Quantitative characterization of sustained release tablets with diclofenac sodium by means of near-infrared spectroscopy and chemometry

Abstract

A NIR-chemometric method for direct quantitative determination of diclofenac sodium and two major excipients (matrix-forming excipient and diluent) in sustained release, inert matrix type tablets was developed. The 26 tablet batches were prepared according to an experimental design. The NIR spectra of samples were recorded in the transmittance mode and the spectral ranges were selected using Principal Component Analysis (PCA), scores plot and loadings plot. Multiple pre-processing methods were tested and 6 multivariate models for quantitative determination were developed based on partial least squares (PLS) methodology for each substance. The models with the best prediction capability were fully validated in accordance with the current guidelines and regulations. Validation results showed that the methods have good precision, trueness and accuracy. The tolerance limits were ± 10% for diclofenac sodium assay and ± 5% for Kollidon® SR and lactose DC (direct compressible), respectively.