Pharmacology
Pharmacology is the study of the actions of drugs on the body and the
way the body metabolizes drugs. The study of pharmacology includes
the biochemical action on the body by drug and incorporates the
knowledge and ideas from other scientific disciplines like biology,
chemistry and physiology.
In this section of the course, we will cover dosage forms and
administration, pharmacology itself, pharmacodynamics and a quick
overview of body systems like the cardiovascular system, skin, and
endocrine systems
Source of Drugs
 Natural Sources of Drugs
 Drugs that originate from plants or animals
 Examples:
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Acetylsalicylic acid (ASA or Aspirin) originates from the bark of the
willow tree.
Cocaine originates from the coca plant (Erythroxylum coca)
Morphine and Codeine originate from the Papaver somnifera plant
Digoxin comes from the Foxglove plant
Vincristine and Vinblastine are called vinca alkaloids and come from
the periwinkle plant.
Niacin is a B vitamin (B3) is found in green vegetables
Cyanocobalamine is a B vitamin (B12) found in eggplant and meats
Insulin was originally isolated from pork (porcine) or bovine (cow)
pancreas
Unusual Sources of drugs
 Lepirudin (Refludan®) is an anticoagulant that is used in
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hospital to treat PE and DVT. Source: ?
The saliva of leeches known as Hirudo medicinalis. A leech
is a blood sucking worm
Premarin® is conjugated estrogens used to treat vaginal
bleeding and to treat post menopausal Sx in middle aged
women. Source:?
The urine of pregnant mares
Captopril is an ACE inhibitor used to treat hypertension
and CHF. Source:?
Brazilian arrowhead viper: a poisonous snake
Synthetic Drug Sources
 Most synthetic drugs are really semi-synthetic in that
the drug is chemically modified from a natural source.
 Examples are:
 Oxycodone (Oxycontin®)
 Succinylcholine (Quelicin®)
 Piperacillin/Tazobactam (Zosyn®)
 Amoxicillin (Amoxil®)
Genetically Engineered Drugs
 Recombinant DNA technology is a new modality that arised in the late 1970’s
and early 1980’s. Greatly accelerated by the Human Genome Program
completion in the late 1990’s.
 Involves sequencing the gene for a human protein, carrying a vector for that
gene (usually a virus), have the vector infect a host (usually a bacteria, E. Coli)
and allowing the bacteria to mass produce the gene product for us to market.
 Examples:
 Recombinant human insulin . Recombinant insulin has almost completely
replaced insulin obtained from animal sources (e.g. pigs and cattle) for the
treatment of insulin-dependent diabetes ]
 Recombinant human growth hormone. (HGH, somatotropin). Growth
hormone is administered to patients whose are growth hormone deficient.
 Recombinant blood clotting factor VIII. Recombinant factor VIII is a bloodclotting protein that is administered to patients with hemophilia
 Recombinant hepatitis B vaccine. Prevention of hepatitis B infection is
controlled through the use of a recombinant hepatitis B vaccine, which
contains a form of the hepatitis B virus surface antigen that is produced in
yeast cells.
Drug Nomenclature
 Chemical name: the name of a drug according to its
chemical structure.
 Generic Name: the name given to a drug in agreement
with the originally manufacturer and the FDA. Also
called the nonproprietary name
 Trade Name: the trademark name given to a drug by
the original manufacturer. It is also called the
proprietary name. No other manufacturer can legally
use this name for their version of the drug
Dosage Formulations
 The Dose formulation are different vehicles for the
same drug in which each type of formulation, or
vehicle, provides certain advantages and disadvantages
Solid Dose Forms
 Tablets
 Tablets are a solid dosage form of drug in which the drug
is mixed with various active ingredients that provide a
convenient way to give the drug. For the most part the
inactive ingredient impart stability, color, taste, and bulk
to the dose form
 Advantages are: stability, convenience, and masking bad
taste
 Disadvantages are: difficulty in swallowing is taken
orally, slow to act in the body
 Tablets can be manufactured to be chewable, effervescent,
enteric coated, or made into a controlled release dosage form
 Some examples of different tablets types are:
 Chewable vitamins and aspirin for adults
 Enteric coated aspirin (Ecotrin®), Depakote ®, Videx EC
(didanosine), Nexium®, Protonix ®, and Voltaren® EC. Enteric
coated drugs are coated to protect either the stomach from the drug
or the drug from the stomach.
 Effervescent drugs most commonly release carbon dioxide.
Example : Alkaseltzer®
 Controlled release dosage forms where design to release the drug
slowly over time in the GI tract. Examples: Toprol XL (metoprolol
succinate), Tiazac ® CD (diltiazem CD), Calan® (verapamil CD),
Procardia XL (nifedipine) and Glucotrol XL (glipizide). Controlled
release dosage form should never be chewed!!
Capsule Dosage Forms
 Capsule have many of the same advantages and
disadvantages as tablets.
 One advantage over tablets is the gelatin coating of the
capsule is much easier to swallow that tablets
Ointments
 Mixture of a drug into a semisolid vehicle base
 Types of bases used: white petrolatum, lanolin, PEG base,
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waxes, and hydrophilic petrolatum
Oleaginous ointments can be used to carry drug and to be
an emollient
Water soluble ointments carry drug and can be easily
washed off is needed.
In general, ointments that carry drug are more potent than
the cream version of the same drug
Liniments are ointment that possess a chemical agent that
acts as a irritant. I.e. Methanol, camphor, etc
Creams
 Vehicles in which a drug is mixed into a semisolid
fluid medium.
 Creams are emulsions that are either water in oil or oil
in water based.
 More popular because they are not as greasy as
ointment bases
 Lotion are similar to cream except water
concentrations are higher
Liquid Dosage Forms
 Solutions are aqueous mediums were the drug is completely
dissolved in water. The drug is called the solute and the water is
the vehicle or called the solvent. Commonly used to deliver
medications like oral solution, enemas, irrigation solutions, IV
solutions and others
 Suspensions are aqueous mediums where the drug is not
completely dissolved in the medium but is “suspended” in the
medium to produce a mixture that is homogenized upon
shaking.
 Viscous Solutions are mediums that are similar to suspensions in
that the drug is suspended into the medium. Include Jellies and
mucilages (Metamucil®). Magmas and milks are in this category
 Syrups are viscous solutions that have a high concentration of
sugar. Simple Syrup USP is 85% sucrose in water
Non Aqueous Solutions
 Hydroalcoholic solutions are a mixture of water and
alcohol.
 Elixir are mixture of alcohol, water, and sugar and a least
one active ingredient.
 The alcohol is meant to solubilize a drug that is
normally not soluble in water alone and also to prevent
the crystallization of sugar and to act as a preservative
 Examples are Digoxin Elixir and Donnatal Elixir
Extractives
 Extractives are liquids that are hydroalcoholic or purely
alcohol solutions that contain a drug in high potency.
 The crude drug found in plants usually are macerated, and
pressed and dried. The material is exposed to an extractive
which draws the active drug(s) into the extractive.
 Tincture is a hydroalcoholic extractive of a drug where the
potency of drug is equal to 100 mg of the crude ingredient
per ml. i.e. Tincture of Opium 1 ml contains the equivalent
of 10 mg morphine (this is how much morphine is in 100
mg of crude opium poppy)
 Fluidextracts are 10x the potency of tinctures