Photoactivation of corticosteroids in UVB-exposed skin.
Summary of "Photoactivation of corticosteroids in UVB-exposed skin."
The photodegradation of flumethasone (FM) and fluocinolone acetonide (FC) was studied in solution and in the pig skin. Both glucocorticosteroids applied to the pig skin were unstable under UVB light. The photoproducts formed in the skin were the lumi-, photolumi- and andro-derivatives for FM, the same found in vitro. Instead, FC hydroperoxide formed in solution was not found in the skin: the reactivity and oxidative ability of this photoproduct towards biological substrates (lipids, proteins) seems the reason of the lack of its detection in the ex vivo model. In fact, it demonstrated to quickly oxidize amino acids and peptides, and to react with BSA both in the dark and under irradiation. Moreover, the presence in the irradiated pig skin of the FC andro-derivative, which usually forms in H-donating environment, seems consistent with the mechanism of Norrish I fragmentation followed by H-abstraction, likely from the surrounding biological substrates. These findings indicate that photoreactivity of these compounds may take place in the skin of patients exposing themselves to sunlight and is a warning about possible skin damage as a result of that. Furthermore, photolability of these drugs in the skin might cause loss of their therapeutic activity.
Affiliation
Department of Pharmaceutical Sciences, University of Padova, Italy. giorgia.miolo@unipd.it
Journal Details
This article was published in the following journal.
Name: Journal of photochemistry and photobiology. B, Biology
ISSN: 1873-2682
Pages: 35-41
Links
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/21324709
- DOI: http://dx.doi.org/10.1016/j.jphotobiol.2011.01.009
Medical and Biotech [MESH] Definitions
Dermatitis, Photoallergic
A delayed hypersensitivity involving the reaction between sunlight or other radiant energy source and a chemical substance to which the individual has been previously exposed and sensitized. It manifests as a papulovesicular, eczematous, or exudative dermatitis occurring chiefly on the light-exposed areas of the skin.
Hydroxycorticosteroids
A group of corticosteroids carrying hydroxy groups, usually in the 11- or 17-positions. They comprise the bulk of the corticosteroids used systemically. As they are relatively insoluble in water, salts of various esterified forms are often used for injections or solutions.
Ficusin
A naturally occurring furocoumarin, found in PSORALEA. After photoactivation with UV radiation, it binds DNA via single and double-stranded cross-linking.
Carcinoma, Basal Cell
A malignant skin neoplasm that seldom metastasizes but has potentialities for local invasion and destruction. Clinically it is divided into types: nodular, cicatricial, morphaic, and erythematoid (pagetoid). They develop on hair-bearing skin, most commonly on sun-exposed areas. Approximately 85% are found on the head and neck area and the remaining 15% on the trunk and limbs. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1471)
Dermatitis, Phototoxic
A nonimmunologic, chemically induced type of photosensitivity producing a sometimes vesiculating dermatitis. It results in hyperpigmentation and desquamation of the light-exposed areas of the skin.
PubMed Articles
Percutaneous permeation of betamethasone 17-valerate incorporated in lipid nanoparticles.
Corticosteroids are therapeutic agents widely used in the pharmacological treatment of skin diseases such as eczema or psoriasis. Unfortunately, their use is restricted by the side effects that freque...
Immediate-Type Hypersensitivity to Succinylated Corticosteroids.
Background: Despite their frequent use, systemic corticosteroids have rarely elicited immediate-type reactions. Objective: We report two male patients, aged 26 and 70 years, respectively, with severe...
Abstract We morphologically investigated animal skin exposed to W/O emulsion containing 10 wt % ultrafine TiO(2) particles that had been characterized. After 4 h, exposed skin was investigated by ligh...
For optoelectronic applications, colloidal CdSe quantum dots (QDs) have been integrated into solid devices by using optically transparent polymer matrices that embedded the colloidal QDs. We systemati...
Rapid, photoactivatable turn-on fluorescent probes based on an intramolecular photoclick reaction.
Photoactivatable fluorescent probes are invaluable tools for the study of biological processes with high resolution in space and time. Numerous strategies have been developed in generating photoactiva...
Clinical Trials
RATIONALE: Testing of skin that has been exposed to artificial sunlight may help in understanding the genetic processes involved in the development of skin cancer. PURPOSE: This trial is...
The purpose of this study is to evaluate the potential of Tazarotene Foam to induce a photoallergic reaction when exposed to UV and VIS light on skin of healthy volunteers.
This is a prospective randomized, double-blind study to compare the clinical efficacy of infantile hemangioma treatment using propranolol with corticosteroids as compared to therapy with c...
Celecoxib in Preventing Skin Cancer
RATIONALE: Celecoxib may be effective in preventing skin cancer by decreasing redness caused by exposure to ultraviolet light and changing potential skin cancer biomarkers. It is not yet k...
Safety of Cat-PAD to Treat Cat Allergy in Cat Allergic Subjects With Controlled Asthma
Cat allergy is an increasingly prevalent condition, affecting 10-15% of patients with allergic rhinoconjunctivitis and/or asthma. Cat-PAD is a novel, synthetic, allergen-derived peptide de...
