Glycation alter serum albumin binding of valsartan and nateglinide when studied contemporarily

In this research work, an attempt was made to study alteration in glycated serum albumin binding of valsartan and nateglinide using validated HPLC-UV method and ultrafiltration as in vitro protein binding study model. The chromatographic conditions involved stationary phase Kromasil-100 C18 (100?×?4.6?mm, 3.5?µm) with mobile phase of 10?mM phosphate buffer, acetonitrile, isopropyl alcohol in the ratio of 30:65:5 as isocratic mode at a flow rate of 0.8?mL/min; and the eluent was monitored at 218?nm. Protein precipitation technique was used to extract the drugs from human plasma. The calibration curve was found linear in the range from 50 to 5000?ng/mL. Glycation of human serum albumin was achieved at different concentration levels using D-(+)-glucose and glycated human serum albumin (Gly-HSA) were prepared. Valsartan and nateglinide were not affected the plasma protein binding of each other when studied using HSA. The unbound fraction of valsartan and nateglinide was increased to 10–20 times when spiked with Gly-HSA. About 20% increase in unbound fraction of valsartan was observed when spiked with 10?µg/mL of nateglinide. Furthermore, the unbound fraction of nateglinide was increased nearly to 10% more when incubated with Gly-HSA as compare to recombinant human serum albumin.