Lead, Cadmium and Nickel Contents of Some Medicinal Agents

Thirty nine brands of pharmaceutical dosage forms (28 tablets, 4 syrups, 6 suspensions and one chewing gum) that are available in United Arab Emirates pharmaceutical markets were investigated for the presence of three heavy metals; lead, cadmium and nickel. Amongst the samples, 13 products were manufactured locally in United Arab Emirates and 26 products were imported from around the world. The samples were prepared by acid digestion procedure and the resultant solutions were analyzed for heavy metals by using a validated graphite furnace atomic absorption spectrometric method. Calibration curves were achieved using different concentration of lead, nickel and cadmium ranged from 0.001 to 0.05 μg/ml. The mean recoveries of metals from the samples were 86.4 to 97%. The %relative standard deviation for the intraassay and interday precision for the metals were <5%. Amongst the 39 samples of pharmaceutical dosage form all exhibited a positive response for lead, cadmium and nickel except three products whose Ni levels were below quantification level. The products contained variable amounts of heavy metals as of 0.0017 to 11.88 μg lead; 0.0011 to 0.5559 μg cadmium and 0.0011 to 2.6428 μg nickel, respectively. Based on maximum recommended daily dose (g) of these products, maximum daily ingested mass of lead was 0.0034 to 11.88 μg/d, 0.0013 to 0.56 μg/d for cadmium and 0.0011 to 2.64 μg/d for nickel, respectively. The results were compared with those of oral permitted daily exposure levels of United State Pharmacopeial National Formulary 2013. All the products were safe to consume and contained lower level of lead, cadmium and nickel than Oral Permitted Daily Exposure levels, except three products which showed higher level of lead than oral permitted daily exposure levels. Hence the raw materials used in manufacturing of these medicinal agents might be responsible for the presence of higher level of lead.