| abstract |
An aqueous composition for reducing pain at the site of injection of local parenteral anesthetic material, for improving the onset thereof, and for increasing its duration, and a means for preparing and dispensing the same, the composition containing a local parenteral anesthetic which in normal doses gives an acid pH of from about 2.5 to about 6.9, wherein the anesthetic comprises from about 0.5 to about 2.0% by weight of the composition, the composition further containing sufficient NaHCO3 to maintain the pH thereof between about 7.0 and about 7.6, and further containing from about 0.0004 moles of dissolved CO2 per ml of composition up to the saturation level of dissolved CO2 at a CO2 head pressure of up to about 2.5 atmospheres. |