Foam fractionation in recovery of captopril

Abstract

Toxic effect caused due to the presence of pharmaceuticals in waste water has been recognized as one of the emerging issue in the presentday environmental pollution. The aim of the present work is to investigate the feasibility of foam fractionation technique in batch mode for the recovery of captopril from dilute aqueous solution and to compare the performance of drug recovery from two feed solutions, one containing pure drug and the other containing formulated drug (tablet). Captopril is an anionic compound used as antihy- pertensive drug. Presence of this drug can cause aquatic toxicity. The performance of recov- ery was investigated as a function of gas velocity, pH of feed solution, collector-colligend ratio (j), colligend (drug) concentration, feed volume, column height and aliphatic chain length of the collector (surface active agent) and finally, optimum condition had been deter- mined. Percentage recovery was enhanced to 90% (approx) for pure drug at the optimum pH value of 3.75, j = 4 at an optimum gas velocity. The optimum gas velocity depends on feed volume. Percentage recovery (Rp) decreases with increase of chain length. Enrichment ratio (Er) was enhanced with the increase of foam height in the column. Rp and Er were found lower in formulated type of captopril in comparison to the pure drug due to the presence of other soluble ingredients in tablet.