Seema Desai

Release of drugs via the skin has been always a challenging part for research due to obstacle properties shown by the outermost layer of skin stratum corneum. In the previous two decades, the transdermal drug delivery system has turn into a established technology that offers important clinical repayment over additional dosage forms. Because transdermal drug delivery offers controlled as well as programmed rate of release of the drug into the patient, it is capable to maintain steady state blood concentration. It’s a advantageous form of drug delivery because of the apparent advantages e.g. suitable and pain-free self-administration for patients, prevention of hepatic first-pass metabolism and the GI tract for poorly bioavailable drugs than other routes of deliverance.Thepresent article reviews the choice of drug candidates and polymers, advantages, disadvantages of formulation, design and the methods of evaluation, augmentation techniques based on drug/vehicle optimization such as selection of drug, prodrugs and ion pairs, supersaturated drug solutions, vesicles, liposomes, particles and complexations. This review also emphases on the recent innovations in TDDS, which be able to used for the research and improvement of pharmaceutical dosage form intended for transdermal drug delivery.

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.

Efficient Helicobacter pylori elimination requires delivery of the antibiotic locally in the stomach. High dose of metronidazole (250 to 750 mg) is difficult to incorporate in floating tablets but can simply be given in liquid dosage form.  By keeping the above observation in mind, we made an attempt to build up a new raft forming oral in situ gelling system of metronidazole with improved residence time using sodium alginate as gelling polymer to eliminate H. pylori.  Methods: oral in situ gelling formulations were prepared using sodium alginate, xanthan gum, calcium carbonate, and sodium bicarbonate. Prepared formulations were evaluated for density, viscosity, floating lag time, floating duration, swelling index and in vitro drug release. Results. All formulations (F1–F12) showed floating within 180 s and had floating duration  of more than 24 h. every formulations showed excellent pourability. It was observed that concentration of sodium alginate and xanthan gum had major influence on floating lag time, cumulative percentage drug release and other evaluation parameters. The batch F11 was optimized since it have good pourability with extended release of 10 hrs. Conclusion: oral in situ gelling system of metronidazole  can be formulated by  use of sodium alginate as a gelling polymer and xanthan gum as release retardant to control  the drug release for more than  10 hrs.