Abstract:
A simple accurate and precise UV Spectroscopic (Simultaneous Equation Method) and
Stability Indicating HPLC methods were developed and validated for simultaneous
estimation of Nifedipine and Candesartan cilexetil in Synthetic Mixture. In Simultaneous
Equation Method, drugs were determined by Absorptivity values of NIF and CAN at selected
wavelength of 235nm and 255nm respectively. The Linearity range was found to be 6-
21μg/ml and 3.2-11.2μg/ml for NIF and CAN respectively. The correlation coefficient of
NIF and CAN was found to be 0.999 and 0.998 respectively. The Stability Indicating HPLC
method has shown adequate separation of NIF and CAN in Synthetic mixture. The separation
was achieved on Column Phenomenex Luna C18 (250mm X 4.6mm, i.d.5μm particle size)
with mobile phase of Methanol: Phosphate Buffer (pH-4) in the ratio of (65:35v/v). The flow
rate was 1.0ml/min and detection wavelength was 240nm. The retention time for NIF and
CAN was obtained 4.313min and 8.116min respectively. The linearity of the proposed
method was in the range of 6-18μg/ml and 3.2-9.6μg/ml for NIF and CAN respectively.
Correlation coefficient was 0.999 and 0.998 for NIF and CAN respectively. The method was validated as per ICH Q2(R1) guidelines and acceptance criteria for linearity, recovery,
precision, and robustness. The Forced degradation study was carried out as per ICH guideline
under acidic, basic, oxidative, thermal and Photolytic conditions. All peaks of degraded
product were resolved from the drug with different retention time effectively, as it employed
as a stability indicating one.
