Routes Of Administration Flashcards
Name the 5 routes of administration?
Oral, Rectal, Parental, Topical and Respiratory
What’s the most common oral route?
Peroral, involves swallowing medication to be absorbed in GI tract
Name 2 disadvantages of the oral route?
-drug may not be completely absorbed
-hostile conditions eg. pH, microbiome
-absorption variability due to food intake
-slower onset of action
Give an advantage and disadvantage of rectal route.
+ alternative for drugs inactivated by GI fluids
+ alternative when oral route for patient is precluded eg. vomiting
- inconvenient
Name 3 parental forms of administration.
Intravenous, intramuscular and subcutaneous
What is the topical route?
Application onto skin for local effect (eg. creams) OR systemic absorption (eg. patch)
Name 2 forms of respiratory administration.
Intranasal and pulmonary
What are 2 advantages of oral administration?
-convenient/simplest
-high surface area
-good blood supply
What are 3 advantages of tablets?
-convenient to take
-better chemical stability compared to liquid
-relatively cheap to produce
Name 3 types of modified-release tablets.
~pulsatile
~delayed-release
~prolonged-release
Name the 7 types of tablets.
~disintegrating
~gastro-resistant
~modified-release
~effervescent
~dispersible
~sublingual and buccal
~lozenges and pastilles
Name commonly used excipients.
~filler (bulk)
~disintegrant (starch swell w/ H20)
~binder (adhesive for tablet)
~lubricant (between machinery)
~glidant (inter-particulate)
Give 3 advantages and 2 disadvantages of capsules.
+easily to identify (colours)
+minimal excipient needed
+high drug loading is possible
-not suitable for highly soluble substances
-more costly than oral tablets
What is the main solvent used in oral solutions and why is it good?
Water
-lack of toxicity
-low cost
-must be distilled water
What are the 6 excipents used for oral solutions?
-Viscosity enhancers
-Preservatives
-Sweetners
-Antioxidants
-Flavouring agents
-Colouring
What are the factors affecting chemical degradation of solutions?
-pH
-High Temperature
-UV light (containers that reduce light transmission)
-Catalysis
-Oxygen (Antioxidants)
What role does co-solvents play in oral solutions?
Enhance water solubility for drugs that are not water-soluble
What are the 4 ways to enhance drug solubilty?
-pH modifications
-Co-solvents (alcohol)
-Complexations (cyclodextrins)
-Surfactants (micelles)
What are the 3 causes for particle movement in suspension?
-Brownian Motion / Diffusion (only small particles)
-Gravity (sedimentation - only larger particles)
-External agitation (shaking by patients)
What types of drugs cannot be administered IV?
-water in oil emulsions
What are 3 advantages of parental route of administration?
-rapid onset of action
-high bioavailaibity
-suitable for unconscious patients
-infusion allows prolonged release
What are 3 disadvantages of parental route of administration?
-requires healthcare professional
-needle phobia
-manufacturing is more costly
-shelf-life is shorter
What are the vehicles for injections?
- ‘water for injections’
- ‘saline for injections’ (infusions due to large volume)
- co-solvent system
- solubilising agents
What are 3 advantage and disadvantages of inhaled route?
+ Rapid Absorption
+ Avoids harsh GI enviroment
+ Avoids Hepatic first metabolism
- complex delivery device (high cost)
- Dose may not be consistnet
- Mucus clearance (not suitable for long lasting formulations)
What are the 3 phases of drug adminstration for inhaled route?
1) Deposition
2) Dissolution
3) Absorption
What are the 3 mechanisms for particle deposition for inhaled route?
- Inertial Impaction >5um
- Gravitational Sedimentation 1um-5um
- Brownian Diffusion 0.5um-1um
What does mucociliary clearance mean for absorption of inhaled drugs?
drug must absorb within 24hours as mucus will clear the drug out after 24hours
Give 3 advantages of the nasal route?
-Easy administration
- Direct route to brain is possible
- low enzymatic activity
- Avoids first-pass effect
- potential for rapid onset of action
What are the 3 chambers of the eye?
- Anterior
- Posterior
- Vitreous
What produces tears?
lacrimal gland
What are the 3 different types of ocular delivery?
- Cornea
- Periocular
- Intravitreal
What are 3 disadvantages of ocular route?
- tears
- blinking (fluid clearance)
- maximum dose 20-30ul
What are 3 advantages of ocular route?
- patient can administer
- potential for rapid onset of action
- Avoid first pass metabolism
What are formulation considerations with the ocular route?
- close to neutral pH
- isotonic
- particle free
- sterile
