Pharmacokinetic and Bioequivalence Evaluation of Two Cefprozil Dispersible Tablets in Healthy Chinese Volunteers

This study aimed to assess the bioequivalence of 2 cefprozil dispersible tablet formulations (250 mg) in healthy Chinese volunteers under fasting and fed conditions and to determine the pharmacokinetics of cefprozil. A randomized, single-dose, open-label, 2-formulation, 2-period study was conducted. The elimination period for this study was 7 days. Forty-eight healthy volunteers received 250-mg cefprozil dispersible tablets in each study period under both test and reference conditions. The test and the reference cefprozil were bioequivalent in healthy Chinese volunteers, and there was no significant food effect in individuals receiving either formulation. No serious adverse event was recorded, and no volunteers withdrew from the study.

Population Pharmacokinetics of Cis-, Trans-, and Total Cefprozil in Healthy Male Koreans

Cefprozil, one of cephalosporin antibiotics, has been used extensively in clinics. However, pharmacokinetic (PK) information on cefprozil is still very limited. There have been no reports of population pharmacokinetics (PPKs). A PPK model for cefprozil will be a great advantage for clinical use. Thus, the aim of this study was to develop a PPK model for cefprozil for healthy male Koreans. Clinical PK and demographic data of healthy Korean males receiving cefprozil at a dose of 1000 mg were analyzed using Phoenix^® NLME™. A one-compartment model with first-order absorption with lag-time was constructed as a base model. The model was extended to include covariates that influenced between-subject variability. Creatinine clearance significantly influenced systemic clearance of cefprozil. The final PPK model for cis-, trans-, and total cefprozil was established and validated. PPK parameter values of cis- and total cefprozil were similar to each other, but different from those of trans-isomer. Herein, we describe the establishment of accurate PPK models of cis-, trans-, and total cefprozil for healthy male Koreans for the first time. It may be useful as a dosing algorithm for the general population. These results might also contribute to the development of stereoisomeric cefprozil.

Clinical Outcomes of Failing to Dose-Reduce Cephalosporin Antibiotics in Older Adults with CKD

BACKGROUND AND OBJECTIVES

Current dosing recommendations for cephalosporin antibiotics are on the basis of pharmacokinetic studies and are frequently ignored in practice. This study was undertaken to investigate the clinical outcomes of failing to dose-reduce cephalosporin antibiotics in CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Retrospective cohort study conducted in Ontario, Canada using linked population-based health care databases. Nine thousand three hundred forty-seven outpatients (median age 83; interquartile range, 77-88 years; 57% women) with an eGFR<30 ml/min per 1.73 m2 and no prior history of dialysis were dispensed oral cephalexin, cefuroxime, or cefprozil between April of 2007 and March of 2016. Two thirds of the patients (6253 of 9347) received a higher than recommended daily dose of cephalexin (>1000 mg), cefuroxime (>500 mg), or cefprozil (>500 mg). The primary outcome was a hospital encounter (emergency room visit or hospital admission) with a condition listed as a possible side-effect of cephalosporins. Secondary outcomes were antibiotic treatment failure and all-cause mortality. All measures were assessed in the 30 days after cephalosporin initiation.

RESULTS

Patients who received a higher than recommended dose of a cephalosporin antibiotic were similar in multiple indicators of baseline health to patients who received a reduced dose. Overall, 6% of patients presented to hospital with a possible cephalosporin side-effect, 13% failed antibiotic treatment, and 3% died. Compared with a reduced dose, receiving a higher dose of antibiotic was not associated with a different rate of side-effects (adjusted odds ratio, 1.00; 95% confidence interval, 0.84 to 1.20), treatment failure (1.01; 0.88 to 1.15), or death (0.99; 0.76 to 1.29).

CONCLUSIONS

In this study we failed to demonstrate any association between the dose of cephalosporin antibiotic administered to elderly patients with CKD and the risk of side-effects leading to hospitalization, treatment failure, or mortality.

An LC-MS/MS method for simultaneous determination of cefprozil diastereomers in human plasma and its application for the bioequivalence study of two cefprozil tablets in healthy Chinese volunteers

A rapid and sensitive liquid chromatography-tandem mass spectrometric method was developed for the first time and validated for the determination of cefprozil diastereomers in human plasma. The plasma samples were prepared by protein precipitation using acetonitrile. Detection was performed using an electronic spray ion source in the negative ion mode, operating in the multiple reaction monitoring of the transitions m/z 388.0 to m/z 205.0 for cefprozil diastereomers and m/z 346.1 to m/z 268.1 for cephalexin (the internal standard). The calibration curves of cis-cefprozil and trans-cefprozil were linear in the ranges 0.125-16.0 µg/mL and 0.0403-1.72 µg/mL, respectively. The lower limits of quantification of cis- and trans-cefprozil were 0.125 and 0.0403 µg/mL in human plasma, respectively. The intra- and inter-day precisions of cis- and trans-cefprozil were all <9.7%, and the accuracy ranged from 99.2 to 104.7% and from 100.6 to 102.2%, respectively. The validated method was successfully applied to a bioequivalence study of two cefprozil formulations in 24 healthy Chinese volunteers. The two cefprozil tablets were bioequivalent by measurement of cis-, trans- and total cefprozil. We suggest that the bioequivalence of cefprozil formulations can be evaluated only using cis-cefprozil as the analyte in future studies.

Spectrophotometric methods for the determination of cefprozil in bulk and dosage form

Two simple spectrophotometric methods were developed for the determination of cefprozil in pure bulk and in tablets forms. The first is a colorimetric method based on the coupling of cefprozil, after being hydrolyzed by sodium hydroxide (0.1N), with ascorbic acid as a chromogen (method A). It has been established that cefprozil reacts with ascorbic acid to form a 1:1 water soluble colored product with maximum absorbance (λmax) at 408 nm and molar absorptivity of 7.2 × 10(3)L mol(-1) cm(-1). The second method (Method B) utilizes a direct reaction between cefprozil and sodium hydroxide (1N). A colored product with λmax at 486 nm and molar absorptivity of 7.4 × 10(3) L mol(-1) cm(-1) is formed after heating cefprozil with sodium hydroxide (1N). The absorbance-concentration plot was rectilinear over the range 5-25 µg/ml in both methods with correlation coefficient values not less than 0.999. The detection limits (L.O.D.) were 0.96 µg/ml and 0.93 µg/ml for method A and method B respectively. The methods were validated using the USP liquid chromatography method for cefprozil assay. The results obtained by the USP liquid chromatography method for the tablets dosage form were statistically compared with those of the developed methods and evaluated at 95% confidence limits.