USE OF AMINOLEVULINIC ACID AND DERIVATIVES THEREOF
The invention provides the use of a photosensitiser which is 5-aminolevulinic acid (5-ALA) or a derivative (e.g. an ester) of 5-ALA, or a pharmaceutically acceptable salt thereof, in the manufacture of a composition for use in methods of photodynamic therapy (PDT) on an animal, wherein said PDT comprises: (a) administering to said animal a composition comprising said photosensitiser; and (b) photoactivating said photosensitiser, and wherein side-effects (e.g. pain and/or erythema) of said PDT are prevented or reduced by use of one or more of (i)-(iv): (i) said composition comprises said photosensitiser in a concentration of less than 10% wt (e.g. 0.5 to 8% wt), (ii) said composition is administered for less than 2 hours (e.g. 30 minutes to 90 minutes) prior to said photoactivation, (iii) said photoactivation is carried out with a light source having a fluence rate of less than 50 mW/cm 2 (e.g. 5 to 40 mW/cm 2 ), (iv) said photoactivation is carried out with sunlight. Preferably, side-effects of PDT are prevented or reduced by using (iii) or (iv) in combination with (i) and/or (ii).
1 .- 44 . (canceled)
45 . A method of reducing or preventing side-effects in the photodynamic treatment of acne comprising:
(a) administering to an area characterized by acne on a patient in need of such treatment a composition comprising methyl ALA ester at a concentration of less than 10%, or the equivalent concentration of a pharmaceutically acceptable salt, for a period of less than 2 hours, and
(b) administering photoactivating light to the affected area.
46 . The method of claim 45 , wherein the administered compound is methyl ALA ester hydrochloride salt.
47 . The method of claim 45 , wherein the concentration of methyl ALA ester is in the range from 0.5 to 8%, or the equivalent concentration of a pharmaceutically acceptable salt.
48 . The method of claim 47 , wherein the concentration of methyl ALA ester is in the range from 2 to 8%, or the equivalent concentration of a pharmaceutically acceptable salt.
49 . The method of claim 48 , wherein the concentration of methyl ALA ester is 8%, or the equivalent concentration of a pharmaceutically acceptable salt.
50 . The method of claim 45 , wherein the administered compound is methyl ALA ester hydrochloride salt.
51 . The method of claim 45 , wherein the composition is a cream.
52 . The method of claim 45 , wherein the composition is administered for a period of 5 to 90 minutes.
53 . The method of claim 52 , wherein the composition is administered for a period of 30 to 90 minutes.
54 . The method of claim 53 , wherein the composition is administered for a period of 90 minutes.
55 . The method of claim 45 , wherein the photoactivating light has a peak wavelength in the range 631 to 637 nm.
56 . The method of claim 45 , wherein the total light dosage is about 37 J/cm 2 .
57 . The method of claim 45 , wherein the photoactivating light has a fluence rate of about 21 to about 74 mW/cm 2 .
58 . The method of claim 45 , wherein the light is provided by an LED lamp.