Sampling study raises red flags for antibiotics sold in Kenya

A study of antibiotic formulations sold in pharmacies in Nairobi county, Kenya, has found that almost 38 per cent of samples failed to meet standards laid out in the US Pharmacopoeia (USP), making them substandard and potentially counterfeit.

The research – published in the journal BioMed Research International – looked at 53 samples from the bewildering array of 106 brands of amoxicillin or amoxicillin/clavulanic acid found in the Kenyan market, mostly important but also produced domestically.

Studies have shown that having too many brands of the same molecule poses challenges in ensuring quality, say the study authors, from Kenyatta University and the Kenya Medical Research Institute.

The samples were tested for the presence of active pharmaceutical ingredients (APIs), potency and dissolution testing immediately on sampling. In the case of oral suspensions, the samples were tested seven days after mixing to check on their stability.

The headline results is that after that seven-day period, three of 13 (23 per cent) of the amoxicillin and eight of 12 amoxicillin/clavulanic acid oral suspensions had API levels below recommended limits.

Among the solid oral dosage forms, three out of 22 (13.6 per cent) of amoxicillin capsules failed weight testing – which can be an indicator of counterfeiting – while all amoxicillin/clavulanic acid capsules were compliant.

All of the amoxicillin samples contained API at the labelled concentration on initial testing but two of six amoxicillin/clavulanic acid products – or 33 or per cent – were out of specification when it came to potency.

And finally, 10 per cent (two of 19) of amoxicillin samples and 50 per cent (two of four) of amoxicillin/clavulanic acid samples failed dissolution testing, used to check if the active ingredient is bioavailable.

That all adds up to failure rate of 37.7 per cent, with the failures all imported products, say the authors.

There was no provision in the study to check whether the failures were due to substandard production or outright falsification, but overall it suggests too many Kenyans are still being exposed to medicines that may not work as intended.

“Ensuring availability of quality essential medicines to the public through frequent post-market surveillance is an important contribution in the fight against antimicrobial resistance and reduction in disease burden through mitigating treatment failures,” they conclude.