An improved method for preparing a composition including a heparinoid, a local anesthetic, and a buffer for treatment of a lower urinary tract disease or condition can comprise: (i) providing a heparinoid in solid form or liquid form; (ii) providing a local anesthetic in solid form or liquid form; (iii) adding a liquid buffer to the heparinoid in solid form or liquid form; (Iv) adding the local anesthetic to the mixture of the liquid buffer and the heparinoid; and (v) if necessary, adjusting the pH of the mixture of the liquid buffer, the local anesthetic, and the heparinoid so that a pH is achieved of from about 6.8 to about 8.3 is achieved without precipitation of the local anesthetic.