Myristyl nicotinate is an
ester prodrug under development for delivery of
nicotinic acid to skin for treatment and prevention of conditions that involve skin barrier impairment such as chronic photodamage and
atopic dermatitis or for mitigating skin barrier impairment that results from
therapy such as
retinoids or
steroids. The formulation stability of
myristyl nicotinate is crucial because even small amounts of free
nicotinic acid cause skin
flushing, an effect that is not harmful but would severely limit tolerability. We report here reversed-phase HPLC methods for the rapid analysis of
myristyl nicotinate and
nicotinic acid in dermatological preparations. Because of the large differences in polarity,
myristyl nicotinate and
nicotinic acid were analyzed by different chromatographic conditions, but they can be rapidly extracted from cream formulations using HPLC mobile phase as a
solvent followed by HPLC analysis in less than 10 min. The methods were validated in terms of linearity, precision and accuracy and mean recovery of
myristyl nicotinate from topical creams ranged from 97.0-101.2%.
Nicotinic acid at levels of 0.01% in the formulations could be quantified. Stability studies show that
myristyl nicotinate formulations are stable at room temperature for 3 years with less than 0.05% conversion to
nicotinic acid. These methods will be effective for routine analysis of
myristyl nicotinate stability in dermatological formulations.