Polymer and a topical composition comprising the polymer

A polymer according to formula I

• wherein,
• R═R1═H or carbon atoms in the range from 1 to 2,
• R2═R3═H or carbon atoms in the range from 1 to 5,
• A=L-PR-L1-B wherein,
• L=—R5—NH—COO—R6—R7 or —R5—COO—R6—R7 wherein,
• R5 is carbon atom in the range from 1 to 6,
• R6 is carbon atom in the range 1 to 4,
• R7 is sulphur;
• or R7 is a triazine linked to —CH2—CH2—N(CH2—CH3)—,
• PR is a photoresponsive substance,
• L1 is carbonate linker,
• B is a benefit agent,
• R4 is A;
• or R4 is a group selected from —[CH2—CH2—O—]x, —[CH2—CH(R)—O—]x and mixtures thereof, where x is in the range from 1 to 10;
• m=1 to 10,000;
• and n=1 to 10,000;
• and
• wherein the photoresponsive substance is selected from the group consisting of a coumarin compound and a hydroquinone compound.