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: The development of facile and rapid quantification of biologically active biomolecules such as isotretitoin in therapeutic drugs contained in many generic formu- lations is necessary for determining their efficiency and their quality to improve the human health care. Isotretritoin finds its applications in the maintenance of epithelial tissues. Different processes to date such as normal phase HPLC, or gas chromatrography am- ong others are able to separate and quantify isote- troin. However, the extraction is quite complex and in the case of HPLC, the analysis requires long retention times. In such context, an isocratic reversed- phase high-performance liquid chromatography (HP- LC) technique coupled with an UV-vis detector is described here for easy separation and quantification of 13-cis-retinoic (isotretinoin) from soft gelatin capsule formulations. The isotretinoin was extracted from three different commercial drug samples with tetrahydrofuran (THF) solvent by a procedure that can be completed in less than 10 minutes. Subsequent separation and quantification were accomplished in less than 5 minutes under isocratic reversed-phase conditions on a Lichrospher RP18 column and a mobile phase consisting of 0.01% TFA/acetonitrile (15/85, v/v) at a flow rate of 1.0 mL/min. Isotretoin was detected for the three samples via its UV-vis absorbance at 342 nm. The method was validated and the results showed good linearity, precision and accuracy for sensitive and selective quantitative determination of isotretinoin in the different pharmaceutical formulations. We found that the average isotretinoin content in two of the three commercial pro- ducts fell outside the 90-110% United States Pha- rmacopeia specifications. Consequently, the facile extraction and the precise method for the biomole- cule quantification open up tremendous possibilities in improving the quality control of drugs which can exist as different generic brands.Journal of Biomedical Science and Engineering 05/2010; 3(5):454-458. DOI:10.4236/jbise.2010.35063
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ABSTRACT: A simple, precise and accurate high performance thin layer chromatographic method has been developed for the simultaneous estimation of Isotretinoin and Erythromycin in pharmaceutical gel. The separation was car-ried out on Merck TLC aluminum sheets of silica gel 60 F 254 , (20 × 10 cm) with 250 µm thickness using toluene: DMSO: methanol (6.5:0.2:2.5, v/v/v) as a mobile phase. HPTLC separation of the two drugs fol-lowed by densitometric measurement of their spots at 340 nm for Isotretinoin before derivatization and 410 nm for Erythromycin after derivatization with 10% H 2 SO 4 and heating at 100C for 15 min. The drugs were satisfactorily resolved with R F values of 0.38 ± 0.02 and 0.55 ± 0.02 for Isotretinoin and Erythromycin, re-spectively. The accuracy and reliability of the method was assessed by evaluation of linearity (30-150 ng spot -1 for Isotretinoin and 1200-6000 ng spot -1 for Erythromycin), precision (intra-day RSD 0.62-0.79% and inter-day RSD 0.43-0.71% for Isotretinoin and intra-day RSD 0.47-1.71% and inter-day RSD 0.42-1.49% for Erythromycin), accuracy (98.91 ± 0.92% for Isotretinoin and 99.27 ± 0.72% for Erythromycin), and specific-ity, in accordance with ICH guidelines.American Journal of Analytical Chemistry 01/2010; 01(03). DOI:10.4236/ajac.2010.13018
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ABSTRACT: The chemical stability of tretinoin (RA) and isotretinoin (13RA) in ethanol and dermatological cream preparations exposed to solar simulated light (SSL), UVA, and visible light has been studied. Photostability was monitored by an HPLC method that allowed simultaneous analysis of RA and 13RA, thus allowing photodegradation due to isomerization to other retinoids and photolysis to non-retinoid products to be monitored. Both retinoids undergo both isomerization and photolysis following SSL, UVA and visible light exposure but RA is more sensitive to photodegradation than 13RA. Degradation of both retinoids by photolysis is considerably greater in cream formulations than in ethanol and the photodegradation follows second order kinetics. Rate constants and half-lives for degradation of RA and 13RA in ethanol solution and cream preparations subjected to different light sources are reported. The UVA component of SSL is the major contributor to photodegradation. Since UVA penetrates deeply into skin, our results suggest that photodegradation of RA may contribute to the photosensitivity associated with RA therapy. Our studies suggest that development of improved formulations and the use of effective UVA sunscreens may reduce the side effects of RA therapy.International Journal of Pharmaceutics 04/2008; 352(1-2):123-8. DOI:10.1016/j.ijpharm.2007.10.045 · 3.79 Impact Factor