Research Article | 29 Apr 2026

Antimicrobial activity and toxicological evaluation of didecyldimethyl- ammonium chloride complexed with fatty alcohol ethoxylate

Olga Gruznova^1,2, Dmitry Gruznov³, Natalya Pavlova⁴, Gulizar Shcherbakova¹, Ekaterina Shuteeva¹, Nikolay Kuvshinchikov¹, Nikolay Popov¹, Valeriya Tyumentseva⁵, Viktoriya Pchelkina⁶, Anton Lobanov⁷, Polina Tyubaeva^8,9, and Ivetta Varyan^8,9Show more

1. Laboratory of Veterinary Sanitation, All-Russian Research Institute of Veterinary Sanitation, Hygiene and Ecology – Branch of Federal State Budget Scientific Institution “Federal Scientific Center – K.I. Skryabin, Ya.R. Kovalenko All-Russian Research Institute of Experimental Veterinary Medicine, Russian Academy of Sciences”, Moscow, Russia.

2. Laboratory of Liquid-Phase Oxidation, N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, Russia. .

3. Laboratory of Veterinary Medicine and Environmental Safety in Beekeeping, All-Russian Research Institute of Veterinary Sanitation, Hygiene and Ecology – Branch of Federal State Budget Scientific Institution “Federal Scientific Center – K.I. Skryabin, Ya.R. Kovalenko All-Russian Research Institute of Experimental Veterinary Medicine, Russian Academy of Sciences”, Moscow, Russia.

4. Laboratory of Pharmacology and Toxicology, All-Russian Research Institute of Veterinary Sanitation, Hygiene and Ecology – Branch of Federal State Budget Scientific Institution “Federal Scientific Center – K.I. Skryabin, Ya.R. Kovalenko All-Russian Research Institute of Experimental Veterinary Medicine, Russian Academy of Sciences”, Moscow, Russia.

5. Laboratory of Sanitary Microbiology, All-Russian Research Institute of Veterinary Sanitation, Hygiene and Ecology – Branch of Federal State Budget Scientific Institution “Federal Scientific Center – K.I. Skryabin, Ya.R. Kovalenko All-Russian Research Institute of Experimental Veterinary Medicine, Russian Academy of Sciences”, Moscow, Russia.

6. Experimental Clinic-Laboratory of Biologically Active Substances of Animal Origin, V.M. Gorbatov Federal Research Center for Food Systems, Russian Academy of Sciences, Moscow, Russia.

7. Department of General Chemistry, Moscow Pedagogical State University, Moscow, Russia.

8. Department of Physical Chemistry of Synthetic and Natural Polymer Compositions, Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia.

9. Academic Department of Innovational Materials and Technologies Chemistry, Plekhanov Russian University of Economics, Moscow, Russia. .

Corresponding author: Olga Gruznova (gruznova_olga@bk.ru)

Received: 13-12-2025 , Accepted: 24-03-2026 Published: 29-04-2026

VETERINARY WORLD | Article No. 25 | pg no. 1724-1746 | Vol. 19, Issue 4 | DOI: 10.14202/vetworld.2026.1724-1746

Citations: —

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Abstract

Background and Aim: Effective disinfection is critical for controlling pathogenic and opportunistic microorganisms in livestock environments. Didecyldimethylammonium chloride (DDAC), a quaternary ammonium compound, is widely used due to its strong antimicrobial properties; however, improving its efficacy without increasing toxicity remains a key challenge. This study aimed to evaluate the antimicrobial activity of DDAC in combination with fatty alcohol ethoxylate (FAEO8) and to assess the toxicological safety of the resulting complex preparation.

Materials and Methods: The antimicrobial activity of DDAC, FAEO8, and DDAC–FAEO8 was evaluated against Staphylococcus aureus, Escherichia coli, and Salmonella Typhimurium using minimum inhibitory concentration (MIC) determination, inhibition zone diameter assays, scanning electron microscopy, potassium ion (K⁺) leakage analysis, and membrane potential assays. Toxicological evaluation included acute and sub-acute oral toxicity studies in rats and dermal irritation/corrosion tests in rabbits, conducted in accordance with international and national guidelines.

Results: The DDAC–FAEO8 complex exhibited significantly enhanced antimicrobial activity compared to DDAC alone, with MIC reductions of 44.4%, 30.8%, and 26.7% against S. aureus, E. coli, and S. Typhimurium, respectively. At concentrations ≥2× MIC, the complex inhibited >99% of microbial growth and demonstrated prolonged bacteriostatic effects. Microscopic analysis revealed pronounced structural damage and cell lysis, while K⁺ leakage and membrane depolarization assays confirmed disruption of bacterial membrane integrity. FAEO8 alone showed no bactericidal activity but did contribute to changes in membrane permeability. Toxicological assessment indicated that the complex preparation was non-lethal at doses up to 2000 mg/kg, with no significant pathological alterations observed. Subacute exposure showed minimal physiological changes, and dermal testing confirmed that the diluted formulation (40 mg/mL) was non-corrosive, with only mild, reversible irritation.

Conclusion: The combination of DDAC with FAEO8 enhances antimicrobial efficacy through membrane disruption mechanisms while maintaining low toxicity. This additive interaction highlights the potential of DDAC–FAEO8 as an effective and safe disinfectant for veterinary applications.

Keywords: acute toxicity, antimicrobial activity, disinfectants, didecyldimethylammonium chloride, fatty alcohol ethoxylate, membrane disruption, surfactants, veterinary sanitation.