Abstract

Light kaolin powder B.P is used in the formulation of liquid oral anti-diarrhoeal medications. Previously reported study showed that some Kaolin liquid formulations available in pharmacies contain lead and cadmium at concentrations above the limit established by International Conference on Harmonization (ICH). This study was carried out to investigate the contents of lead, cadmium and nickel present in pharmaceutical-grade light kaolin powder. Three randomly selected samples coded D, E and F, of light kaolin powder B.P. obtained from Ogonoh Ventures, a registered reputable supplier of Active Pharmaceutical Ingredients (APIs) in Benin City as a gift. The contents of lead, cadmium and nickel present as heavy metal contaminants were investigated using Atomic Absorption Spectrophotometer. Cadmium and nickel were found in samples E and F. The concentrations of these metals were in the range of 10 – 15 µg/kg (Cadmium) and 15 – 35 µg/kg (NIckel). Lead was detected in the three samples investigated and the concentration was in the range of 20 - 30 µg/kg. The oral permitted daily intake of lead, cadmium and nickel in the maximum daily doses of samples of light kaolin B.P were less than the limits recommended by the ICH, Thus samples of light kaolin B.P were considered to be safe for the production of liquid oral formulations.

Keywords: Light kaolin BP, anti-diarrhoeal formulation, elemental impurities, International Conference on Harmonization.