In vitro study of the interaction between artemether-lumefantrine and ciprofloxacin/metronidazole

This study investigated the in vitro interactions between artemether-lumefantrine and ciprofloxacin or metronidazole in their co-administration. Commercial brands of artemether-lumefantrine, ciprofloxacin and metronidazole tablets were evaluated for some physical properties such as organoleptics, dimensions, weight uniformity, crushing strength and friability. The effects of their interactions on the disintegration times and drug release profiles of artemether-lumefantrine, metronidazole, and ciprofloxacin tablets were investigated. Interaction studies using Fourier transform infra-red (FTIR) analysis were also carried out. All the commercial brands of tablets used in the study met BP specifications in their weight uniformity, friability (≤ 1.0%), and crushing strengths (5.0 – 12.0 kgF). There was no significant (p ≥ 0.05) effect on the disintegration times of artemether-lumefantrine tablet in the presence of ciprofloxacin or metronidazole and vice versa. However, there was significant (p ≤ 0.05) retardation of artemether-lumefantrine release in the presence of ciprofloxacin or metronidazole. FTIR analysis showed no appreciable shift in spectral bands of artemether-lumefantrine in the presence of ciprofloxacin or metronidazole. The in vitro interaction between tablet formulations of artemether-lumefantrine and ciprofloxacin or metronidazole and vice versa, showed that a more drug release retardation is seen between artemether-lumefantrine and metronidazole than with ciprofloxacin and these changes in drug release indicated an absorption interaction, possibly due to alteration in gastric pH.