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1.
Am J Trop Med Hyg ; 103(2): 894-908, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32394884

RESUMEN

Falsified and substandard medicines may undermine the progress toward the Sustainable Development Goals. The present study investigated the quality of 13 essential medicines in Cameroon and the Democratic Republic of Congo (DR Congo). Five hundred six medicine samples were collected from the government and faith-based health facilities, private pharmacies, and informal vendors (total 60 facilities). Collected samples were analyzed according to the U.S. Pharmacopeia (USP) for identity, content, and dissolution of their active pharmaceutical ingredients (APIs) and for uniformity of dosage units. Three samples (0.6%) were identified as falsified. Overall, 8.5% of the samples failed USP specifications for the content of the API and 11.7% failed dissolution testing. Medicines from informal vendors showed a higher out-of-specification rate (28.2%) than other types of drug outlets (12.3%; P < 0.0001). All three falsified medicines had been sold by informal vendors. The failure rate of medicines stated to be produced in Europe (5.1%) was lower than that for medicines from Asia (17.7%; P = 0.0049) and Africa (22.2%; P = 0.0042). Medicines against noncommunicable diseases showed a higher failure rate than antibiotics (25.3% versus 12.1%; P = 0.0004). Four hundred fifty-one of the samples were analyzed in Cameroon and the DR Congo with the Global Pharma Health Fund Minilab (thin-layer chromatography and disintegration testing). The three falsified medicines were readily detected in Minilab analysis. However, substandard samples were detected with low sensitivity. A well-enforced ban of medicine sales by informal vendors and increased attention to supplier qualification in the procurement process may reduce the prevalence of substandard and falsified medicines.


Asunto(s)
Medicamentos Falsificados , Medicamentos Esenciales/normas , Medicamentos de Baja Calidad , Antagonistas de Receptores Adrenérgicos beta 1/análisis , Antagonistas de Receptores Adrenérgicos beta 1/normas , Agonistas de Receptores Adrenérgicos beta 2/análisis , Agonistas de Receptores Adrenérgicos beta 2/normas , Antibacterianos/análisis , Antibacterianos/normas , Antihipertensivos/análisis , Antihipertensivos/normas , Camerún , Cromatografía Líquida de Alta Presión , República Democrática del Congo , Diuréticos/análisis , Diuréticos/normas , Medicamentos Esenciales/análisis , Humanos , Hipoglucemiantes/análisis , Hipoglucemiantes/normas
2.
Anal Chem ; 91(15): 9962-9969, 2019 08 06.
Artículo en Inglés | MEDLINE | ID: mdl-31283188

RESUMEN

The World Health Organization (WHO) model "List of Essential Medicines" includes among indispensable medicines antibacterials and pain and migraine relievers. Monitoring their concentration in the environment, while challenging, is important in the context of antibiotic resistance as well as their production of highly toxic compounds via hydrolysis. Traditional detection methods such as high-performance liquid chromatography (HPLC) or LC combined with tandem mass spectrometry or UV-vis spectroscopy are time-consuming, have a high cost, require skilled operators and are difficult to adapt for field operations. In contrast, (electrochemical) sensors have elicited interest because of their rapid response, high selectivity, and sensitivity as well as potential for on-site detection. Previously, we reported a novel sensor system based on a type II photosensitizer, which combines the advantages of enzymatic sensors (high sensitivity) and photoelectrochemical sensors (easy baseline subtraction). Under red-light illumination, the photosensitizer produces singlet oxygen which oxidizes phenolic compounds present in the sample. The subsequent reduction of the oxidized phenolic compounds at the electrode surface gives rise to a quantifiable photocurrent and leads to the generation of a redox cycle. Herein we report the optimization in terms of pH and applied potential of the photoelectrochemical detection of the hydrolysis product of paracetamol, i.e., 4-aminophenol (4-AP), and two antibacterials, namely, cefadroxil (CFD, ß-lactam antibiotic) and doxycycline (DXC, tetracycline antibiotic). The optimized conditions resulted in a detection limit of 0.2 µmol L-1 for DXC, but in a 10 times higher sensitivity, 20 nmol L-1, for CFD. An even higher sensitivity, 7 nmol L-1, was noted for 4-AP.


Asunto(s)
Medicamentos Esenciales/análisis , Técnicas Electroquímicas/métodos , Luz , Fenoles/química , Acetaminofén/análisis , Acetaminofén/metabolismo , Cefadroxilo/análisis , Cefadroxilo/metabolismo , Doxiciclina/análisis , Doxiciclina/metabolismo , Medicamentos Esenciales/metabolismo , Concentración de Iones de Hidrógeno , Hidrólisis , Límite de Detección , Oxidación-Reducción , Fármacos Fotosensibilizantes/química
3.
BMC Pharmacol Toxicol ; 15: 13, 2014 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-24593851

RESUMEN

BACKGROUND: Access to good-quality medicines in many countries is largely hindered by the rampant circulation of spurious/falsely labeled/falsified/counterfeit (SFFC) and substandard medicines. In 2006, the Ministry of Health of Cambodia, in collaboration with Kanazawa University, Japan, initiated a project to combat SFFC medicines. METHODS: To assess the quality of medicines and prevalence of SFFC medicines among selected products, a cross-sectional survey was carried out in Cambodia. Cefixime, omeprazole, co-trimoxazole, clarithromycin, and sildenafil were selected as candidate medicines. These medicines were purchased from private community drug outlets in the capital, Phnom Penh, and Svay Rieng and Kandal provinces through a stratified random sampling scheme in July 2010. RESULTS: In total, 325 medicine samples were collected from 111 drug outlets. Non-licensed outlets were more commonly encountered in rural than in urban areas (p < 0.01). Of all the samples, 93.5% were registered and 80% were foreign products. Samples without registration numbers were found more frequently among foreign-manufactured products than in domestic ones (p < 0.01). According to pharmacopeial analytical results, 14.5%, 4.6%, and 24.6% of the samples were unacceptable in quantity, content uniformity, and dissolution test, respectively. All the ultimately unacceptable samples in the content uniformity tests were of foreign origin. Following authenticity investigations conducted with the respective manufacturers and medicine regulatory authorities, an unregistered product of cefixime collected from a pharmacy was confirmed as an SFFC medicine. However, the sample was acceptable in quantity, content uniformity, and dissolution test. CONCLUSIONS: The results of this survey indicate that medicine counterfeiting is not limited to essential medicines in Cambodia: newer-generation medicines are also targeted. Concerted efforts by both domestic and foreign manufacturers, wholesalers, retailers, and regulatory authorities should help improve the quality of medicines.


Asunto(s)
Cefixima/análisis , Claritromicina/análisis , Medicamentos Falsificados , Omeprazol/análisis , Piperazinas/análisis , Sulfonas/análisis , Combinación Trimetoprim y Sulfametoxazol/análisis , Cambodia , Etiquetado de Medicamentos , Medicamentos Esenciales/análisis , Fraude , Vigilancia en Salud Pública , Purinas/análisis , Control de Calidad , Citrato de Sildenafil
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