Conformation and kinetic characteristics of the interactions of local anesthetics lidocaine (xycaine), tetracaine (dicaine), bupivacaine, and new RU-1117 compound with proven anesthetic activity with Visiton (1% hydroxypropylmethylcellulose in phosphate buffer) were studied. It was found that complex formation between the local anesthetics and hydroxypropylmethylcellulose is a time-dependent reversible process. The equilibrium is attained within 2.5-8.0 h and depends on the chemical nature of local anesthetic.