliability and the possibility of applying the successive layers of drug entities using the same equipment. The aim of this study was to develop pellet formulations that could be used to improve the dissolution and bioavailability of a poorly water-soluble model drug, glimepiride. In solution/suspension layering, drug particles are dissolved in the binding liquid and particularly coated with the aim of providing a desired drug release profile.
Method: Multiparticulate formulation by liquid layering technology was prepared by conventional pan coating process. Selection of the suitable carrier, and pan speed were critical variables that were found to affect the dissolution of drug. Carrier loaded pellets were prepared by using mannitol, microcrystalline cellulose and starch as carriers, and pan was rotated at different speed such as 126.96.36.199.60 rpm. The prepared drug loaded pellets were evaluated by HPLC method. In vitro dissolution studies were carried out to study the effect of nature of carrier, and pan speed on drug release.
Results: Mannitol was found to be the effective carrier of active ingredient. Its characteristics of high solubility, low hygroscopicity and extreme inertness help in improving stability and dissolution of finished formulation. The results showed that drug release of glimepiride was found to increase with pellets having mannitol as carrier and at a pan speed of 40rpm. The compatibility between drug and polymers in the drug loaded pellets was confirmed by HPLC studies. It may be concluded that F6 is an ideal formulation for once a day administration.