Laser-assisted drug delivery in dermatology: from animal models to clinical practice

Abstract

Topical medicaments are the mainstay of the dermatologists' therapeutic arsenal. Laser-assisted drug delivery enhances the ability of topically applied medicaments to penetrate the skin. We discuss the mechanisms of laser-assisted drug delivery and animal models that have informed clinical practice. We review clinical studies that have employed laser-assisted drug delivery for a range of indications to date including non-melanoma skin cancer, vitiligo, scarring, vaccination, local anaesthesia, analgesia, viral warts, infantile haemangiomas and cosmetic uses. Studies thus far suggest that laser pre-treatment improves transepidermal absorption of topical agents and allows for a much deeper penetration of drugs than is possible with topical medicaments alone. This may allow more efficacious action of current treatments, such that conventional duration of treatment can be shortened or lower concentrations of active agents be used, potentially obviating side effects of treatment. The prospect of using laser technologies to facilitate transdermal vaccination and as an adjunct for inflammatory dermatoses and cosmetic indications remains in its infancy. As larger trials are published, involving greater numbers of patients and utilising various laser and topical medicament parameters, we will enhance our understanding of this nascent modality of treatment delivery.

Laser‐assisted photodynamic therapy for superficial basal cell carcinoma and Bowen's disease: a randomized intrapatient comparison between a continuous and a fractional ablative CO2 laser mode

“…Additionally, the laser on its own adds therapeutic effect. Several preclinical studies showed facilitated accumulation of topically applied drugs . Clinical studies demonstrated enhanced lesion response when CO 2 or erbium‐doped yttrium aluminium garnet (Er:YAG) laser preceded PDT compared to PDT or laser alone .…”

“…Several preclinical studies showed facilitated accumulation of topically applied drugs. [13][14][15][16] Clinical studies demonstrated enhanced lesion response when CO 2 or erbium-doped yttrium aluminium garnet (Er:YAG) laser preceded PDT compared to PDT or laser alone. 2,[17][18][19][20][21][22][23][24][25] Ablative laser-assisted PDT is considered to offer good tolerability, satisfactory aesthetics and might provide other advantages such as reduced photosensitizer incubation time.…”

Pharmacological Targeting of the Epidermal Barrier

“…By means of laser, fractional photothermolysis can be performed: i.e., multiple vertical columns of tissue in the SC and underlying layer are thermally destroyed to create unimpeded channels. On treated skin, the channels and the surrounding thermally coagulated tissue enhance penetration while the untreated area serves as a reservoir for regeneration [115].…”

Laser Assisted Drug and Cosmeceutical Delivery System of the Skin

“…As molecular size of the agent increases, there is greater frictional resistance and Dm decreases, decreasing overall flux. 7,8 Heat generation by laser also has the influence on Km and Dm. L can be different on the thickness of the coagulation surrounding wall.…”