Lec.3 B                                              

        specialist pharmacist

 

                                                             Ghada Ali AL-Hussiany      

 

Pharmacognasy :

 

Drugs from natural sources, crude drugs, official& non official drugs.

 

Classification of natural products.

 

          Crude drug generally applies to the products from plant &animal origin found in a raw form .However, the term is also applied to inclusion of pharmaceutical products from mineral kingdom in original form & also from organic origin & inorganic origin such as kaolin bentonite etc.

 

         The term crude drug is referred in relation to the natural product that has not been advanced in value or improved condition by any process or treatment beyond that which is essential for its proper packing &prevention from deterioration.

 

         Crude drug are further grouped as organized (cellular) or unorganized (a cellular) according to whether they contain a regular organized cellular structure or not.i:e organized drugs comprise those crude drug materials which represent a part of the plant (made up of cells) . Unorganized drugs are a diverse group of solid & liquid materials which do not consist of parts of plants & are obtained from natural sources by a variety of extraction procedures.The crude drugs may be classified in pharmacognosy according to:

 

1.  Their alphabetical status.

 

2.  Taxonomy of plants &animals from which they are derived.

 

3.  Their morphology.

 

4.  The chemical nature of their active constituents.

 

5.  Chemo taxonomical status.

 

6.  Their pharmacological action & therapeutic applications.

 

Alphabetical classification

 

           The crude drugs are arranged according  to the alphabetical order of their Latin & English names . Some of the pharmacopoeias & reference books which classify crude drugs according to this system  e.g British pharmaceutical codex , British pharmacopoeia  these crude drugs like acacia ,dill ,benzain , senna .

 

Taxonomical ( Biological ) classification.

 

The drugs are classified according to plants or animals from which they are obtained in phylum , orders ,families , genus , species , sub family , division , class.

 

  Morphology classification

 

     The crude drugs are grouped according to the part of the plant or animal represented into organized &unorganized drugs. The organized drugs are divided into parts of plants like leaves , flowers , fruits , seeds , woods , barks & subterranean parts like roots & rhizomes. The unorganized drugs are dried latex, gum, extracts , etc.