An article of manufacture according to the present invention comprises a composition including a glycosaminoglycan, a local anesthetic, and a buffer packaged in a syringe or vial constructed from either glass or a plastic selected from the group consisting of cyclic olefin polymer, cyclic olefin copolymer, or high density non-nucleated polypropylene. The composition has unexpectedly improved stability on storage. The composition can be formulated for treatment of a urinary tract disease or condition, such as interstitial cystitis, also known as bladder pain syndrome or hypersensitive bladder syndrome.