Pharmaceutical formulations of a hif hydroxylase inhibitor

A pharmaceutical composition formulated to prevent or reduce the photodegradation of an active ingredient [(4-hydroxy-1-methyl-7-phenoxy-isoquinoline-3-carbonyl)-amino]-acetic acid, the composition comprising the active ingredient [(4-hydroxy-1-methyl-7-phenoxy-isoquinoline-3-carbonyl)-amino]-acetic acid, and an effective amount of a photostabilizing agent, which photostabilizing agent:

• i) prevents the transmission of light at a wavelength range of between about 200 nm and 550 nm;
• and
• ii) is admixed with the active ingredient, or provided in an outer coating or shell surrounding the active ingredient, such that the composition upon exposure to light contains less than about 0.2% w/w photodegradation product of [(4-hydroxy-1-methyl-7-phenoxy-isoquinoline-3-carbonyl)-amino]-acetic acid relative to the amount of [(4-hydroxy-1-methyl-7-phenoxy-isoquinoline-3-carbonyl)-amino]-acetic acid.