ESTIMATION OF IPRATROPIUM BROMIDE BY EXTRACTION FREE SPECTRO-PHOTOMETRIC METHOD USING SULPHONAPTHALEIN DYEAbstract
The present paper portrays a simple, rapid, nonextractive spectrophotometric method for the estimation of an anticholinergic drug, Ipratropium Bromide. The method is based on the formation of an instantaneous stable yellow colored ion pair complex of drug with a chloroformic solution of reagent Bromophenol Blue (BPB) which shows absorption maxima at 416 nm. Job’s plot of continuous variation affirmed the development of 1:1 complex between drug and reagent. The optical parameters were optimized, and the calibration curve was found to be linear in the range of 10 µgmL-1 to 80 µgmL-1. The detection limit was found to be 2.75 μg mL-1 with Sandell’s sensitivity 0.083 μgcm-2. Stability constant (log Kf) was calculated as 6.6. Molar absorptivity was found to be 4.29 × 103 L mol-1 cm-1 with Gibb’s free energy change of – 3.1 × 104 kJ mol-1. The method was validated as per ICH guidelines and had many advantages like low detection limits, high sensitivity and not requiring adjustment of critical conditions, thus paving the way for the application of the proposed methods in routine quality control evaluation.
S. M. Raj and V. G. Jamakandi *
KLE University’s College of Pharmacy, Vidyanagar, Hubballi, Karnataka, India.
27 January 2019
10 May 2019
14 June 2019
01 October 2019