Future of the transdermal drug delivery market--have we barely touched the surface?

Introduction: Transdermal drug delivery is the movement of drugs across the skin for absorption into the systemic circulation. Transfer of the drug can occur via passive or active means; passive transdermal products do not disrupt the stratum corneum to facilitate delivery whereas active technologies do. Due to the very specific physicochemical properties necessary for successful passive transdermal drug delivery, this sector of the pharmaceutical industry is relatively small.

The effect of formulation excipients on the penetration and lateral diffusion of ibuprofen on and within the stratum corneum following topical application to humans.

Distribution profiles of topically applied drugs can be influenced by the presence of excipients. This study investigated the effect of common topical excipients on the simultaneous lateral diffusion and stratum corneum (SC) penetration of a model compound, ibuprofen (IBU) in humans. IBU solutions with and without propylene glycol (PG), polyethylene glycol 200 (PEG 200), and/or octisalate (OS) were dosed onto the forearm of participants.

Nanoparticles do not penetrate human skin--a theoretical perspective.

The penetration of intact particles in the nanometer range (nanoparticles, [NP]) through human skin is a controversial topic, which has attracted much interest from both the pharmaceutical and the personal care industries. Concerns have also been raised about the possible implications that dermal exposure to NP may have for human health, particularly from physical sunblock formulations. Here we use a theoretical approach to determine the feasibility of NP penetration of healthy human skin.

A commentary on transdermal drug delivery systems in clinical trials.

The number of drugs available as marketed transdermal products is limited to those that exhibit the correct physicochemical and pharmacokinetic properties that enable their effective delivery across the skin. In this respect, there are less than 20 drugs that are currently marketed in the US and EU as products that deliver systemic levels of their active ingredients. An analysis of clinical trials conducted in the transdermal sector shows a similar picture with only nine drugs accounting for approximately 80% of all transdermal clinical trials listed on ClinicalTrials.