Analytical technologies for real-time drug dissolution and precipitation testing on a small scale.
OBJECTIVE
This review focuses on real-time analytics of drug dissolution and precipitation testing on a comparatively small scale.


RESULTS
Miniaturisation of test equipment is an important trend in pharmaceutics, and several small-scale experiments have been reported for drug dissolution and precipitation testing. Such tests typically employ analytics in real-time. Fibre optic ultraviolet (UV) analytics has become a well-established method in this field. Novel imaging techniques are emerging that use visible or UV light; also promising is Fourier transform infrared imaging based on attenuated total reflection. More information than just a rate constant is obtained from these methods. The early phase of a dissolution process can be assessed and drug precipitation may eventually be observed. Some real-time techniques are particularly well suited to studying drug precipitation during formulation dispersion; for example, turbidity, focused beam reflectance measurement and Raman spectroscopy.


CONCLUSIONS
Small-scale dissolution tests equipped with real-time analytics have become important to screen drug candidates as well as to study prototype formulations in early development. Future approaches are likely to combine different analytical techniques including imaging. Miniaturisation started with mini-vessels or small vials and future assays of dissolution research will probably more often reach the level of parallel well plates and microfluidic channels.
Institute of Pharma Technology, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland.
Martin
M
Kuentz
D011232:Chemical Precipitation; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D065546:Drug Liberation; D005336:Fiber Optic Technology; D008027:Light; D004364:Pharmaceutical Preparations / Q000032:analysis*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
D004364:Pharmaceutical Preparations
drug dissolution; imaging; precipitation; real-time analytics; small-scale testing