Study On New Fast Methods Of Raman Spectroscopy For Testing Counterfeit Drugs

The drug safety affects people’s quality of life, physical health and even risks theirlives. It also concerns the economic development, social stability, and it even related toproliferation of ethnic. During the past decades, there has been a marked increase in thenumber of reported case of drug safety. Counterfeit pharmaceutical products have becomea serious worldwide problem, especially in the developing countries. Many methods havebeen developed to identify the counterfeit(s) and adulterant(s), including chemistry,spectroscopy, and chromatographic separation-based methods. Some chromatographymethods which have served as the resort along this track of analytical strategy, such as highperformance liquid chromatography coupled with mass spectrometry (HPLC-MS).However, complicated operations and costly equipments of these technologies restrictedtheir applicability, especially for the developing areas/countries. In the contrary,spectroscopy has the natural advantage of convenient, cheap and fast for the prescreeningpurpose.In this study, we establish two typies of simple and fast methods based on Ramanspectroscopy and chemometrics to determine the counterfeit drugs without any samplepretreatment. One is the system of counterfeit drugs discriminant analysis, which includedthree analytical modules. The other is the method based on the Raman spectroscopy anddiscriminative model with small training set to determination of hypoglycemic drugs.Part ⅠThe system of rapid detection of counterfeit drugs: The system is proposedaccording to the characteristics of Raman spectrums of active pharmaceutical ingredientand true drugs. The system consists of three modules. They are overall spectrum module,characteristic segment spectrum module and characteristic peaks module, whichdiscriminate the possible counterfeit(s) from point, line and flat angles, respectively. Thesecond module is the core of the system. This module applies the convolution function ofconvolution spectroscopy to Raman spectroscopy; one spectrum can be converted intohundreds of thousands of convolution curve. According to the characteristic of theconvolution curve, some characteristic segments of the convolution curve are screened todetermine the counterfeit drugs, so we call the module, convolution curve screening (CCS)method. The algorithms are exemplified by six kinds of hypoglycemic (glibenclamide,gliclazide, pioglitazone, glipizide and Acarbose) tablets and12common pharmaceuticalexcipients. The total sensitivity, specificity, accuracy and efficiency reach97.50%,100.0%,99.60%and96.35%respectively. Part Ⅱ Determination of hypoglycemic drugs by Raman spectroscopy-discriminativemodel with small training set. In order to discriminate hypoglycemic drugs by the Ramanspectroscopy technology, six kinds of hypoglycemic tablets, including106samples, weregathered and analyzed using a portable Raman spectrometer. The sample data werepretreated with the methods of baseline correction, smoothing and vector normalization,followed by principal component analysis (PCA). The anterior10principal componentswere then used as the new variables, and analyzed by Fisher multi-types linear discriminate,Bayes multi-types stepwise discriminate, K-nearest neighbor (KNN) and radial basisfunction (RBF) neural network algorithm, respectively. The results demonstrated that eachof the four methods provided rapid, non-destructive identification of hypoglycemic drugs.The most prominent among them is PCA combined with the method of Bayes multi-typesstepwise discriminate analysis, which offers an effective approach to the rapiddiscrimination of different kinds of hypoglycemic tablets.The study will provide an effective preliminary screening technique for considerablecounterfeit(s) with high rapidity, accuracy and cost-effectiveness. The methods areconsidered to be of great importance in the food, drug and health care products market toensure the people’s safety and health.