Abstract: Methods and apparatus (10) for Raman spectral analysis of a sample (12), such as a pharmaceutical dosage form, are disclosed. Delivery optics (16) are used to deliver probe light to a delivery region (13) on the sample, and collection optics (20) are used to collect, from a collection region (17) on the sample spaced from the delivery region, the probe light following scattering through the sample. Each of a plurality of target Raman spectral features are measured in the collected light, and a spectral distortion of the collected light arising during scattering through the sample is determined. A property of the sample is then quantified using the target Raman spectral features in combination with the determined spectral distortion, such that the quantified property is compensated for the spectral distortion.

Abstract: There are disclosed methods and apparatus for automatic analysis of pharmaceutical dosage forms. In some aspects a dosage form may be grasped by a gripper which is used to bring the dosage form to a test location and to present the dosage form in a plurality of different alignments between delivery and collection optics. Probe light scattered through the dosage form is collected during each alignment. The collected probe light for the plurality of alignments is then used for Raman spectral analysis of the dosage form. In other aspects a rotation stage is used to rotate a dosage form on the stage to a preferred alignment before being grasped by a gripper. The gripper is then used to carry the dosage form to the test location for optical analysis.

Abstract: Apparatus for carrying out spatially offset Raman spectroscopy (SORS) is described. The apparatus comprises a rotatable prism arranged such that a spatial offset between an entry region and a collection region at a sample is dependent upon an angle of rotation of the prism.