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Administrative data

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route
Endpoint conclusion:
no study available
Effect on fertility: via inhalation route
Endpoint conclusion:
no study available
Effect on fertility: via dermal route
Endpoint conclusion:
no study available

Effects on developmental toxicity

Effect on developmental toxicity: via oral route
Endpoint conclusion:
no study available
Effect on developmental toxicity: via inhalation route
Endpoint conclusion:
no study available
Effect on developmental toxicity: via dermal route
Endpoint conclusion:
no study available

Toxicity to reproduction: other studies

Description of key information

No studies investigating toxicity on reproduction are available for delta-5 -norandrostendion (ZK 67026). However, ZK 67026 has a structural similarity to Nandrolon (ZK 5221), which is classified as anabolic steroid according to German legislation (TRGS-905).

There are internal data available on the interaction of ZK 67026 and sex hormone receptors:

Internal data from transactivational assays also showed androgenic potential of ZK 67026 at 10 nM [88% compared to 109% (ZK 5221)] and 1 µM [30% compared to 65% (ZK 5221)], which was lower, but in a similar range compared to ZK 5221. Further, ZK 67026 showed a low binding affinity towards the estrogen receptor, which was lower compared to ZK5221. The agonistic/antagonistic profile at the progesterone receptor of ZK 67026 was comparable to the profile of ZK 5221.

In addition, only the position of one double bond and a 17-keto group (ZK 67026) instead of a 17-hydroxy group (ZK 5221) differs between both substances. But the isomerisation of this double bond from 5,10 -position to 4,5 -position, as well as the transformation to the 17-hydroxy group will easily occur in vivo. Therefore, a close effect relationship between ZK 67026 and ZK 5221 has to be assumed in vivo. These information were described in an internal communication by N. Schmees to D. Müller (9. Jun 2016).

Justification for classification or non-classification

There are no studies on the reproductive toxicity of delta-5 -norandrostendion (ZK 67026) available. However, ZK 67026 showed slightly weaker but comparable androgenic potential in vitro as the structural similar nandrolone (ZK 5221), which is classified according to German legislation (TRGS-905) for anabolic steroids as Repr. (F) Cat. 1A and Repr. (D) Cat. 1B. Further, ZK 67026 may be transformed to ZK 5221 in vivo.

Based on in vitro hormone receptor binding data and a read across to nandrolone (ZK 5221), ZK 67026 is classified with category Repr. (F) Cat. 1A and Repr. (D) Cat. 1B according to Regulation (EC) 1272/2008 (CLP).

Additional information

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