Geeta M. Patel

The aim of this study was to develop a pH independent enteric coated extended release pellets containing flurbiprofen. The drug loaded pellets were prepared by using extrusion/ spheronization method using microcrystalline cellulose in combination with dicalcium phosphate dihydrate as pellet forming agents. Core pellets were coated with polymers Eudragit RS-100 and Eudragit RL-100 in a fluid bed coater to achieve a sustainable release for 24 hours. The pellets were subjected to physicochemical studies, SEM study, in-vitro drug release, kinetic studies and stability studies. DSC and FTIR studies shown there was no interaction between drug and polymers. The physicochemical properties of pellets were found within the limits. The drug release from the optimized formulations was extended for a period of 24 hrs i.e. first 2 hrs no drug release was observed and gradually drug release was increased up to 24 hrs. From the above results, achievement of site specific release to lower part of gastrointestinal tract might be due to Eudragit RL 100. The optimized formulation was subjected to stability studies and showed no significant changes in drug content, physicochemical parameters and release pattern. In conclusion, development of novel and good approach to achieve the site specific release of drug Flurbiprofen.

  A novel mucoadhesive, thermoresponsive vaginal gel for microbicide was developed with gelation temperature 24-35 °C. Poloxamer 407 (P407) or: and poloxamer 188 (P188) were used to confer the temperature-sensitive gelation property. The mixtures of P407 (15%) and P188 (15–20%) existed as a liquid at room temperature, but gelled at 30–36°C. To modulate the gel strength and the bioadhesive force of Ciclopirox olamine gel, mucoadhesive polymer such as polyox WSR N-60K was used. Among bioadhesive polymers, polyox polymer enhanced gel strength most efficiently. These polymers reinforced the bioadhesive forces 4-7 fold compared to P407/P188 (15:15) alone and 3-6 fold compared to P407/P188 (15:20) alone. Differential scanning calorimetry (DSC) was employed to investigate the effect of poloxamer gel on the conformational changes of rat vaginal membrane. The in-situ gelling liquid with polyox polymer inserted into the vagina of women without difficulty and leakage and retained in the vagina at least 6-8 h. These results suggest that in situ-gelling and mucoadhesive vaginal microbicide gel for women can be further developed as a more convenient and effective vaginal dosage form for treating sexually transmitted disease.   Key-words: Mucoadhesion, Vaginal drug delivery, Polyox polymers, Microbicide, Sexually transmitted disease, Conformational change

  The present research work aimed at development and optimization of niosome based gel (NBG) for the vaginal delivery of Tenofovir disoproxil fumarate (TDF). The TDF was   incorporated into niosomes using span 60 and cholesterol. Box-Behnken statistical screening design with 3 factors, 3 levels, and 15 runs was selected to statistically optimize the formulation parameters. The independent variables selected were parts of cholesterol (X1), surfactant loading (X2), amount of stabilizer (X3). Fifteen batches were prepared by thin film hydration method and evaluated for percentage drug entrapment (PDE) and vesicle size. The transformed values of the independent variables and the PDE (dependent variable) were subjected to multiple regressions to establish a full-model second-order polynomial equation. F value was calculated to confirm the omission of insignificant terms from the full-model equation to derive a reduced-model polynomial equation to predict the PDE of niosome. A model was validated for accurate prediction of the PDE by performing checkpoint analysis. The niosomal dispersion was incorporated in to Carbopol 940NF gel. The NGB was evaluated for drug content, pH, spreadability, consistency and texture analysis. The in-vitro drug release study shows sustained release gel effect whereas the in-vivo study shows no signs of irritation on the applied vaginal site in rat. The gel was kept for 6 weeks accelerated stability studies. The niosomes and niosomal gel showed maximum stability at 2 to 8 °C.   Key-words: Niosome, vaginal drug delivery, Tenofovir disoproxil fumarate, span 60, Box Behnken design