CYCLIC IMIDE DERIVATIVES

Compounds are described of the formula wherein: R is C3-6alkyl or C1-3alkylthioC1-3alkyl; R is an optionally substituted C1-6alkyl or C1-6alkoxy group, aryl, heteroaryl, arylC1-4alkyl, heteroarylC1-4alkyl or a side-chain of a natural alpha -amino acid; R is hydrogen, C1-6alkyl, CHR COR (where R is a side-chain of a natural alpha -amino acid and R is hydroxyl, C1-6alkoxy or NHR where R represents a hydrogen atom or a C1-6alkyl group) or a group (CH2)nX (where n is 1 to 6 and X is hydroxyl, C1-4alkoxy, heteroaryl or a group NR R where R and R are each hydrogen or C1-6alkyl or the group NR R forms a 5 to 7 membered cyclic amine); and Het is an optionally substituted cyclic imide where the cyclic imide ring system has the formula (i), (ii) or (iii) in which A, B, C and D are each CH or 1 or 2 of A, B, C and D represents N and the others represent CH, and E and F may each independently represent CH or N; and physiologically acceptable salts and solvates thereof. These compounds inhibit metalloproteases involved in tissue degradation. Compounds of the invention may be formulated for use in a variety of conditions involving tissue degradation including arthropathy, dermatological conditions, bone resorption, inflammatory diseases, tumour invasion and multiple sclerosis and related diseases involving myelin degradation, and in the promotion of wound healing.