Skip to main content
. Author manuscript; available in PMC: 2015 Sep 28.
Published in final edited form as: J Control Release. 2014 Apr 18;190:15–28. doi: 10.1016/j.jconrel.2014.03.053

Table 1. Routes of administration.

Advantages, disadvantages, potential targets and examples of the most commonly used routes of administration for drug delivery. The number of top 100 commercial drugs and their route of administration was determined by counting the best selling drugs in 2013 as determined by Drugs.com [155].

Route of Administration Advantages Disadvantages Targets Examples Number of Top 100 Commerical Drugs
Injections: IV, IM and SQ

  • Rapid onset (IV)

  • Up to 100% bioavailability

  • Controlled depot release (IM, SQ)

  • Suitable for most therapeutic molecules

  • Difficult for patient to self administer (IV)

  • Patients fear of needles leads to noncompliance

  • Higher instance of infection

  • Tissue with blood access (IV)

  • Systemic

  • Vaccines (IM)

  • Chemotherapy (IV)

  • Insulin (SQ)

 42
Oral

  • Patient compliant and most convenient

 Poor bioavailability

  • Overwhelmingly non-targeted

  • Not viable for larger therapeutics (peptides/proteins)

  • Potentially inconsistent due to presence of food

  • Systemic

  • Pills

  • Liquid medications

 54
Inhalation

  • Direct target to lungs

  • Fast absorption

  • Inconsistent delivery stemming from variation in patient-to-patient technique

  • Lungs

  • Brain

  • Systemic

  • Inhalers

  • Anesthetics

 7
Transdermal

  • Less side-effects due to direct delivery to skin

  • Bypasses first-pass degradation

  • Patients can potentially use incorrect dose (creams)

Absorption dependent on skin condition and location

  • Skin

  • Systemic (lesser extent)

  • Patches

  • Creams

 4