Analysis and Stability Study of Octyl Nicotinate in Aqueous Solutions and Skin Homogenate by LC

Octyl nicotinate is an ester prodrug which is under development for delivery of nicotinic acid to skin for treatment and prevention of dermatological 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. We report here an isocratic RF-LC method with water/acetonitrile (10:90, v/v) as a mobile phase, for the rapid analysis of octyl nicotinate in aqueous solutions. The method was validated in terms of linearity, precision, accuracy and mean recovery of octyl nicotinate from skin homogenate ranging from 98.8 to 102.6%. Separation and quantification of amounts as low as 0.25 μg mL⁻¹ octyl nicotinate was accomplished. The kinetic of degradation of octyl nicotinate in aqueous solution at 310, 333, 343, and 353 K was studied. The hydrolysis rate constants for degradation of octyl nicotinate in phosphate buffer and skin homogenate were reported. This method will be effective for routine analysis of octyl nicotinate stability in different formulations in future studies.