stability studies

The aim of the present investigation was to design a mucoadhesive liposomal system of Prednisone for the treatment of arthritis, severe allergic reaction multiple sclerosis that is capable of delivering entrapped drug over an extended period of time. Mucoadhesive liposomal formulations were prepared by different concentration of lecithin and cholesterol by thin film hydration technique followed by coating of liposomes by 0.2 % w/v of chitosan and Liposomes were evaluated for entrapment efficiency, particle size, zeta potential, surface morphology and in-vitro drug release and stability study of coated formulation. Particle size of the F4, F5 and F6 formulation was found to be 212 nm, 131 nm and 340 nm respectively and zeta potential were -164.9 mV, 165 mV and -9.6 mV, respectively. Highest entrapment efficiency was observed in the ranged of 83 % to 98% for formulation F1 Ë—F8 and CF1-CF2 were 90.87 % to 94.68%.  The percent drug release from F1-F8 was varied and affected by drug loading, soyalecitin and cholesterol concentration and followed non-Fickian diffusion mechanism. 2x3 factorial design were applied and studied the effect of parameter on entrapment efficiency and in vitro drug release at 2hrs, 6hrs, 12 hrs by using QI Macros R software.

A simple, fast and precise reverse phase, isocratic HPLC method was developed for the separation and quantification of Sildenafil and Duloxetine in pharmaceutical dosage form. The quantification was carried out using Symmetry C18-ODS 4.6X150mm, 3µm enhanced polar selectivity column and mobile phase comprised of potassium dihydrogen phosphate buffer and acetonitrile and water in proportion of ratio 30:65:5 and degassed under ultra-sonication. The flow rate was 0.6mL/min and the effluent was monitored at 244nm. The retention time of Sildenafil and Duloxetine were 4.3 and 3.4 respectively. The method was validated in terms of linearity, precision, accuracy, and specificity, limit of detection and limit of quantization. Linearity of Sildenafil and Duloxetine were in the range of 100 to 300µg/mL and 30 to 90µg/mL respectively. The percentage recoveries of both the drugs were 98.7% and 99.8% for Sildenafil and Duloxetine respectively from the tablet formulation.The method was found to be precise, accurate and specific during the study. The proposed method enables rapid quantification and simultaneous analysis of both drugs from commercial formulations without any excipients interference. The method can be used for routine analysis of marketed products of Sildenafil and Duloxetine in combined tablet formulation