A novel rapid quantitative analysis of drug migration on tablets using laser induced breakdown spectroscopy

There have been few reports wherein drug migration from the interior to the surface of a tablet has been analyzed quantitatively until now. In this paper, we propose a novel, rapid, quantitative analysis of drug migration in tablets using laser induced breakdown spectroscopy (LIBS). To evaluate drug migration, model tablets containing nicardipine hydrochloride as active pharmaceutical ingredient (API) were prepared by a conventional wet granulation method. Since the color of this API is pale yellow and all excipients are white, we can observe the degree of drug migration by visual inspection in these model tablets. In order to prepare tablets with different degrees of drug migration, the temperature of the drying process after tableting was varied between 50 to 80 °C. Using these manifold tablets, visual inspection, Fourier transform (FT)-IR mapping and LIBS analysis were carried out to evaluate the drug migration in the tablets. While drug migration could be observed using all methods, only LIBS analysis could provide quantitative analysis wherein the average LIBS intensity was correlated with the degree of drug migration obtained from the drying temperature. Moreover, in this work, we compared the sample preparation, data analysis process and measurement time for visual inspection, FT-IR mapping and LIBS analysis. The results of the comparison between these methods demonstrated that LIBS analysis is the simplest and the fastest method for migration monitoring. From the results obtained, we conclude that LIBS analysis is one of most useful process analytical technology (PAT) tools to solve the universal migration problem.