Abstract
An enantioselective stability-indicating high performance liquid chromatographic method was developed for the analysis of arotinolol in standard solution. The degradation behaviour of arotinolol was investigated under different stress conditions recommended by International Conference on Harmonization (ICH). Resolution of the drug and complete separation from its degradation products were successfully achieved on a Chirobiotic V column, using UV detector set at 315 nm, polar organic mobile phase (POM) consisting of methanol:glacial acetic acid:triethylamine, 100:0.02:0.03, (v/v/v), and a flow rate of 1 ml/min. The drug was subjected to oxidation, hydrolysis, photolysis, and heat to apply stress conditions. The drug was found to degrade in alkaline, acidic, oxidative conditions and when exposed to heat. The drug was stable to sunlight. The method reported here has also been successfully applied to pharmaceutical formulation and to human plasma that spiked with stock solutions of arotinolol enantiomers.
Arotinolol enaniomers were recovered from plasma by using liquid liquid extraction procedure with ethyl ether. The method was highly specific, where degradation products and coformulated compounds did not interfere, and was sensitive with good precision and accuracy and was linear over the range of 50-400 ng/ml (R-2 > 0.9981) with a detection limit of 20 ng/ml for each enantiomer. The mean extraction efficiency for arotinolol was in the ranges 96-104% for each enantiomer. The mean relative standard deviation (RSD) of the results of within-day precision and accuracy of the drug were <= 7.1%. There was no significant difference between inter- and intra-day studies for each enantiomers which confirmed the reproducibility of the assay. The overall recoveries of arotinolol enantiomers from pharmaceutical formulations were in the ranges 97.6-101.8%. (C) 2010 King Saud University. All rights reserved.