Volume 98, Issue 1
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



Global Pharma Health Fund (GPHF) Minilab™, a semi-quantitative thin-layer chromatography (TLC)–based commercially available test kit, is widely used in drug quality surveillance globally, but its diagnostic accuracy is unclear. We investigated the diagnostic accuracy of Minilab system for antimicrobials, using high-performance liquid chromatography (HPLC) as reference standard. Following the Minilab protocols and the Pharmacopoeia of the People’s Republic of China protocols, Minilab-TLC and HPLC were used to test five common antimicrobials (506 batches) for relative concentration of active pharmaceutical ingredients. The prevalence of poor-quality antimicrobials determined, respectively, by Minilab TLC and HPLC was amoxicillin (0% versus 14.9%), azithromycin (0% versus 17.4%), cefuroxime axetil (14.3% versus 0%), levofloxacin (0% versus 3.0%), and metronidazole (0% versus 38.0%). The Minilab TLC had false-positive and false-negative detection rates of 2.6% (13/506) and 15.2% (77/506) accordingly, resulting in the following test characteristics: sensitivity 0%, specificity 97.0%, positive predictive value 0, negative predictive value 0.8, positive likelihood ratio 0, negative likelihood ratio 1.0, diagnostic odds ratio 0, and adjusted diagnostic odds ratio 0.2. This study demonstrates unsatisfying diagnostic accuracy of Minilab system in screening poor-quality antimicrobials of common use. Using Minilab as a stand-alone system for monitoring drug quality should be reconsidered.

[open-access] This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Article metrics loading...

Loading full text...

Full text loading...



  1. WHO, 2017. Definitions of Substandard and Falsified (SF) Mdical Products. Available at: http://www.who.int/medicines/regulation/ssffc/definitions/en/. Accessed September 23, 2017.
  2. Kelesidis T, Falagas ME, , 2015. Substandard/counterfeit antimicrobial drugs. Clin Microbiol Rev 28: 443464.
  3. Pan H, Luo H, Chen S, Ba-Thein W, , 2016. Pharmacopoeial quality of antimicrobial drugs in southern China. Lancet Glob Health 4: e300e302.
  4. Martino R, Malet-Martino M, Gilard V, Balayssac S, , 2010. Counterfeit drugs: analytical techniques for their identification. Anal Bioanal Chem 398: 7792.
  5. Kovacs S, Hawes SE, Maley SN, Mosites E, Wong L, Stergachis A, , 2014. Technologies for detecting falsified and substandard drugs in low and middle-income countries. PLoS One 9: e90601.
  6. GPHF, 2017. The GPHF-Minilab™–Protection against Counterfeit Medicines. Available at: https://www.gphf.org/en/minilab/index.htm. Accessed August 30, 2017.
  7. World Health Organization, 2011. Survey of the Quality of Selected Antimalarial Medicines Circulating in Six Countries of Sub-Saharan Africa. Available at: http://www.who.int/medicines/publications/WHO_QAMSA_report.pdf. Accessed June 16, 2016.
  8. Visser BJ, de Vries SG, Bache EB, Meerveld-Gerrits J, Kroon D, Boersma J, Agnandji ST, van Vugt M, Grobusch MP, , 2016. The diagnostic accuracy of the hand-held Raman spectrometer for the identification of anti-malarial drugs. Malar J 15: 160.
  9. Visser BJ, 2015. Assessing the quality of anti-malarial drugs from Gabonese pharmacies using the MiniLab®: a field study. Malar J 14: 273.
  10. Vijaykadga S, Cholpol S, Sitthimongkol S, Pawaphutanan A, Pinyoratanachot A, Rojanawatsirivet C, Kovithvattanapong R, Thimasarn K, , 2006. Strengthening of national capacity in implementation of antimalarial drug quality assurance in Thailand. Southeast Asian J Trop Med Public Health 37: 510.
  11. Roger B, Richard T, Kimberly H, Lorraine M, Karen P, , 2009. Pilot study comparing technologies to test for substandard drugs in field settings. Afr J Pharm Pharmacol 3: 165170.
  12. Lalani M, Kaur H, Mohammed N, Mailk N, van Wyk A, Jan S, Kakar RM, Mojadidi MK, Leslie T, , 2015. Substandard antimalarials available in Afghanistan: a case for assessing the quality of drugs in resource poor settings. Am J Trop Med Hyg 92: 5158.
  13. Fadeyi I, Lalani M, Mailk N, Van Wyk A, Kaur H, , 2015. Quality of the antibiotics–amoxicillin and co-trimoxazole from Ghana, Nigeria, and the United Kingdom. Am J Trop Med Hyg 92: 8794.
  14. Bate R, Hess K, , 2010. Anti-malarial drug quality in Lagos and Accra–a comparison of various quality assessments. Malar J 9: 17.
  15. Khuluza F, Kigera S, Heide L, , 2017. Low prevalence of substandard and falsified antimalarial and antibiotic medicines in public and faith-based health facilities of southern Malawi. Am J Trop Med Hyg 96: 11241135.
  16. Delepierre A, Gayot A, Carpentier A, , 2012. Update on counterfeit antibiotics worldwide; public health risks. Med Mal Infect 42: 247255.
  17. Syhakhang L, Lundborg CS, Lindgren B, Tomson G, , 2004. The quality of drugs in private pharmacies in Lao PDR: a repeat study in 1997 and 1999. Pharm World Sci 26: 333338.
  18. Sapkota AR, 2010. Self-medication with antibiotics for the treatment of menstrual symptoms in southwest Nigeria: a cross-sectional study. BMC Public Health 10: 610.
  19. IFAD, 2017. Calculating the Sample Size. Available at: https://www.ifad.org/topic/resource/tags/food_and_nutrition_security/2141517. Accessed September 23, 2017.
  20. GPHF, 2016. The GPHF-Minilab™–Training. Available at: https://www.gphf.org/en/minilab/schulungen.htm. Accessed September 5, 2016.
  21. Risha P, Msuya Z, Ndomondo-Sigonda M, Layloff T, , 2006. Proficiency testing as a tool to assess the performance of visual TLC quantitation estimates. J AOAC Int 89: 13001304.
  22. Glas AS, Lijmer JG, Prins MH, Bonsel GJ, Bossuyt PM, , 2003. The diagnostic odds ratio: a single indicator of test performance. J Clin Epidemiol 56: 11291135.
  23. Littenberg B, Moses LE, , 1993. Estimating diagnostic accuracy from multiple conflicting reports: a new meta-analytic method. Med Decis Making 13: 313321.
  24. Newton PN, 2009. Guidelines for field surveys of the quality of medicines: a proposal. PLoS Med 6: e52.
  25. Bossuyt PM, 2015. STARD 2015: an updated list of essential items for reporting diagnostic accuracy studies. BMJ 351: h5527.
  26. Whiting P, Rutjes AW, Reitsma JB, Bossuyt PM, Kleijnen J, , 2003. The development of QUADAS: a tool for the quality assessment of studies of diagnostic accuracy included in systematic reviews. BMC Med Res Methodol 3: 25.
  27. Risha PG, Msuya Z, Clark M, Johnson K, Ndomondo-Sigonda M, Layloff T, , 2008. The use of Minilabs to improve the testing capacity of regulatory authorities in resource limited settings: Tanzanian experience. Health Policy 87: 217222.
  28. Bate R, Tren R, Mooney L, Hess K, Mitra B, Debroy B, Attaran A, , 2009. Pilot study of essential drug quality in two major cities in India. PLoS One 4: e6003.
  29. Kaale E, Risha P, Layloff T, , 2011. TLC for pharmaceutical analysis in resource limited countries. J Chromatogr A 1218: 27322736.
  30. GPHF, 2017. Global Use of the GPHF-Minilab™. Available at: https://www.gphf.org/en/minilab/einsatzgebiete.htm. Accessed September 2, 2017.
  31. Pribluda V, Barojas A, Coignez V, Bradby S, Dijiba Y, El-Hadri L, Hajjou M, Krech L, Phanouvong S, Smine K, , 2014. The three-level approach: a framework for ensuring medicines quality in limited-resource countries. Pharm Regul Aff 3: 2.
  32. Hajjou M, 2015. Monitoring the quality of medicines: results from Africa, Asia, and south America. Am J Trop Med Hyg 92: 6874.
  33. Pisani E, , 2015. Antimicrobial Resistance: What Does Medicine Quality have to do With it? Available at: http://amr-review.org/sites/default/files/ElizabethPisaniMedicinesQualitypaper.pdf. Accessed September 5, 2016.

Data & Media loading...

Supplementary Data

Supplemental Table

  • Received : 08 Apr 2017
  • Accepted : 26 Sep 2017

Most Cited This Month

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error