METHODS

• Excised human abdominal skin tissue samples of 500-µm thickness were pretreated with 
a low-power 1440-nm fractional diode laser (Clear + Brilliant® laser system; Solta Medical, 
Bothell, WA) using either 80 or 320 microscopic treatment zones (MTZ)/cm2, or received no 
laser pretreatment (Table 1)

Table 1. Experimental Parameters 

• Following laser pretreatment, 2% salicylic acid was applied, and uptake was determined at 
various time points up to 24 hours after application (Figure 1)

Figure 1. Study design for testing uptake of topicals on skin tissue. 

PBS, phosphate-buffered saline.

• Samples were filtered and analyzed using high-performance liquid chromatography to obtain 
permeation and retention for laser-treated samples and untreated controls

• Total uptake was calculated as the sum of the normalized cumulative permeation and 
retention in each sample

• Average total uptake was compared between laser-treated samples and untreated controls to 
determine the uptake enhancement ratio

RESULTS

• Cumulative permeation of 2% salicylic acid at 24 hours posttreatment was similar for both 
1440-nm pretreatments (80 and 320 MTZ/cm2; both 0.01 mg/cm2) and untreated control 
(0.009 mg/cm2; Figure 2)

Figure 2. Cumulative permeation of 2% salicylic acid through 24 hours after 1440-nm  
laser pretreatment. 

Values are mean ± standard deviation. MTZ, microscopic treatment zones.

• Retention of 2% salicylic acid was ~9 times greater with 320-MTZ/cm2 pretreatment 
compared to both 80-MTZ/cm2 pretreatment and untreated control (Table 2)

Table 2. Enhancement of 2% Salicylic Acid Retention

SYNOPSIS

• The structure of the stratum corneum can limit uptake and effectiveness of topical medications1; however, lasers can disrupt the stratum corneum and tight junctions in the epidermis, allowing for 
better topical penetration and absorption2

• Non-ablative fractional lasers have less effect on the stratum corneum, can minimize thermal side effects, and can shorten postprocedural downtime compared to ablative lasers3,4

• The relationship between topical uptake and laser device settings, such as wavelength, peak power, and spot density, must be quantified to optimize treatments

Enhanced Uptake of  
2% Salicylic Acid 
Following 1440-nm  
Non-ablative Fractional 
Diode Laser Treatment 

Jordan V. Wang, MD, MBE, MBA1; Paul M. Friedman, MD1,2; Adarsh Konda, PharmD3; Catherine Parker, NP, MSN4; Roy G. Geronemus, MD1
1Laser & Skin Surgery Center of New York, New York, NY; 2Dermatology and Laser Surgery Center, Houston, TX; 3Bausch Health US, LLC, Bridgewater, NJ; 4Solta Medical, Bothell, WA 

OBJECTIVE
• To quantify uptake of topical 2% salicylic  

acid after pretreatment with a 1440-nm  
non-ablative fractional diode laser with  
varying treatment densities

CONCLUSIONS
• In this ex vivo analysis of transdermal 2% 

salicylic acid uptake, low-power 1440-nm  
non-ablative fractional diode laser pretreatment 
with 320 MTZ/cm2 resulted in greater retention 
within skin tissue samples compared to 
untreated controls and the 80-MTZ/cm2 setting

• Retention enhancement following treatment 
with greater MTZ density did not appear to have 
an additive effect on overall uptake at 24 hours, 
supporting the argument that salicylic acid 
uptake may be predominantly transfollicular

• These results may guide the development  
of treatment protocols for clinical use of  
non-ablative fractional laser pretreatment  
to enhance uptake of salicylic acid–containing 
topicals

Presented at the 2021 Fall Clinical Dermatology Conference • October 21-24, 2021 • Las Vegas, NV, and Virtual

Funding information: This study was sponsored by Solta Medical. Medical writing support was provided by MedThink 
SciCom and funded by Solta Medical.  

Disclosures: JVW is an investigator for Solta Medical. PMF serves on the advisory board and speaker bureau for Solta Medical. 
AK and CP are employees of and may hold stock or stock options in Solta Medical. RGG is an investigator and advisory board 
member for Solta Medical.

References: 1. Lee et al. Eur J Pharm Sci. 2016;92:1-10. 2. Machado et al. Aesthetic Plast Surg. 2021;45:1020-1032. 3. Friedman et 
al. J Drugs Dermatol. 2020;19:s3-s11. 4. Farkas et al. Aesthet Surg J. 2013;33:1059-1064.

Parameter Setting
Device wavelength, nm 1440 1440
Spot density, MTZ/cm2 80 320
Peak power, W 1.2 3
Spot size, µm 130 130
Pulse energy, mJ 9 9
MTZ, microscopic treatment zones.

80 MTZ/cm2 320 MTZ/cm2

Control 1.06 ± 0.40 x 9.31 ± 3.96 x

80 MTZ/cm2 — 8.74 ± 3.60 x

MTZ, microscopic treatment zones.

Figure 1

Sample & refill

500-µm skin graft

Topical formulation

PBS solution w/ 0.2% sodium azide

Donor chamber

Permeation/Diffusion chamber
Stir bar

Stir rotation

Figure 2

0.009

0.010

0.010

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

0 5 10 15 20 25 30

C
um

ul
at

iv
e 

pe
rm

ea
ti
o
n,

 m
g/

cm
2

Time, hours

Control
KOVAR-1435nm
TUSCANY-1435nm

Control
80 MTZ/cm2

320 MTZ/cm2