Poster Y2 - Detection of Falsified and Substandard Pharmaceuticals in Tanzania

Introduction: Over thirty percent of pharmaceuticals supplied to African countries are substandard or falsified. Some reasons for this include online business, light sanctions for drug infringers, ignorance, and lack of consumer education. Substandard drugs occur due to insufficient expert knowledge, poor manufacturing processes, or insufficient infrastructure. The World Health Organization (WHO) has defined counterfeit drugs as “one which is deliberately and fraudulently mislabeled with respect to identity and/or source.” Counterfeit pharmaceuticals are produced by criminals who purposefully mislabel the drug's identity. The increase in falsified and substandard pharmaceuticals creates a hazard to the already crippling problem that developing countries face with the following prevalent diseases, malaria, Human Immunodeficiency Virus (HIV), hypertension, diabetes, and tuberculosis. The WHO has established that the distribution of these illegal pharmaceuticals is a major problem that needs attention in developing countries. For many patients with the aforementioned diseases, if they do not receive the proper medication, they will most likely die or suffer prolonged illness.

Materials and

Methods: 100 mg of each pharmaceutical was dissolved in 10 mL of pure ethanol. Glass TLC plates with silica gel 60 were marked with a baseline one centimeter from the bottom. Three microliters of the dissolved pharmaceutical were placed on the baseline tick using a micropipette. The mobile phase was prepared in a beaker so its height would not exceed the one-centimeter baseline of the TLC plate. Once the spot dried, the TLC plate was placed in the beaker, covered with a watch glass, and ran for ten minutes. After removing the plate, the height reached by the mobile phase was marked. The plate was dried, observed under a 254 nm UV light, and the visible spot was outlined in pencil. Retention factor (Rf) values were calculated.

Humidity testing was conducted in a self-made chamber using a Tupperware container, a humidity sensor, and a mini humidifier, set to 90% humidity, reflecting Tanzania’s typical humidity range of 58% to 87%. Temperature testing used a ProJet Finishing Oven set to 38°C, slightly above Tanzania’s highest reported temperature of 36°C, to simulate extreme conditions.

Results, Conclusions, and Discussions: The baseline results for each drug showed consistent Rf values with a standard deviation of 0.02 to 0.03, confirming the mobile phase effectively separated the samples on the TLC plates. This consistency established a reliable standard for comparing other tests.

At 90% humidity, Lisinopril dihydrate and Tenofovir disoproxil fumarate were unaffected, indicating they remain stable at Tanzania's peak humidity of 87%. However, Doxycycline hyclate, Pyrazinamide, and Dapagliflozin exhibited significant Rf deviations, suggesting potential misidentification under these conditions. Despite this, the consistent results at 90% humidity provided a reliable alternative range for these drugs. Further tests at 85% humidity showed all drugs remained within the baseline Rf range, establishing that TLC testing is reliable at or below this humidity level. Users in environments with up to 85% humidity can compare results to baseline values, while those above 85% should refer to the 90% humidity results.

Testing at 38°C revealed minimal Rf variance (up to 0.01), confirming temperature stability up to this point. Given Tanzania’s maximum recorded temperature of 36°C, TLC results are unaffected by typical environmental heat, ensuring reliability even in non-air-conditioned pharmacies.

Collaboration with Arusha Technical College indicated that local pharmacists typically have access to necessary testing supplies, reducing the kit's required contents to a UV light and TLC plates, with optional chemical vials. The testing kit, costing $371.65 initially (including a $313 UV lamp and other supplies), becomes more affordable over time as users only need to replenish TLC plates. This cost-effective method supports pharmaceutical integrity testing in Tanzania.

The findings are crucial as many Tanzanian pharmacies lack air conditioning, leading to variable humidity and temperature conditions. The results validate the exclusion of known sample testing under identical conditions, simplifying the kit compared to Global Pharma Health Fund’s Minilab. A MATLAB-based GUI, to be converted into a free smartphone app, was developed to evaluate drug legitimacy based on user inputs, eliminating the need for costly known samples. By reducing kit complexity and costs, this approach makes pharmaceutical testing more accessible and affordable.

Acknowledgements (Optional): We would like to thank Dr. Dean, Dr. Harman, Dr. DesJardins, as well as the Clemson University Department of Bioengineering for supporting our research.