What is the new method for rapid detection of counterfeit drugs?

In here, we establish two typies of simple and fast methods based on Raman spectroscopy and chemometrics to determine the counterfeit drugs without any sample pretreatment. One is the system of counterfeit drugs discriminant analysis, which included three analytical modules. The other is the method based on the Raman sectroscopy and discriminative model with small training set to determination of hypoglycemic drugs.

Prat 1 The system of rapid detection of counterfeiy frugs: The system is proposed according to the characteristics of Raman spectrums of active pharmaceutical ingredient and true drugs. The system consists of three modules. They are overall spectrum module, characteristic segment spectrum module and characteristic peaks module, which discriminate the possible counterfeit(s) from point, line and flat angles, respectively. The second module is the core of the system. This module applies the convolution function og convolution spectroscopy to Taman spectroscopy; one spectrum can be converted into hundreds of thousands of convolution curve. According to the characteristic of the  covolution curve, some characteristic segments of the convolution curve are screened to determine the counterfeit drugs, so we call the module, convolution curve screening (CCS) method. The algorithms are exemplified by six kinds of hypoglycemic (glbenclamide, gliclazide, pioglitazone, glipizide and Acarbose) tablets and 12 commonn pharmaceutical excipient. The total sensitivity, specificity, accuracy and efficiency reach 97.50%, 100.0%, 99.60% and 96.35% respectively.

Part 2 Determination of hypoglycemic drugs by Raman spectroscopy-discriminative model with small training set. In order to discriminate hypoglycemic drugs by the Raman spectroscopy technology, six kinds of hypoglycemic tablets, including 106 samples, were gathered and analyzed using a portable Raman spectrometer. The sample data were pretreated with the methods of baseline correction, smoothing and vector normalization, followed by principal component analysis (PCA). The anterior 10 principal components were then used as the new vatiables, and analyzed by Fisher multi-types linear discriminate, Bayes multi-types stepwise discriminate, K-nearest neighbor (KNN) and radial basis function (RBF) neural network algorithm, respectively. The results demonstrated that each of 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-types stepwise discriminate analysis, which offers an effective approach to the rapid discrimination of different kinds of hypoglycemic tablets.

The study will provide an effective preliminary screening technique for considerable counterfeit(s) with high rapidity, accuracy and cost-effectiveness. The methods are considered to be of great importance in the food, drug and health care products market to ensure the people's safety and health.

Raman spectroscopy has the advantages of no sample pretreatment, less sample consumption, non-destructive, etc.

The emergence of fiberRaman spectroscopy has the advantages of no sample pretreatment, less sample consumption, and non-destructive. In addition to the emergence of CCD detectors, fiber probe sampling and portable Raman spectrometers, there are many chemical mode discrimination methods and modelless analysis The improvement and development make it have a good application prospect in the rapid detection of counterfeit drugs.-optic probe sampling and portable Raman spectrometers are accompanied by multiple chemical mode discrimination methods and model-free analysis.

The improvement and development of the analytical method make it have a good application prospect in the rapid detection of fake drugs.

On the other hand, with the crackdown on counterfeit drugs, counterfeit and inferior drugs are becoming more and more complicated, and some "high-tech" counterfeit drugs can even pass all indicators of the species in the pharmacopoeia, so new relevant countermeasures need to be studied.

At the same time, the existing methods do have some shortcomings, such as the pattern recognition method is too tedious and time-consuming; the model-free analysis method still needs to solve some bottlenecks in improving the accuracy of the results and the robustness of the method. Pretreatment methods need to be further improved and so on. Therefore, according to the characteristics and difficulties of the rapid detection of counterfeit drugs, we should not stick to experience and conventions, develop or configure suitable portable Raman spectrometers, select sampling and analysis methods according to local conditions, and then provide special and easy-to-use comprehensive discriminant analysis system software. With a complete set of solutions, it really provides an effective technical support for the rapid detection of counterfeit drugs.