FORMULATION AND INVITRO EVALUATION OF GASTRO RETENTIVE INSITU FLOATING GELS OF LOSARTAN POTASSIUM CUBOSOMES

Losartan Potassium is a BCS class III antihypertensive drug having a very short half-life (almost 2 hours).The aim of the present work is to formulate and evaluate a sustained release formulation of Losartan Potassium cubosomes and gastro retentive in-situ floating gels of cubosomes. The dug, excipients and formulations are characterized by FTIR. Cubosomes are prepared by Top down approach employing Glycerol monooleate (GMO) as lipid phase vehicle, pluronic F127 as stabilizer and water as aqueous phase, Losartan Potassium as active pharmaceutical ingredient. The resultant cubosomal dispersion is evaluated for drug release by diffusion studies, subjected to zeta sizing. Floating gels are prepared in a similar manner to cubosomal dispersions employing gelling agents like sodium alginate, xanthan gum, guar gum, carbopol 940B.P.The resultant gel formulations are evaluated for gelation property, pH, viscosity and %cumulative drug release by diffusion studies. The compatibility studies by IR spectroscopy showed no interaction between the drug and excipients. Different formulations by varying ratios of GMO LPF1(10%), LPF2(20%), LPF3(30%), LPF4(40%), LPF5(50%) were prepared. Cubosome formulation LPF3 containing 30%GMO showed a maximum drug release of 93.3% within 5hours. The concentration of GMO from the above cubosomal formulation (30%) is used in formulation of floating gels and sustained release up to 6 hours was observed in gels formulated with carbopol940, sodium alginate, guar gum, xanthan gum(LPFCNGX). In-vitro release kinetics exhibited sustained release and followed zero order kinetics by the selected formulations and satisfactory pH, viscosity values are obtained. cubosomes formulated with GMO serves as potential gastro retentive sustained drug delivery vehicle. Further sustained release will be achieved when they are formulated as floating gels. Key-words: Cubosome, Gastro retentive, in-situ gel, Losartan Potassium, oral drug delivery, GMO