D-Aminolevulinicacidmethylesterhydrochloride

Absorption

In vitro, after 24 hours the mean cumulative absorption through human skin was 0.26% of the administered dose.

Toxicity

The severity of local phototoxic reactions such as erythema, pain and burning sensation may increase in case of prolonged application time or very high light intensity.

Background

Methyl aminolevulinate is a prodrug that is metabolised to Protoporphyrin IX (a photosensitizer) used in photodynamic therapy.

Indications

For topical use, in combination with 570 to 670 nm wavelength red light illumination, in the treatment of non-hyperkeratotic actinic keratoses of the face and scalp in immunocompetent patients when used in conjunction with lesion preparation (debridement using a sharp dermal curette).

Definition

ChEBI: The methyl ester of 5-aminolevulinic acid. A prodrug, it is metabolised to protoporphyrin IX, a photosensitizer, and is used in the photodynamic treatment of non-melanoma skin cancer (including basal cell carcinoma). Topical application (often as the hydro hloride salt) results in an accumulation of protoporphyrin IX in the skin lesions to which the cream has been applied. Subsequent illumination with red light results in the generation of toxic singlet oxygen that destroys cell membranes and thereby kills t e tumour cells.

Pharmacokinetics

After topical application of methyl aminolevulinate, porphyrins will accumulate intracellularly in the treated skin lesions. The intracellular porphyrins (including PpIX) are photoactive, fluorescing compounds and, upon light activation in the presence of oxygen, singlet oxygen is formed which causes damage to cellular compartments, in particular the mitochondria. Light activation of accumulated porphyrins leads to a photochemical reaction and thereby phototoxicity to the light-exposed target cells.

Metabolism

Not Available