Page 482 - Applied Pharmacognosy

• Petroleum ether extract contains fixed oil, resins and
volatile substances, but when the extract is heated
at 105 C until constant weight, the volatile
substances are volatilized leaving only resins,
colouring matter and fixed oil.

• Alcohol can dissolve almost all the substances, but is
generally used for drugs, which contain glycosides,
resins, alkaloids etc.

• Water is used for drugs containing water soluble
substances as chief constituent.