Abstract
Bioequivalence studies of pharmaceutical preparations of medicinal endogenous substances are generally lacking, as the endogenous background is the main obstacle for both experimental design and drug analysis. We conducted a single-dose, self-control, 3-period crossover study to evaluate the bioequivalence of a sustained-release versus an immediate-release preparation of potassium citrate for the treatment of urinary tract stones. This study included a placebo period to monitor the dynamics of endogenous plasma citrate, which could therefore be subtracted during the data processing. Notably, a new convenient method for plasma citrate determination utilizing ultrafiltration extraction and direct reversed-phase high-performance liquid chromatography (HPLC) was successfully applied in the study after validation. To our knowledge, this is the first report using simple reversed-phase HPLC to analyze plasma citrate, and ultrafiltration also significantly simplified the plasma extraction procedure. HPLC was performed using an ODS column, with acetonitrile and 0.02 mol/l sulfuric acid (3:97 v/v) as the mobile phase and ultraviolet detection at 210 nm. Results showed linearity from 10 to 200 microg/ml, an extraction recovery of more than 90% and analysis variability within 15% for additive citrate. The concentration of dog endogenous plasma citrate was determined to be about 30-40 microg/ml. The sustained-release preparation was bioequivalent to the immediate-release preparation in terms of the extent of absorption, but it could not achieve full effects due to a tmax issue.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Methods and Findings in Experimental and Clinical Pharmacology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.