Quality Control of Hand Sanitizers

Importance of the Topic

Hand sanitizers are essential in healthcare and public settings to prevent pathogen transmission. Accurate control of alcohol, hydrogen peroxide, water, and emollient levels is crucial for efficacy and safety. Traditional methods require multiple techniques, reagents, and time, creating a bottleneck in quality control.

Objectives and Study Overview

The goal was to establish a rapid, reagent-free method for simultaneous quantification of ethanol, glycerol, hydrogen peroxide, and water in gel and liquid sanitizers. A chemometric model based on near-infrared spectroscopy (NIRS) was developed and validated against standard reference methods.

Instrumentation

• DS2500 Liquid Analyzer (400–2500 nm, temperature control to 40 °C)
• DS2500 holder for 8 mm disposable vials
• 8 mm disposable borosilicate glass vials
• Vision Air Complete 2.0 software for data acquisition and model development

Methodology

• Gel samples: 98 formulations with 0.5–3 w/w % glycerol, 70–85 w/w % ethanol, 20–22 w/w % water
• Liquid samples: 91 formulations for sanitizing wipes with 70–95 w/w % ethanol, 2–40 w/w % water, 0–4 w/w % hydrogen peroxide
• Transmission spectra collected at 40 °C using an 8 mm pathlength vial
• Chemometric calibration and cross-validation models built in Vision Air Complete

Main Results and Discussion

• Gel formulations:
  • Ethanol: R2 = 0.9832, SECV = 0.37 w/w %
  • Glycerol: R2 = 0.9632, SECV = 0.11 w/w %
  • Water: R2 = 0.9410, SECV = 0.09 w/w %
• Liquid formulations:
  • Ethanol: R2 = 0.9964, SECV = 0.36 w/w %
  • Water: R2 = 0.9999, SECV = 0.18 w/w %
  • H2O2: R2 = 0.9986, SECV = 0.06 w/w %
• High correlation with reference methods (GC, Karl Fischer, titrations) confirms NIR reliability.

Benefits and Practical Applications

• Sub-minute, simultaneous analysis of multiple components
• No chemical reagents, reduced waste and safety risks
• Minimal sample preparation and rapid throughput
• Applicable for routine QA/QC and in-line production monitoring

Future Trends and Applications

Integration with automated sample handling (flow-through cells, robotics) and digital connectivity will enhance process control. Expansion to other liquid formulations and pharmaceutical QC tasks is anticipated.

Conclusion

Near-infrared spectroscopy using the DS2500 Liquid Analyzer provides a fast, accurate, and reagent-free alternative for multi-parameter quality control of hand sanitizers, streamlining production and ensuring product compliance.

References

No external literature references were cited.