The Quality of Selected Essential Medicines Sold in Accredited Drug Dispensing Outlets and Pharmacies in Tanzania

Abstract

IntroductionThe purpose of this study was to investigate the quality of a select group of medicines sold in accredited drug dispensing outlets (ADDOs) and pharmacies in different regions of Tanzania as part of an in-depth cross-sectional assessment of community access to medicines and community use of medicines.MethodsWe collected 242 samples of amoxicillin trihydrate, artemether-lumefantrine (ALu), co-trimoxazole, ergometrine maleate, paracetamol, and quinine from selected ADDOs and pharmacies in Mbeya, Morogoro, Singida, and Tanga regions. The analysis included physical examination and testing with validated analytical techniques. Assays for eight of nine products were conducted using high-performance thin-layer chromatography (HPTLC). For ALu tablets, we used a two-tiered approach, where tier 1 was a semi-quantitative Global Pharma Health Fund-Minilab® method and tier 2 was high-performance liquid chromatography (HPLC) as described in The International Pharmacopoeia’s monograph for artemether-lumefantrine.Results and DiscussionThe physical examination of samples revealed no defects in the solid and oral liquid dosage forms, but unusual discoloration in an injectable solution, ergometrine maleate. For ALu, the results showed that of 38 samples, 31 (81.6%) passed tier 1 testing and 7 (18.4%) gave inconclusive drug content results. The inconclusive ALu samples were submitted for tier 2 testing and all met the quality standards. The pass rate using the HPTLC and TLC/HPLC assays was 93.8%; the failures were the ergometrine maleate samples purchased from both ADDOs and pharmacies. The disintegration testing of the solid dosage forms was conducted in accordance with US Pharmacopeia monographs. Only two samples of paracetamol, 1.2% of the solid dosage forms, failed to comply to standards. The study revealed a high overall rate of 92.6% of samples that met the quality standards. Although the overall failure rate was 7.4%, it is important to note that this was largely limited to one product and likely due to poor distribution and storage rather than poor manufacturing practices.ConclusionsOver 90% of the medicines sold in ADDOs and pharmacies met quality standards. Policy makers need to reconsider ergometrine maleate’s place on the list of medicines that ADDOs are allowed to dispense, by either substituting a more temperature-stable therapeutically equivalent product or requiring those sites to have refrigerators, which is not a feasible option for rural Tanzania.

Post Marketing Surveillance of Anti-malarial Medicines in Tanzania

“…A study which aimed to assess the quality of products in circulation in ADDOs in Tanzania concluded on a similar observation [22]. Failure in appearance, uniformity of weight and chipping of tablets was observed in samples of quinine tablets, Sulfamethoxypyrazine/Pyrimethamine tablets and Sulfadoxine/ Pyrimethamine notably all of which were from domestic manufacturers.…”

“…Notably, all failed samples were products from domestic manufacturers. Kaale et al made a similar observation with paracetamol from domestic manufacturers failing disintegration test [22].…”

“…Another study by Minzi et al [19] on the quality of amodiaquine and SP products marketed in Dar Es Salaam reported that, 13% of the amodiaquine samples failed dissolution test and 11% and 44% of SP samples failed assay and dissolution tests, respectively [19][20][21][22].…”

Availability of Selected Essential Prescription Medicines and Trained Dispensers in Accredited Drug Dispensing Outlets in Tanzania. A Case Study of Hanang District Council in Manyara Region Northern Tanzania

“…This is low number compared to only 40% ADDO Shops, which had employed untrained Dispensers according to the study done in three Districts, Mvomero, Kilombero and Morogoro rural District. 17,18 However it is still high according to the requirement of the pharmacy council which tolerate 0% availability of untrained dispensers in ADDO shops. 19 Most of Dispensers were aged 26-35(54.5%) which is little similar to Kyela district 36-45(36.2%).…”

Substandard and falsified medicine screening technologies

“…Minilab can be used for chemical and physical analysis, employing thin layer chromatography (TLC) and disintegration techniques, respectively. Minilab has been used extensively for PMS around the world and has been supplied to 97 countries (Batson et al 2016;Fadeyi et al 2015;GPHF 2019;Kaale et al 2016;Lalani et al 2015;Petersen et al 2017). TLC is a semi-quantitative technique that separates components in a sample according to differences in polarity, as the components interact between mobile and stationary phases.…”