Biodegradable monophasic cohesive hydrogel comprises homogeneous mixture of identical or different x polymers cross-linked prior to their interpenetration by mixing in monophasic hydrogel form, where the crosslinked polymers are water insoluble and mixed between them, and x is 2-5. Independent claims are included for: (1) the preparation of the biodegradable cohesive monophasic hydrogel comprising crosslinking a first polymer at a rate of crosslinking x1, crosslinking of a second polymer at a rate of crosslinking x2, interpenetration by mixing of two polymers, hydration and final interpenetration by final mixing after hydration; and (2) a kit comprising the hydrogel packed in sterile syringe. ACTIVITY : Dermatological. MECHANISM OF ACTION : None given.