Laser assisted drug delivery: A review of an evolving technology

Abstract

Background: Topically applied drugs have a relatively low cutaneous bioavailability. Objective: This article reviews the existing applications of laser assisted drug delivery, a means by which the permeation of topically applied agents can be enhanced into the skin. Results: The existing literature suggests that lasers are a safe and effective means of enhancing the delivery of topically applied agents through the skin. The types of lasers most commonly studied in regards to drug delivery are the carbon dioxide (CO 2 ) and erbium:yttrium-aluminum-garnet (Er:YAG) lasers. Both conventional ablative and fractional ablative modalities have been utilized and are summarized herein. Limitations: The majority of the existing studies on laser assisted drug delivery have been performed on animal models and additional human studies are needed. Conclusions: Laser assisted drug delivery is an evolving technology with potentially broad clinical applications. Multiple studies demonstrate that laser pretreatment of the skin can increase the permeability and depth of penetration of topically applied drug molecules for both local cutaneous and systemic applications. Lasers Surg.

Ablative Fractional Laser Resurfacing Helps Treat Restrictive Pediatric Scar Contractures

“…Furthermore, the concept of laser-assisted delivery of medications through ablative microchannels raises exciting possibilities for the delivery of a wide variety of substances below the epidermal barrier to the area of interest. 17 Without laser pretreatment, a single application of topical corticosteroid suspension alone would have had minimal effect on the underlying scars.…”

Laser Assisted Drug and Cosmeceutical Delivery System of the Skin

“…In laser-assisted delivery, wavelengths have been commonly used were 2,940 nm and 10,600 nm. 4 These wavelengths make ablative or sub-ablative channels from the stratum corneum. Erbium:yttrium-aluminum-garnet (Er:YAG) laser has 2,940 nm wavelength highly absorbed in the water, which enables precise ablation and minimized heat generation into the surrounding tissues.…”

“…With other parameters controlled, the difference of the absorption rate determines the shape and the composition of channel walls. 4 Recently 1,927 nm Thulium was introduced with unique histologic changes, with ablation of the epidermis with higher water concentration and coagulation formed under ablated space. 5 …”

“…For rejuvenation and other indications, fractional photothermolysis is eventually used to make debulking abnormal or aged tissues, and remodeling by remaining tissues. 4,5,6 Meanwhile, in LAD, fractionated laser channels enables controllable delivery, by making microscopic necrotic columns (MNC). Compared to other resurfacing lasers exploiting stratum corneum or epidermis, laser fractionation can make the LAD procedure more quantitatively controllable, which is critical in clinical application.…”

“…3 To enhance penetration in the epidermal layers, simple removing of stratum corneum is a way of barrier destruction. As an example tape stripping is a simple, efficient, and controllable method to remove stratum corneum for preclinical experiments, 3,4 nonetheless it is not clinically available for most of the cases because of irritation and difficulty in recovering. Iontophoresis, sonophoresis and transfollicular positive-pressure delivery are other enhancing methods by facilitating the function of existing channels.…”