Development of Green Methods for the Determination of Elemental Impurities in Commercial Pharmaceutical Tablets

In this study, two methods based on the use of diluted acids were developed: microwave-assisted wet digestion (MAWD) and microwave-assisted ultraviolet digestion (MAWD-UV). These methods are evaluated for the digestion of oral pharmaceutical drugs and further determination of elemental impurities from classes 1 (As, Cd, Hg and Pb) and 2A (Co, Ni and V) by inductively coupled plasma optical emission spectrometry (ICP-OES). Commercial drugs for the treatment of type 2 diabetes are used. No prior comminution is performed. For MAWD, the optimized conditions were 2 mol L−1 or 3 mol L−1 HNO3, 1 mL of 50% H2O2 and a 45 min or 55 min irradiation program. For MAWD-UV, the condition using 1 mol L−1 HNO3, 1.6 mL of 50% H2O2 and a 55 min irradiation program enabled the digestion of all samples. In this way, efficient methods are proposed for the digestion of commercial pharmaceutical tablets for further determination of class 1 and 2A elemental impurities (ICH Q3D guidelines).

Human Health Risk Assessment of Heavy Metals and Metalloids in Herbal Medicines Used to Treat Anxiety: Monitoring of Safety

The present study estimated the human health risk assessment and daily intake of heavy metals and metalloids in herbal medicines used to treat anxiety in Brazil. Six different brands of herbal medicines were purchased in the city of Campo Grande/MS, Brazil: Pasalix®, Calman®, Serenus®, Maracugina®, Prakalmar® and Calmasyn®. In total, eight elements including As, Ba, Cd, Co, Cr, Cu, Fe, and Pb were analyzed using optical emission spectrometry with inductively coupled plasma (ICP OES). Only the concentration of As in the herbal medicine Prakalmar® is above the values established by United States Pharmacopoeia Convention (USP) and Brazilian Pharmacopoeia (BF) for permitted concentration of elemental impurities in drugs substances. The concentration of Ba, Cd, Co, Cr and Cu in all herbal medicines are lower than the values set by USP and FB. The concentration of Pb in Calman® is lower than the limits established by BF, but higher than those established by USP. Pasalix, Serenus®, Calmasyn®, Prakalmar® and Marcacugina® have a higher Pb concentration than the values allowed by USP and BF. All herbal medications have concentrations within safe ranges for human consumption, with the exception of Calmasyn®, which has Pb over the value defined by USP for oral permissible daily exposure (PDE) for elemental impurities. The values of estimated daily intake (EDI) of metal (loid)s in adults and children obtained from the consumption of the herbal medicines are below the values stipulated by the minimal risk levels (MRLs). All the hazard index (HI) values recorded in this study were below 1. However, monitoring by regulatory agency is necessary, large doses of heavy metal may cause acute or chronic toxicities.

The Use of SEM/EDX Analysis to Investigate the Pore Effect on the Mechanical Properties of some Selected Tropical Hardwoods

Previous studies have investigated the effect of moisture content on the physical and mechanical properties of timber species. This study investigated the effect of the tube-like grain pores in the wood and the presence of elemental impurities on the failure mechanism of four tropical hardwoods. The four hardwood species are Mahogany, Albizia, Beech and Birch. The moisture content of each wood specie was determined at normal temperature, mechanical tests were conducted to determine the strength of each wood samples, while the Scanning Electron Microscopy/ Energy Dispersion X-ray (SEM/EDX ) analysis was carried out to determine the high-resolution images and elemental peaks of the wood specie. The work concluded that beech wood failed earlier when compared to the other three samples due to high moisture content that is above the fibre saturation point. The SEM/EDX test revealed that the early failure was also as a result of the presence of large pores and elemental impurities in the sample of Beech wood.

Multielemental Screening and Analytical Method Validation for Determination of Elemental Impurity in Sucroferric Oxyhydroxide by Using (ICP-MS)

A highly selective, specific, precise sensitive and reliable ICPMS method has been developed and validated by using ICP-MS for the determination of multielement in Sucroferric oxyhydroxide. The described ICP-MS method provides specific detection and quantification of minor and trace elements from 0.3J(30%) to 2J(200%) of its individual specification of each element i.e Ag, As, Au, Ba, Cd, Co, Cr, Cu, Hg, Ir, Li, Mo, Ni, Os, Pb, Pd, Pt, Rh, Ru, Sb, Se, Sn, Tl, and V.The analytical method found to be Linear for each individual element with working concentration range from 30%, 50%, 100%, 150% and 200% i.e 0.3J, 0.5J, 1J, 1.5J and 2J with correlation coefficient not less than 0.990.The % recoveries of elemental impurities of each individual elements at three different concentrations with spiking in samples were found to be an acceptable range as 70% to 150%.The method was found to be precise and robust and its relative standard deviation was below 20%.The actual observed relative standard deviation in Precision was found to be in an acceptable range. Therefore developed method can be use for routine quantitative analysis of elemental impurities like Ag, As, Au, Ba, Cd, Co, Cr, Cu, Hg, Ir, Li, Mo, Ni, Os, Pb, Pd, Pt, Rh, Ru, Sb, Se, Sn, Tl, and V to ensure the quality of drug product.