PTCB - Chapter 7 - Routes and Formulations - Definitions

Local effect
- when drug activity is at the site of administration (ex. mouthwash)

Systemic effect
- when a drug is introduced into the venous (circulatory) system and carried to the site of activity (ex. swallow tablet)

DOSAGE FORMS

• Enteral route
• oral
• buccal (between the cheek)
• sublingual (under the tongue)
• rectal (rectum)
• Parenteral route
• intraocular (eye)
• intranasal (nose)
• inhalation (inhale)
• intravenous, intramuscular, intradermal ➤ injections
• dermal (topically on skin)
• subcutaneous
• vaginal

Disintegration

- the breaking apart of a tablet into smaller pieces

Dissolution

- when the smaller pieces of a disintegrated tablet dissolve in solution

pH

- the pH scale measures the acidity or the opposite (alkalinity) of a substance. Seven is the neutral midpoint of the scale, values below which represent increasing acidity, and above which represent increasing alkalinity

Gastrointestinal Organs and their pH

- stomach (pH 1-2)

- large intestine (pH 7-8)

- small intestine (pH 5-7)

Aqueous

- water based

Solution

- a clear liquid made up of one or more substances dissolved in a solvent

Liquid Formulations

• Solution
• a clear, not necessarily colorless, liquid made up of one or more ingredients dissolved in a solvent. A solvent is a liquid that can dissolve another substance to form a solution
• Aqueous solutions
• are the most common kind of oral solution. Water was used as the solvent
• Nonaqueous solutions
• solutions that predominately contain solvents other than water, either alone or in addition to water
• Syrups
• concentrated or nearly saturated solutions of sucrose (sugar) in water. They are more thicker than water, and contain less than 10% alcohol
• Elixirs
• clear, sweetened, hydroalcoholic liquids intended for oral use. They can contain either alcohol soluble or water soluble drugs. Usually less sweet and less thicker than syrups, and are generally less effective in masking taste. Their alcohol content ranges from 5-40% (10-80 proof), though a few commercial elixirs contain no alcohol
• Spirits or essences
• alcoholic or hydroalcoholic solutions of volatile substances (usually volatile oils) with alcohol contents ranging from 62-85% (124-170 proof). They are most frequently used as flavoring agents but some spirits are used for their medicinal effect
• Tinctures
• alcoholic or hydroalcoholic solutions of nonvolatile substance. Tinctures of potent drugs have 10 grams of the drug in each 100 mL of tincture; they are called 10% tinctures. Nonpotent tinctures generally have 20 grams of the drug per 100 mL of tincture
• Suspensions
• formulations in which the drug does not completely dissolve in the solvent. The drug particles are suspended in the formulation. Since they are intended for oral administration, suspensions are sweetened and flavored
• Emulsions
• mixture of oil and water
• Gels
• made using substances called gelling agents that increase the viscosity of the medium in which they are placed

Emulsifier

- a stabilizing agent in emulsions

Emulsions

- mixture of two liquids that do not mix with each other in which one liquid is dispersed through the other by using a stabilizer called an emulsifier

Buccal

- pouch between the teeth and cheek in the mouth

Sublingual

- under the tongue

Water soluble

- the property of a substance being able to dissolve in water

Hemorrhoid

- painful swollen veins in the anal/rectal area, generally caused by strained bowel movements from hard stools

Buffer system

- ingredients in a formulation designed to control the pH

Necrosis

- increase in cell death

Sterile

- a sterile condition is one which is free of all microorganisms, both harmful and harmless

Syringe needle recommendations

- intravenous 🠊 needle gauge 16-20 🠊 needle length 1-1.5'' 

- intramuscular 🠊 needle gauge 19-22 🠊 needle length 1-1.5'' 

- subcutaneous 🠊 needle gauge 24-27 🠊 needle length 3/8-1''

- intradermal 🠊 needle gauge 25-26 🠊 needle length 3/8''

🠊 needle with smallest number causes coring

🠊 needle with highest gauge hurts less

Intravenous

- injections are administered directly into veins (ex. blood transfusion)

Intramuscular

- injections are administered into muscle tissue and generally result in a slower onset but longer duration of action compared to IV administration (ex. haloperidol)

Subcutaneous

- injections are administered into the subcutaneous tissue of the skin (ex. insulin, vaccines)

Intradermal

- injections are administered into the top layer of the skin at a slight angle using short needles (ex. immunization)

Diluent

- a solvent that dissolves a freeze dried powder or dilutes a solution

Injectability

- the ease of flow when a suspension is injected into a patient

Syringeability

- the ease with which a suspension can be drawn from a container into a syringe

Intravenous administration complications

- thrombus (blood clot) formation can result from many factors: extremes in solution pH, particulate material, irritant properties of the drug, needle or catheter trauma, and selection of too small a vein for the volume of solution injected

- phlebitis, or inflammation of the vein, can be caused by the same factors that cause thrombosis

Colloids

- particles up to a hundred times smaller than those in suspensions that are, however, likewise suspended in a solution

Depot

- the area in the muscle where the formulation is injected during an intramuscular injection

Biocompatibility

- not irritating; does not promote infection abscess

Viscosity

- the thickness of a liquid. A measure of a liquid's resistance to flow

Wheal

- a raised, blister like area on the skin caused by an intradermal injection

Conjunctiva

- the eyelid lining

Lacrimal canalicula

- the tear ducts

Lacrimal gland

- the gland that produces tears for the eye

Ophthalmic

- related to the eye

🠊 normal volume of tears in the eye is 7 microliters

🠊 eye can hold up to 10 microliters without spillage

🠊 ophthalmic ointment tubes are typically small, holding approx. 3.5 grams of ointment

Nasal cavity

- the cavity behind the nose and above the roof of the mouth that filters air and moves mucus and inhaled contaminants outward and away from the lungs

Nasal inhaler

- a device that contains a drug that is vaporized by inhalation

Nasal mucosa

- the cellular lining of the nose

Alveolar sacs (alveoli)

- the small sacs of specialized tissue that transfer oxygen out of inspired air into the blood and carbon dioxide out of the blood and into the air for exhalation

🠊 Particle size is the critical factor with inhalation dosage forms

🠊 Large particles (about 20 microns) hit in the back of the mouth and throat are eventually swallowed rather than inhaled

🠊Particles from 1 to 10 microns reach the bronchioles

🠊 Smaller particles (0.6 microns) penetrate to the alveolar sacs (alveoli) of the lungs where absorption is rapid, but retention is limited since a large fraction of the dose is exhaled

Hydrates

- absorbs water

Percutaneous absorption

- the absorption of drugs through the skin, often for a systemic effect

Stratym corneum

- the outermost cell layer of the epidermis

Contraceptive

- device or formulation designed to prevent pregnancy

Intrauterine device (IUD)

- an intrauterine contraceptive device that is placed in the uterus for a prolonged period of time