Pharmaceutical formulations of a HIF hydroxylase inhibitor

A tablet comprising a tablet core and a coating, wherein the tablet core comprises [(4-hydroxy-1-methyl-7-phenoxy-isoquinoline-3-carbonyl)-amino]-acetic acid, and the coating comprises a photostabilizing agent, wherein the photostabilizing agent:

• i) consists essentially of from about 0.1 to about 2 mg/cm2 titanium dioxide and from about 0.1 to about 0.4 mg/cm2 Allura Red AC or from about 0.1 to about 0.4 mg/cm2 Allura Red AC in aluminum lake;
• and
• optionally at least one additional dye selected from the group consisting of:
• from about 0.004 to about 0.4 mg/cm2 iron oxide red;
• from about 0.009 to about 0.2 mg/cm2 iron oxide yellow;
• from about 0.01 to about 0.03 mg/cm2 Sunset Yellow FCF;
• and
• from about 0.01 to about 0.03 mg/cm2 Sunset Yellow FCF in aluminum lake;
• wherein the amount of photostabilizing agent is based on surface area of the tablet core;
• and
• ii) prevents the transmission of light at a wavelength range of between about 200 nm and 550 nm
• and further wherein the tablet 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.