Single Blind, Randomized, Controlled Trial of a Lightening Product With and Without Iontophoresis versus Tretinoin and Vehicle for Hyperpigmentation

January 2015 | Volume 14 | Issue 1 | Original Article | 13 | Copyright © January 2015


Molly Wanner MD MBA,a Neil Houston BA,b Emilia Javorsky MPH,c Minsheng Yuan MD,d
Maria Alora-Palli MD,e Alexa B. Kimball MD MPHf

aDepartment of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, MA
bClinical Unit for Research Trials and Outcomes in Skin (CURTIS), Department of Dermatology, Massachusetts General Hospital, Boston, MA
cUniversity of Massachusetts Medical School, Worcester, MA
dDepartment of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, MA
eClinical Unit for Research Trials and Outcomes in Skin (CURTIS), Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, MA
fClinical Unit for Research Trials and Outcomes in Skin (CURTIS),
Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, MA

Abstract
BACKGROUND: Hyperpigmentation is a common concern and has many causes including lentigines and melasma. Currently available topical products for hyperpigmentation are limited by their potential for irritation, lack of demonstrated efficacy or regulatory concerns..
OBJECTIVE: To compare the efficacy of a new skin lightening product with and without iontophoresis to a known effective product (tretinoin) and placebo on hyperpigmentation caused by lentigines and/or melasma. Secondary objectives included an assessment of the product’s effects on the appearance of rhytides and roughness.
METHODS AND MATERIALS: Eighty subjects were randomized into one of four treatment groups: proprietary lightening product, proprietary lightening product with iontophoresis, tretinoin 0.05% cream, or vehicle control. Seventy-four subjects completed all study visits. Blinded assessments of subjects were performed at each visit under ambient and Wood’s light.
RESULTS: The proprietary skin lightening product improved facial hyperpigmentation versus placebo under ambient light (P = 0.05) and Wood’s lamp (P = 0.01) examination. Tretinoin also improved facial hyperpigmentation versus placebo under Wood’s lamp (P = 0.01). The proprietary product was better tolerated than tretinoin, with fewer subject reported side effects.
CONCLUSION: The investigational product was effective and may be better tolerated than tretinoin cream.

J Drugs Dermatol. 2015;14(1):13-18.

INTRODUCTION

Hyperpigmentation is a common dermatologic concern. In photoaged skin, hyperpigmentation may manifest as lentigines, melasma, or seborrheic keratoses, and can respond to topical treatment. Medications such as tretinoin, hydroquinone, mequinol, and azelaic acid, as well as over the counter products such as arbutin, niacinamide, ascorbic acid, kojic acid, and glycolic acid have been studied for hyperpigmentation. 1–4 These are thought to exert their effects on hyperpigmentation via impact on melanin biosynthesis, melanosome transfer, or epidermal desquamation.5–8
Tretinoin, in particular, is thought to decrease pigmentation by promoting epidermal turnover and inhibiting tyrosinase.1,9 Double blind studies support the use of tretinoin 0.05% and 0.1% for lentigines.1,10,11 wrinkles and photoaging.11–16 However, its use is limited by local side effects such as irritation and redness.11,12
The inability to cross the stratum corneum can limit the efficacy of topical products. Iontophoresis provides a strategy for enhancing penetration through the stratum corneum. Iontophoresis uses electrical current to exert its effect, and in combination with water or botulinum toxin has been used to treat hyperhidrosis. 17,18 At high current, iontophoresis may change the structure of the skin,19 enhancing the ability of both charged and uncharged molecules to enter the skin. In the treatment of hyperpigmentation, iontophoresis has been used in combination with Vitamin C.20,21 In a twelve week, split-face study, iontophoresis used with Vitamin C showed improvement over control.20
The purpose of this study was to evaluate a topical, investigational over the counter product for reduction of hyperpigmentation with and without iontophoresis and in comparison to tretinoin. The study had the secondary objective of evaluating fine lines;