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Vitamin A palmitate photostability and stability over time.
J Cosmet Sci. 2004 May-Jun; 55(3):233-52.JC

Abstract

Vitamin A palmitate photostability in relation to UVA and UVB was tested in hydroxy ethyl cellulose hydrogels at pH 4.0, 5.6, 7.0, and 8.0, alone and with the addition of sunscreens (3,4-methylbenzilidencamphor or butyl methoxy dibenzoylmethane) or an antioxidant (butylated hydroxy toluene). The photostability of vitamin A palmitate was also tested in encapsulated systems (Tagravit A1 microcapsules, Lipotec liposomes, phosphatidylcholine liposomes, and Lipotec nanocapsules) dispersed in gels at pH 5.6 and 7.0. The stability of retinyl palmitate over time in hydroxy ethyl cellulose hydrogels at pH 5.6 and 7.0 (stored one month at 25 degrees C or 40 degrees C), alone or with butylated hydroxy toluene, was also tested. The stability of retinyl palmitate over time in encapsulated systems, dispersed in gels at pH 5.6 and 7.0, was also studied. O/W emulsions were also prepared to compare the stability of vitamin A palmitate introduced in a lipophilic/hydrophilic medium (O/W emulsions) and a hydrophilic medium (hydrogels). HPLC analysis showed that encapsulated systems such as Lipotec nanocapsules, Tagravit A1 microcapsules, phosphatidylcholine liposomes, and Lipotec liposomes protect the vitamin A ester over time from hydrolysis and from oxidation to retinaldeide and retinoic acid, and that Lipotec nanocapsules and phosphatidylcholine liposomes also improve the vitamin's photostability. A change in pH (from 5.6 to 7.0) of the gels did not influence the vitamin ester's stability. pH levels of 4.0 and 8.0 determined a decrease in the stability of retinyl palmitate in the gels. A high concentration of sunscreens improved the photostability of retinyl palmitate in the gels at pH 5.6 and 7.0. Butylated hydroxy toluene protected retinyl palmitate from degradation induced by light at all the pH levels studied and by heat at pH 5.6 and 7.0, as can be seen from the study of the photostability of vitamin A palmitate under UVB and UVA and of stability over time. Rheological studies showed a slight decrease in the viscosity of the gels after UVB-UVA irradiation and a higher decrease in the viscosity of the gels and the emulsions after storage at 25 degrees C and 40 degrees C. This decrease can be attributed to a partial degradation of hydroxy ethyl cellulose and of emulsifier, as can be seen from the decrease in shear stress versus shear rate values under these conditions of storage, denoting a depolymerization of the rheological modifier.

Authors+Show Affiliations

Dipartimento di Scienza e Tecnologia del Farmaco, Universita degli Studi di Torino, 10125 Turin, Italy.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

15264052

Citation

Carlotti, M E., et al. "Vitamin a Palmitate Photostability and Stability Over Time." Journal of Cosmetic Science, vol. 55, no. 3, 2004, pp. 233-52.
Carlotti ME, Rossatto V, Gallarate M, et al. Vitamin A palmitate photostability and stability over time. J Cosmet Sci. 2004;55(3):233-52.
Carlotti, M. E., Rossatto, V., Gallarate, M., Trotta, M., & Debernardi, F. (2004). Vitamin A palmitate photostability and stability over time. Journal of Cosmetic Science, 55(3), 233-52.
Carlotti ME, et al. Vitamin a Palmitate Photostability and Stability Over Time. J Cosmet Sci. 2004 May-Jun;55(3):233-52. PubMed PMID: 15264052.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Vitamin A palmitate photostability and stability over time. AU - Carlotti,M E, AU - Rossatto,V, AU - Gallarate,M, AU - Trotta,M, AU - Debernardi,F, PY - 2004/01/26/accepted PY - 2004/7/21/pubmed PY - 2004/8/20/medline PY - 2004/7/21/entrez SP - 233 EP - 52 JF - Journal of cosmetic science JO - J Cosmet Sci VL - 55 IS - 3 N2 - Vitamin A palmitate photostability in relation to UVA and UVB was tested in hydroxy ethyl cellulose hydrogels at pH 4.0, 5.6, 7.0, and 8.0, alone and with the addition of sunscreens (3,4-methylbenzilidencamphor or butyl methoxy dibenzoylmethane) or an antioxidant (butylated hydroxy toluene). The photostability of vitamin A palmitate was also tested in encapsulated systems (Tagravit A1 microcapsules, Lipotec liposomes, phosphatidylcholine liposomes, and Lipotec nanocapsules) dispersed in gels at pH 5.6 and 7.0. The stability of retinyl palmitate over time in hydroxy ethyl cellulose hydrogels at pH 5.6 and 7.0 (stored one month at 25 degrees C or 40 degrees C), alone or with butylated hydroxy toluene, was also tested. The stability of retinyl palmitate over time in encapsulated systems, dispersed in gels at pH 5.6 and 7.0, was also studied. O/W emulsions were also prepared to compare the stability of vitamin A palmitate introduced in a lipophilic/hydrophilic medium (O/W emulsions) and a hydrophilic medium (hydrogels). HPLC analysis showed that encapsulated systems such as Lipotec nanocapsules, Tagravit A1 microcapsules, phosphatidylcholine liposomes, and Lipotec liposomes protect the vitamin A ester over time from hydrolysis and from oxidation to retinaldeide and retinoic acid, and that Lipotec nanocapsules and phosphatidylcholine liposomes also improve the vitamin's photostability. A change in pH (from 5.6 to 7.0) of the gels did not influence the vitamin ester's stability. pH levels of 4.0 and 8.0 determined a decrease in the stability of retinyl palmitate in the gels. A high concentration of sunscreens improved the photostability of retinyl palmitate in the gels at pH 5.6 and 7.0. Butylated hydroxy toluene protected retinyl palmitate from degradation induced by light at all the pH levels studied and by heat at pH 5.6 and 7.0, as can be seen from the study of the photostability of vitamin A palmitate under UVB and UVA and of stability over time. Rheological studies showed a slight decrease in the viscosity of the gels after UVB-UVA irradiation and a higher decrease in the viscosity of the gels and the emulsions after storage at 25 degrees C and 40 degrees C. This decrease can be attributed to a partial degradation of hydroxy ethyl cellulose and of emulsifier, as can be seen from the decrease in shear stress versus shear rate values under these conditions of storage, denoting a depolymerization of the rheological modifier. SN - 1525-7886 UR - https://www.unboundmedicine.com/medline/citation/15264052/Vitamin_A_palmitate_photostability_and_stability_over_time_ L2 - https://medlineplus.gov/vitamina.html DB - PRIME DP - Unbound Medicine ER -