European Journal of Biomedical and Pharmaceutical Sciences

AN IN VITRO RELEASE STUDY OF DRUG – DRUG INTERACTION BETWEEN LUMEFANTRINE AND AMOXICILLIN

Chioma Nnennaya Chinaka*, Nkemakolam Nwachukwu, Chinedum Peace Babalola

ABSTRACT

An in vitro investigation of the drug – drug interaction between a commercial brand each of an artemisinin combination therapy (ACT) antimalarial (Sample A) containing 120 mg Lumefantrine (LMF) and 20 mg Artemeter (ATM) tablet and an antibiotic, amoxicillin (Sample B), containing 500 mg amoxicillin trihydrate (AMO) capsules on the drug release profile of LMF and AMO by dissolution studies was conducted. Lumefantrine release profile was conducted in fresh preparations of the following media (a) a surfactant, 1% w/v benzalkonium chloride (BZK) in 0.1 M Hydrochloric acid, HCl (pH 1.63) and (b) 1% w/v BZK and AMO in 0.1 M HCl . Amoxicillin release profile was conducted in medium of (a) 0.1 M HCl (pH 1.5), (b) 1% w/v BZK in 0.1 M HCl and (c) LMF and 1% w/v BZK in 0.1 M HCl. USP II method for dissolution testing was used. Reverse Phase Liquid Chromatography (HPLC) was used in analysis of withdrawn drug samples. Results show a three fold release of AMO in media containing 1% w/v BZK and 0.1 M HCl than in 0.1 M HCl alone. A similar result was obtained in the medium containing LMF and 1% w/v BZK and this can be attributed to the presence of the surfactant. The HPLC retention time was higher for LMF (7.13 min) than AMO (1.21 min). Lumefantrine release was significantly reduced in amoxicillin (25.02%) at the time for 30% of drug release (T30) while there was an increment of 16.32% at T50 (time for 50% drug release) suggesting the existence of a non time dependent interaction between LMF and AMO. However the level of interaction could not be ascertained in the presence of the 1% w/v BZK.

Keywords: Lumefantrine, amoxicillin, surfactant, drug – drug interaction, dissolution studies, USP (United States Pharmacopoeia).