Pharmacotherapeutic group: dermatological, ATCvet code: QD08AC52.
Chlorhexidine digluconate (ATCvet classification QD08AC02) is a Bisbiguanide antimicrobial agent against Gram-positive and Gram-negative bacteria. It is both bactericidal and bacteriostatic depending on the concentration used. Growth inhibition is achieved by a direct effect on ATP-ase so interfering with the energy transport mechanisms. The bactericidal effect of chlorhexidine results from coagulation of the bacterial cell contents. Chlorhexidine digluconate is incorporated in the product for its activity against Staphylococcus pseudintermedius. Typical MIC values found in clinical Staphylococcus pseudintermedius isolates are 2.0 mg/L (2005). Staphylococcus pseudintermedius resistance to chlorhexidine has not been reported.
Miconazole nitrate (ATCvet classification QD01AC02) is an imidazole antifungal agent with activity against yeasts such as Malassezia pachydermatis.
It is both fungicidal and fungistatic depending on the concentration used. Miconazole inhibits ergosterol incorporation into cell membranes so increasing concentrations of cytotoxic hydrogen peroxide within the fungal cell wall. Miconazole nitrate has been incorporated in the product for its activity against Malassezia pachydermatis. Typical MIC values found in clinical Malassezia pachydermatis isolates are 1 – 4.0 µg/mL (2012). Malassezia pachydermatis resistance to miconazole has not been reported.
High concentrations of chlorhexidine digluconate are achieved in the hair coat and on the skin for the 10 minute period following shampooing. These concentrations are well in excess of the MICs for Staphylococcus pseudintermedius. Chlorhexidine digluconate is poorly absorbed from the gastrointestinal tract on ingestion. There is little or no percutaneous absorption. In humans it has been shown that 26% remains on the skin at 29 hours after application.
High concentrations of miconazole nitrate are achieved in the hair coat and on the skin for the 10 minute period following shampooing. These concentrations are well in excess of the MICs for Malassezia pachydermatis. There is little absorption through skin or mucous membranes when applied topically.