Investigations on safety-relevant aspects of the formaldehyde substitute aminolipin

Status:

completed 12/2021

Aims:

As a consequence of the new classification of formaldehyde as carcinogenic and germ cell mutagenic as well as the reduction of the occupational exposure limit for formaldehyde, a not insignificant formaldehyde dilemma arose, particularly for the macro-anatomical practical course in preclinical medical education. The main goals of the research project were to conduct and evaluate further studies in the safe application of the new formaldehyde substitute aminolipin for the fixation and preservation of whole human specimen, organs and tissue.

Activities/Methods:

To evaluate the toxicological profile of aminolipin for humans, certified studies according to OECD-guidelines were conducted regarding, among others, skin corrosion and skin irritation, eye damage, skin sensitisation, acute toxicity, and carcinogenicity. Additional studies were conducted regarding the physicochemical parameters of aminolipin. The efficacy of aminolipin fixing solutions against bacteria, fungi and viruses was tested in certified suspension tests according to DIN EN. Preparation samples from intra-arterially fixed body donors with various solutions containing aminolipin were microbiologically tested for putative human pathogens to prove their biocidal efficacy. In addition, the extent to which aminolipin can replace formaldehyde in the histopathological fixation routine was tested.

Results:

Based on present results on toxicology and intrinsic properties, a possible risk assessment was drawn up, which shows a lower risk for the health and safety of students and professionals compared to formaldehyde. In particular, aminolipin is non-volatile, not sensitising to the skin and there is no evidence of mutagenic and genotoxic potential. The biocidal efficacy tests revealed that aminolipin is to be classified as bactericidal, levurocidal and as limited virucidal PLUS, i.e. virucidal efficacy against all enveloped viruses and additionally against adeno-, noro- and rotaviruses. In the microbiological analyses of the body donors fixed with aminolipin, no bacteria and fungi relevant for clinical diagnostics were detected. Pathogen spread beyond organ boundaries, which normally happens in a putrefaction process after a few days post mortem, could be prevented by aminolipin fixation. The aminolipin fixation solutions investigated for histopathology showed to be suited as a substitute for formaldehyde. The data constitute an excellent basis for the development of customised aminolipin products for routine histopathology in a second step.

The so far conducted studies on the new active substance aminolipin verify a significantly lower safety risk to humans in comparison to formaldehyde; at the same time, the newly developed biocide has a high fixation capacity.

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