Formulations and uses of retinoic acid receptor selective agonists

A method of treating acne vulgaris, the method comprising:

• administering to a subject a topical formulation comprising a single active ingredient, wherein the active ingredient consists of a RAR selective agonist, wherein the RAR selective agonist is not more than 0.005% of the formulation, and wherein the RAR selective agonist has the structure:
• wherein the dotted bond is either present and forms a double bond, or is absent;
• R1, R2, R3 and R4 are independently hydrogen or alkyl;
• n is 1, 2 or 3;
• X is —C(R8)(R9)— for n=1, 2 or 3;
• or X is oxygen for n=1;
• wherein R8 and R9 are independently hydrogen or alkyl;
• R5 is hydrogen, alkyl, alkoxy, alkoxy-alkyl-, alkylthio, alkyl-NR10—, alkenyl, alkenyloxy, alkynyl, benzyl, cycloalkyl-alkyl or phenyl-alkyl;
• wherein R10 is hydrogen or alkyl;
• m is 0 when the dotted bond is present;
• or m is 1 when the dotted bond is absent;
• wherein Ar is phenyl or a heteroarylic ring;
• R6 is hydrogen, halogen, alkoxy or hydroxy;
• R7 is hydrogen or alkyl;
• and
• Y
• is —COO—, —OCO—, —CONR10—, —NR10CO—, —CH═CH—, —C≡C—, —COCH═CH—, —CHOHCH═CH—, —CH2O—, —CH2S—, —CH2SO—, —CH2SO2—, —CH2NR10—, —OC H2—, —SCH2—, —SOCH2—, —SO2CH2— or —NR10CH2—,
• with the proviso that when Y
• is —OCO—, —NR10CO—, —OCH2—, —SCH2—, —SOCH2—, —SO2CH2— or —NR10CH2—, R5 is hydrogen, alkyl, alkoxy-alkyl-, alkenyl, alkynyl, benzyl, cycloaslkyl-alkyl or phenyl-alkyl;
• or a pharmaceutically active salt of carboxylic acids of formula I.