Simultaneous estimation of chlorthalidone and efonidipine hydrochloride in bulk and tablet dosage form.

Chlorthalidone and efonidipine hydrochloride are anti-hypertensive agents with different mechanisms of action. These drugs are generally used as monotherapy; however, recent study suggests their use in combination reduces the mortality rate. Based on this evidence, Zuventus Healthcare limited developed a combination dosage (Efnocar Ct) which has been recently approved for its use. Hence, a new, sensitive, precise and robust method was developed and validated to determine the purity of the compounds in bulk as well as tablet dosage forms. The HPLC analysis was achieved on Zobrax 150 column using acetonitrile and ammonium formate (60:40% v/v) as the mobile phase and the detection was achieved at a λ max of 248nm. The linearity was achieved between the concentration range of 3µg/ml - 18µm/ml for chlorthalidone and 10µg/ml - 60µg/ml concentration range for efonidipine hydrochloride. The % recovery for chlorthalidone was 100.03% and that for efonidipine was 100.24%, indicating the method to be accurate. The LOD and LOQ values for chlorthalidone was 0.01µg/ml and 0.02µg/ml and for efonidipine it was 0.26µg/ml and 0.88µg/ml. This indicates the sensitivity of the method. Robustness studies have shown no significant variations and degradation studies have shown acceptable results. The results of the proposed method for linearity, accuracy, sensitivity and robustness were within the acceptable limits. [ABSTRACT FROM AUTHOR]