1. An aqueous composition suitable for injection, comprising: a biological therapeutic agent which, when used to create a solution with a concentration of 100 mM of a biological therapeutic agent in water, results in a solution with a viscosity of at least 10 cP； guanidine and / or a guanidine derivative, moreover, the guanidine derivative has the following formula: where R1 is absent, or represents CH, CH, CH, or CH (n = 1-10)； and / or R2 is absent, or is any chemical functional group that slightly reduces the ability of the guanidine group to lower the viscosity of the composition； and R1 and R2 are never absent simultaneously； where guanidine and / or a guanidine derivative are present in the composition at a concentration of at least 25 mM, but not more than 100 mM； iodine； in this case, the composition has a viscosity of not more than 10 cP.2. A composition according to claim 1, characterized in that it is an aqueous ophthalmic composition suitable for intravitreal injection. The composition of claim 1, further comprising a stabilizer. 4. A composition according to claim 3, characterized in that the stabilizer is trehalose. The composition of claim 1, further comprising a surfactant. The composition according to claim 1, characterized in that the viscosity of the composition does not exceed 7 cP. 7. The composition of claim 1, wherein the biological therapeutic agent is an antibody. A composition according to claim 1, wherein the biological therapeutic agent is an IgG1 / lambda isotype antibody. The composition of claim 1, wherein the biological therapeutic agent is an isolated monoclonal antibody that specifically binds to a C5 protein. The composition according to p. 1, characterized1. Водная композиция, пригодная для инъекции, содержащая:биологический терапевтический агент, который при использовании для создания раствора с концентрацией от 100 мМ биологического терапевтического агента в воде приводит к образованию раствора с вязкостью по меньшей мере 10 сП；
