Benzathine penicillin G: a model for long‐term pharmacokinetic comparison of parenteral long‐acting formulations. (7th January 2013)

• Record Type: Journal Article
• Authors: Shahbazi, M. A.; Azimi, K.; Hamidi, M.
• Is Part Of: Journal of clinical pharmacy and therapeutics. Volume 38:Number 2(2013:Apr.)
• Page Start: 131
• Page End: 135
• Publication Date: 2013-01-07
• Subjects: Clinical pharmacology -- Periodicals; Chemotherapy -- Periodicals; 615
• DOI: 10.1111/jcpt.12014
• Languages: English
• ISSNs: 0269-4727

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Summary</title> <p> <bold>What is known and Objective: </bold> Long‐acting intramuscular penicillin G injection is an important product for the management of some severe infections. However, testing the bioequivalence of such long‐acting formulations is difficult. Our aim was to undertake such a test using a generic formulation containing 1 200 000 IU of benzathine penicillin G powder and an innovator's product (Retarpen<sup>®</sup> 1·2 million units; Sandoz, Switzerland).</p> <p> <bold>Methods: </bold> In an open, double‐blind, randomized, two‐periods, two‐group crossover study, 12 healthy male volunteers received both formulations of benzathine penicillin G on two different days with a 5‐month washout period between the doses and a sampling period of over 500 h. A simple, sensitive and rapid high‐performance liquid chromatography (HPLC)‐UV method was developed and validated for determination of penicillin G plasma concentrations and other pharmacokinetic (PK) parameters.</p> <p> <bold>Results and Discussion: </bold> The analytical method used produced linear responses within a wide analyte concentration range with average within‐run and between‐run variations of below 15% with acceptable recovery, accuracy and sensitivity. The primary PK parameters we used were maximum plasma concentration (<italic>C</italic><sub>max</sub>), time to reach the maximal concentration (<italic>T</italic><sub>max</sub>) and the area under the plasma concentration vs. time curve from time zero to the last sampling time (AUC<sub>0→t</sub>) using a standard non‐compartmental approach. Based on these parameters, the two formulations were bioequivalent.</p> <p> <bold>What is new and Conclusion: </bold> We illustrate the bioequivalence testing of a very long‐acting product. The data indicate that the generic test formulation and the branded reference formulation were bioequivalent in fasting healthy Iranian male volunteers.</p> </abstract>