Abstract  Assessment of acute toxicity of squalan in rats was conduced according "guidelines for toxicity studies issued by Ministry of Health and Welfare of Japan (MHW) - 1993. The test item was administered orally to rats (male and female) at the unique dose of 2000 mg/kg and its acute toxicity was assessed. Observation period was conduced from J0 (administration) to J14. No deaths occurred throughout the observation period, no abnormality was observed and the body weight gain increased normally. Based on these results, it is concluded that the oral LDL0 (lethal dose lowest) of squalan is greater than 2 000mg/kg.

Abstract  The test has been realized according OCDE 84/449 L251 method on 10 animals (wistar rats - 5 females and 5 males). The test item was administrated by oral gavage at the unique dose of 2 ml/kg. Animals were observed from J0 (oral administration) to J14. No mortality, neither no clinical sign were observed after oral administration of 2 ml/kg. In the test conditions, the substance is considered as nontoxic after oral administration of a unique dose 2 ml/kg.

Abstract  Tetradecane (TD), testosterone (TS), and dimethyl sulfoxide (DMSO) were separately inuncted on rabbit pinnas once a day; the pinnas were biopsied on days 1, 3, 7, and 28. Untreated pinnas and squalane-treated pinnas were used as controls. Three-dimensional images of sebaceous glands were reconstructed from their serial histologic sections using a computer-image analysis system. By stereometry, the sebaceous gland volumes gradually increased during the course of treatments with TS and DMSO, whereas the volumes of TD-treated sebaceous glands increased, reached the maximum on day 7, and then decreased. The acinus number was increased by all the substances, the DMSO-treated sebaceous glands on day 28 showing the largest number of acini. The volumes of individual acini increased until day 28 with TS treatment, whereas with TD and DMSO treatments they increased, reached the maximum on day 7, and then decreased. Stereographically, each untreated control sebaceous gland was composed of 20-30 pear-shaped acini. On day 28, acini of TS-treated sebaceous glands were swollen and ovoid in shape, DMSO-treated sebaceous glands resembled a bunch of grapes, and acini of TD-treated sebaceous glands were widely scattered and showed globular swelling arising from an elongated tube. Hyperplastic responses of sebaceous glands are quite different according to substances applied topically.