Trehalose

Endpoint summary

Link to relevant study record(s)

Reference

Endpoint:

basic toxicokinetics, other

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

key study

Study period:

Feb. 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Objective of study:

absorption

distribution

excretion

metabolism

Qualifier:

no guideline followed

Principles of method if other than guideline:

Assessment of the toxicokinetic behaviour of the substance to the extent that can be derived from the relevant available information (physicochemical properties)

GLP compliance:

no

Specific details on test material used for the study:

no physical test performed

Type:

absorption

Results:

oral route identified as major route, dermal route as potential second route.

Type:

distribution

Results:

no specific distribution pattern identifiable

Type:

metabolism

Results:

specific enzyme (Trehalase) present, 100 % metabolism possible

Type:

excretion

Results:

excretion unlikely, to a small extent by urin

Absorption:

Based on above data the substance may be absorbed through the skin in relevant amounts (molecular weight < 500 g/Mol, -1 < log P_OW< 4, see EUROPEAN COMMISSION HEALTH & CONSUMER PROTECTION DIRETORATE-GENERAL: Guidance Document on Dermal Absorpiton Sanco/222/2000 rev. 7 19 March 2004).

Although the calculated log P_OWis below the threshold for dermal absorption of log P_OW= -1, the experimental procedure does not allow determination in such range. Therefore absorption via skin cannot be excluded.

For exposure assessments a default value of 100 % of absorption after dermal exposure may be appropriate.

The uptake after direct inhalation of the substance may be of low relevance due to the high mean diameter of particles, which significantly exceeds the maximum inhalable particle diameter of 10 µm. Uptake by inhalation after evaporation is unlikely, the substance is a solid at room temperature has a very low vapour pressure. Additionally the substance decomposes upon heating.

For exposure assessments a default value of 10 % of absorption via inhalation may be appropriate.

The absorption after oral ingestion cannot be calculated due to lack of data; by default an absorption of 100 % may be appropriate, until specific data will be available. Observations in repeated dose toxicity studies show significant absortion by oral route.

 

Distribution:

The substance is hydrophilic and Protein binding should be quite low, resulting in a low distribution volume. Therefore distribution to specific organs should only depend on the blood flow rate of the organs with lung, kidney and liver as potentially primary targets. Crossing of membrane barriers like the Blood/Brain barrier seems unlikely. However, as the substance is made up of natural occurring sugars, certain receptors may exist, enhancing the membrane crossing ability.

 

Metabolism and Excretion:

 

The substance is a disaccharide which will be metabolized by the Enzyme Trehalase in the small intestines. The metabolic products are Glucose, which are further metabolized.

 

The substance will most likely be completely metabolized. Excretion is rather unlikely, to a small extent urinary excretion may be present.

Conclusions:

The toxicokinetic behaviour of Trehalose was assessed based on physicochemical properties and known metabolism pathways.
The substance is of natural origin and specific enzymes for metabolism are present.

Description of key information

physicochemical data and text book information used to assess the toxicokinetic properties. As a natural occuring substance fulfilling storage functions in non-mammal animals and fungus, bioaccumulation is not further regarded.

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Absorption rate - oral (%):

100

Absorption rate - dermal (%):

100

Absorption rate - inhalation (%):

10