Qualitative and Quantitative Analysis of Counterfeit Fluconazole Capsules: A Non-invasive Approach Using NIR Spectroscopy and Chemometrics

The ultimate goal of the study is to present a method of authentication of hard-shell capsules of medicines packed in polyvinylchloride (PVC) blisters without damaging the primary packaging. This is done by collecting NIR spectra in a non-invasive mode and subsequent analysis of measurements by a one-class classification procedure. The first part of the study demonstrates that NIR spectra collected through a PVC blister and capsule shell do carry information about the medication itself. Firstly, this is done by visual inspection of spectra of the sample, its interfering layers and main pharmaceutical ingredients. Secondly, three regression models for quantification of active pharmaceutical ingredient (API) are built. The possibility of calibration and prediction of API through several nuisance layers using NIR spectroscopy is demonstrated. In order to solve the authentication problem the data driven soft Independent modeling of class analogies method is applied to the collected NIR spectra. The constructed model is validated using laboratory prepared mixtures. Afterwards, the model was applied to real counterfeited samples. Capsules of fluconazole are used for demonstration of the proposed approach."