The impact of impurities in various crude A. annua extracts on the analysis of artemisinin by liquid chromatographic methods

Pilkington, Josh L.; Preston, Chris; Gomes, Rachel L.

Abstract

Analysis of Artemisia annua extracts by liquid chromatographic methods has traditionally been complicated by the presence of significant quantities of impurities. It has been observed that these impurities often remain as a solid residue after sample reconstitution, but the possibility of artemisinin remaining entrained within this waxy layer has not been detailed in the literature. This investigation found that A. annua extract impurities have a critical impact on the quantification of artemisinin by liquid chromatographic methods. Extended sample reconstitution times of up to 24 hours are required in order for the mobile phase (acetonitrile) to penetrate the residue and solubilise the artemisinin contained within.

Extracts produced using ethyl acetate, hexane-ethyl acetate (95:5, v/v), hexane and ethanol were examined in the study. Extended residue reconstitution times resulted in a significant increase in the number and concentration of impurities in the mobile phase, requiring the development of a new HPLC-UV analytical method to exact adequate separation of artemisinin for quantification. The solvent selectivity and capacity for each of the solvent extraction approaches was then determined using the new reconstitution and HPLC-UV methods.

Citation

Pilkington, J. L., Preston, C., & Gomes, R. L. (2012). The impact of impurities in various crude A. annua extracts on the analysis of artemisinin by liquid chromatographic methods. Journal of Pharmaceutical and Biomedical Analysis, 70, 136-142. https://doi.org/10.1016/j.jpba.2012.06.015

• Journal Article Type: Article
• Acceptance Date: Jun 10, 2012
• Online Publication Date: Jun 18, 2012
• Publication Date: 2012-11
• Deposit Date: Mar 13, 2013
• Publicly Available Date: Mar 13, 2013
• Journal: Journal of Pharmaceutical and Biomedical Analysis
• Print ISSN: 0731-7085
• Electronic ISSN: 1873-264X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 70
• Pages: 136-142
• DOI: https://doi.org/10.1016/j.jpba.2012.06.015
• Keywords: Artemisia annua, Artemisinin, Extract Reconstitution, HPLC-UV, Malaria, Selectivity
• Public URL: https://nottingham-repository.worktribe.com/output/1009123
• Publisher URL: http://dx.doi.org/10.1016/j.jpba.2012.06.015
• Additional Information: NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Pharmaceutical and Biomedical Analysis. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Pharmaceutical and Biomedical Analysis, 70, (2013), 136-142. doi: 10.1016/j.jpba.2012.06.015