Spectrophotometric Analysis of Oxytetracycline Brands Available Over-the-Counter for Veterinary Use in South Western Nigeria

Chemotherapy with oxytetracycline in livestock is reportedly faced with increasing therapeutic failure and resistant bacteria strains circulating in humans, animals and the environment. This study determined the actual concentrations in some dosage forms of oxytetracycline available in Southwest Nigeria labelled for veterinary use by spectrophotometric method of analysis. Eight 5% (50mg/ml) and four 20% (200mg/ml) preparations of injectable oxytetracycline were purchased from veterinary pharmacies in Ibadan. The mean concentration of oxytetracycline obtained from formulations ranged between 0.484mg/ml and 0.757 mg/ml. Al l the commercial formulat ions contained less than the label led concentration when 1mg/ml of these samples was compared with 1mg/ml of the analytical grade of oxytetracycline. Therapy failures and development of bacterial resistance to oxytetracycline could therefore result from proliferation of fake or sub- s tandard drugs and indiscriminate use or abuse. There is need for strict regulation and quality control of importation, marketing and use of veterinary drugs in Nigeria. Also, there is need for pharmaco-vigilance a n d p h a rma c o - e p i d emi o l o g i c a l investigation of chemotherapeutic agents,which is recommended to ensure their efficacy for animal health and food safety.