Stability-indicating RP-HPLC method development and validation for simultaneous estimation of telmisartan and rosuvastatin calcium in bulk and in tablet dosage form

Background: The stability-indicating chromatographic method was developed and validated for simultaneous estimation of telmisartan and rosuvastatin calcium in bulk and in tablet dosage form. The RP-HPLC elution was carried out at 242.0 nm using column Oyster ODS3 (150 x 4.6 mm, 5 pm) isocratically, and a mobile phase containing 10 mM phosphate buffer with 1.1 g octane-1-sulfonic acid sodium salt having pH 2.5 (adjusted with 5% OPA) and acetonitrile, with a proportion of 500:500, v/v was pumped through the column maintained at ambient (about 25 degrees C) temperature with 1.0 mL/min flow rate. The proposed method was validated according to ICH Q2 (R1) guideline. Results: Telmisartan and rosuvastatin were eluted at 2.553 min and 4.505 min, respectively. The method is linear from 99.9073 to 299.7218 pg/mL for telmisartan (R-2 =1.000) and 23.6841 - 71.0522 pg/mL for rosuvastatin (R-2 = 0.999). The average recovery percentage was found 100.51, 99.76, and 99.14% for telmisartan and 99.68, 99.72, and 98.56% for rosuvastatin at three different levels. Results of method repeatability and intermediate precision were found within acceptable limits. Results of solution stability showed that mobile phase was stable for 2 days; standard and sample preparations are stable for 1 day at room temperature as well as in the refrigerator (2-8 degrees C). Also, forced degradation study results show that method is stability indicating as capable of distinguishing the active analytes peak from the degraded product. Conclusion: The developed stability-indicating method is linear in studied concentration range as well as precise, accurate, specific, and robust. Hence, successfully this method can be used for routine analysis and stability study.