Pharmacokinetic study on the mechanism of interaction of sulfacetamide sodium with bovine serum albumin: a spectroscopic method.

The binding of sulfacetamide sodium (SAS) to bovine serum albumin (BSA) was investigated by spectroscopic methods, namely fluorescence, FT-IR and UV-vis absorption spectral studies. The binding parameters were evaluated by a fluorescence quenching method. The thermodynamic parameters, DeltaH(0), DeltaS(0)and DeltaG(0) were observed to be -49.03 k J mol(-1), -99.9 J K(-1) mol(-1) and -18.96 k J mol(-1), respectively. These indicated that the hydrogen bonding and weak van der Waals forces played major roles in the interaction. Based on Förster's theory of non-radiation energy transfer, the binding average distance, r, between the donor (BSA) and acceptor (SAS) was evaluated and found to be 3.72 nm. The spectral results showed that binding of SAS to BSA induced conformational changes in BSA. The effect of common ions and some of the polymers used in drug delivery for controlled release were also tested on the binding of SAS to BSA.