subdermal

As adjectives the difference between subdermal and epidural

is that subdermal is just below the skin while epidural is (anatomy) situated on or outside the dura mater.

As a noun epidural is

(medicine) an injection of anaesthetic into the epidural space of the spine, especially associated with pain relief during childbirth.

As adjectives the difference between subdermal and transdermal

is that subdermal is just below the skin while transdermal is through the unbroken skin.

As a noun transdermal is

a transdermal patch or implant.

As adjectives the difference between subdermal and intradermal

is that subdermal is just below the skin while intradermal is in medicine, injections or infusions fall into the parenteral category of drug/substance delivery methods intradermal means within, about, or below a dermal tissue layer (typically the skin) and describes the location of administration.

As adjectives the difference between subcutaneous and subdermal

is that subcutaneous is pertaining to the fatty layer under the skin while subdermal is just below the skin.