chromatography

To develop rapid, rugged, precise and an accurate stability indicating analytical method for estimation of related substances in Ursodeoxycholic Acid tablets. The separation of impurities and Ursodeoxycholic Acid drug is achieved by an isocratic chromatographic method on C18, 250 mm x 4.6 mm, 5µm column. The mobile phase consists of buffer, acetonitrile and methanol in the ratio of 35:28:37 v/v/v pumped at a flow rate of 1.0 ml/minute 35:37:28v/v/v pumped at a flow rate of 1.0 ml/minute. The detection was carried out by using refractive index (RI) detector. The proposed chromatographic method was validated and found to be linear over the concentration range from LOQ to 150.0% of impurity limit level.  Overall mean recovery of Chenodeoxycholic acid impurity was found to be 100.6±4.0%w/w The method was found to be simple, stability indicating, precise, accurate and robust which can be utilized for estimation of related substances in Ursodeoxycholic Acid tablets

Screening and expression of protease producing 5 strains of Alternaria sp. were obtained from the various places in Chennai, Vellore, Tamilnadu, India. The isolates were positive on tyrosin caesin nitrate agar (1%) and thus are selected as protease producing strain. The microbial growth is revealed by the mycelial dry weight determination. Maximum growth is observed in the case of Alternaria tenuis (0.47 mg). Equally, the maximum growth is observed in Alternaria solani (0.45 mg). Total protein was determined using BSA as standard. Proteinase activity was estimated using casein as the substrate. Finally the enzyme protease was purified by column chromatography. The protein was characterized using SDS-PAGE. Maximum protein content is observed in the case of Alternaria triticola (0.902 mg) and Alternaria triticina (0.753 mg). Maximum proteinase content  is observed in Alternaria triticina  (0.591 mg). This results showed that microbes under study is a good producer of extra cellular protease, which can be beneficial for industries.