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1.
Malar J ; 20(1): 433, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34758840

RESUMO

BACKGROUND: Insecticide-treated nets and indoor residual spraying of insecticides are used as the vector control interventions in the fight against malaria. Measuring the actual amount of deposits of insecticides on bed nets and walls is essential for evaluating the quality and effectiveness of the intervention. A colorimetric "Test Kit" designed for use as a screening tool, able to detect the type II pyrethroids on fabrics and sprayed walls, was used for the first time to detect deltamethrin on long-lasting insecticidal nets (LLINs) deployed on Bioko Island, Equatorial Guinea. METHODS: LLINs were analysed using the colorimetric Test Kit performed in situ, which leads to the formation of an orange-red solution whose depth of colour indicates the amount of type II pyrethroid on the net. The kit results were validated by measuring the amount of extracted insecticide using high-performance liquid chromatography (HPLC) with diode array detection (DAD). RESULTS: Deltamethrin concentration was determined for 130 LLINs by HPLC-DAD. The deltamethrin concentration of these nets exhibited a significant decrease with the age of the net from 65 mg/m2 (< 12 months of use) to 31 mg/m2 (> 48 months; p < 0.001). Overall, 18% of the nets being used in households had < 15 mg/m2 of deltamethrin, thus falling into the "Fail" category as assessed by the colorimetric Test Kit. This was supported by determining the bio-efficacy of the nets using the WHO recommended cone bioassays. The Test Kit was field evaluated in situ and found to be rapid, accurate, and easy to use by people without laboratory training. The Test Kit was shown to have a reliable linear relationship between the depth of colour produced and deltamethrin concentration (R2 = 0.9135). CONCLUSION: This study shows that this colorimetric test was a reliable method to assess the insecticidal content of LLINs under operational conditions. The Test Kit provides immediate results and offers a rapid, inexpensive, field-friendly alternative to the complicated and costly methods such as HPLC and WHO cone bioassays which also need specialist staff. Thus, enabling National Malaria Control Programmes to gain access to effective and affordable monitoring tools for use in situ.


Assuntos
Colorimetria/normas , Mosquiteiros Tratados com Inseticida/normas , Inseticidas/análise , Nitrilas/análise , Piretrinas/análise , Animais , Bioensaio , Cromatografia Líquida de Alta Pressão , Guiné Equatorial , Feminino , Humanos , Ilhas , Reprodutibilidade dos Testes , Fatores de Tempo
2.
Am J Trop Med Hyg ; 96(5): 1117-1123, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28219992

RESUMO

AbstractPoor-quality medicines are a major problem for health-care systems in resource-poor settings as identifying falsified medicines requires a complex laboratory infrastructure such as a Medicines Quality Control Laboratory. We report here an evaluation of a low-cost, handheld near-infrared spectrometer (NIRS) device by analyzing a library of artemisinin-based combination therapy (ACT) medicines to determine its usefulness as a drug-screening tool. The "SCiO" research prototype device was used to collect NIR spectra of a library of ACT and artesunate monotherapy medicine samples previously collected in Bioko Island and Equatorial Guinea and Kintampo, Ghana. The quality of these samples had been categorized as falsified, substandard, and quality assured based on the amount of stated active pharmaceutical ingredients detected using high-performance liquid chromatography photodiode array. Numerical analyses were performed on the NIR spectra to assess the usefulness of NIR to identify falsified and substandard medicines. The NIRS device was successful at detecting falsified medicines in all cases where the library contained both quality assured and falsified medicines of the same stated brand of medicines. The NIRS device was successful at identifying substandard amounts of artesunate but not amodiaquine in the ACT samples (N = 15) of artesunate-amodiaquine. This work reveals that this low-cost, portable NIRS device is promising for screening ACTs for falsified samples and could enable widespread drug screening at all points of the health system.


Assuntos
Amodiaquina/análise , Antimaláricos/análise , Artemisininas/análise , Computadores de Mão , Medicamentos Falsificados/análise , Artesunato , Cromatografia Líquida de Alta Pressão , Combinação de Medicamentos , Contaminação de Medicamentos/prevenção & controle , Guiné Equatorial , Gana , Humanos , Aplicativos Móveis , Controle de Qualidade , Sensibilidade e Especificidade , Espectrofotometria Infravermelho/instrumentação , Espectrofotometria Infravermelho/métodos
3.
BMJ Glob Health ; 2(4): e000409, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29082025

RESUMO

INTRODUCTION: Poor-quality artemisinin-containing antimalarials (ACAs), including falsified and substandard formulations, pose serious health concerns in malaria endemic countries. They can harm patients, contribute to the rise in drug resistance and increase the public's mistrust of health systems. Systematic assessment of drug quality is needed to gain knowledge on the prevalence of the problem, to provide Ministries of Health with evidence on which local regulators can take action. METHODS: We used three sampling approaches to purchase 677 ACAs from 278 outlets on Bioko Island, Equatorial Guinea as follows: convenience survey using mystery client (n=16 outlets, 31 samples), full island-wide survey using mystery client (n=174 outlets, 368 samples) and randomised survey using an overt sampling approach (n=88 outlets, 278 samples). The stated active pharmaceutical ingredients (SAPIs) were assessed using high-performance liquid chromatography and confirmed by mass spectrometry at three independent laboratories. RESULTS: Content analysis showed 91.0% of ACAs were of acceptable quality, 1.6% were substandard and 7.4% falsified. No degraded medicines were detected. The prevalence of medicines without the SAPIs was higher for ACAs purchased in the convenience survey compared with the estimates obtained using the full island-wide survey-mystery client and randomised-overt sampling approaches. Comparable results were obtained for full island survey-mystery client and randomised overt. However, the availability of purchased artesunate monotherapies differed substantially according to the sampling approach used (convenience, 45.2%; full island-wide survey-mystery client, 32.6%; random-overt sampling approach, 21.9%). Of concern is that 37.1% (n=62) of these were falsified. CONCLUSION: Falsified ACAs were found on Bioko Island, with the prevalence ranging between 6.1% and 16.1%, depending on the sampling method used. These findings underscore the vital need for national authorities to track the scale of ineffective medicines that jeopardise treatment of life-threatening diseases and value of a representative sampling approach to obtain/measure the true prevalence of poor-quality medicines.

4.
Biodivers Data J ; (4): e8051, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27660527

RESUMO

BACKGROUND: The cicadas of the Indian subcontinent, like many other insects in the region, have remained understudied since the early part of the 20th Century, and await modern taxonomic, systematic and phylogenetic treatment. This paper presents an updated systematic catalogue of cicadas (Hemiptera: Cicadidae) from India, Bangladesh, Bhutan, Myanmar, Nepal and Sri Lanka, the first in over a century. NEW INFORMATION: This paper treats 281 species, including: India and Bangladesh (189 species), Bhutan (19 species), Myanmar (81 species), Nepal (46 species) and Sri Lanka (22 species). For each species all recognized junior synonyms are included with information on the type material and additional specimens where relevant. The global distributional range and notes on the taxonomy of each species are included where appropriate. Two lists are provided: (1) species known to occur in India and Bangladesh (treated as a geographic unit), Bhutan, Myanmar, Nepal and Sri Lanka; and (2) species previously listed from these countries in error. A bibliography of species descriptions is provided, with the papers containing the original descriptions provided where copyright allows.

5.
Am J Trop Med Hyg ; 94(5): 993-1001, 2016 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-26951346

RESUMO

Poor quality antimalarials, including falsified, substandard, and degraded drugs, are a serious health concern in malaria-endemic countries. Guidelines are lacking on how to distinguish between substandard and degraded drugs. "Forced degradation" in an oven was carried out on three common artemisinin-based combination therapy (ACT) brands to detect products of degradation using liquid chromatography mass spectrometry and help facilitate classification of degraded drugs. "Natural aging" of 2,880 tablets each of ACTs artemether/lumefantrine and artesunate/amodiaquine was undertaken to evaluate their long-term stability in tropical climates. Samples were aged in the presence and absence of light on-site in Ghana and in a stability chamber (London), removed at regular intervals, and analyzed to determine loss of the active pharmaceutical ingredients (APIs) over time and detect products of degradation. Loss of APIs in naturally aged tablets (both in Ghana and the pharmaceutical stability chamber) was 0-7% over 3 years (∼12 months beyond expiry) with low levels of degradation products detected. Using this developed methodology, it was found that a quarter of ACTs purchased in Enugu, Nigeria (concurrent study), that would have been classified as substandard, were in fact degraded. Presence of degradation products together with evidence of insufficient APIs can be used to classify drugs as degraded.


Assuntos
Antimaláricos/química , Artemisininas/química , Temperatura Alta , Estabilidade de Medicamentos , Armazenamento de Medicamentos , Fatores de Tempo , Clima Tropical
6.
Am J Trop Med Hyg ; 92(6 Suppl): 95-104, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25897062

RESUMO

In 2003, a stratified random sample survey was conducted in the Lao People's Democratic Republic (Laos) to study the availability and quality of antimalarials in the private sector. In 2012, this survey was repeated to allow a statistically valid analysis of change through time. The counterfeit detection device 3 (CD-3) was used to assess packaging quality in the field and HPLC and mass spectroscopy analysis chemical analysis performed. The availability of oral artesunate monotherapies had significantly decreased from 22.9% (22) of 96 outlets in southern Laos in 2003 to 4.8% (7) of 144 outlets in 2012 (P < 0.0001). All the samples collected in the 2012 survey contained the correct active pharmaceutical ingredients (APIs) in contrast to the 21 (84%) falsified artesunate samples found in the 2003 survey. Although none of the medicines found in 2012 survey had evidence for falsification, 25.4% (37) of the samples were outside the 90-110% pharmacopeial limits of the label claim, suggesting that they were substandard or degraded. Results obtained from this survey show that patients are still exposed to poorly manufactured drugs or to ineffective medicines such as chloroquine. The quality of artemisinin-based combination therapies (ACTs) used in Laos needs to be monitored, since falsified ACTs would have devastating consequences in public health.


Assuntos
Antimaláricos/economia , Antimaláricos/normas , Medicamentos Falsificados , Estudos Transversais , Embalagem de Medicamentos , Laos , Legislação de Medicamentos , Comprimidos
7.
PLoS One ; 10(5): e0125577, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26018221

RESUMO

BACKGROUND: Artemisinin-based combination therapies are recommended by the World Health Organisation (WHO) as first-line treatment for Plasmodium falciparum malaria, yet medication must be of good quality for efficacious treatment. A recent meta-analysis reported 35% (796/2,296) of antimalarial drug samples from 21 Sub-Saharan African countries, purchased from outlets predominantly using convenience sampling, failed chemical content analysis. We used three sampling strategies to purchase artemisinin-containing antimalarials (ACAs) in Enugu metropolis, Nigeria, and compared the resulting quality estimates. METHODS: ACAs were purchased using three sampling approaches--convenience, mystery clients and overt, within a defined area and sampling frame in Enugu metropolis. The active pharmaceutical ingredients were assessed using high-performance liquid chromatography and confirmed by mass spectrometry at three independent laboratories. Results were expressed as percentage of APIs stated on the packaging and used to categorise each sample as acceptable quality, substandard, degraded, or falsified. RESULTS: Content analysis of 3024 samples purchased from 421 outlets using convenience (n=200), mystery (n=1,919) and overt (n=905) approaches, showed overall 90.8% ACAs to be of acceptable quality, 6.8% substandard, 1.3% degraded and 1.2% falsified. Convenience sampling yielded a significantly higher prevalence of poor quality ACAs, but was not evident by the mystery and overt sampling strategies both of which yielded results that were comparable between each other. Artesunate (n=135; 4 falsified) and dihydroartemisinin (n=14) monotherapy tablets, not recommended by WHO, were also identified. CONCLUSION: Randomised sampling identified fewer falsified ACAs than previously reported by convenience approaches. Our findings emphasise the need for specific consideration to be given to sampling frame and sampling approach if representative information on drug quality is to be obtained.


Assuntos
Antimaláricos/normas , Antimaláricos/uso terapêutico , Antimaláricos/química , Artemisininas/análise , Artesunato , Cromatografia Líquida de Alta Pressão , Humanos , Malária Falciparum/tratamento farmacológico , Nigéria , Farmácias , Setor Privado , Logradouros Públicos , Controle de Qualidade , Fatores de Risco , Comprimidos
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