Abstract: This work describes a general framework for assessing the active pharmaceutical ingredient (API) and excipient concentrations simultaneously in pharmaceutical dosage forms based on laboratory-scale measurements. The work explores the comprehensive development of a near infrared (NIR) analytical protocol for the quantification of the API and excipients of a pharmaceutical formulation. The samples were based on a paracetamol (API) formulation with three excipients: microcrystalline cellulose, talc, and magnesium stearate. The developed method was based on laboratory-scale samples as calibration samples and pilot-scale samples (powders and tablets) as model test samples. Both types of samples were produced according to an experimental design. The samples were measured in reflectance mode in a Fourier-transform NIR spectrometer. Additionally, a new method for determining the minimum number of calibration samples was proposed. It was concluded that the use of laboratory-scale samples to construct the calibration set is an effective way to ensure the concentration variability in the development of calibration models for industrial applications. With this method, both API and excipients can be determined in high-throughput applications in the pharmaceutical industry.
Abstract: Near infrared spectroscopy (NIRS) has been extensively used as an analytical method for quality control of solid dosage forms for the pharmaceutical industry. Pharmaceutical formulations can be very complex, containing typically one or more active product ingredients (API) and various excipients, yielding very complex NIR spectra. Multivariate calibration is used to overcome the non-selectivity problem, which is a characteristic of NIRS. The NIR spectra interpretability can be improved using the concept of net analyte signal (NAS). NAS is defined as the part of the spectrum unique to the analyte of interest. The objective of this work was to compare two different methods to calculate the NAS vector while analyzing the advantages of the NAS based methodology. This assessment was made in a qualitative and this work it can be establish that the use of the NAS theory. From the results obtained it can be concluded that use of the NAS theory enhances the NIRS spectrum interpretability. Moreover, figures of merit such as sensitivity, selectivity, and limit of detection can be calculated in a straightforward manner, with the NAS theory.
Abstract: Terfenadine samples prepared by crystallization in different media and supersaturation conditions were used to investigate the polymorphism of the substance. The study was based on DSC melting curves. An empirical parametric equation was used for modelling the experimental data. The signal recorded was resolved into the corresponding overlapping peak components by fitting analysis. Four polymorphic phases were identified.
