Pharmacology and Therapeutics
`
`Comparing 2.5°/o, 5°/o, and 10°/o Benzoyl Peroxide on
`lnfl~mmafory Acne Vulgaris
`
`Ono !-f. M1us, JR., PH.D., ALBERT M. KLIGMAN, M.D., PH.D., PETER PocH1, M.D.,
`AND HARRIET COMITE, M.D.
`
`From the Departments of Dermatology, University of
`Pennsy/vania Sc/:iool of Medicine, Philadelphia,
`Pennsylvania, and Boston University School of Medicine,
`Boston, Massachusetts
`·
`
`ABSTRACT: A 2.5% formulation of benzoyl peroxide was
`compared with its vehicle, and with a 5% and a 10% proprietary
`benzoyl peroxide gel preparation in three double-blind studies
`involving 153 patients with mild to mode;ately severe acne
`vulgaris. The 2.5% benzoyl peroxide formulation was more
`effective than its vehicle and equivalent to the 5% and 10%
`concentrations in reducing the number of inflammatory lesions
`(papules and pustules). Desquamation, erythema, and symp(cid:173)
`toms of burning with the 2.5% ge! were less frequent than
`with (he 10% preparation but equivalent to the 5% gel. The
`2.5% formulation also significantly reduced Propionibacterium
`~cnes and the percentage of free fatty acids in the surface
`lipids after 2 weeks of topical application.
`
`Benzoyl peroxide, in concentrations of 5%, 10%,
`
`and 20%, has been used effectively in the treat(cid:173)
`5 This compound
`ment of aerie for more than 20 years. 1
`•
`has been shown to suppress Propionibacterium acnes
`in vivo, the pr.obable basis for its therapeutic effect. 6
`With such concentrations, · side effects such as ery(cid:173)
`thema, desquamation, and burning, itching, or stinging
`are fairly common. This paper describes clinical trials
`of a 2.5% benioyl peroxide gel, which was compared
`with 5% and l 0% benzoyl peroxide gels in groups of
`patients with inflaryimatory acne vulgaris. Antibacterial
`and !ipid studi~s we.re also performed on the 2.5%
`benzoyl 'peroxide formulation.
`
`Address for correspondence: Otto H. Mills, Jr., Ph.D., UMDNJ(cid:173)
`Robert Wood Johnson Medical School, One Robert Wood Johnson
`Place, New Brunswick, NJ 08903.
`
`Subjects, Materials, and Methods
`
`Clinical Studies
`The same methods were used to conduct three double(cid:173)
`blind studies. After giving informed consent, subjects with
`mild to moderately severe inflammatory acne vulgaris of the
`face (minimum of 10 inflammatory lesions) were assigned to
`one of the three treatment groups. A total of 153 subiects,
`74 men and 79 women (average age of 20 years), participated
`in the three studies. In the first, 25 subjects used 2.5% ben(cid:173)
`zoyl peroxide gel and 25, the gel vehicle for this formulation.
`In the second, 26 used the 2.5 gel and 27, a 5% gel. The
`third study consisted of 25 subjects who used the 2.5% gel
`~nd 25, a 10% benzoyl peroxide gel. The subjects received
`no medications for any reasons during the 4-week period
`prior to the start of the study.
`The study participants were instructed to wash daily with
`a non-medicated soap, rinse, and dry with a clean towel
`before applying the study medication to the face twice daily
`(morning and evening) for 8 weeks. Subjects were examin~d
`before treatment for baseline determinations and at weeks
`2, 4, 6, .and 8 after the start of treatment. At each v·,s·,t, the
`number of facial inflammatory lesions {papules and pustules)
`was recorded. In addition, the frequency and severity of side
`effects such as erythema, peeling, and burning were noted.
`A global assessment of improvement was also made by the
`investigator at each visit, according to the following criteria:
`"excellent," greater than 75% improvement; "good," ab~ut
`500/o improvement; "fair," about 25% improvement; and
`"poor," little or no improvement.
`
`Antibacterial and lipid Studies
`
`Ten subjects who had a P. acnes count of 100,000 colonies
`per cm 2 or greater on the face were selected for this study.
`A score of 3 or greater on the follicular porphyrin fluorescence
`scale was also required for admission. The density of P. acnes,
`the degree of porphyrin fluorescence, and the ratio of free
`fatty acids to triglycerides found in lipid samples were de(cid:173)
`termined before and after 7 and 14 days of twice-daily ap(cid:173)
`plications of the 2.5% benzoyl peroxide formulation to the
`face. All applications were maqe by laboratory technicians.
`At each sample day (O, 7, 14), the skin was prepared by
`wiping the surfa~e of the forehead for 30 seconds with a
`piece of gauze saturated with 0.1 % Triton X-100 (Rohm and
`Haas, Philadelphia, PA), followed by a distilled water rinse
`
`664
`
`1 of 5
`
`Almirall EXHIBIT 2027
`
`Amneal v. Almirall
`IPR2019-00207
`
`

`

`No. 10
`
`BENZOYL PEROXIDE IN ACNE
`
`Mil/set al.
`
`TABLE 1 . Comparison of Effects of 2 .5% Benzoyl Peroxide and Vehicle
`
`2.5% Benzoyl Peroxide
`
`Vehicle
`
`Week
`
`Number of
`Subjects
`
`Mean Number
`of lesions•
`
`Mean%
`Reduction
`
`Number of
`Subjects
`
`Mean Number
`of Lesions•
`
`Mean%
`Reduction
`
`0
`2
`4
`6
`8
`
`25
`25
`24
`25
`25
`
`• Papules and pustules.
`t By t-test.
`
`13.6
`10.8
`9.3
`7.5
`6.8
`
`20.4%
`31.4%
`44.1%
`50.9%
`
`25
`25
`25
`22
`25
`
`13.7
`13.8
`13.0
`13.1
`11.2
`
`-2.7%
`2.8%
`3.4%
`17.6%
`
`:t Difference in baseline counts.
`
`665
`
`P Valuet for
`Average
`Treatment
`Difference
`
`0.91,t
`<0.01
`O.Q2
`<0.01
`0.01
`
`and a 30-second wipe with hexane. This procedure removed
`environmental contaminants, desquamating cells, and surface
`bacteria and lipids. Two areas were protected by plastic
`weighing boats with several perforations to aflow evaporation
`of sweat. After 1 hour, the site was sampled by the detergent
`scrub technique of Williamson and Kligman.9 A sterile glass
`cylinder with an internal area of 3.8 cm2 was placed over the
`site. One ml of 0.1% Triton X-100 in 0.075% phosphate
`buffer (pH 7.9) was added and the surface scrubbed with a
`blunt Teflon (Arthur H. Thomas, Philadelphia, PA) spatula
`for one minute. This procedure was repeated, and the two
`samples were pooled. Subsequently, tenfold dilutions were
`made in 0.5% buffered Triton X-100; the samples were drop(cid:173)
`plated on brain heart agar with 0. 1 % Tween 80 (Atlas Chem(cid:173)
`ical, Wilmington, DE) and incubated anaerobically for 7 days
`in a Gas Pak (Arthur H. Thomas, Philadelphia, PA) jar system.
`P. acnes was identified by colony morphology, by suscep(cid:173)
`tibility to P. acnes bacteriophage, and, when indicated, by
`1
`biochemical testing. 10
`• 1
`At the other site on the forehead, lipid samples were col(cid:173)
`lected by putting 2 ml of hexane-containing methyl nervon(cid:173)
`ate, as an internal standard, in the glass cup, as above. The
`site was scrubbed for 30 seconds with a blunted Teflon po(cid:173)
`liceman. The solution was taken up on a Pasteur pipette and
`passed through a 0.45-millipore filter to remove skin debris
`and bacteria. It was then placed in Teflon-capped glass
`screwtop vials. The vials were uncapped, dried overnight in
`a vacuum at 40 C, then capped and stored at 40 C until lipid
`thin-layer chromatography was done by the method of
`Oowning. 12
`Each subject was examined under Wood' s light for por(cid:173)
`phyrin fluorescence prior to washing and obtaining samples.8
`
`The intensity of fluorescence was graded on a O to 6 scale
`with O = none, 1 to 2 = mild fluorescence, 3 to 4 == moderate,
`and 5 to 6 = heavy fluorescence.
`
`Statistical Methods
`Fisher's exact test 13 was used to compare treatment groups
`with respect to side effects at each visit during the treatment
`period. A group t-test14 was used to compare treatment
`groups with regard to the reduction in number of papules
`and pustules from baseline. A paired t-test 14 was used to
`analyze changes from baseline counts within treatment
`groups. The Wilcoxon rank-sum test 14 was used to analyze
`changes estimated by global ratings.
`
`Results
`
`Results on efficacy and side effect data are presented
`separately for each study. No subject was obliged to
`drop out of any study because of adverse effects.
`
`Study 1: 2.5% Benzoy/ Peroxide Versus Vehicle
`
`The 2.5% benzoyl peroxide was more effective than
`the vehicle in reducing the number of inflammatory
`lesions (papules and pustules) at all follow-up visits
`(Table 1).
`The 2.5% benzoyl peroxide was also significantly
`more effective than the vehicle in global ratings at all
`evaluations. Mild peeling, burning, and itching were
`
`TABLE 2 . Comparison of Effect of 2.5% and 5.0% Benzoyf Peroxide Ce/
`
`2.50/o Benzoyl Peroxide
`
`5% Benzoyl Peroxide
`
`Week
`
`Number of
`Subjects
`
`Mean Number
`of Lesions•
`
`Mean%
`Reduction
`
`Number of
`Subjects
`
`Mean Number
`of Lesions
`
`Mean%
`Reduction
`
`a
`2
`4
`6
`8
`
`26
`26
`25
`26
`26
`
`• Papules and pustules.
`t By <·Cest.
`
`21.3
`14.8
`B .3
`10.0
`9.6
`
`32.2%
`40.3%
`54.3%
`55.9%
`
`27
`27
`27
`25
`25
`
`19.4
`13.5
`12.9
`10.6
`7.8
`
`30.6%
`35.1%
`47.2%
`57.7%
`
`:t Difference in baseline counts.
`
`P Valuet for
`Average
`Treatment
`Difference
`
`0.47t
`0.75
`0.51
`0.41
`0.94
`
`2 of 5
`
`

`

`666
`
`INTERNATIONAL JOURNAL OF DERMATOLOGY
`
`December 1986
`
`Vol. 25
`
`TABLE 3. Comparison of Effects of 2.5% and 10% Benzoyl Peroxide Gel
`
`2.5% Benzoyl Peroxide
`
`10% Benz.oyl Peroxide
`
`Week
`
`Number of
`Subjects
`
`Mean Number
`of lesions•
`
`Mean%
`Reduction
`
`Number of
`Subjects
`
`Mean Number
`of Lesions
`
`Mean%
`Reduction
`
`0
`2
`4
`6
`8
`
`25
`25
`24
`24
`24
`
`• Papules and pustules.
`t By I-test.
`
`19.7
`16.1
`12.8
`10.9
`10.5
`
`18.3%
`35.0%
`44.7%
`46.7%
`
`24
`25
`24
`23
`24
`
`23.7
`19.0
`\4.9
`14.5
`13.2
`
`19.8%
`17.1%
`38.8%
`44.7%
`
`:f: Difference in baseline counts.
`
`P \Jaluet for
`Average
`Treatment
`Difference
`
`.17:f:
`.66
`.47
`.75
`.57
`
`more frequent in the benzoyl peroxide group than in
`the vehicle group, but only statistically significantly so
`for peeling at week 8. There was no significant differ(cid:173)
`ence in the incidence of erythema, although 2.5%
`benzoyl peroxide more often induced erythema at
`week 2.
`
`Study 2: 2.5% Versus 5.0% Benzoy/ Peroxide
`
`No significant difference in efficacy between the
`2.5% and the 5.0% benzoyl peroxide formulations was
`noted. In both groups, a significant reduction in pa(cid:173)
`pules and pustules was observed at 2, 4, 6, and 8 weeks
`(Table 2). The global ratings confirmed the lack of sig(cid:173)
`nificant difference in efficacy between the 2.5% and
`5.0% gel formulations. There was no significant dif(cid:173)
`ference between the two preparations in regard to
`burning, peeling, or erythema.
`
`Study 3: 2.5% Versus 10% Benzoyl Peroxide
`
`Both 2.5% and 10% benzoyl peroxide gels reduced
`the number of papules and pustules from baseline
`counts, but there was no statistically significant differ(cid:173)
`ence between the two groups (Table 3). Statistical
`eval~ati?n of the investigator's global response ratings
`also indicated that there was no significant difference
`between the efficacy of 2.5% and 10% benzoyl per(cid:173)
`oxide.
`There was a statistically significant difference in the
`frequency and severity of burning, erythema, and
`peeling among subjects who used 10% benzoyl per(cid:173)
`oxide than among those who used the 2.5% concen(cid:173)
`tration at all follow-up visits (Table 4).
`
`also a significant reduction in the ratio of free fatty
`acids to triglycerides.
`
`Discussion
`
`The 2.5% benzoyl peroxide formulation was signif(cid:173)
`icantly more effective than its vehicle in reducing the
`number of papules and pustules and was comparable
`to the 10% benzoyl peroxide by lesion counts. By the
`same measurement, there were no differences be(cid:173)
`tween the 2.5% gel and the 5% benzoyl peroxide gel;
`both were clinically effective. The incidence of irrita(cid:173)
`tion was lower with 2.5% than with 10% benzoyl per(cid:173)
`oxide. It should be pointed out that in two of these
`clinical studies there would need to have been much
`larger patient groups to assure "statistical power" for
`differences between treatments. The differences be(cid:173)
`tween the 2.5% benzoyl peroxide and its vehicle is
`not a question. A clear significant difference between
`these two exists. When the 2.5% versus 5% and 2.5%
`versus 10% studies were reviewed {m "statistical
`power," it is evident that, with the number of subjects
`involved, the power of the test was not high enough
`to assure a difference that was statistically significant.
`However, we feel these studies are clinically significant
`and present important information for clinicians and
`those working in dermatopharmaco\ogy.
`Also, these studies do not represent a titration of
`percent.concentration of drug in the same vehicle. The
`2.5% formulation vehicle was different from those of
`
`TABLE 4. Frequency and Severity of Burning, Erythema, and
`Peeling• (Total Number of Reports for 8 Weeks)
`
`2.5% Benzoyl Peroxide Gel
`
`10% Benzoyl Peroxide Gel
`
`Bacteriology and Free Fatty Acids
`
`Mild Moderate
`
`Mild
`
`Moderate
`
`A marked reduction in the quantity of P. acnes was
`observed after 1 week (Table 5). The intensity of fol(cid:173)
`licular porphyrin fluorescence was also reduced by 1
`week and markedly suppressed by 2 weeks. There was
`
`Burning
`Erythema
`Peeling
`
`20
`22
`so
`
`4
`9
`
`Burning
`Erythema
`Peeling
`
`57
`51
`36
`
`20
`30
`55
`
`• Possibly or probably related to drug.
`
`3 of 5
`
`

`

`No. 10
`
`BENZOYL PEROXIDE IN ACNE
`
`Mills et al.
`
`667
`
`TABLE 5. Effect of Topical Application of 2.5% Benzoyl Peroxide Gel on Quantitative P. acnes Counts,
`Follicular Porphyrin Fluorescence and Free Fatty Acids in Skin Surface lipids
`
`P. acnes (log/cm2
`
`)
`
`Follicular Porphyrin Fluorescence
`(Grades 0-6)
`
`Free Fatty Acids/Triglycerides
`
`WeekO
`
`Week 1
`
`Week 2
`
`WeekO
`
`Week 1
`
`Week2
`
`Weeko
`
`Week 1
`
`Week2
`
`5.8285
`6.2775
`5.2775
`6.6455
`6.1015
`5.6243
`6.7383
`6.3647
`6.4372
`5.7035
`6.083
`
`4.9254
`4.3647
`3.7547
`4.0223
`5.5538
`3.1684
`5.6657
`4.0223
`5.7383
`4.6021
`4.504
`<0.001
`
`4.4694
`3.6455
`3.6455
`4.4994
`4.0223
`3.4025
`5.6021
`3.7383
`5.6455
`3.1684
`4.108
`<0.001
`
`6
`6
`6
`5
`4
`4
`5
`6
`5
`6
`5.30
`
`4
`5
`6
`4
`3
`4
`3
`4
`3
`4
`4.00
`<0.01
`
`2
`3
`4
`2
`2
`2
`
`3
`2
`2
`2.30
`<0.001
`
`0.47
`0.84
`0.38
`0.22
`1.77
`0.93
`1.25
`0.22
`1.05
`0.19
`0.732
`
`0.16
`0.73
`0.16
`0.19
`1.12
`0.86
`1.19
`0.16
`0.99
`0.19
`0.575
`<0.02
`
`0.14
`0.66
`0.14
`0.11
`0.86
`0.55
`0.89
`0.14
`0.60
`0.10
`0.419
`<0.01
`
`Subject
`Number
`
`1
`2
`3
`4
`5
`6
`7
`8
`9
`10
`Mean
`p value
`
`the 5% and 10% formulations, but we think it impor(cid:173)
`tant that we saw these results with percent concentra(cid:173)
`tions of drug that were one-fourth to one-half less than
`the highest concentration.
`The laboratory results from the in vivo study of P.
`acnes showed the 2.5% benzoyl peroxide gel reduced
`the anerobic population by 97% after twice-daily
`treatments for 1 week and by 99% after 2 weeks. This
`outcome is in agreement with previous work using a
`different 2.5% benzoyl peroxide formulation. 15
`Regarding the clinical changes of peeling and ery(cid:173)
`thema and the symptoms of burning, there were no
`differences between 2.5% versus 5%, but differences
`did exist between the 2.5% and its vehicle and the
`2.5% and 10% formulations. With this in mind, the
`lower concentration of benzoyl peroxide should be
`useful for treating patients with easily irritated skin.
`Also, in combination topical therapy with comedofytic
`agents, 2.5% benzoyl peroxide might lessen the ex(cid:173)
`pected degree of irritation.
`
`Drug Names
`
`2.5% benzoyl peroxide: Clear by Design
`5.0% benzoyl peroxide: Desquam X-5
`10.0% benzoyl peroxide: Desquam X-10
`
`References
`
`l. Frank L. Active oxygen acne therapy-oxygenation vs. reduction
`of the follicular structures. Cutis. 1965;1 :306-308.
`
`2. Pace WE. A benzoyl peroxide-sulfur cream for acne vulgaris.
`Can Med Assoc J. l 965;93:252-254.
`3. Oanto JL, Maddin WS, Steward WO, et al. A controlled trial of
`benzoyl peroxide and precipitated sulfur cream in acne vul(cid:173)
`garis. Appl Ther. 1966;8:624- 625.
`4. Belknap BS. Treatment of acne with 5 percent benzoyl peroxide
`gel or 0.05 percent of retinoic acid cream. Cutis. 1979;23:
`856- 859.
`5. Smith EB, Padilla RS, McCabe JM, et al. Benzoyl peroxide lotion
`(20 percent) in acne. Cutis. 1980;25:90-92.
`6. Kligman AM, Mills OH, McGinley KJ, et al. Acne therapy with
`tretinoin in combination with antibiotics. Acta Derm Verereol.
`1975;74(Suppl):l 1 l-115.
`7. Martin RJ, Kahn G, Gooding JW, et al. Cutaneous porphyrin
`fluorescence as an indication of antibiotic absorption and ef(cid:173)
`fectiveness. Cutis. 1973;12:758-764.
`8. McGinley Kl, Webster CF, Leyden JJ . Facial follicular porphyrin
`fluorescence: correlation with age and density of Propioni(cid:173)
`bacterium acnes. Br J Dermatol. 1980;102:437-441 .
`9. Williamson P, Kfigman AM. A new method for the quantitative
`investigation of cutaneous bacteria. J Invest Dermatol.
`1965;45:498-503.
`10. Marples RR, McGinley KJ. Corynebacterium acnes and the an(cid:173)
`aerobic diphtheroids from human skin. J Med Microbiol.
`1974;7:349-357.
`11. McGinley Kl, Webster CF, Leyden JI. Regional variation of cu(cid:173)
`taneous propionibacterium. J Appl Env Microbiol. 1978;35:
`62-66.
`12. Downing OT. Photodensitometry in the thin-layer chromato(cid:173)
`graphic analysis of neutral lipids. J Chromatogr. 1968;38:91 -
`99.
`13. Ostle B. Statistical inference: testing hypotheses: statistics in re(cid:173)
`search. Iowa City, IA: Iowa State University Press, 1963;119-
`321.
`14. Seigel S. The case of k independent samples: nonparametric
`statistics for the behavioral sciences. New York: McGraw(cid:173)
`Hill, 1956:101-117.
`15. Leyden JJ, McGinley KL Mills OH, et al. Topical antibiotics and
`topical antimicrobial agents in acne therapy. Acta Derm Ve(cid:173)
`nereol. 1980;89(Suppl):75- 82.
`
`4 of 5
`
`

`

`This document is a scanned copy of a printed document. No warranty is given about
`the accuracy of the copy. Users should refer to the original published version of the
`material.
`
`5 of 5
`
`