CONICET | Buscador de Institutos y Recursos Humanos

tAlbendazole (ALB) is a broad-spectrum anthelmintic, which exhibits two solid-state forms (Forms I andII). The Form I is the metastable crystal at room temperature, while Form II is the stable one. Because thedrug has poor aqueous solubility and Form II is less soluble than Form I, it is desirable to have a methodto assess the solid-state form of the drug employed for manufacturing purposes.Therefore, a Partial Least Squares (PLS) model was developed for the determination of Form I of ALBin its mixtures with Form II. For model development, both solid-state forms of ALB were prepared andcharacterized by microscopic (optical and with normal and polarized light), thermal (DSC) and spectro-scopic (ATR-FTIR, Raman) techniques. Mixtures of solids in different ratios were prepared by weighingand mechanical mixing of the components.Their Raman spectra were acquired, and subjected to peak smoothing, normalization, standard normalvariate correction and de-trending, before performing the PLS calculations. The optimal spectral region(1396?1280 cm−1) and number of latent variables (LV = 3) were obtained employing a moving windowof variable size strategy.The method was internally validated by means of the leave one out procedure, providing satisfactorystatistics (r2= 0.9729 and RMSD = 5.6%) and figures of merit (LOD = 9.4% and MDDC = 1.4). Furthermore,the method?s performance was also evaluated by analysis of two validation sets. Validation set I wasused for assessment of linearity and range and Validation set II, to demonstrate accuracy and precision(Recovery = 101.4% and RSD = 2.8%). Additionally, a third set of spiked commercial samples was evaluated,exhibiting excellent recoveries (94.2 ± 6.4%).The results suggest that the combination of Raman spectroscopy with multivariate analysis could beapplied to the assessment of the main crystal form and its quantitation in samples of ALB bulk drug, inthe routine quality control laboratory.