Ranjith Kumar

The aim of the present work was to develop and validate a simple and efficient method for the analysis of Ambrisentan in pharmaceutical dosage forms by reverse phase high pressure liquid chromatography. A stainless steel column 150 mm long, 4.6 mm internal diameter filled with octasilyl silica chemically bonded with silica gel particles of 5 mm diameter was used for elution. The retention time of Ambrisentan was 4.451 min. The method showed a good linearity in the concentration range of 12.5-250 µg/mL with a correlation coefficient of 1.000. The validation characteristics included specificity, linearity, limit of detection, limit of quantification, precision, robustness and stability. Validation acceptance criteria were met in all cases. The method could be successfully used for the analysis of Ambrisentan in pharmaceutical dosage forms.

In the present investigation efforts were made to develop Misoprostal loaded microspheres to obtain a desirable drug release profile by Ionic gelation method using hydrophilic polymers and cross linking agent to decrease the gastric irritation and to enhance the drug penetration. Microspheres were prepared by using sodium alginate and calcium chloride in different ratios.  All the microspheres were evaluated for particle size, percentage yield, drug entrapment efficiency, stability studies and for in vitro release kinetics and found to be within the limits. Among all the formulations S7 was selected as optimized formulation based on the physico chemical properties and drug release studies. In vitro drug release study of formulation S7 showed 97.17% drug release up to 12h in a controlled manner, which is essential for an anti ulcer therapy. The innovator Misoprostal marketed product shows the drug release of 95.23 in 1 h. The drug release of optimized formulation S7 followed zero order release and Higuchi kinetics indicating diffusion controlled drug release. FT- IR study showed no drug excipient interaction takes place.