Infrared imaging spectroscopy and chemometric tools for in situ analysis of an imiquimod pharmaceutical preparation presented as cream.
In the present work the homogeneity of a pharmaceutical formulation presented as a cream was studied using infrared imaging spectroscopy and chemometric methodologies such as principal component analysis (PCA) and multivariate curve resolution with alternating least squares (MCR-ALS). A cream formulation, presented as an emulsion, was prepared using imiquimod as the active pharmaceutical ingredient (API) and the excipients: water, vaseline, an emulsifier and a carboxylic acid in order to dissolve the API. After exposure at 45°C during 3 months to perform accelerated stability test, the presence of some crystals was observed, indicating homogeneity problems in the formulation. PCA exploratory analysis showed that the crystal composition was different from the composition of the emulsion, since the score maps presented crystal structures in the emulsion. MCR-ALS estimated the spectra of the crystals and the emulsion. The crystals presented amine and C-H bands, suggesting that the precipitate was a salt formed by carboxylic acid and imiquimod. These results indicate the potential of infrared imaging spectroscopy in conjunction with chemometric methodologies as an analytical tool to ensure the quality of cream formulations in the pharmaceutical industry.
Institute of Chemistry, University of Campinas - UNICAMP, P.O. Box 6154, 13083-970 Campinas, SP, Brazil. Electronic address: renato.lajarim@ufscar.br.
Renato Lajarim
RL
Carneiro
Ronei Jesus
RJ
Poppi
D000634:Aminoquinolines / Q000032:analysis* / Q000737:chemistry; D000077271:Imiquimod; D016018:Least-Squares Analysis; D015999:Multivariate Analysis; D025341:Principal Component Analysis; D063465:Skin Cream / Q000032:analysis*; D013055:Spectrophotometry, Infrared; D019265:Spectroscopy, Near-Infrared
D000634:Aminoquinolines; D000077271:Imiquimod
Imiquimod; Infrared imaging spectroscopy; Multivariate curve resolution; Pharmaceutical formulations analysis; Principal component analysis