Bulk Liquid Membranes for Separation and Recovery of Pharmaceutical Products

In this present paper the behavior of two important pharmaceutical compounds, namely: nicotinic acid (vitamin PP/B3) and para-aminobenzoic acid (vitamin B10) to the transport through a liquid membrane of chloroform containing Aliquat 336 have been studied. The influence of operational parameters such as: solute concentration in the feed phase, stripping agent concentration in the stripping phase, transport time was monitored. The assessment of the obtained results allowed establishing of optimal transport conditions as well as identification of a kinetic transport model for nicotinic acid corresponding to consecutive irreversible 1st order reactions. The maximum transport efficiency was 96% and it was obtained at a concentration of 10-4 mol/L nicotinic acid in the feed phase and a concentration of 1 mol/L sodium hydroxide in the stripping phase. The transport time necessary to achieve this efficiency was 6 h. The results obtained led to important conclusions regarding the possibility of separating these two compounds. Analytical control of the process was done spectrophotometrically. The maximum absorbance was obtained at their characteristic wavelengths, namely 262 nm for nicotinic acid and respectively 267 nm for para-aminobenzoic acid.