Fast assessment of the surface distribution of API and excipients in tablets using NIR-hyperspectral imaging

This paper puts forward a methodology to study the surface distribution of the compounds in tablets with low content of API. The methodology encompasses the possibility of scanning the surface of the tablet by using NIR hyperspectral spectroscopy with multivariate curve resolution (MCR) to obtain selective pictures for each individual compound and to study their distribution in the surface measured in a fast way. As an example of the performance of the proposed methodology commercial Lorazepam tablets (1% mass fraction of API approximately and four excipients) were analyzed. The results obtained show the ability of the proposed methodology to use as an expedite approach to evaluate the uniformity of the contents between and within tablets. Also a procedure to estimate the homogeneity distribution of API in the two halves of the tablet is proposed. The inclusion of hyperspectral imaging systems in the manufacturing and development of pharmaceutical products is allowing a successful improvement in the quality control of solid dosage forms. The correct distribution not only of active pharmaceutical ingredient (API) but also of the rest of excipients is essential to assure the correct behavior of the tablet when ingested. This is especially relevant in tablets with low content of potent APIs, in which the prescribed intake dosage frequently corresponds to half-a-tablet. Therefore, the aim of this work is to study the surface distribution of the compounds in tablets with low API content. The proposed procedure includes the scanning of the tablet surface using near infrared hyperspectral spectroscopy in association with multivariate curve resolution (MCR) techniques to obtain selective pictures for each individual compound and to allow the fast assessment of their distribution in the measured surface. As an example, a set of commercial Lorazepam tablets (approximately 1% mass fraction of API, and four excipients) were analyzed. The results obtained show the capacity of the proposed methodology as an expedite approach to evaluate the uniformity of the contents between and within tablets. A method to estimate the homogeneity distribution of API in the two halves of the tablet is also proposed.