Simultaneous Determination of Telmisartan and Amlodipine Besylate in Tablet Dosage form by Spectrophotometry S. Angayer Kanchana, Ajithadas Aruna, V. Niraimathi and A. Jerad SureshSimultaneous Determination of Telmisartan and Amlodipine Besylate in Tablet Dosage form by SpectrophotometryAuthor(s): S. Angayer Kanchana, Ajithadas Aruna, V. Niraimathi and A. Jerad Suresh
Two new simple, accurate and precise spectrophotometric methods have been developed for simultaneous determination of telmisartan and amlodipine in pharmaceutical dosage form. The methods employed were absorbance correction method (Method A) and dual wavelength method (Method B). The method A employs wavelength 350.4 nm for direct estimation of amlodipine where telmisartan shows nil absorbance. Estimation of telmisartan is carried out after correction for absorbance of telmisartan at 239 nm. In method B, amlodipine was determined by plotting the difference in absorbance at 247.4 and 299 nm (difference is zero for telmisartan) against the concentration of amlodipine. Similarly, for the determination of telmisartan, the difference in absorbance at 226 and 248 nm (difference is zero for amlodipine) was plotted against the concentration of telmisartan. Both the drugs obey the Beer’s law in the range 5-50µg/mL for amlodipine at 239 nm and 5-40 µg/mL at 350.4 nm and 5-35 µg/mL for telmisartan at 239 for Method A, and 5-50 µg/mL for amlodipine and 5-30 µg/mL for telmisartan for Method B. The results of analysis have been validated statistically and by recovery studies.