QUICK/SLOW BIPHASIC RELEASE OF A POORLY WATER SOLUBLE ANTIDIABETIC DRUG FROM BI-LAYER TABLETS

Objective: The objective of the present work is to develop a bi-layer tablet consisting of an Immediate Pulse Release [IPR] layer and a sustained release [SR] layer that can produce a distinct biphasic release having two different drug release rates. The IPR layer is intended to release a fraction of the dose rapidly at a faster rate and the SR layer is meant for slow release of the remaining dose at a slower rate for a desired period of time.Methods: The quantitative determination was carried out by UV spectrophotometer. Solid dispersion was prepared by melt method. IPR layer was prepared by direct compression method, SR layer was prepared by wet granulation method. In-vitro drug release study from tablets was carried out in USP II tablet dissolution rate test apparatus. FTIR, DSC, XRD studies were performed.Results: 89% of the incorporated drug was released within 30 min in acid solution of pH 1.2 from the IPR tablet prepared with the highest amount of gelucire due to solid state transformation of the drug. The SR layer (SR8) comprising of SAL, CG and CMC produced prolonged drug release (70% in 10 h). The optimized IPR3 layer and SR layers were compressed to form bi-layer tablets from which 23-37% drug was released immediately in 30 min, and the remaining drug was released slowly for 7 to 10 h depending upon the compositions of the tablets.Conclusion: This study revealed that bi-phasic release of GPZ consisting of an initial quick release and subsequent slow release could be achieved by formulating bi-layer tablets using the existing tablet technology, and such formulation may be able to control hyperglycaemia effectively for a longer period of timeÂ