STABILIZATION OF AQUEOUS SOLUTION OF LIDOCAINE OR ITS SALT AND AQUEOUS SOLUTION OF LIDOCAINE OR ITS SALT

摘要

PROBLEM TO BE SOLVED: To provide a stabilization process for an aqueous solution of lidocaine or its salt having an alkaline pH near that of living bodies and provide an aqueous solution of lidocaine or its salt of excellent stability, having a weak alkaline pH near that of living bodies. ;SOLUTION: In order to stabilize an aqueous solution of lidocaine or its salt having a pH of 7.0-7.7, salicylic acid or its salt is added to the aqueous solution containing lidocaine or its salt in a concentration of 0.1-2.5%. Highly stabilized lidocaine or its salt aqueous solution having a pH of 7.0-7.7 contains lidocaine or its salt in a concentration of 0.1-2.5%. Thus, the aqueous solution of lidocaine or its salt is stabilized at a pH of 7.0-7.7 and they can be stored in the form of a solution without precipitation of crystals for a long period of time. The aqueous lidocaine or its salt solution containing salicylic acid or its salt according to this invention can alleviate the pain on the injection into the living body because the pH of the solution is 7.0-7.7. In addition, as lidocaine or its salt can be stored stably in the solution form for a long period of time, they can be readily and simply used without any operations needed for preparation of the solution.;COPYRIGHT: (C)1999,JPO