Abstract
Background: In recent years, the use of generic drugs has been increasing due to their effectiveness and to the increasing variety of drugs that are now available in generic formulations. Although several generic oral formulations of azithromycin are available in China, information concerning the bioavailability of these formulations in the Chinese population is unavailable.
Objective: The purpose of this study was to compare the bioequivalence and tolerability of a single oral dose of 2 commercial brands of 500-mg azithromycin granules in healthy Han Chinese volunteers.
Methods: In a randomized, open-label, 2-period crossover study, the bioequivalence and tolerability of 2 commercial formulations of azithromycin granules (test: Dayin Ocean Biochemical Company Ltd., Shandong, China; reference: Taiyang Drug Company Ltd., Beijing, China) were compared in healthy adult Han Chinese volunteers. Both the test and the reference formulations were administered to each subject. The 2 treatment phases were separated by a 3-week washout period. Liquid chromatography-tandem mass spectrometry was used to determine plasma drug concentrations. The formulations were considered bioequivalent if the natural log-transformed ratios of Cmax and AUC were within the predetermined equivalence range of 70% to 143% and 80% to 125%, respectively, and if P ≤ 0.05 for the 90% CIs.
Results: Twenty-four male Han Chinese volunteers (mean [SD] age, 21.0 [2.0] years [range, 18-25 years]; mean [SD] weight, 67.6 [5.6] kg [range, 56-81 kg]; mean [SD] height, 176.0 [5.0] cm [range, 165-188 cm]) were enrolled. Twenty-two subjects completed the study, with 2 withdrawing for personal reasons. No period or sequence effect was observed. The 90% CIs for the corresponding ratios of Cmax, AUC from hour 0 to time t, and AUC from hour 0 to any time point were 85.9 to 103.9, 83.6 to 106.0, and 84.7 to 105.9 (in the 2 one-sided t tests; all, P < 0.05), respectively. Similar results were found in data without a logarithmic transformation. There were no significant differences in the plasma concentration-time curves of the test and reference formulations. No adverse events were reported by the subjects or revealed by clinical or laboratory tests.
Conclusions: Single oral doses of 2 commercial brands of azithromycin granules (500 mg) were equivalent with regard to the rate and extent of absorption among these healthy Han Chinese volunteers. Both formulations were well tolerated.
Key words: bioequivalence, pharmacokinetic parameters, azithromycin, Han Chinese volunteers, mass spectrometry
Full Text
The Full Text of this article is available as a PDF (509.4 KB).
References
- 1.Kremer CJ. Azithromycin—a new macrolide. Prim Care Update Ob/Gyns. 2002;9:174–175. [Google Scholar]
- 2.Kanfer I, Skinner MF, Walker RB. Analysis of macrolide antibiotics. J Chromatogr A. 1998;812:255–286. doi: 10.1016/s0021-9673(98)00276-3. [DOI] [PubMed] [Google Scholar]
- 3.Ferrara A, Dos Santos C, Cimbro M, Gialdroni Grassi G. Comparative antimicrobial activity and post-antibiotic effect of azithromycin, clarithromycin and roxithromycin against some respiratory pathogens. Int J Antimicrob Agents. 1996;7:181–186. doi: 10.1016/s0924-8579(96)00320-2. [DOI] [PubMed] [Google Scholar]
- 4.Wyrick PB, Davis CH, Knight ST, Choong J. In-vitro activity of azithromycin on Chlamydia trachomatis infected, polarized human endometrial epithelial cells. J Antimicrob Chemother. 1993;31:139–150. doi: 10.1093/jac/31.1.139. [DOI] [PubMed] [Google Scholar]
- 5.SiChuan Drug Safe Credit network . Azithromycin came into buffer area. 2007. http://www.credit-scda.net. Accessed May 15. [Google Scholar]
- 6.Portoles A, Terleira A, Almeida S. Bioequivalence study of two formulations of enalapril, at a single oral dose of 20 mg (tablets): A randomized, two-way, openlabel, crossover study in healthy volunteers. Curr Ther Res Clin Exp. 2004;65:34–46. doi: 10.1016/S0011-393X(04)90003-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.State Food and Drug Administration (SFDA) Guidance for bioavailability and bioequivalence studies of chemicals. 2005. http://www.sda.gov.cn/gsz05106/08.pdf. Accessed March. [Google Scholar]
- 8.US Food and Drug Administration . Definition of bioequivalence. 2007. http://www.fda.gov/cder/ogd/02-10_BCBS_gjb/sld028.htm. Accessed May 2. [Google Scholar]
- 9.Pineyro-Lopez A, Pineyro-Garza E, Torres-Alanis O. Bioavailability of two oral formulations of azithromycin 500 mg: A randomized, open-label, two-period crossover comparison in healthy Mexican adult subjects. Clin Ther. 2005;27:1607–1611. doi: 10.1016/j.clinthera.2005.10.002. [DOI] [PubMed] [Google Scholar]
- 10.Ferrante L, Bompadre S, Cingolani ML. Bioavailability study of two different formulations of azithromycin. Curr Ther Res Clin Exp. 1996;57:288–298. [Google Scholar]
- 11.Bahrami G, Mirzaeei S, Kiani A. High performance liquid chromatographic determination of azithromycin in serum using fluorescence detection and its application in human pharmacokinetic studies. J Chromatogr B Analyt Technol Biomed Life Sci. 2005;820:277–281. doi: 10.1016/j.jchromb.2005.03.042. [DOI] [PubMed] [Google Scholar]
- 12.Wilms E, Trumpie H, Veenendaal W, Touw D. Quantitative determination of azithromycin in plasma, blood and isolated neutrophils by liquid chromatography using pre-column derivatization with 9-fluorenylmethyloxycarbonyl-chloride and fluorescence detection. J Chromatogr B Analyt Technol Biomed Life Sci. 2005;814:37–42. doi: 10.1016/j.jchromb.2004.09.058. [DOI] [PubMed] [Google Scholar]
- 13.World Medical Association Declaration of Helsinki . Recommendations guiding medical doctors in biomedical research involving human subjects. WMA; Ferney-Voltaire, France: 1989. http://www.wma.net. Accessed September 10, 2004. [Google Scholar]
- 14.European Agency for the Evaluation of Medicinal Products, International Conference on Harmonisation-World Health Organization. Guideline for Good Clinical Practice [EMEA Web site]. ICH Topic E6. Geneva, Switzerland: WHO; 2002. 2002. http://www.emea.eu.int. Accessed July 15, [Google Scholar]
- 15.Chen BM, Liang YZ, Chen X. Quantitative determination of azithromycin in human plasma by liquid chromatography-mass spectrometry and its application in a bioequivalence study. J Pharm Biomed Anal. 2006;42:480–487. doi: 10.1016/j.jpba.2006.05.011. [DOI] [PubMed] [Google Scholar]
- 16.Nirogi RV, Kandikere VN, Shukla M. Sensitive and selective liquid chromatography-tandem mass spectrometry method for the quantification of azithromycin in human plasma. Analytica Chimica Acta. 2005;553:1–8. [Google Scholar]
- 17.US Food and Drug Administration (FDA). Guidance for industry: Bioavailability and bioequivalence studies for orally administered drug products—general considerations. 2003. [FDA Web site], http://www.fda.gov/cder/guidance/index/htm. AccessedNovember 1, [Google Scholar]
- 18.Schuirmann DJ. A comparison of the two one-sided tests procedure and the power approach for assessing the equivalence of average bioavailability. J Pharmacokinet Biopharm. 1987;15:657–680. doi: 10.1007/BF01068419. [DOI] [PubMed] [Google Scholar]
- 19.Vol. 2. 2005. Ministry of Public Health of the People's Republic of China; pp. 173–176. (Pharmacopoeia of the People's Republic of China (appendix)). [Google Scholar]
