Dilip G. Maheshwari

A simple, accurate, and precise UV spectrophotometric method has been developed and validated for simultaneous estimation of Cilnidipine and Valsartan in synthetic mixture. The estimation of drugs was done by Second Order Derivative spectrophotometric method using 219 nm and 227 nm wavelength. Methanol was used as a solvent. The Linearity was obtained in the concentration range of 2-10 µg/ml for Cilnidipine and 5-25 µg/ml for Valsartan with R2 0.9994 and 0.9980 respectively. Accuracy was determined by recovery studies and showed % recovery between 98 to 102 % for both the drugs. The LOD and LOQ values of Cilnidipine were found to be 0.33 and 1.01 and for Valsartan values were found to be 0.18 and 0.55. The developed method was validated as per the ICH Guidelines Q2 (R1).

Simple, accurate and precise and economical UV–spectroscopy method have been developed and validated for the estimation of Tadalafil and Fluoxetine HCl in a synthetic mixture. Tadalafil is used in treatment of Erectile Dysfunction and Fluoxetine HCl is used in depression. The Tadalafil and Fluoxetine HCl stock solutions are prepared in methanol solution. At zero crossing point (ZCP) of Tadalafil (230nm) Fluoxetine HCl showed a measurable derivative absorbance, whereas at zero crossing point (ZCP) of Fluoxetine HCl (235nm) Tadalafil showed a appreciable derivative absorbance value. The Tadalafil and Fluoxetine HCl are linear in concentration range of 5-25 μg/ml. Developed method was validated according to the ICH Q2 (R1) guidelines. The precision were found within limits (RSD< 2%). Accuracy were determined by recovery studies and showed % recovery between 97 to 100 % for both the drugs Tadalafil and Fluoxetine HCl. The LOD and LOQ values of Tadalafil at ZCP 230 nm were found to be 0.24 and 0.74 correspondingly and for Fluoxetine HCl at ZCP235nm were found to be 0.29 and 0.89 correspondingly.

A simple, accurate, reliable and reproducible first order derivative method was developed for the simultaneous determination of Cefoperazone sodium (CEFO) and Tazobactam sodium (TAZO) in pharmaceutical formulation. The linearity was carried out by using the concentration range 5-50 µg/ml for CEFO (275.2 nm ZCP of TAZO) and 2-50 µg/ml for TAZO (225 nm ZCP of CEFO) respectively. The correlation coefficient of CEFO and TAZO was found to be 0.999 and 0.998 respectively. At zero crossing point (ZCP) of CEFO (225nm) TAZO showed a measurable derivative absorbance, whereas at zero crossing point (ZCP) of TAZO (275.20nm) CEFO showed a appreciable derivative absorbance value. Precision study showed that %RSD was within range of acceptable limits (< 2%). The % recovery for CEFO and TAZO was found to be within range of 98-101% and 98-102%respectively. The percentage assay was found to be 101.05% and 99.41% for CEFO and TAZO. The result of analysis has been validated as per ICH guideline. This method has applied successfully for determination of CEFO and TAZO in its pharmaceutical formulation.