Formulation engineering using the hydrophilic/lipophilic deviation method for antimicrobial applications

Overview

This research proposes a novel formulation engineering approach for designing antimicrobial and antiviral surfactant systems using the Hydrophilic/Lipophilic Deviation (HLD) method. The core insight treats microbial phospholipid bilayers as an oil phase, enabling the design of surfactant systems that create Winsor III microemulsions with these bilayers. Under these formulation conditions, surfactant adsorption onto the bilayer destroys the membrane structure, effectively killing microorganisms or deactivating viruses without requiring cationic surfactants.

This approach offers a promising alternative to traditional cationic surfactant-based disinfectants, potentially reducing formulation costs, minimizing environmental impact, and addressing concerns about cationic surfactant resistance or sensitivity. Applications include surface disinfection, antimicrobial coatings, sanitization products, and antiviral treatments for healthcare, food safety, and consumer products.

Technical specifications

Key technical features:

• Application of the HLD equation to phospholipid bilayer systems for the first time in disinfectant design
• Determination of the equivalent alkane carbon number (EACN) of phospholipid bilayers by dissolving target phospholipids in solvents of known EACN
• Design of cationic-free surfactant systems optimized at HLD = 0 for maximum adsorption at the oil/water interface
• Optimization of surfactant adsorption onto phospholipid bilayers to achieve membrane disruption
• Proof-of-concept methodology combining detergency testing with disinfection efficiency measurements

Research approach:

• Measure oil-equivalency (EACN) of representative phospholipids
• Design cationic-free surfactant formulations targeting HLD = 0 for the target phospholipid
• Validate phospholipid removal from test fabrics using standard detergency testing
• Measure disinfection efficiency on target microorganisms as a function of formulation HLD

Technology readiness level

This technology is at an early research stage (TRL 2-3). The HLD equation has been previously validated for designing surfactant formulations for solid non-particulate soils, as demonstrated in published research on detergency correlations. However, the method has not yet been applied to disinfectant design. Future validation will begin with EACN measurements of representative phospholipids, followed by formulation design and proof-of-concept testing through detergency and disinfection efficiency studies.