The polymer matrix gel is obtained from the matrix, and a shell containing an amount of the matrix or gel.

A polymer matrix containing at least one active substance forms a biodegradable gel in the presence of water, the gel releasing the active substance(s) into the environment when it is degraded by microorganisms, is new. Independent claims are also included for: (1) gel formed by contacting the polymer matrix with a limited amount of water; (2) packaging containing a predetermined amount of a matrix or gel as above; (3) dressing containing a gel as above in which the active substance is an antimicrobial agent; (4) mould-repelling paint containing a gel as above in which the active substance is an antimicrobial agent; (5) cosmetic composition containing a gel as above in which the active substance is an antimicrobial agent; (6) flower care product comprising a polymer matrix or gel as above. ACTIVITY : Antimicrobial; Fungicide; Antiseborrheic; Dermatological. No biological data given. MECHANISM OF ACTION : None given.