Aqueous liquid preparations and light-stabilized aqueous liquid preparations

An aqueous eye drop consisting essentially of (+)-(S)-4-[4-[(4-chlorophenyl)(2-pyridyl)methoxy]piperidino]butyric acid monobenzenesulfonate as a sole therapeutic agent, and sodium chloride at not less than 0.2 w/v % and not more than 0.8 w/v %, wherein the sodium chloride prevents precipitation of the sole therapeutic agent in the eye drop upon exposure to light, and wherein the eye drop has a pH in the range of 8.1-8.5.

A method of light-stabilizing (+)-(S)-4-[4-[(4-chlorophenyl)(2-pyridyl)methoxy]piperidino]butyric acid or a pharmacologically acceptable acid addition salt thereof as a sole therapeutic agent in an aqueous solution, the method comprising:

• adding a water-soluble metal chloride to an aqueous solution consisting essentially of the (+)-(S)-4-[4-[(4-chlorophenyl)(2-pyridyl)methoxy]piperidino]butyric acid or the pharmacologically acceptable acid addition salt thereof as the sole therapeutic agent in an amount sufficient to prevent precipitation of the sole therapeutic agent upon exposure to light, wherein the metal chloride has a concentration selected from the range of a lower limit concentration of 0.15 w/v % and an upper limit concentration of 1.5 w/v %, and wherein the aqueous solution has a pH in the range of 8.1-8.5.