Chemical identity testing by remote-based dispersive Raman spectroscopy

The advent of robust, rugged, and current Good Manufacturing Practices (cGMP) compliant hand-held Raman spectrometers provides a wealth of opportunities for the analytical pharmaceutical chemist to bring the laboratory to the sample. This paper discusses the use of hand-held Raman spectrometers for the development of qualitative chemical identification methods for a number of well-known pharmaceutical products (tablets and capsules). Methods were developed on two different instruments and transferred to a third instrument for application of the methodology to independently obtained drug products. A novel decision algorithm is presented for the assessment of the correlation between the Raman spectrum of the unknown sample to the spectrum of the authentic reference material. This novel algorithm considers accuracy but more importantly precision (uncertainty/reliability), thus removing human bias that is associated with typical spectral searching approaches. The results presented in this paper show the reliability of developing, validating, and transferring chemical identification assays on hand-held Raman spectrometers.