The Canon of Medicine - Book 2 (materia Medica)

Book 2 (materia Medica)

The Canon described no less than 700 preparations of medications, their properties, mode of action and their indications. He devoted in fact a whole volume to simple and compound drugs in The Canon of Medicine. It credits many of them to a variety of Arabic, Greek and Indian authors, and also includes some drugs imported from China, along with many of Ibn Sina's own original contributions. Using his own expertise, he was often critical of the descriptions given by previous authors and revised many of their descriptions. In inhalational drug therapy, the Canon described the inhalation of essential oils from pine and eucalyptus to alleviate respiratory symptoms. Both of these compounds are still present in modern-day proprietary inhalational medicines.

The Canon of Medicine deals with evidence-based medicine, experimental medicine, clinical trials, randomized controlled trials, efficacy tests, risk factor analysis, and the idea of a syndrome in the diagnosis of specific diseases.

According to A. C. Crombie, the Canon contained "a set of seven rules that laid down the conditions for the experimental use and testing of drugs" which were "a precise guide for practical experimentation" in the process of "discovering and proving the effectiveness of medical substances based in part on Galen." The emphasis of the Canon on tested medicines laid the foundations for an experimental approach to pharmacology. The Canon laid out the following rules and principles for testing the effectiveness of new drugs and medications, which still form the basis of clinical pharmacology and modern clinical trials:

1. "The drug must be free from any extraneous accidental quality."
2. "It must be used on a simple, not a composite, disease."
3. "The drug must be tested with two contrary types of diseases, because sometimes a drug cures one disease by Its essential qualities and another by its accidental ones."
4. "The quality of the drug must correspond to the strength of the disease. For example, there are some drugs whose heat is less than the coldness of certain diseases, so that they would have no effect on them."
5. "The time of action must be observed, so that essence and accident are not confused."
6. "The effect of the drug must be seen to occur constantly or in many cases, for if this did not happen, it was an accidental effect."
7. "The experimentation must be done with the human body, for testing a drug on a lion or a horse might not prove anything about its effect on man."

The Canon lists 800 tested drugs, including plant and mineral substances, with comments on their application and effectiveness. For each one, he described their pharmaceutical actions from a range of 22 possibilities (including resolution, astringency and softening), and their specific properties according to a grid of 11 types of diseases.