Development of a system for in-line drug content testing using near infrared reflectance spectroscopy.

摘要

In today's competitive world, it is vital for companies to produce consistently high quality products at the lowest possible cost. Companies can achieve this goal if the production process is controlled by quick and reliable methods. The pharmaceutical industry analyses a small quantity of tablets using High Performance Liquid Chromatography and Ultraviolet spectroscopy and this analysis requires approximately three days. After this time, if the drug content is far from the one desired, the batch corresponding to those tablets can not be released for sale, and the time, effort and money placed on that product is wasted. Near-Infrared Spectroscopy (NIRS) offers a fast, easy and, perhaps most important, non-invasive and non-destructive analytical technique. The purpose of this research is to quantify the drug content of moving tablets with NIRS using the diffuse reflectance mode. A tungsten halogen light source was first used to directly illuminate the tablets, and the diffuse reflectance radiation was collected with the use of a fiber optic probe. The best signal to noise ratio was not achieved with this set up and the spectral acquisition was performed allowing the system to do signal averaging. This step made the system slower, so an improved optical system (a dual tungsten light source) was used in the second part of the research. Finally, a more stable conveyor belt was integrated to the system to reduce vibration. All these improvements allowed obtaining an approximate error of 4 mg in tablets with a total drug quantity of 75--125 mg of ibuprofen.