Route of administration
Since oral dosage forms of herbal medicines are usually used clinically, the oral route of administration is ordinarily the most suitable for use with test animals. Additional routes may be used to approximate the intended route of administration in man.
Frequency of administration
Ordinarily, doses selected for a study should be established by means of a dose-response relationship but since such relationships often cannot be demonstrated with herbal medicines in whole animals, it may be sufficient to select one or more doses that provide a desired effect.
Selection of doses for animal studies should be in accordance with customary clinical doses.
It is essential that all studies include a negative (vehicle only) control group of animals and, if possible, a positive control group, that is, a group of animals in which the effect of a drug known to be positive is examined.