Browsing by Author "Lopez-Yunez, Alfredo"

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    Detecting Counterfeit Pharmaceuticals through UV Spectrophotometry
    (Office of the Vice Chancellor for Research, 2015-04-17) Figueroa, Gabriela; Palacio, Luis A.; Ray, Bruce D.; Petrache, Horia I.; Lopez-Yunez, Alfredo
    According to the World Health Organization between 10%-30% of medicines, in Africa, Asia and South America, are counterfeit or sub-standard, affecting the health of millions of people. Currently, there is no effective way to check the quality of a medicine at the point of care, leaving many with treatable diseases at risk. The goal of this study is to identify UV-Vis (240nm - 500nm) absorbance patterns that would indicate if a drug is sub-standard or counterfeit. UV-Vis spectroscopy was selected as the method for testing due to the maturity and availability of the technology. Pure Acetaminophen and Tylenol were used as controls for proof of concept. Samples were prepared by dissolving different combinations of the pure active ingredient and adulterants such as cement, rice flour, vitamin C and lactose in three different types of solvents (H2O, 0.1 M HCl, 0.1 NaOH). Various concentrations (ranging from 0.01mg/ml to 0.04mg/ml) and mixing ratios were analyzed using a UV-Vis Spectrophotometer. It was found that adulterants significantly decrease the absorption of acetaminophen at 245nm by interacting with its benzene ring, while showing a slight increase in other parts of the spectrum. UV-Vis scans show that the amount of change in absorbance at specific wavelengths, coupled with characteristic wavelength shifts produced by different solvents, can be used for detection of counterfeit drugs. The methods presented here could be used for quality control of medicines at or near the point of care in parts of the world at higher risk of encountering defective pharmaceuticals.
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    Finding Active Ingredients in Pharmaceuticals by UV Spectrophotometry
    (Office of the Vice Chancellor for Research, 2014-04-11) Figueroa, Gabriela; Palacio, Luis A.; Ray, Bruce D.; Petrache, Horia I.; Lopez-Yunez, Alfredo
    The active ingredient in any pharmaceutical is the chemical that will ultimately deliver the desired effect on a patient. Knowing the quality and the quantity of the active ingredient in a pill right before ingestion is of paramount importance for the patient’s health and the desired results. Unfortunately drugs only undergo quality control testing at the manufacturing plant but not at the point of sale. Moreover, to an untrained eye, one pill may not appear different from another and if the wrong pill or the wrong dose is taken, adverse health effects may arise. Indeed, manufacturers of counterfeit drugs rely on these two points of appearance and testing. In this study we examine whether ultra violet (UV) spectrophotometry absorbance can be used to separate an active ingredient’s UV peaks from the combination of peaks generated by the inactive ingredients of the tablet. A well-understood active ingredient, acetaminophen, was used for this study. Samples were prepared by crushing Tylenol tablets, dissolving the powder in different solvents (0.1M HCl, 0.1M NaOH, and H2O) at various concentrations and mixed by vortex. After preparation, the samples were measured by UV Spectroscopy. Experimental results were compared to standard UV curves for the pure active ingredient to correlate the observed changes in absorbance within the relevant UV wavelength range. We observe that more than one solvent is needed to identify the active ingredient. Development of a simple method to accurately identify the quality of the active ingredient will provide an additional safeguard to consumers, particularly in regions where counterfeit drugs are prevalent.