Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

5.1   Pharmacodynamic properties
Pharmacotherapeutic group: Chlorhexidine, combinations, ATC code: D08A C52.

Mechanism of Action
Bisbiguanide antiseptics exert their lethal effect upon bacterial cells through nonspecific interaction with acidic phospholipids of the cell membranes.

Chlorhexidine gluconate is a cationic biguanide. Its antimicrobial action is due to the disruption of the cell membrane and the precipitation of cell contents. It has a bactericidal or bacteriostatic action against a wide range of gram-positive and gramnegative bacteria. It is relatively ineffective against mycobacteria. It inhibits some viruses and is active against some fungi. It is inactive against bacterial spores. It has a superior residual property in comparison to currently available skin antiseptics. Chlorhexidine gluconate has a strong binding property to skin and has a residual property on the skin that has been documented at 48 hours.
Chlorhexidine gluconate is not neutralised in the presence of organic matter.

Isopropyl alcohol is a rapidly bactericidal and a fast acting broad spectrum antiseptic, but is not considered persistent. Its mechanism of action appears to be denaturation of proteins.

Pharmacodynamic effects
ChloraPrep is a sterile antiseptic solution containing a combination of 2% Chlorhexidine gluconate in 70% Isopropyl alcohol, which is effective for both rapid and persistent reduction of bacterial load across various body regions for a broad spectrum of organisms. Isopropyl alcohol (70%) provides an immediate kill of transient and resident microorganisms on the stratum corneum and 2% Chlorhexidine gluconate binds to the superficial cell layers of the epidermis and provides a residual, or persistent, antimicrobial property that prevents regrowth of microorganisms.

Clinical efficacy and safety
Clinical studies with 2% Chlorhexidine gluconate in 70% Isopropyl alcohol have demonstrated that the combination offers equal or similar effectiveness in reducing skin bacterial load and more sustained antibacterial effects over longer periods after application, compared to the individual components alone, as well as to other commonly used antiseptics such as Povidone-iodine.

ChloraPrep meets the criteria for chemical disinfectants and antiseptic products as established by European Standards:
EN 1040 - basic bactericidal activity (Phase 1)
EN 1275 - basic yeasticidal activity (Phase 1)
EN 13727 - bactericidal activity (Phase 2/Step 1)
EN 13624 - fungicidal activity (Phase 2/Step 1)

ChloraPrep meets these EN criteria for bactericidal and fungicidal activity for the following organisms at contact times ranging from 5 to 15 minutes, with the exception of Aspergillus brasiliensis. Additional testing of ChloraPrep at full concentration against Aspergillus brasiliensis for exposure up to 60 minutes met EN 13624 criteria, as follows: Table: In vitro microbiocidal effects
Strain             Contact time        Conditions         Result             EN Criteria Pseudomonas        5 min               100%, 75%,         >5.69 log          EN 1040 aeruginosa                             50%                reduction
Staphylococcus 5 min                   100%, 75%,         >4.67 log          EN 1040 aureus                                 50%                reduction
Candida            15 min              100%, 75%,         > 4.25 log         EN 1275 albicans                               50%                reduction
Enterococcus       5 min               100%, 75%,         > 5.71 log         EN 13727 hirae                                  50% in clean       reduction
0.3 g/L bovine serum albumin
Pseudomonas         5 min              100%, 75%,         > 5.55 log         EN 13727 aeruginosa                             50% in clean       reduction
0.3 g/L bovine serum albumin
Staphylococcus      5 min              100%, 75%,         > 5.78 log         EN 13727 aureus                                 50% in clean       reduction
0.3 g/L bovine serum albumin
Candida             15 min             100%, 75%,         > 4.17 log         EN 13624 albicans                               50% in clean       reduction
0.3 g/L bovine serum albumin
Aspergillus         60 min             100%               > 4.26 log         EN 13624 brasiliensis                                              reduction

Pharmacokinetic Properties

5.2   Pharmacokinetic properties
Absorption
There is little absorption of isopropyl alcohol or of chlorhexidine gluconate through intact skin.

Pharmacokinetic studies have not been conducted with the product.