Pharmaceutical quality of antimalarial drugs: quinine sulfate and Artemether/Lumefantrine tablets sold on Bukavu Market

Background Generic antimalarial drugs sold in sub-Saharan Africa require tighter control as counterfeiting has grown more and more out of control. The study aimed to analyze the pharmaceutical quality of quinine sulfate (QS) and Artemether/Lumefantrine(AL) tablets marketed in Bukavu city compared to the current trends in other African cities. Results The samples were purchased in community pharmacies or from ambulatory street vendors and analyzed using a set of thirteen simple tests, including visual inspection, UV spectrometry, TLC, and conventional quality control procedures. More than 93% of AL samples had an acceptable global quality score of > 90%. Around 16.6% of QS batches did not satisfy the requirements about hardness, friability, and mass uniformity. Only 33.3% met the disintegration quality; 33.3% did not contain quinine; 8.33% had an active ingredient other than quinine. Conclusion The findings strongly alert the circulation of fake antimalarial medicines observed in many countries. Simple TLC procedures may help to detect any low-quality generics to avoid microbial resistance and guarantee the health of the population. Pharmacists and regulatory authorities are alerted to the circulation of low-quality generic quinine preparations in the country.

Pharmaceutical Quality of Antimalarial Drugs: Quinine Sulfate and Artemether/lumefantrine Tablets Sold on Bukavu Market

Background: Malaria is a tropical parasitic disease caused by Plasmodium species, mainly falciparum, transmitted by the female Anopheles mosquito, strongly affecting sub-Saharan Africa and Indian areas. Generic antimalarial drugs sold in these regions require tighter quality control as counterfeiting has grown more and more out of control. The study aimed to analyze the pharmaceutical quality of Quinine sulfate and Artemether/Lumefantrine tablets marketed in Bukavu city compared to current trends in other African cities. Methods: We set up 13 simple TLC and UV spectrometric quality-control tests and applied them to analyze five Quinine brands divided into 12 batches and two Artemether/Lumefantrine brands divided into 12 batches. Quality scores were expressed as a percentage of compliance with each or the whole set of 13 tests. The samples were collected from community pharmacies and ambulatory street vendors. For comparison, available literature data related to the subject was retrieved from Google Scholar and PubMed search. Results: The analysis showed 16.6% of QS batches failed quality specifications concerning hardness, friability, and uniformity of mass; 66.6% failed the disintegration test; 33.3% did not contain quinine, and 8.33% had an active ingredient other than quinine. Only 3 batches exhibited a global score >90%. For Artemether/Lumefantrine, 93% of batches had an acceptable quality score >90%. Conclusion: The findings strongly support literature data from many countries. Simple TLC procedures may help to detect any low-quality generics to avoid microbial resistance and guarantee the health of the population. Pharmacists and regulatory authorities are alerted to the circulation of low-quality generic quinine preparations in the country.

Discrimination of Isointense Bitter Stimuli in a Beer Model System

Prior work suggests humans can differentiate between bitter stimuli in water. Here, we describe three experiments that test whether beer consumers can discriminate between different bitterants in beer. In Experiment 1 (n = 51), stimuli were intensity matched; Experiments 2 and 3 were a difference from control (DFC)/check-all-that-apply (CATA) test (n = 62), and an affective test (n = 81). All used a commercial non-alcoholic beer spiked with Isolone (a hop extract), quinine sulfate dihydrate, and sucrose octaacetate (SOA). In Experiment 1, participants rated intensities on general labeled magnitude scales (gLMS), which were analyzed via ANOVA. In Experiment 2, participants rated how different samples were from a reference of Isolone on a 7-point DFC scale, and endorsed 13 attributes in a CATA task. DFC data were analyzed via ANOVA with Dunnett’s test to compare differences relative to a blind reference, and CATA data were analyzed via Cochran’s Q test. In Experiment 3, liking was assessed on labeled affective magnitude scales, and samples were also ranked. Liking was analyzed via ANOVA and rankings were analyzed with a Cochran–Mantel–Haenszel test. Experiment 1 confirmed that samples were isointense. In Experiment 2, despite being isointense, both quinine (p = 0.04) and SOA (p = 0.03) were different from Isolone, but no significant effects were found for CATA descriptors (all p values > 0.16). In Experiment 3, neither liking (p = 0.16) or ranking (p = 0.49) differed. Collectively, these data confirm that individuals can discriminate perceptually distinct bitter stimuli in beer, as shown previously in water, but these differences cannot be described semantically, and they do not seem to influence hedonic assessments.

Investigations on sensing of picric acid in aqueous medium via fluorescence quenching of quinine sulfate

This research describes systematic investigations on sensing of high explosives such as picric acid (PA), RDX, NTO, and trinitrotoluene (TNT) in aqueous medium via fluorescence quenching of quinine sulfate (QS). Although all the explosives exhibit fluorescence quenching of QS, highest response is observed for PA. Fluorescence quenching of [Formula: see text][Formula: see text]50% (in contrast to pristine QS) at [Formula: see text][Formula: see text]390 nm is observed for 10 nm (2.29 [Formula: see text]g of PA dissolved in 20 [Formula: see text]l of distilled water). The analysis of the Stern–Volmer (SV) plot implies dominance of static quenching mechanism in comparison to dynamic quenching mechanism. Furthermore, the effect of operational temperature on fluoresce quenching response for PA has been investigated, and values of enthalpy, entropy, and Gibbs free energy of interaction at various temperatures are estimated. The temperature-dependent studies reveal that fluorescence quenching is due to formation of strong hydrogen bonds, complemented by computational analysis.