Ja. Jones et al., DEVELOPMENT AND TRANSFERABILITY OF NEAR-INFRARED METHODS FOR DETERMINATION OF MOISTURE IN A FREEZE-DRIED INJECTION PRODUCT, Journal of pharmaceutical and biomedical analysis, 11(11-12), 1993, pp. 1227-1231
Near-infrared reflectance (NIR) methods for non-invasive and non-destr
uctive measurement of moisture in a lyophilized product were developed
independently at two sites. NIR spectra were collected with the same
model instrument at each site. The spectra were scanned through the ba
ses of unopened glass vials using a horizontal instrument accessory. T
he primary reference data for moisture content were generated using Ka
rl-Fischer titration on the same individual vials. The NIR calibration
equations were developed with second derivative; spectral data using
regression programs within the NIR software. These calibration equatio
ns were validated using independent test data from additional vials of
product from the original site, and cross tested against similar data
from the other site to check their robustness. This cross comparison
demonstrated that a calibration equation from one site could satisfact
orily be used for predicting moisture contents in product manufactured
at the other site. Expected variations arising from differences in vi
al material, manufacturing process, analysts and instruments appeared
to be satisfactorily accommodated. Finally, two test data sets were ob
tained by scanning a set of samples on two spectrometers at one site.
The results from these data sets were comparable using the calibration
equation developed solely on one of the two instruments. The results
from all calibration and lest sets are presented and discussed, and an
assessment of the method transferability between instruments and site
s is given.