Methyl-5-aminolevulinate hydrochloride cream is a topical cream formulation containing the hydrochloride salt of methyl-5-aminolevulinate, a lipophilic methyl ester of 5-aminolevulinic acid, with photosensitizer prodrug activity. Upon topical administration, methyl-5-aminolevulinate in the cream is selectively absorbed by tumor cells where it is converted to the photosensitizer protoporphyrin IX (PpIX). Upon photoirradiation, PpIX is activated and transfers energy to oxygen, generating singlet oxygen and superoxide and hydroxyl radicals, which may result in free-radical-mediated DNA damage and cell death.

Providing storage is as stated on the product vial and the vial is kept tightly sealed, the product can be stored for up to 24 months.
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20°C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour.