Antimicrobial and acaricide sanitizer tablets produced by wet granulation of spray-dried soap and clove oil-loaded microemulsion

PLoS One. 2024 Nov 11;19(11):e0313517. doi: 10.1371/journal.pone.0313517. eCollection 2024.

Abstract

A novel sanitizer tablet containing clove essential oil (CO) microemulsion was developed. A preformulation study using nuclear magnetic resonance and thermal analyses showed component compatibility. The main components of the samples remained intact despite a color change, probably due to a strong acid-base interaction between eugenol and diethanolamine. The CO microemulsion showed acaricidal and larvicidal activities superior to the commercial product, with product efficacy of 99.9% and larvae mortality of 94%. Optimal spray-drying conditions were achieved with inlet and outlet temperatures of 50°C and 40°C, respectively, an aspiration rate of 1 m3 min⁻1, and a 0.25 L h⁻1 injection flow. The feed suspension comprised 50% (v/v) liquid soap, 37.5% (v/v) water, 12.5% (v/v) ethanol, and 5.0% (w/v) silica. This formulation and processing parameters allowed for successful free-flow powder formation, providing a suitable matrix for incorporating the CO microemulsion via wet granulation without heating. Finally, sanitizer tablets produced from such granules resulted in a uniform product with low weight variation (coefficient of variation of 0.15%), eugenol content of 95.5% ± 3.3, and friability of 0.58%. Furthermore, the tablets showed rapid aqueous dispersion, forming a colloidal system with particle sizes of 221 nm and a zeta potential of -17.2 mV. Antimicrobial activity tests demonstrated the effectiveness of the sanitizer tablet against bacteria and fungi, exhibiting comparable antimicrobial potency to isolated CO. Hence, the sanitizer tablet developed represents a promising candidate as a practical and efficient solution for pest control, offering strong antimicrobial and acaricidal activity.

MeSH terms

  • Acaricides* / chemistry
  • Acaricides* / pharmacology
  • Animals
  • Anti-Infective Agents / chemistry
  • Anti-Infective Agents / pharmacology
  • Clove Oil* / chemistry
  • Clove Oil* / pharmacology
  • Emulsions* / chemistry
  • Larva / drug effects
  • Soaps / chemistry
  • Soaps / pharmacology
  • Spray Drying
  • Tablets*

Substances

  • Clove Oil
  • Acaricides
  • Emulsions
  • Tablets
  • Anti-Infective Agents
  • Soaps

Grants and funding

This work was supported by the Brazilian Agencies CAPES, CNPq, FAPDF (00193-00000817/2021-64); FAPDF Demanda Espontânea - 04/2021 (0019300000229/202121) and UnB (COPEI-DPI/DEX 01/2021). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.