Simple, sensitive and specific spectrophotometric methods were developed and validated for quantization of enalapril and amlodipine in tablet dosage form. Three new analytical methods were developed based on the simultaneous estimation of drugs in a binary mixture without prior separation. In simultaneous equation method, the drugs were determined by using the absorptivity values of enalapril and amlodipine at selected wavelengths, viz., 209 and 238 nm, respectively. Second method is based on the determination of graphical absorbance ratio at two selected wavelengths; one being the isoabsorptive point for the drugs (219 nm) and the other being the absorption maximum of amlodipine (238 nm), in this method both the drugs obeyed the Beer-Lambert`s law in the concentration range of 6-18 Î¼g mL-1. The third method is based on the derivative spectrophotometric method at zero crossing wavelengths. These methods are simple, accurate and rapid and they require no preliminary separation and can therefore be used for routine analysis of both drugs in quality control laboratories.
Gopal Garg, Shailendra Saraf and Swarnlata Saraf, 2008. Development and Validation of Simultaneous Estimation of Enalapril Maleate and Amlodipine Besylate in Combined Dosage Forms. Trends in Applied Sciences Research, 3: 278-284.