Sports Medicine : Topical vs. Transdermal
Drug Delivery - a function of formulation
Topical
Peripheral tissue activity
Systemic side effects less likely
If analgesic, applied directly over painful site
Insignificant serum levels
Transdermal
Systemic activity
Potential for adverse effects
If analgesic, may be applied away from painful site
Serum levels necessary for effect
Medications that relieve pain, reduce inflammation, and relax
muscles can have side effects that are detrimental to athletic
performance, such as drowsiness. However, when these medications
are administered topically, the therapeutic benefit can be enhanced
while significantly reducing the risk of adverse effects.
For example, research has shown that topically-applied ketoprofen
provides a high local concentration of drug below the site of application
but decreases systemic exposure and significantly reduces the risk
of gastrointestinal upset or bleeding. When properly compounded
into an appropriate base, tissue concentrations of ketoprofen were
found to be 100-fold greater below the application site (knee)
compared to systemic concentrations. Muscle relaxants can be similarly
prepared to minimize the risk of drowsiness.
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