Drug Nomenclature and Sources of Drugs
When a new drug is synthesized, it is first assigned a code or number (usually
identifying with its inventor, manufacturer/ pharmaceutical company). If it is found
promising after clinical evaluation, the manufacturer wants to put it in the market; the
new drug is given a generic name to designate its pharmacological class (nonproprietary name). If the new drug gets official recognition by drug regulatory
authority, its manufacturer gives it a proprietary or trade name.
Chemical name: IUPAC name, generally long and hard to remember.
Generic, Official, Approved or Trivial name:
The chemical is entered in pharmacopoeias under this name.
The chemical compound is known throughout the world by this generic name.
Approved names are generally used by researchers and non-clinical teachers.
Proprietary, Brand or Trade name:
One chemical compound can have several proprietary names.
Even one proprietary name may not contain single chemical.
Manufacturers and clinicians prefer to use brand names.
|Generic name||Trade name|
It is a drug compendium consisting of officially recognized drug preparations/
It gives the information on source, properties, purity, potency of recognized drugs
and tests for their identity.
A pharmacopoeia is the official publication of drug standards.
It is revised regularly. The different pharmacopoeias are:-
IP The International or Indian Pharmacopoeia
USP The United States Pharmacopoeia
BP The British Pharmacopoeia
BPC The British Pharmaceutical Codex
EP European Pharmacopoeia
I.Vet.P The Indian Veterinary Pharmacopoeia
B.Vet.C. The British Veterinary Codex
NF The National Formulary (USA)
NF The National Formulary of India
BNF The British National Formulary
ADR The Accepted Dental Remedies
NB: The abbreviation of the pharmacopoeia is mentioned after the name of the
drug. For example, Tr. Benzoin Co. I.P. i.e. the tincture of benzoin
corresponding to the standard tincture of benzoin mentioned in the Indian
Sources of drugs:
(1) Drugs from plant sources:
The ancient or original sources of drugs are the plants collectively known as
medicinal plants. All parts of the medicinal plants have therapeutic values.
Root : Sarpgandha
Rhizome : Ginger, Haldi
Bark : Cinchona, Catechu, Acacia
Leaves : Atropine, Cocaine, Physostigmine
Flowers : Digitalis, Chrysenthemum
Fruits : Papaya, Anise
Seeds : Nux vomica, Kali mirchi, Methi
(2) Drugs from animal sources:
Hormones : Oxytocin, Insulin, Thyroxine, Gonadotrophins
Vitamins : Cod or shark liver oil (Rich sources of Vitamin A & D)
Antisera : Antisnake venom, Canine distemper antiserum etc.
Others : Heparin, Liver extract, Immunoglobulins, Blood/Plasma.
(3) Drugs from microbial sources:
Fungi/ Actinomycetes : Sources of antibiotics (penicillin, streptomycin,
and Bacteria gentamicin, neomycin etc.)
|Viruses/ Bacteria||:||Preparation of vaccines|
|Yeasts||:||Dried yeast as source of Vitamin B-complex|
(4) Drugs from mineral sources: (Inorganic salts)
Antacid : Magnesium oxide, Sodium bicarbonate
Purgative : Magnesium sulphate
Expectorant: Potassium iodide
Diuretic : Potassium nitrate
Haematinic : Ferrous sulphate
Mineral oils : Liquid paraffin (Laxative effect) – Long term administration
interferes with Vitamin A & D, Calcium and Phosphorus
(5) Synthetic drugs:
Majority of the current day dugs are from synthetic source. Examples are –
(6) Semi-synthetic drugs: Examples are –
Agonists and antagonists of morphine
Dihydrostreptomycin – from streptomycin
Semi-synthetic penicillins – from penicillin.
(7) Gene therapy:
It means prevention or treatment of disease through manipulation of gene
It is insertion of specific genes (therapeutic genes) exogenously into the
The concept of gene therapy has its origin from the fact that manipulation of
gene expression could change the function of abnormal genes or
supplementation of a non-functional gene or suppression of an abnormal
Gene therapy refers to introduction of functional genetic material into target
cells to replace or supplement defective genes, or to modify target cells so as
to achieve therapeutic goals.
In contrast to all other drugs, this kind of therapy can impart new functions to
Gene therapy holds a great promise for curing a number of diseases which at
present can at best be only palliated or controlled.
Gene defects result in failure to synthesize a functional protein or in the
synthesis of a dysfunctional protein. Equipping the cell (specially the one
which physiologically expresses it) with a normal copy of the defective gene
would overcome the deficiency at the site where it is needed on a long term
(may be permanent) basis.
Recombinant DNA technology forms the basis of synthesis of therapeutic
Technique of gene delivery into host:
It is highly complicated and different from that of conventional drug delivery
systems. The technique involves inserting a therapeutic gene first into a vector. The
vector may be either viral (Retro or Adenovirus) or non-viral vector (plasmid DNA,
liposomes, microsomes). A vector with a gene is then introduced into the patient
through either in vivo or ex vivo means.
In vivo gene transfer: The vector, usually a retrovirus carrying the gene is injected
systemically or directly into the concerned organ.
Ex vivo gene transfer: The patient’s tissue cells (blood/ bone marrow) are isolated
and maintained in tissue culture. These are then transfected
with vector carrying the relevant gene and injected back into
Applications of gene therapy:
Severe combined immunodeficiency
Growth hormone deficiency
Insulin dependent diabetes etc.
These are therapeutic agents produced through biotechnological means, but not
by conventional laboratory (chemical) synthesis.
The principle of biopharmaceuticals and the process of their development have
origin from the advancement in the knowledge of molecular cell biology and
Therefore, biopharmaceuticals popularly known as Designer Proteins are the
promising therapeutic tools of the future.
Examples are –
Functional human peptides: ADH, Oxytocin, GnRH, ACTH, TSH/TRH, Calcitonin,
Insulin, Somatostatin, Growth hormone, Cyclosporin
Enzymes/ Peptides : Streptokinase, Asparaginase, DNAase,
Erythropoietin, Clotting factors, Interferons,
Monoclonal antibodies, Vaccines etc.