HPLC detection of plasma concentrations of diclofenac in human volunteers administered with povidone-ethylcellulose-based experimental transdermal matrix-type patches.

By developing a high-performance liquid chromatography (HPLC) method, we estimated the blood concentrations of diclofenac in human volunteers administered with the transdermal patches prepared with povidone-ethylcellulose and oral diclofenac tablets. Drug-excipient interaction studies were done using the FTIR technique. The external morphology of the prepared patch before and after application to human skin was analyzed with scanning electron microscopy. FTIR studies revealed that there was no predominant interaction between the drug and polymers. In vivo studies revealed that the average concentrations of drug in plasma were 376, 1562, 2953, 2902, 2864, and 2948 ng/ml after 2, 4, 8, 24, 30, and 48 h from patches each containing 50 mg of diclofenac diethylamine, respectively, and the mean concentrations of drug in plasma after the oral administration of marketed tablet containing 50 mg diclofenac sodium were 383.7, 2569, 3693.5, 162.5, and 55.3 ng/ml at 2, 4, 8, 24, and 30 h after oral administration. Values of Cmax were 3693.5 after oral administration and 2953.8 ng/ml in the case of transdermal application. From this study, we have achieved the sustained blood level of diclofenac from the experimental patches along with an analytical method based on HPLC to determine the diclofenac blood level. Copyright 2006 Prous Science.