HPTLC Method Development and Validation for the Simultaneous Estimation of Diosgenin and Levodopa in Marketed Formulation

The stationary phase silica gel G60F254 was selected for separation and the sample was developed using a mixture of Toluene:Ethyl acetate:Formic acid:GAA in the ratio 2:1:1:0.75 v/v as mobile phase. Quantification was carried out at 194 nm for Diosgenin and 280 nm for Levodopa using absorbance reflectance mode. The Rf value of Levodopa and Diosgenin was found to be 0.27+0.2 and 0.61+0.2 respectively. Linearity was found to be in the concentration range of 100 to 700 ng/spot of Levodopa and 600 to 1800 for Diosgenin the correlation coefficient value is 0.9954 and 0.9934. The results of analysis were validated in terms of accuracy and precision. The LOD was found to be 1.03 ng and 5.69 ng of Levodopa and Diosgenin respectively. LOQ was found to be 3.14 ng and 17.25 ng/spot of Levodopa and Diosgenin respectively. The content uniformity test was carried out as per the USP specification. The proposed HPTLC method provides a faster and cost effective quantitative control for routine analysis of Levodopa and Diosgenin.