Procedures 5--- dosage and group Low Median High Vehicle/Control no slight or obvious solvent /excipient toxicity median or severe normal control ♂早 randomized separately same volume, different concentrationProcedures 5---- dosage and group Low Median High Vehicle /Control no slight or obvious solvent /excipient toxicity median or severe normal control ➢ ♂♀ randomized separately ➢ same volume, different concentration