Claims for Patent: 6,559,183

Summary for Patent: 6,559,183

Title:	Nano-emulsion of 5-aminolevulinic acid
Abstract:	The present invention relates to a composition comprising a nano-emulsion that contains 5-aminolevulinic acid as well as a carrier in an aqueous phase. This invention also relates to a pharmaceutical preparation containing this composition. The nano-emulsions of this type can be used in photodynamic therapy as well as in the photodiagnostic detection of proliferatives cells.
Inventor(s):	Schmid; Hans W. (Zug, CH), Burmeister; Gerd (Oberarth, CH)
Assignee:	ASAT AG Applied Science & Technology (Zug, CH)
Application Number:	09/831,564
Patent Claims:	1. A composition comprising a nanoemulsion which comprises an active substance which can be converted into protoporphyrin IX, the active substance being selected from the group consisting of at least one of 5-aminolevulinic acid, a salt compound thereof, a complex compound thereof, an addition compound thereof, precursors thereof, and metabolites thereof, and (b) a carrier in an aqueous phase, with the carrier being formed from at least one lipid and from at least one emulsifier comprising soybean lecithin. 2. The composition of claim 1, wherein the average size of the emulsified particles is from 10 to 200 nm. 3. The composition of claim 1 wherein the active substance is present in a proportion of from 1 to 25% by weight based on the total weight of the composition. 4. The composition of claim 1 wherein the composition additionally comprises adjuvants and/or additives which are customary in cosmetics or pharmacy. 5. The composition of claim 4 wherein the composition is present in the form of a gel and, based on the total weight of the composition, comprises from 5 to 15% of active substance, from 45 to 55% of carrier and from 1 to 5% of adjuvants, with the remainder being water. 6. The composition of claim 4 wherein the composition is present in the form of a lotion and, based on the total weight of the composition, comprises from 5 to 15% of active substance, from 15 to 25% of carrier and from 15 to 25% of adjuvants, with the remainder being water. 7. The composition of claim 1 wherein the content of active substance is reduced by not more than 5% after one year of storage at room temperature. 8. The composition of claim 1 wherein the composition is in the form of a pharmaceutical preparation. 9. The composition of claim 8 wherein the composition can be applied topically. 10. A kit which comprises a topically applicable composition as claimed in claim 9 and at least one component selected from the group consisting of: (a) an essentially light-impermeable sheet-like material, (b) means for attaching the sheet-like material to a site of application, and (c) means for applying the composition to a site of application. 11. A process for preparing a composition as claimed in claim 1 wherein a mixture comprising a carrier and an aqueous phase is prepared and converted into a nanoemulsion, with the active substance being added before and/or after the conversion into the nanoemulsion, and, after that, adjuvants and/or additives are admixed where appropriate. 12. The process of claim 11, process is carried out while excluding oxygen and/or light. 13. The process of claim 11 wherein the process is carried out at a temperature of from 5 to 45.degree. C. 14. A method of photodynamic therapy comprising topically applying a nanoemulsion that contains the composition of claim 1; then incubating in order to allow the composition of claim 1 to penetrate into tissue that is being treated; then irradiating the tissue with radiation. 15. The method of claim 14 wherein the tissue being treated has a disease associated with cell proliferation. 16. The method of claim 15, wherein the disease is a tumor disease. 17. The method of claim 16, wherein the disease is a basal cell carcinoma, a squamous cell carcinoma, Bowen's disease, solar keratosis, condylomata acuminata (CIN), intraepithelial neoplasia of the vulva (VIN), or a nodose or subcutaneous cancer disease. 18. The method of claim 15, wherein the disease is psoriasis. 19. A process for photodynamic therapy, wherein a composition as claimed in claim 1 is administered in an effective quantity to a diseased organism, incubation is performed for a period which is suitable for ensuring that an adequate quantity of the active substance is present in the tissue being treated, and thereafter the tissue is irradiated with light. 20. A method for detecting proliferating cells comprising selectively concentrating a photosensitizer that is produced by metabolism of the composition of claim 1 in proliferating cells as compared with normal cells; and then determining an extent to which the photosensitizer has been concentrated. 21. The method of claim 20 wherein proliferating cells are those of tumor diseases.