Abstract: A biodegradable single-phase cohesive hydrogel includes a homogenous mixture of 2 to 5 identical or different polymers interpenetrating each other in a single phase, wherein the polymers are independently crosslinked prior to interpenetration by mixing, and the crosslinked polymers are insoluble in water and miscible with each other.

Abstract: The invention relates to a sterilized composition comprising at least one hyaluronic acid or biologically acceptable salt thereof, alone or in a mixture, and magnesium ascorbyl phosphate, in a ratio [HA]/[MAP] by mass of the amount of hyaluronic acid or salt thereof [HA] to the amount of magnesium ascorbyl phosphate [MAP] of greater than or equal to 1, the amount of magnesium ascorbyl phosphate being between 0.001% and 1% by weight, relative to the total weight of said composition, with an elastic component G? which is retained or improved after sterilization and is between 5 and 400 Pa. It also relates to a composition of the invention which further includes dimethyl sulfone, to methods for producing same, and to uses thereof.