Homogeneity analysis of medicine tablets by laser induced breakdown spectroscopy combined with multivariate methods

Abstract

Pharmaceutical tablets need to have a homogenous chemical structure, especially in cases where the patient may divide the tablet in half prior to consumption. This work aims to demonstrate the viability of using laser induced breakdown spectroscopy (LIBS) for analyzing the homogeneity and determining the chemical composition of losartan potassium tablets. This was accomplished by obtaining the spectra of 10 tablet points in 30 successive laser pulses, which revealed four main peaks (C, H, N, and O) as well as a high concentration of calcium and potassium in the core tablets and titanium in the coating—all of which are excellent analytical objectives for LIBS. It is possible to say that the generated plasma meets the minimum requirement for local thermodynamic equilibrium because the physical parameters of the plasma, including temperature (T) and electronic density (N_e), were calculated throughout the Boltzmann plot and Stark broadened line, respectively, and the McWhirter criterion was met. In addition, T and N_e changes have been used for homogeneity analysis. Different peak comparisons cannot provide us with further data because the major structural components are similar, making it challenging to differentiate between them. So relative standard deviation (RSD) and principal component analysis (PCA) were used to comprise the whole spectra, which showed that the homogeneity of the tablet’s core is better than that of the coating and is acceptable.