Effects of Time of Administration and Posture on the Pharmacokinetics of Cefprozil

Abstract

The effects of time of administration, sleep and posture on the pharmacokinetics of cefprozil were evaluated in a single-dose 3-way crossover study. After a 6-hour fast, 12 healthy male volunteers received oral cefprozil 250mg at 1200h (treatment A), 1200h (treatment B) and 2400h (treatment C) with a 7-day washout interval between each treatment. During the study period, volunteers receiving treatment A remained in a sitting/standing position or were ambulatory, those receiving treatment B were in the supine position, and those receiving treatment C were sleeping. Blood samples were taken over an 8-hour period and the plasma samples were analysed for the concentrations of cefprozil by a high performance liquid chromatography-ultraviolet method. Plasma concentration vs time data were analysed using noncompartmental analysis methods. Mean peak plasma concentrations (Cmax) were 4.51, 5.02 and 4.91 mg/L for treatments A, B and C, respectively. Corresponding mean values of the area under the plasma concentration-time curve (AUC(0-infinity)) were 12.6, 12.6 and 14.2 mg/L.h, respectively. The mean half-life (t1/2) values were 1.30, 1.23 and 1.50 hours for treatments A, B and C, respectively. Mean AUC(0-infinity), Cmax and t1/2 values following treatment B were not significantly different from those of treatment A. However, the mean AUC(0-infinity) and t1/2 values of cefprozil following treatment C were significantly greater than those of either treatment A or B. The mean Cmax value following treatment C was not significantly different than that of either treatments A or B. From these results, it was concluded that posture has no effect on the pharmacokinetics of cefprozil.(ABSTRACT TRUNCATED AT 250 WORDS)

HPLC determination of cefprozil in tablets using monolithic and C18 silica columns

“…The explanation of this improvement was associated to the very low noise of the assays (about 0.25–0.50 mAU), which was interpreted as a total result of acetonitrile usage in mobile phase, high absorptivity of CPZ at 200 nm and avoiding use of buffers to maintain pH. In addition, literature search shows that 245 nm 31, 254 nm 24, and 280 nm 19, 20, 22, 25, 28–30 wavelengths were mainly preferred in UV‐based detections of CPZ. Method development studies exhibited that CPZ absorbs UV light about 79% less at 245 nm, 81% less at 254 nm, and 70% less at 280 nm when compared with 200 nm (Fig.…”

“…Being mostly focused on bioavailability and bioequivalency, the reported assays describe quantitative determination of CPZ in biological fluids such as breast milk 19, plasma 20, and middle ear fluid 21, 22, and in some pharmaceutical preparations such as tablets 23, 24 and oral suspensions 25. Within the methods used to determine CPZ, LC with MS 26–28 or UV 19, 20, 22, 24–25, 28–31 detection was popular. Among these, MS detection shows its superiority over UV detection in terms of specificity and detection limits because of unique capabilities such as multiple and selected reaction monitoring.…”