A rapid HPLC method for simultaneous determination of tretinoin and isotretinoin in dermatological formulations.
ABSTRACT A rapid method using an isocratic high-pressure liquid chromatography and UV detection for determination of both all-trans retinoic acid (tretinoin) and 13-cis retinoic acid (isotretinoin) in dermatological preparations is presented. Tretinoin and isotretinoin samples were extracted with acetonitrile by a procedure that can be completed in less than 10 min. Subsequent separation and quantification of amounts as low as 10 pmol was accomplished in less than 15 min using reversed-phase HPLC with isocratic elution with 0.01% trifluoroacetic acid (TFA)/acetonitrile (15:85, v/v). Validation experiments confirmed the precision and accuracy of the method. When applied to commercial tretinoin samples, recoveries of 104.9% for cream formulations and 107.7% for gel formulations were obtained. Application of the method for analysis of a tretinoin cream exposed to solar simulated light (SSL) demonstrated detection of the major photoisomerization product isotretinoin as well as 9-cis retinoic acid, demonstrating the utility of the method for studies of tretinoin photostability. The method should also facilitate studies of the formulation compatibility and photocompatibility of tretinoin with agents that may improve its clinical tolerability.
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ABSTRACT: Ultradeformable vesicles are highly promising tools to enhance the percutaneous transport of different drugs such as tretinoin across the skin barrier, and also to increase the formulationstability at absorption site and reduce the drug induced irritation.European Journal of Pharmaceutics and Biopharmaceutics. 05/2014;
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ABSTRACT: During the last years, the EU market is flooded by illegal cosmetics via the Internet and a so-called "black market". Among these, skin-bleaching products represent an important group. They contain, according to the current European cosmetic legislation (Directive 76/768/EEC), a number of illegal active substances including hydroquinone, tretinoin and corticosteroids. These may provoke as well local as systemic toxic effects, being the reason for their banning from the EU market. To control this market there is a need for a fast screening method capable of detecting illegal ingredients in the wide variety of existing bleaching cosmetic formulations. In this paper the development and validation of an ultra high pressure liquid chromatographic (UHPLC) method is described. The proposed method makes use of a Waters Acquity BEH shield RP18 column with a gradient using 25mM ammonium borate buffer (pH 10) and acetonitrile. This method is not only able to detect the major illegal (hydroquinone, tretinoin and six dermatologic active corticosteroids) and legal whitening agents, the latter having restrictions with respect to concentration and application (kojic acid, arbutin, nicotinamide and salicylic acid), but can also quantify these in a run time of 12min. The method was successfully validated using the "total error" approach in accordance with the validation requirements of ISO-17025. During the validation a variety of cosmetic matrices including creams, lotions and soaps were taken into consideration.Journal of pharmaceutical and biomedical analysis 05/2013; 83C:82-88. · 2.45 Impact Factor
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ABSTRACT: Seborrheic keratosis is one of the most common skin benign tumors in humans with a high occurrence rate of 80%-100% in people of >50 years of age; however, its pathogenesis is still unclear. The standard treatment includes cryotherapy and laser surgery for physically removing lesions. Drug therapy for this condition has not been well established. We aimed to evaluate the use of all-trans retinoic acid (ATRA)-loaded microneedle (MN) patches as a simple, alternative therapeutic option to traditional surgical treatments. This therapeutic strategy was designed to induce the proliferation of basal keratinocytes and accelerate stratum corneum turnover, leading to the lesion falling off the surface of the skin. The MN patch induced epidermal hyperplasia and marked expression of heparin-binding epidermal growth factor-like growth factor mRNA and protein corresponding to ATRA activity in the skin of HR-1 hairless mice. The acceleration of stratum corneum turnover was also observed by the dansyl chloride method. The skin irritation study in mice and safety study in humans support the safety findings of our study. Overall, MN patches can offer an effective and safe means of ATRA delivery into the skin, and the ATRA-loaded MN patch appears to be an effective pharmaceutical product providing a novel therapeutic option for seborrheic keratosis.Journal of Controlled Release 06/2013; · 7.63 Impact Factor