Research Techniques Made Simple: Drug Delivery Techniques, Part 2: Commonly Used Techniques to Assess Topical Drug Bioavailability.
Assessing the extent of absorption of topical drugs into the various skin layers has been one of the biggest challenges of recent dermatological research. Although skin biopsy samples can be used to directly measure topical drug absorption, biopsies are invasive and not practical for obtaining kinetic data. Common alternative techniques used to assess the bioavailability of topical drugs include in vitro (Franz cell chamber), ex vivo (isolated perfused skin models), and in vivo (vasoconstrictor assay, tape stripping/dermatopharmacokinetics, and microdialysis) techniques. Despite the popularity of these techniques, each technique has its own advantages and disadvantages that limit its use. Consideration of each technique requires that there is a rational linkage to the drug's clinical endpoint and/or site of action. In this article, we review these in vitro, ex vivo, and in vivo techniques, focusing on the basic concepts and the advantages and disadvantages of each technique.
Albert Einstein College of Medicine, Bronx, New York, USA.
Parth
P
Patel
Lake Erie College of Osteopathic Medicine, Bradenton, Florida, USA.
Shawn
S
Schmieder
Albert Einstein College of Medicine, Bronx, New York, USA; Department of Dermatology, Nova Southeastern University, Fort Lauderdale, Florida, USA. Electronic address: kkderm@gmail.com.
Karthik
K
Krishnamurthy
D000279:Administration, Cutaneous; D000287:Administration, Topical; D000305:Adrenal Cortex Hormones / Q000494:pharmacology*; D001682:Biological Availability; D016503:Drug Delivery Systems / Q000379:methods; D006801:Humans; D066298:In Vitro Techniques; D017551:Microdialysis / Q000379:methods; D008953:Models, Anatomic; D036301:Qualitative Research; D012107:Research Design; D012680:Sensitivity and Specificity; D012867:Skin / Q000187:drug effects* / Q000378:metabolism; D012869:Skin Absorption / Q000187:drug effects*
D000305:Adrenal Cortex Hormones