The parenteral administration of hydrophobic substances in vivo requires the use of organic solvents to ensure sufficient solubility and avoid precipitation. Dimethyl sulfoxide is commonly used for this purpose. Based on the common assumption that polyethylene glycol (PEG) is non-toxic, our local regulatory authorities recently recommended the use of PEG instead. However, mice injected intraperitoneally (i.p.) with PEG 200 at a dose of 8 mL/kg (i.e. 9 g/kg) did not tolerate PEG 200 well, and half of the animals had to be euthanized. Our results demonstrate that although PEG 200 is generally considered to be harmless, it can be toxic when injected i.p. and is painful for the recipient mice. Nevertheless, it can be used as a solvent for repeated i.p. injections in mice at a dose of 2 mL/kg (i.e. 2.25 g/kg) without obvious signs of systemic toxicity.

中文翻译：

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注意事项：腹膜内注入小鼠的聚乙二醇200的毒性。

在体内肠胃外施用疏水性物质需要使用有机溶剂以确保足够的溶解度并避免沉淀。二甲基亚砜通常用于此目的。基于聚乙二醇（PEG）无毒的普遍假设，我们当地的监管机构最近建议改用PEG。但是，腹膜内（ip）以8 mL / kg（即9 g / kg）的剂量注射PEG 200的小鼠不能很好地耐受PEG 200，因此必须对一半的动物实施安乐死。我们的结果表明，尽管通常认为PEG 200是无害的，但ip注射时它可能是有毒的，并且会给受体小鼠带来痛苦。然而，它可以用作溶剂，以2 mL / kg（即2.25 g / kg）的剂量在小鼠中反复腹腔注射，而没有明显的全身毒性迹象。