Use of near-infrared spectrometry for quantitative determinations of selamectin and moisture in topical formulations.
A rapid near-infrared spectrometric (NIR) method was qualified for use with the quantitative analysis of selamectin and moisture in topical formulations. Selamectin is currently marketed as a pet endectocide and is available in several formulations for cats and dogs. The use of NIR in this investigation replaces the in-process testing by liquid chromatography and concurrently provided moisture content that would otherwise only be available with additional Karl Fischer titration investigations. A seven-factor partial least square regression (PLS) of the second derivative spectra encompassing the wavelength region of 1450-2200 nm was used to quantify both selamectin and moisture content. A second three-factor PLS solely for water content was also applied and compared with the full model. This qualification confirms that this method may be used to quantitate selamectin and moisture as a process tool or to examine finished good samples. Each sample can be rapidly analyzed within 5 min on the current bench top system.
Webster
Gregory K
GK
Quality Operations, Pfizer Global Manufacturing, One Pfizer Way, Lee's Summit, MO 64081, USA. greg.webster@pfizer.com
Farrand
Douglas A
DA
Johnson
Erin
E
Litchman
Mark A
MA
Broad
Neville
N
Maris
Simon
S
D000977:Antiparasitic Agents / Q000032:analysis*; D002138:Calibration; D002853:Chromatography, Liquid; D006813:Humidity; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000032:analysis*; D016018:Least-Squares Analysis; D009824:Ointments; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet; D019265:Spectroscopy, Near-Infrared
D000977:Antiparasitic Agents; D009824:Ointments; D007559:Ivermectin; C414354:selamectin