Quality assessment of internet pharmaceutical products using traditional and non-traditional analytical techniques

This work investigated the use of non-traditional analytical methods to evaluate the quality of a variety of pharmaceutical products purchased via internet sites from foreign sources and compared the results with those obtained from conventional quality assurance methods. Traditional analytical techniques employing HPLC for potency, content uniformity, chromatographic purity and drug release profiles were used to evaluate the quality of five selected drug products (fluoxetine hydrochloride, levothyroxine sodium, metformin hydrochloride, phenytoin sodium, and warfarin sodium). Non-traditional techniques, such as near infrared spectroscopy (NIR), NIR imaging and thermogravimetric analysis (TGA), were employed to verify the results and investigate their potential as alternative testing methods. Two of 20 samples failed USP monographs for quality attributes. The additional analytical methods found 11 of 20 samples had different formulations when compared to the U.S. product. Seven of the 20 samples arrived in questionable containers, and 19 of 20 had incomplete labeling. Only 1 of the 20 samples had final packaging similar to the U.S. products. The non-traditional techniques complemented the traditional techniques used and highlighted additional quality issues for the products tested. For example, these methods detected suspect manufacturing issues (such as blending), which were not evident from traditional testing alone.