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/B) and para-aminobenzoic acid (vitamin B 3 10) 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
10-4mol/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.