In vitro release

The aim of the present study is to minimize the local gastrointestinal irritation which is one of the major side effects of Piroxicam (PR) by the formulation  oral  stomach specific in situ gelling emulsion ingestion by kinetic control of drug release. Material and method: In situ emulgel were prepared by using castor oil as oil phase ,tween 80 and span 80 as emulsifiers, sodium alginate was used as gelling agent,  xanthan gum was used as release retardant ,calcium carbonate was used as cross linking agent, pH triggered ionic gelation is the mechanism involved in the present study. Various evaluation tests were done for all formulations Results: Formulation F9 containing 2.5% of sodium alginate, 2 % of CaCO3, 1 % of sodium bicarbonate and 0.8% of Xanthan gum was selected as optimized batch based on  Q10 86.02±0.17 %, floating time 122.15±2.47 sec and drug content 91.86±1.02 %. The release pattern of drug was found to follow Korsemeyer and Highuchi model. The DSC study exposed that there was no incompatibility. Pharmacodynamic study on Wistar rats were showed significant anti inflammatory and anti arthritic activity of the optimized formulation. Further, in vivo toxicity studies carried out in wistar rats revealed no signs of gastric ulceration upon prolonged dosing. Conclusion: It was concluded that the oral stomach specific In situ gelling emulsion of piroxicam could be an effective dosage form which minimize the gastric irritation by coating drug with castor oil and remains buoyant and control the drug release for 24hrs.

Gastro retentive drug delivery is an approach to prolong gastric residence time, thereby targeting site-specific drug release in the upper gastro intestinal tract (GIT) for local and systemic effect. The present study has been a satisfactory attempt to formulate floating drug delivery system of Valacyclovir, an orally administrated antiviral drug with a view of improving its oral bioavailability and giving sustained release of the drug. In present study design expert trial 8.0.6.1 software is used for designing of experiment. In central composite design based on response surface methodology yielded nine experimental runs. These nine formulations are evaluated for precompressional parameters like bulk density, tapped density, angle of repose and carr’s index. Formulations are also evaluated for postcompressional parameters like hardness, thickness, weight variation etc. all the formulations shows results in the acceptable range. All preliminary formulations are subjected to invitrobouyancy and dissolution study. The data obtained from the in vitro release study was fit to various kinetic models to explain the release profile of the drug. Kinetic models used were zero and first-order equations, Krosmeyersand peppas and Higuchi models. Based on results obtained from the prelimimary formulations five optimized formulations are selected and validated. Short-term stability study was done for optimized formulations.