Author(s)

R. K. Bhogadi^1*, A. Satyanarayana², N. Someswara Rao³, Srinivas Arutla¹, A. Malleswara Reddy¹

¹Dr. Reddy’s Laboratories Ltd., IPDO, Bachupally, Hyderabad, India.
²Department of PNCO, Andhra University, Visakhapatnam, India.
³Department of Inorganic and Analytical Chemistry, Andhra University, Visakhapatnam, India.

A single RP-HPLC method is developed for estimation of isomeric impurities of vitamin D₃ analogue-Calcipotriol/Calcipotriene (Calci) and impurities of Betamethasone dipropionate (BD). The developed method is capable of separating impurities of Calci and BD, specifically pre-Calcipotriene (Pre-Calci) from other known and unknown impurities. Pre-Calci is isolated and is characterised using few analytical techniques. These impurities are separated using a RP-C₁₈ 150 × 4.6 mm, 2.7 μm column maintained at 50°C. The mobile phase consisted of mixture of water, methanol, acetonitrile and tetrahydrofuran eluted in gradient mode. Detection was done at 264 nm and 240 nm for Calci and BD impurities respectively. The method can be used for determining quality of Calci and BD drugs and ointment based drug products. It is stability indicating related substance method for both the drugs and drug products.

Calcipotriene, Pre-Calcipotriene, HPLC, Photo Isomers, Ointment

Bhogadi, R. , Satyanarayana, A. , Rao, N. , Arutla, S. and Reddy, A. (2015) Stability Indicating RP-HPLC Method for Estimation of Impurities of Vitamin D₃ Analogue and Corticosteroid Used as Antipsoriatic Drugs. An Attempt to Characterize Pre-Calcipotriene. American Journal of Analytical Chemistry, 6, 1050-1058. doi: 10.4236/ajac.2015.613100.