Search

Capecitabine is a prodrug of 5-fluorouracil, employed as a monotherapy or combination chemotherapy agent for treatment of colorectal cancer. Combination therapy of capecitabine consists of oxaliplatin, and hence, it becomes essential to determine that co-administration does not affect its metabolism. High-performance liquid chromatography and high-performance thin-layer chromatography methods were developed and validated to determine the plasma concentration of capecitabine. In this study, blood samples from 12 patients with colorectal cancer were collected and analyzed by both methods with a reference internal standard. Two groups consisting of six patients each were formed: the first group was treated with capecitabine monotherapy, the second group with capecitabine + oxaliplatin combination therapy. The results of analysis from both the methods indicated that there is no significant drug-drug interaction. The co-administration of oxaliplatin did not affect the metabolism of capecitabine. Both assay methods were compared for their sensitivity, robustness and specificity. It was found that both the assay methods were suitable for therapeutic drug monitoring of capecitabine., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

A rapid, sensitive and selective high-performance thin-layer chromatography (HPTLC) method was developed and validated for the determination and pharmacokinetics of pirfenidone in rat serum. One-step protein precipitation by methanol is reported, and serum samples were separated by HPTLC using a simple mobile phase of toluene-methanol in the ratio of 8:2. The retardation factor of pirfenidone in the serum sample was 0.45 with the detection performed at 315 nm. The calibration curve was linear over the range of 100-1,200 ng/spot with a lower limit of quantitation of 40 ng/spot. The mean recovery of pirfenidone in serum was in the range of 70.6-75.8%, and intra-day and inter-day precision were both <14.1%. This method was successfully applied to the pharmacokinetic study of pirfenidone in rats on oral administration of the drug at a dose of 15.0 mg/kg., (© The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)