Buruli ulcer (BU) imposes a serious economic burden on affected households and on health systems that are involved in diagnosing the disease and treating patients. Research is needed to find cost-effective therapies for this costly disease. Plants have always been an important source of new pharmacologically active molecules. Consequently we decided to undertake the study of plants used in traditional treatment of BU in Benin and investigate their antimycobacterial activity as well as their chemical composition. Extracts from forty-four (44) plant species were selected on account of reported traditional uses for the treatment of BU in Benin and were assayed for antimycobacterial activities. Crude hydroethanolic extract from aerial parts of Holarrhena floribunda (G. Don) T. Durand and Schinz was found to have significant antimycobacterial activity against M. ulcerans (MIC = 125 µg/mL). We describe here the identification of four steroidal alkaloids from Mycobacterium ulcerans growth-inhibiting fractions of the alkaloidal extract of the aerial parts of Holarrhena floribunda. Holadysamine was purified in sufficient amount to allow the determination of its MCI (=50 µg/mL). These results give some support to the use of this plant in traditional medicine.

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EThe oral quinine drops were prepared -Raman and NIR spectroscopy methods were developed and validated -The methods were applied for analysis the real and substandard drugs. Poor quality antimalarial drugs are one of the public's major health problems in Africa. The 14 depth of this problem may be explained in part by the lack of effective enforcement and the 15 lack of efficient local drug analysis laboratories. To tackle part of this issue, two 16 spectroscopic methods with the ability to detect and to quantify quinine dihydrochloride in 17 children's oral drops formulations were developed and validated. Raman and Near Infrared 18 (NIR) spectroscopy were selected for the drug analysis due to their low cost, non-destructive 19 and rapid characteristics. Both of the methods developed were successfully validated using 20 the total error approach in the range of 50-150% of the target concentration (20% W/V) 21 within the 10% acceptance limits. Samples collected on the Congolese pharmaceutical market 22 were analyzed by both techniques to detect potentially substandard drugs. After a comparison 23 of the analytical performance of both methods, it has been decided to implement the method 24 based on NIR spectroscopy to perform the routine analysis of quinine oral drop samples in the 25 Quality Introduction 31Malaria remains one of the most rampant illnesses worldwide and is one of the main 32 causes of child mortality in developing countries [1][2]. The treatment of uncomplicated 33 malaria is based on conventional antimalarial drugs (e.g. chloroquine, artemisinin derivatives, 34 atovaquone, etc.). These drugs are essentially used as combinations due to the growing 35 resistance observed with single-drug therapy [3]. However, quinine is still recommended 36 alone in the treatment of severe and/or cerebral malaria attacks as well as for chloroquine-37 resistant falciparum malaria [4]. Four quinine based dosage forms are found on the 38 pharmaceutical market in DRC: tablets (250 and 500 mg), ampuls (250 and 500 mg/2mL), 39 syrup (100 mg /mL) and oral drops (200 mg /mL). The last three dosage forms are the most 40 used with 0-5 year old children. In 2009, the Health Ministry of the DRC warned citizens 41 against quinine oral drops "Quinizen 20%" that were found to have been counterfeit and 42 substandard [5]. 43Poor quality (substandard, counterfeit and degraded) or substandard/spurious/falsely-44 labelled/falsified/counterfeit anti-malarial drugs constitute a major public health concern 45 especially in developing countries where the pharmaceutical market is poorly regulated and 46The use such drugs may lead to therapeutic failure, death and reinforce drug resistance [7, 8]. t vVibrational spectroscopic techniques, such as Near Infrared (NIR) and Raman 49 spectroscopies are frequently used techniques in the field of quantitative drug analysis [9-11] 50 and in the fight against counterfeit drugs [12][13][14][15]. These techniques have the advantages of 51 being non-destructive, fast, requiring little or no sample...

As serious but neglected public health problems, poor quality medicines, i.e. for antimalarial medicines, urged to be fought. One of the approaches is to consider the analytical chemistry and separative techniques. In this study, a generic liquid chromatographic method was firstly developed for the purpose of screening 8 antimalarial active ingredients, namely amodiaquine (AQ), piperaquine (PPQ), sulfalene (SL), pyrimethamine (PM), lumefantrine (LF), artesunate (AS), artemether (AM) and dihydroartemisinine (DHA) by applying DoE/DS optimization strategy. Since the method was not totally satisfying in terms of peak separation, further experiments were undergone applying the same development strategy while splitting the 8 ingredients into five groups. Excellent prediction was observed prior to correlation between retention times of predicted and observed separation conditions. Then, a successful geometric transfer was realized to reduce the analysis time focusing on the simultaneous quantification of two WHO's recommended ACTs in anti-malarial fixed-dose combination (AM-LF and AS-AQ) in tablets. The optimal separation was achieved using an isocratic elution of methanol-ammonium formate buffer (pH 2.8; 10 mM) (82.5:17.5, v/v) * These authors have equally contributed to this article. # Corresponding author. J. K. Mbinze et al.128 at 0.6 ml/min through a C18 column (100 mm × 3.5 mm, 3.5 μm) thermostated at 25˚C. After a successful validation stage based on the total error approach, the method was applied to determine the content of AM/LF or AS/AQ in seven brands of antimalarial tablets currently marketed in West, Central and East Africa. Satisfying results were obtained compared to the claimed contents.

Liquid chromatographic methods in isocratic mode for the analysis of poor quality medicines are privileged due to their simplicity and facility in methods development. They are generally fast; do not need to be re-equilibrated between sample injections; have larger flexibility with acceptable changes on different column dimensions; and are applicable to LC systems equipped with simple or high developed pumps. In this study, we focused on developing simple isocratic methods using classical mobile phase composed by methanol and ammonium formate buffer for the analysis of most common antimalarial medicines marketed in malaria endemic countries and susceptible of being counterfeit/falsified, substandard and degraded. The selected medicines were quinine and related cinchona alkaloids in tablets and injectable forms; artemether/lumefantrine tablets; and artemisinin compounds (arteether, artemether, and artesunate) in injectable forms. The current methods were developed thanks to simple methodological approach consisting in sequential isocratic runs through adjustment or adaptation of existing methods to obtain optimal analytical conditions without complex design of experiments that might be long and costly. Then, the new methods presented shorter analysis time; allowed increase of sample analysis throughput; and obviously consumed little mobile phase solvents on classical analytical columns: 50-250 mm of length (L), 4.6 mm of internal diameter (I.D.), and 3.5-5.0 µm of particle size (dp).