Myramistin

Myramistin is a cationic surfactant and disinfectant preservative. Myramistin exhibits high bactericidal activity against Staphylococcus aureus and Escherichia coli, shows lower activity against yeasts and fungi, and is active against HIV, measles virus, mumps virus, as well as influenza viruses of the H3N2 and H5N1 subtypes. Myramistin adsorbs to the negatively charged microbial cell membrane, leading to increased membrane permeability and disruption of membrane integrity, which ultimately results in leakage of intracellular contents, enzyme inactivation, and the death of bacteria/fungi/enveloped viruses^[1][2][3][4]. In Vitro:Myramistin (30-50 μg/mL) exhibits dose-dependent anti-HIV activity in MT-4 cells, and inhibits HIV p24 production in Jurkat-tat cells when added simultaneously with HIV-1^[1].
Myramistin (10-20 μg/mL; 17-24 h) inhibits the growth of Staphylococcus aureus FDA 209P, Staphylococcus aureus INA 00761, and Bacillus mesentericus VKPM B-4177, with MIC values of 20, 10, and 10 μg/mL, respectively^[2].
Myramistin (5-10 μg/mL; 17-24 h) inhibits the growth of Staphylococcus aureus FDA 209P, with an MIC of 5 μg/mL^[2].
Myramistin (0.005-0.05%) potently inhibits the replication of measles virus strain Edmonson and mumps virus strain PetroNov/03 in Vero cell cultures, with optimal prophylactic concentrations of 0.05% and 0.005%, respectively^[3].
Myramistin (0.5-1000 μg/mL; 24 h) potently inhibits and kills Staphylococcus aureus (ATCC 209p), with an MIC of 8 μg/mL and an MBC of 16 μg/mL; it also inhibits and kills Escherichia coli (CDC F-50), with an MIC of 32 μg/mL and an MBC of 128 μg/mL^[4].
After a 1-minute exposure in suspension, Myramistin (0.1-0.2%; 1-15 min) produces a log₁₀ reduction factor of ≥ 6.00 against Staphylococcus aureus (ATCC 209p) and a log₁₀ reduction factor of ≥ 4.56 against Escherichia coli (CDC F-50); a 15-minute exposure completely inhibits the growth of both strains^[4].
Myramistin (0.1-0.2%; 1-15 min) reduces the log₁₀ reduction coefficient of Staphylococcus aureus (ATCC 209p) on metal surfaces by ≥ 3.20 and that of Escherichia coli (CDC F-50) by ≥ 3.41 after 1 minute of exposure; its activity is reduced by 1-3 log₁₀ units compared with that in suspension tests^[4]. In Vivo:Miramistin (0.2%; topical; 5-minute exposure) achieves a 2.6 log₁₀ reduction in viable E. coli on the skin of Sprague-Dawley rats with experimentally induced bacterial skin infection^[4].