Quantitative Characterization of Powder Blends for Tablets with Indapamide by Near-infrared Spectroscopy and Chemometry

A NIR-chemometric method, that is able to directly quantify the active pharmaceutical ingredient (API) and two major excipients in pharmaceutical powder blends for manufacturing indapamide sustained release (SR) tablets, was developed and fully validated. In order to develop calibration models for the assay of indapamide, hydroxypropylmehylcelulose (HPMC) and lactose, the NIR spectra of 25 series of powder blends (prepared according to an experimental design) were recorded. Further, they were analyzed by testing different pre-processing methods and using partial least-square regression (PLS). Using the best calibration models: Second Derivate (SD) for indapamide, First Derivate+Multiplicative Scatter Correction (FD+MSC) for HPMC and lactose, the methods were fully validated according to the ICH guidance. The validation results showed good precision, trueness and accuracy, between ±10% acceptance limits for the prediction of indapamide content and between ±5% acceptance limits for the prediction of lactose and HPMC content. Such quick NIR-chemometric methods require no sample preparation and successfully implement the Process Analytical Technology (PAT) concept in the manufacturing process of indapamide sustained release tablets.