Determination of the crushing strength of intact tablets using Raman spectroscopy.
In the present study, the Raman spectroscopy technique was used as a non-invasive, rapid analytical method for measuring the crushing strength of tablets. The compressed tablets were individually detected, using Raman spectroscopy, and the respective crushing strength values were measured, using a tablet hardness tester as a reference method. The tablets were compressed from a granule mass containing theophylline anhydrate as an active substance. For measuring the crushing strength of the tablets, Raman spectra were recorded from the tablets. Partial least squares (PLS) regression models were constructed to obtain information from the spectra. The correlation between measured and predicted crushing strength values for the tablets was shown to be very favorable. With Raman spectroscopy, shifting of the baseline was observed as the crushing strengths of tablets (and the smoothness of the tablet surface) were increased. Consequently, correlation between the crushing strength data on the present tablets and Raman spectra was observed. Multiple scanning electron (SEM) and non-contact laser profilometry (LP) micrographs from the surfaces of the tablets were taken to describe the surfaces and applied as supportive information for the proposed spectroscopy approach. In conclusion, Raman spectroscopy is a promising alternative for established off-line/at-line tablet-testing methods for some tablet formulations.
Virtanen
Satu
S
Division of Pharmaceutical Technology, 00014 University of Helsinki, P.O. Box 56, Helsinki, Finland. satu.virtanen@helsinki.fi
Antikainen
Osmo
O
Yliruusi
Jouko
J
D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000737:chemistry; D006244:Hardness; D006245:Hardness Tests / Q000295:instrumentation / Q000379:methods*; D007834:Lasers; D016018:Least-Squares Analysis; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D013607:Tablets; D013806:Theophylline / Q000008:administration & dosage / Q000737:chemistry
D001993:Bronchodilator Agents; D013607:Tablets; D013806:Theophylline