Eutectic formulations of cyclobenzaprine hydrochloride and amitriptyline hydrochloride

A pharmaceutical composition of comprising a eutectic of Amitriptyline HCl and mannitol, wherein the pharmaceutical composition comprises amounts of Amitriptyline HCl and mannitol selected from:

• 40%±2% Amitriptyline HCl and 60%±2% mannitol, 45%±2% Amitriptyline HCl and 55%±2% mannitol, 50%±2% Amitriptyline HCl and 50%±2% mannitol, 55%±2% Amitriptyline HCl and 45%±2% mannitol, 60%±2% Amitriptyline HCl and 40%±2% mannitol, 65%±2% Amitriptyline HCl and 35%±2% mannitol, 70%±2% Amitriptyline HCl and 30%±2% mannitol, 80%±2% Amitriptyline HCl and 20%±2% mannitol, 85%±2% Amitriptyline HCl and 15%±2% mannitol, and 90%±2% Amitriptyline HCl and 10%±2% mannitol by weight.