Mj. Thompson et al., LC STUDIES ON THE POTENTIAL INTERACTION OF PARABEN PRESERVATIVES WITHSORBITOL AND GLYCEROL, Journal of pharmaceutical and biomedical analysis, 11(3), 1993, pp. 233-240
Pharmaceutical formulations often contain one or more paraben preserva
tives in conjunction with a polyol such as sorbitol or glycerol. In on
e of these experimental formulations a number of unknown polar peaks h
ave been detected near the solvent front by reversed-phase LC. These d
egradation products were not attributable to the active drug component
or a hydrolysis product. The possibility of an interaction between th
e polyols and paraben preservatives has been explored using a three-va
riable, two-level, factorial design to determine the relative signific
ance of the factors involved in the formation of these unknown peaks.
The factors examined were pH, temperature and the ratio of polyol to p
araben. This study has shown that pH and temperature are key factors a
ffecting the formation of these unknown peaks. On the basis of these r
esults suitable conditions can be suggested for minimizing the product
ion of these unknown peaks. It seems clear that a number of pharmaceut
ical formulations containing a polyol and a paraben would present pote
ntial problems for assay validation on storage owing to the formation
of these degradation products, particularly if the drug component is p
olar and elutes near the solvent front.