Determination of oxaprozin in human plasma with high performance liquid chromatography (HPLC) and its application / 生物医学工程学杂志

The present research was aimed to develop a high performance liquid chromatography (HPLC) method to determine oxaprozin in plasma and to evaluate the bioavailability of two oxaprozin enteric coated tablets. A C18 column was used to separate the plasma after protein precipitation and the mobile phase was methanol-12. 5mmol/L ammonium acetate buffer solution (pH=3.0)(71:29). The calibration curve was linear in the concentration range of 0. 50-70. 56 microg . mL-1, and the intra and inter-day RSDs were less than 12. 33% and 10. 42% respectively. A single dose of 0. 4 g reference preparation or test preparation of oxaprozin enteric coated tablets was administered to 20 healthy volunteers according to a randomized crossover study. AUC0-->264h were (4 917. 44 +/- 629. 57) microg . h . mL-1 and (4 604. 30+/-737. 83) microg . h . mL-1, respectively; Cmax were (52. 34+/-7. 68) microg . mL-1 and (48. 66+/-4. 87) microg . mL-1, respectively; Tmax were (18. 70+/-2.27) h and (19. 30+/-1. 63) h, respectively; The relative bioavailability of test preparation was 94.0% +/- 13. 7%. The method is simple, rapid and selective for oxaprozin determination. There is no significant difference in the main pharmacokinetic parameters between the test formulation and reference formulation and the two formulations are in bioequivalence.

Bioequivalence research of cyclosporin soft capsules / 生物医学工程学杂志

This paper is aimed to study the bioavailability and bioequivalence of Cyclosporin Soft Capsules (test preparation and reference preparation) in Chinese healthy volunteers. A high performance liquid chromatography-ultraviolet (HPLC-UV) method for determining the concentration of Cyclosporin A in human whole blood was developed and methodological validated. In accordance with the randomized two-period self crossover study, 24 volunteers received a single oral dose of 400 mg of test preparation or reference preparation. Multiple blood samples were collected post dose and then the concentration of Cyclosporin A in human whole blood samples was determined using the validated assay. The pharmacokinetic parameters including AUC0-t, Cmax, Tmax, and T1/2 were calculated using the non-compartmental method. The bioequivalence of the two preparations was evaluated. After receiving single dose of 400 mg of Cyclosporine A, the pharmacokinetic parameters of T1/2, Cmax, Tmax, and AUC0-t, of Cyclosporin A were (10.114 +/- 6.329) h and (9.717 +/- 4.076) h, (2021.235 +/- 298.581) ng x ml(-1) and (1992.192 +/- 1286.923) ng x ml(-1) (1.729 +/- 0.361) h and (1.813 +/- 0.323) h, (9824.811 +/- 1633.026) ng x h x ml(-1) and (10316.514 +/- 1395.955) ng x h x ml(-1) for test preparation and reference preparation, respectively. The statistical results suggested that these parameters were comparable between the two preparations. The results showed that the test preparation was bioequivalent with the reference preparation in healthy volunteers.