The present invention concerns a moisture-absorbing tablet (10) comprising a compacted composition (11) comprising a desiccant, characterised in that it comprises a solid gel (12) adhered directly to the compacted composition and comprising at least one volatile active substance, at least one gelling agent and optionally at least one curing agent. The present invention also concerns a method for preparing such a moisture-absorbing composition and a device for diffusing a volatile active substance in a homogeneous and non-decreasing manner comprising said tablet.
