| Titre : |
Photostabilization of ascorbic acid with citric acid, tartaric acid and boric acid in cream formulations |
| Type de document : |
texte imprimé |
| Auteurs : |
I. Ahmad, Auteur ; M. Ali Sheraz, Auteur ; S. Ahmed, Auteur ; Z. Shad, Auteur ; F. H. M. Vaid, Auteur |
| Année de publication : |
2012 |
| Article en page(s) : |
p. 240-245 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Cinétique chimique
Cosmétiques
Formulation (Génie chimique)
Photodétérioration
Stabilisants (chimie)
Vitamine C
|
| Index. décimale : |
668.5 Parfums et cosmétiques |
| Résumé : |
This study involves the evaluation of the effect of certain stabilizers, that is, citric acid (CT), tartaric acid (TA) and boric acid (BA) on the degradation of ascorbic acid (AH2) in oil-in-water cream formulations exposed to the UV light and stored in the dark. The apparent first-order rate constants (0.34–0.95 × 10−3 min−1 in light, 0.38–1.24 × 10−2 day−1 in dark) for the degradation reactions in the presence of the stabilizers have been determined. These rate constants have been used to derive the second-order rate constants (0.26–1.45 × 10−2 M−1 min−1 in light, 3.75–8.50 × 10−3 M−1 day−1 in dark) for the interaction of AH2 and the individual stabilizers. These stabilizers are effective in causing the inhibition of the rate of degradation of AH2 both in the light and in the dark. The inhibitory effect of the stabilizers is in the order of CT > TA > BA. The rate of degradation of AH2 in the presence of these stabilizers in the light is about 120 times higher than that in the dark. This could be explained on the basis of the deactivation of AH2-excited triplet state by CT and TA and by the inhibition of AH2 degradation through complex formation with BA. AH2 leads to the formation of dehydroascorbic acid (A) by chemical and photooxidation in cream formulations. |
| Note de contenu : |
- MATERIALS AND METHODS : Preparation of cream formulations - pH measurements - Spectral measurements - Light intensity measurements - Photolysis of cream formulations - Thin-layer chromatography (TLC) of photolysed creams - Assay of ascorbic acid in creams
- RESULTS AND DISCUSSION : Products of ascorbic acid photodegradation - Spectral changes in photodegraded creams - Assay of ascorbic acid in creams - Kinetics of photodegradation - Effect of stabilizers - Statistical evaluation of stabilizers and concentration - Degradation of AH2 in presence of stabilizers in the dark - Mode of interaction |
| DOI : |
10.1111/j.1468-2494.2012.00708.x |
| En ligne : |
http://onlinelibrary.wiley.com/doi/10.1111/j.1468-2494.2012.00708.x |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=15034 |
in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE > Vol. 34, N° 3 (06/2012) . - p. 240-245
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Photostabilization of ascorbic acid with citric acid, tartaric acid and boric acid in cream formulations in INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Vol. 34, N° 3 (06/2012)
