Polarographic behaviour and determination of acrivastine in capsules and human urine.

A sensitive method for the quantitative determination of acrivastine was developed based on the reduction of the drug at the dropping mercury electrode. A well-developed polarographic wave was produced in Britton-Robinson buffers over the pH range 0.0-11. The overall reduction process was diffusion-controlled with limited adsorption properties. At pH 5, the diffusion-current constant (I(d)) was 5.45+/-0.05 (n=9). The current versus concentration plot was linear over the range 1.2-20.0 and 0.4-12.0 mug/ml using the direct current tast (DC(t)) and differential pulse polarography modes, respectively, with a minimum detectability (S/N=3) of 0.03 mug/ml (8.6x10(-7) M) using the latter technique. The mechanism for the reduction was suggested and the number of electrons involved in the electrode reduction was established. The method was applied for the determination of acrivastine in capsules. Pseudoephedrine, which is frequently co-formulated with acrivastine, did not interfere with the assay. The method was also successfully applied to spiked human urine, the percent recovery (n=3) was 97.07 with a confidence limit (t.s.) of +/-2.33.