Method of Preparing Single-Phase Modified Sodium Hyaluronate Gel

A method of preparing a single-phase modified sodium hyaluronate gel, comprising the following steps:

• (1) preparing a sodium hyaluronate solution with a mass fraction between 5% to 15% in an alkaline condition at a pH value between 11 to 14, wherein the sodium hyaluronate has a molecular weight between 1.5 million to 4 million Daltons;
• (2) adding a cross-linking agent to a solution of step (1), wherein the cross-linking agent and the sodium hyaluronate has a molar ratio between 9% to 15%;
• rapidly mixing for 20 to 40 minutes to form a gel;
• (3) allowing the gel of step (2) to stand after subjecting the gel of step (2) to a water bath at constant temperature;
• (4) dialyzing the gel of step (3) with a dialysis membrane to remove un-reacted cross-linking agent and hydroxide ion;
• (5) homogenizing;
• and
• (6) adding a mobile phase and mixing sufficiently to obtain a high viscosity stabilized single-phase modified sodium hyaluronate gel.