Methods of making l-ornithine phenyl acetate

Disclosed is a process for making L-ornithine phenyl acetate salt (V) comprising: preparing a solution of phenyl acetate salt by mixing a phenyl acetic acid and a base in a solvent; intermixing L-ornithine benzoate with the above solution; isolating a composition comprising L-ornithine phenyl acetate. The process may include forming an L-ornithine benzoate salt intermediate. The process may also include intermixing a halide salt of L-ornithine with silver phenyl acetate. The present application also relates to various compositions obtained from these processes, including crystalline forms.