ABSTRACT
BACKGROUND & OBJECTIVES: Resistance to conventional antimalarials triggered off new policies to circumvent the devastating consequences of malaria especially in the trans-Saharan Africa. The use of artemisinin-based combinations as first line drug in treatment of uncomplicated malaria was then advocated and adopted by the World Health Organization (WHO). In Nigeria, this new policy has witnessed a surge in the number of circulating brands of such combinations. Unfortunately, at present, there are no "on-the-spot" cheap and reliable assay procedures for artesunate-based combinations. This is what the present research aims to achieve. METHODS: Ultraviolet absorption spectroscopy was used to establish the wavelength of maximum absorbance for pure powder of artesunate and then the Beer's plot generated. This was validated and used to assay nine brands (X1-X9) of artesunate in Nigerian drug market. RESULTS: Distinctive ultraviolet absorption at 287 nm of pure sample of Artesunate in simulated intestinal fluid (SIF) afforded a simple, precise and the most reliable method for the analysis of nine different brands of Artesunate marketed in Nigeria. SIF does not have any appreciable absorption in the ultraviolet region. This simple method yielded a Beer's plot for Artesunate with high correlation (R2) of 0.9972 +/- 0.00016 and was reproducible. The Beer's plot was obeyed in concentration range of 10-200 mg%. The limits of detection (sensitivity) and quantitation were found to be 0.471 mg/ml and 1.27 mg/ml respectively. The results showed that only four out of the nine brands assayed had deviations from label claims that were within acceptable limits. INTERPRETATION & CONCLUSION: Based on these convincing data, simple ultraviolet spectroscopy at 287 nm could be used to assay artesunate in formulations.
Subject(s)
Antimalarials/analysis , Artemisinins/analysis , Dosage Forms , Nigeria , Reproducibility of Results , Spectrophotometry, UltravioletABSTRACT
BACKGROUND & OBJECTIVES: The availability of numerous brands of artesunate in our drug market today places clinicians and pharmacists in a difficult situation of choice of a suitable brand or the possibility of alternative use. The aim of the present study was to predict the bioequivalence of nine brands of artesunate tablets marketed in Nigeria using in vitro tests. METHODS: The in vitro dissolution study was carried out on the nine brands of artesunate tablets using the basket method according to US Pharmacopoeia (USP) guidelines. Other general quality assessment tests like hardness and disintegration time were also determined. RESULTS: All the brands tested passed the British Pharmacopoeia (BP) standard for disintegration time. Only AT2, AT4, AT6 and AT9 passed the standard for hardness. There were significant differences in the dissolution profiles of the nine brands. All the brands except AT1, however, released >70% of artesunate within 30 min. Four of the brands AT5, AT6, AT7 and AT8 exhibited >90% dissolution in <10 min. The other brands AT1, AT2, AT3, AT4 and AT9 (innovator brand) have calculated similarity factors of 23.8, 59.8, 50, 54.8 and 100. INTERPRETATION & CONCLUSION: Based on the in vitro tests, AT5, AT6, AT7 and AT8 are considered bioequivalent and interchangeable, while AT2, AT3 and AT4 are considered bioequivalent and interchangeable with the innovator brand (AT9). AT1 has very low dissolution rate, which will likely result in poor bioavailability. The results show the need for constant monitoring of new brands of artesunate introduced into the drug market to ascertain bioequivalence and conformity with pharmacopoeia standards.
Subject(s)
Antimalarials/chemistry , Artemisinins/chemistry , Biological Availability , Chemistry, Pharmaceutical , Humans , Models, Biological , Nigeria , Sesquiterpenes/chemistry , Solubility , Tablets/chemistry , Therapeutic EquivalencyABSTRACT
Starch obtained from Dioscorea dumetorium was employed as a disintegrant in Sodium Salicylate based tablets at concentrations of 5 -15w/w. Properties of the starch evaluated include: bulk and tapped densities; water uptake by capillarity; Hausner's quotient and percent compressibility. Compound tablets were evaluated for hardness; friability; disintegration time and dissolution rate. Batches of tablets containing equivalent concentrations of AC-di-sol or maize starch were employed as standards. Results obtained indicate that Dioscorea dumetorium starch performed as much better as a disintegrant in sodium salicylate tablets as maize starch but less than Ac-di-sol