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Title: Topical acne vulgaris
medication with a sunscreen
United States Patent: 7,326,408
Issued: February 5, 2008
Inventors: Angel; Arturo
(Santa Rosa, CA), Osborne; David W. (Santa Rosa, CA), Dow; Gordon J.
(Santa Rosa, CA)
Assignee: Dow
Pharmaceutical Sciences (Petaluma, CA)
Appl. No.: 11/823,385
Filed: June 27, 2007
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Abstract
Increased compliance in the use of
topical sunscreens is obtained by combining a topical sunscreen agent in a
formulation containing an antibacterial medication such as azelaic acid or
an antibiotic.
Description of the
Invention
FIELD OF THE INVENTION
The invention pertains to the field of topically applied medications used
to treat acne vulgaris.
BACKGROUND OF THE INVENTION
It is well established that both acute and chronic sun exposure has
general detrimental effects to the skin over time. Intervention with the
use of sunscreens and sunblocks at a young age is advocated by
dermatologists around the world. However compliance is minimal. Avoidance
of sun exposure early in life is thought to be particularly important
because the carcinogenic effects of the sun are cumulative and are
manifested years after the exposure. For children, compliance is dependent
primarily on the diligence of the parents. During the teenage years
responsibility shifts to the individual, yet teenagers are notoriously
noncompliant with the use of sunscreens. In fact the "sun exposed
appearance" is regarded as desirable among teenagers generally. Sunscreen
use for outdoor activities by adolescents and young adults is highly
important for healthy skin, i.e., to minimize the risk of developing skin
cancers and to reduce the premature signs of skin aging over time.
Therefore, the public health need is great to improve and to facilitate
the regular use of sunscreens among adolescents and young adults. It is
particularly important to protect the facial area which receives intense
and repeated sun exposure.
Recent studies published by the American Academy of Dermatology highlight
the lack of compliance of young adults and teenagers in the use of
sunscreens. In a study entitled "New American Academy of Dermatology
Survey Finds People Aware of the Dangers of the Sun, But Sun Protection
Not Necessarily Practiced," Am. Acad. Dermatol. (Apr. 29, 2003), it was
reported that, although 79% of surveyed parents and grandparents apply
sunscreen to children when they play outdoors, this number drops to only
34% for independent young people under the age of 25. In another study
entitled, "New Study Finds High School Students Get Enough UV Exposure on
an Average Day to Cause Sunburn", Am. Acad. Dermatol. (Apr. 24, 2002), it
was reported that, when high school students between the ages of 12 and 17
were provided with Ultraviolet B dosimeters to wear on their wrists, UVB
exposure that occurred during regular daily activities was sufficient to
cause sunburn in some students. Moreover, even though UVB exposure was
less on cloudy days, the amount of UVB exposure on these days was higher
than expected and 80% of the sun's UV rays pass through the clouds. The
study also estimated that almost 80% of a person's lifetime sun exposure
occurs before the age of 18 Therefore, reducing the exposure of teenagers
to harmful rays of the sun is extremely important. In another study
entitled "Skin Cancer Awareness and Sun Protection Behaviors in College
Students", J. Acad. Dermatol., Abstract P1321, page P107 (March 2005), it
was reported that the majority of college students do not use sunscreen on
a regular basis. In fact, fully 81% of college students surveyed reported
that they never, rarely, or only sometimes use sunscreen.
In a recent article, Kullavanijaya, P, and Lim, HW, J. Am. Acad. Dermatol.,
52:937-958 (June 2005), incorporated herein by reference, review the
various types of ultraviolet radiation, the harms that these rays can
cause upon exposure to skin, and various types of sun protective agents
that are applied to protect the skin. As disclosed by Kullavanijaya and
Lim, most presently available sunscreen agents are effective primarily in
blocking UVB rays and are photolabile, that is they are degraded upon
exposure to ultraviolet radiation. Many of the available sunscreens also
induce adverse effects such as irritation, allergic contact reactions,
photoallergy, and phototoxic effects.
Newer sunscreen agents such as benzene
1,4-di(3-methylidene-10-camphosulfonic acid (MEXORYL SX.RTM., L'Oreal,
Clichy, France) (described in U.S. Pat. No. 4,585,597, incorporated herein
by reference), drometriazole trisiloxane (MEXORYL XL.RTM., L'Oreal, Clichy,
France) (described in U.S. Pat. No. 4,585,597),
methylene-bis-benzotriazoyl tetramethylbutylphenol (bisoctrizole, TINOSORB
M.RTM., Ciba Specialty Chemicals, Basel, Switzerland) (described in U.S.
Pat. Nos. 5,869,030; 5,980,872; and 6,521,217, each of which is
incorporated herein by reference), and bis-ethylhexyloxyphenol
methoxyphenol triazine (anisotriazine, TINOSORB S.RTM., Ciba Specialty
Chemicals) (described in U.S. Pat. Nos. 5,869,030; 5,980,872; and
6,521,217), as well as the inorganic sunscreen agents titanium oxide
(TiO.sub.2) and zinc oxide (ZnO) are reported by Kullavanijaya and Lim to
not share these disadvantages. These agents are broad spectrum UV
absorbers, are photostable, and have not been found to cause the adverse
effects associated with other sunscreen agents.
Acne vulgaris, often referred to as "acne", is a condition that is
distinct from and is not related to acne rosacea. Acne vulgaris is a
disorder of the pilosebaceous follicle. Common features of acne vulgaris
include increased sebum production, follicular keratinization,
colonization by Propionibacterium acnes, and localized inflammation.
Treatment for acne vulgaris is typically with one or more of a retinoid,
such as tretinoin or isotretinoin, an antibiotic, such as clindamycin or
erythromycin, or other medication such as azelaic acid, a sulfonamide, and
antibacterials such as benzoyl peroxide. Retinoid compounds increase the
sensitivity of skin to the sun and are often inactivated by ultraviolet
light. Therefore, retinoid products are recommended to be used at night or
together with a sunscreen. Sulfonamides likewise increase the sensitivity
of skin to the sun and, therefore, may be combined with a sunscreen.
Benzoyl peroxide is highly reactive and degrades upon exposure to the sun.
Therefore, benzoyl peroxide may be combined with a physical sunscreen to
inhibit this sun-induced degradation. Such problems have not been
associated with the use of antibiotics, such as those of the lincomycin
family, or with azelaic acid or salicylic acid.
Acne rosacea, often referred to simply as rosacea, is a separate distinct
dermatological disorder, which is a chronic inflammatory skin disorder
characterized by enhanced epidermal proliferation leading to erythema,
typically with flushing, scaling, and thickening of the skin. Rosacea is
often exacerbated by exposure to the sun. Therefore, treatment of rosacea
often includes the use of sunscreens. In contrast to rosacea, acne
vulgaris primarily affects young people, during the teenage years and
sunscreens have no known beneficial role in treating acne vulgaris. In
fact many sunscreens have been reported to be comedogenic, that is they
have the potential to induce comedones which are the primary lesions of
acne vulgaris.
The present invention is directed to methods of treating and preventing or
inhibiting recurrences of acne vulgaris and addresses the significant need
for increasing the compliance in the application of topical sunscreens in
individuals suffering from or at risk of developing acne vulgaris,
primarily teenagers and other adolescents and young adults. In this way,
chronic effects of overexposure to harmful rays of the sun, such as skin
cancers, can be greatly reduced.
DESCRIPTION OF THE INVENTION
The present invention addresses a problem that has not been adequately
addressed in the prior art and provides a solution to that problem that is
distinct from the prior art. The present invention, in its several
embodiments, provides a solution to the problem of how to increase
compliance in the use of sunscreens, primarily in young people who
typically receive a high proportion of their lifetime sun exposure before
the age of 20 and who are notoriously non-compliant in the use of
sunscreens, especially to the facial areas.
Although the prior art discloses compositions containing certain
antibacterial compounds (erythromycin or sulfacetamide) in combination
with a sunscreen, the sunscreens in these products are provided either to
reduce phototoxic effects of an anti-acne medication or to reduce the
sun-induced degradation of the medication. The sunscreens in these
compositions were not directed to the problem of reducing facial sun
exposure to the individual, except as mentioned to reduce harmful effects
of the antibacterial compounds present in the composition. Accordingly,
because the prior art is not concerned with the problem of protection from
daily sun exposure in the adolescent and young adult populations, the
prior art does not disclose sunscreens that are photostable to be combined
with these antibacterial compounds.
In contrast, the present invention addresses the problem of lack of
compliance in the use of sunscreens, which sunscreens are utilized to
protect an individual from the harmful effects due to exposure to the sun.
Therefore, certain embodiments utilize a photostable sunscreen agent, as
described in more detail below.
The invention, in one embodiment, is a composition for the topical
treatment of acne vulgaris. According to this embodiment of the invention,
the composition contains one or more sunscreen agents, such as a
photostable broad spectrum sunscreen agent, and one or more anti-acne
vulgaris chemical agents selected from an antibiotic, like an antibiotic
of the lincomycin family, such as lincomycin hydrochloride, lincomycin
phosphate, clindamycin phosphate, and clindamycin hydrochloride, azelaic
acid, and salicylic acid. Typically, the anti-acne vulgaris agent and the
sunscreen agent are dissolved or suspended in a vehicle, such as water,
alcohol, or propylene glycol. The composition of the invention is
preferably used in single daily or multiple times daily application to the
facial area. Preferably, application is once daily, preferably in the
morning. The form of the drug product may be a gel, spray, foam, lotion or
other dosage form that is cosmetically acceptable for use on the face and
which is easily spreadable on the skin. It is preferred to apply the
composition of the invention uniformly to all of the acne prone and sun
exposed facial and neck areas to optimally treat acne and to reduce the
incidence and severity of sunburn and chronic skin damage from solar
radiation. The composition of the invention should be spread uniformly on
the skin, such as by using the hands and fingers, to completely cover the
intended areas of treatment. If the acne medication is used twice daily,
the preferred times of application are morning and midday, that is during
the hours of sunlight.
The invention is not intended to be used for "spot treatment" of
individual acne lesions. Rather, the method of treatment of the invention
involves application to broad areas of the face and neck.
In a preferred embodiment, the composition further contains an
antioxidant. It has been unexpectedly discovered that combining an
antioxidant in a composition containing an antibiotic of the lincomycin
family such as clindamycin, and a sunscreen agent, such as a photostable
broad spectrum sunscreen like zinc oxide, titanium oxide, or Tinosorb M
provides a more stable composition with reduced degradation of the
clindamycin during storage. A preferred antioxidant is sodium thiosulfate.
Other suitable antioxidants include butylated hydroxyanisole (BHA),
butylated hydroxytoluene (BHT), sodium metabisulfite, ascorbic acid,
ascorbyl palmitate, thiourea, acetylcysteine, dithiothreitol, cysteine
hydrochloride, propyl gallate, and the tocopherols.
The invention, in another embodiment, is a method for topically treating
acne vulgaris. Concomitantly, the skin is protected from exposure to the
sun. According to this embodiment of the invention, a composition
containing one or more sunscreen agents, such as a photostable broad
spectrum sunscreen agent, and one or more anti-acne chemical agents, such
as azelaic acid or salicylic acid, or an antibiotic like a member of the
lincomycin family, such as lincomycin hydrochloride, lincomycin phosphate,
clindamycin phosphate, and clindamycin hydrochloride, is applied to the
skin of a subject suffering from or at risk of developing skin lesions due
to acne vulgaris.
The invention, in another embodiment, is a method for increasing the
compliance by individuals such as teenagers and young adults, that is
individuals between the ages of 10 and 25, such as between the ages of 13
and 20, and especially those individuals less than 20 years old, in the
application of sunscreen, especially to the skin of the face. Adolescents
and young adults are often susceptible to, or are suffering from, acne
vulgaris and are highly motivated to apply medication faithfully to treat
or to combat this condition. By combining a sunscreen, such as a
photostable broad spectrum sunscreen agent, in a formulation containing an
anti-acne vulgaris medication, such as azelaic acid or salicylic acid, or
an antibiotic like an antibiotic of the lincomycin family, such as
lincomycin hydrochloride, lincomycin phosphate, clindamycin phosphate, and
clindamycin hydrochloride, such individuals will be concomitantly applying
a sunscreen, even though such individuals would be less likely do so if
the sunscreen were not combined with the anti-acne medication.
As used herein, the term "sunblock" refers to physical sunscreening agents
that block exposure of the skin to ultraviolet light. As used herein, the
term "sunscreen" or "sunscreen agent" refers to either a physical
sunscreen (a sunblocking agent) or a chemical sunscreen. Thus, the term
"sunscreen" is broader than the term "sunblock" and encompasses the term "sunblock".
As used herein, the term "sunscreen formulation" refers to a formulation
that contains a sunscreen and additional components.
As used herein, the terms "photostable sunscreen agent" and "photostable
sunscreen formulations" refer to a sunscreen agent or to a formulation
containing a sunscreen agent which agent or formulation absorbs
ultraviolet radiation at a level that is 50% or higher of the UV
absorbance of the agent or formulation prior to irradiation following
exposure of a 0.5 ml sample per square centimeter (cm.sup.2) in a quartz
petri dish of a formulation containing a sunscreen agent to irradiation of
200 watt-h/m.sup.2 from a xenon lamp source that correlates to the full
spectrum of outdoor sunlight as specified in the International Standard
for Outdoor Daylight D65. The photostable sunscreen formulation may
contain a sunscreen agent which is stable as it exists within the
formulation but which is unstable inherently. Thus, a formulation is
considered to be a photostable sunscreen formulation if it contains a
sunscreen that is inherently unstable but is photostable, as defined
above, when combined with one or more components present in the
formulation.
Sunscreen agents and sunscreen formulations that are suitable for the
present invention are photostable as defined above. It is preferred,
however, that the photostable sunscreen agents and photostable sunscreen
formulations that are used in accordance with the invention be even more
stable than that defined above. In a preferred embodiment, the sunscreen
agent or sunscreen formulation absorbs ultraviolet radiation at a level
that is 75% or higher following the exposure to the xenon lamp source.
This level of photostability is referred to herein as "75% photostability."
It is most preferred that the sunscreen agents or sunscreen formulations
absorb ultraviolet radiation at a level that is 90% or higher following
exposure to the xenon lamp source, referred to herein as "90%
photostability."
As used herein, a "broad spectrum sunscreen agent" is a chemical compound
that absorbs or blocks exposure of both UVB (280 to 320 nm) and UVA (320
to 400 nm). A chemical compound is a broad spectrum sunscreen agent as
defined herein if can be formulated to produce an SPF (Sun Protection
Factor) of 5 to 10, as determined in accordance with the Testing Procedure
specified in 21 C.F.R. Sec. 352.70-352.77 (Subpart D-Testing Procedures),
and has a UV-A/UV-B ratio at least 0.75, or if can be formulated to
produce an SPF of >10 to 15 and has a UV-A/UV-B ratio at least 0.50, or if
it can be formulated to produce an SPF of >15 to 25 and has a UV-A/UV-B
ratio at least 0.33, or if it can be formulated to produce an SPF of >25
and has a UV-A/UV-B ratio at least 0.25. The UV-A/UV-B ratio is calculated
as the ratio between the areas defined by the UV-A and UV-B extinction
capacity, as shown in the following formula wherein A=absorbance and .lamda.=wavelength -- see Original Patent.
As used herein, "a broad spectrum
sunscreen formulation" is a formulation that absorbs or blocks exposure of
both UVB and UVA radiation according to the definition above for a broad
spectrum sunscreen agent. Such a formulation may contain one or more broad
spectrum sunscreen agents or may contain a multiplicity of sunscreen
agents that individually are not broad spectrum agents but, when combined
in a formulation, provide a broad spectrum sunscreen function.
Examples of sunscreen agents that are broad spectrum photostable sunscreen
agents include inorganic sunscreen agents such as titanium oxide and zinc
oxide and tautomeric sunscreen agent compounds such as MEXORYL SX.RTM.,
MEXORYL XL.RTM., bisoctrizole, and anisotriazine.
As a way to improve the sunscreen usage of teenagers and young adults,
this invention embodies a sunscreen, such as a photostable broad spectrum
sunscreen, as a second active component along with a topical acne
medication. Adolescents and young adults are very commonly afflicted with
acne vulgaris and are generally motivated to use preventative topical
medications to control acne and maintain their appearance in a positive
way. Acne afflicts the face and neck areas primarily and these areas are
also the skin areas with the greatest degree of chronic sun exposure.
Additionally patients being treated for acne are at additional risks from
sun exposure due to the detrimental effect of sun exposure in combination
with commonly used acne medications, both topical and oral. Thus, this
invention piggybacks the use of a sunscreen, which is not perceived by
teenagers and young adults to be important, on the use of a topical acne
medication, which is perceived to be important. Any sunscreen or sun block
combined with an antibacterial medication embodies this invention in its
broad conception.
In accordance with a preferred embodiment of the invention, the sunscreen
is a broad spectrum sunscreen agent or combination of agents. The broad
spectrum sunscreen may an inorganic sunscreen agent, such as one or more
of zinc oxide (ZnO), titanium oxide (TiO.sub.2), or ferric oxide
(Fe.sub.2O.sub.3), which may be in a micronized form. These sunscreen are
effective against exposure to UVA (ultraviolet-A) and UVB (ultraviolet-B)
light. Alternatively, the sunscreen may be an organic sunscreening agent.
An example of an organic sunscreen that is suitable for the invention is a
benzotriazole sunscreen, such as methylene bis-benzotriazolyl
tetramethylbutyl phenol (MBBT), marketed under the trade name TINOSORB.RTM.
M (Ciba Specialty Chemicals, Inc., Basel, Switzerland). Other suitable but
less preferred organic sunscreening agents include para-aminobenzoic acid
(PABA) and derivatives, anthranilates, benzophenones, cinnamates including
octylmethoxycinnamate, and salicylates. Other preferred organic sunscreen
agents are a camphor derivative such as terephthalylidene dicamphor
sulfonic acid, marketed under the trade name MEXORYL.RTM. SX (L'Oreal USA,
New York N.Y.), and ibenzoylmethanes such as butyl methoxydibenzoylmethane
(PARSOL.RTM. 1789, AVOBENZONE.RTM., Givaudon-Roure Corporation, Totowa,
N.J.). A less preferred organic broad spectrum sunscreen agent is
oxybenzone, also known as benzophenone, because of recent findings that
oxybenzone is associated with a high incidence of skin irritation and is
absorbed through the skin into the systemic circulation. The choice and
concentration of sunscreens should be made in such a way to achieve a sun
protection factor (SPF) of at least about 5, preferably at least about 10,
and most preferably about 15 or more.
It is also preferred that the sunscreen agent or that the formulation of
the invention containing a sunscreen agent be non-comedogenic. A sunscreen
agent or formulation may be determined to be non-comedogenic by the
following test.
The comedogenicity test is conducted using semi-occlusive patches on the
backs of 20 human volunteers. Subjects exhibiting follicular
hyperkeratosis (microcomedones) with a grade 0.5 to 1.0 are suitable for
inclusion in the study. Microcomedones are graded on a scale of 0 to 3
with 0=none, 0.5=slight (tiny horny masses), 1=mild (small horny masses
involving at least half of the follicles), 2=moderate (moderately sized
horny masses over most of the field) and 3=severe (large globoid
microcomedones over the entire field) based on follicular biopsy samples
from the test area of the back. (Mills, Ohio, The follicular biopsy. In
Serup J, Jemec GBE (eds) Handbook of Non-Invasive Methods and the Skin.
CRC Press, Baca Raton, La. (1995)). Follicular biopsies are conducted at
baseline (up to 45 days prior to study start) and at study end. If a
subject has an irritation score of more than 1 at study end, a rest period
is given until the initiation score is 1 or less, at which time the final
follicular biopsy is performed.
Semi-occlusive patches with 0.1 ml of test product are applied 3 times per
week and left in place for 48-72 hours before reapplication to the same
site for a 4 week period. Assessments of irritation are made on a 6-point
scale with 0=no sign of irritation, 0.5=barely perceptible redness,
1=slight redness, 2=noticeable erythema with slight infiltration, 3=erythema
with marked edema, or 4=erythema with edema and blistering. A negative
control which is a non-occlusive patch without any test material is
applied. The average microdomedone scores for the negative control and the
test material are calculated separately by dividing the total of the score
by the number of test subjects. A test material is judged to be non-comedogenic
if the average score is not more than 0.5 units higher than the negative
control.
The acne medication that is useful in the present invention is azelaic
acid or salicylic acid, or an antibiotic. The acne medication of the
present invention is preferably one that is photostable and that does not
increase sensitivity of the skin to sun exposure. As used herein, the
terms "photostable" in reference to the acne medication means that the
acne medication retains at least 75% of its activity following exposure of
the medication in a 0.5 ml sample per square centimeter (cm.sup.2) in a
quartz petri dish of a formulation containing the acne medication agent to
irradiation of 200 watt-h/m.sup.2 from a xenon lamp source that correlates
to the full spectrum of outdoor sunlight as specified in the International
Standard for Outdoor Daylight D65.
Preferred antibiotics include macrolide antibiotic including erythromycin,
azithromycin, clarithromycin, tilmicosin, and tylosin, and lincomycin-type
antibiotics such as clindamycin hydrochloride, clindamycin phosphate,
lincomycin phosphate, or lincomycin hydrochloride. Additional topical
anti-acne active ingredients may be contained in the composition of the
invention if desired in combination with the salicylic acid, azelaic acid,
or antibacterial compound. Such additional topical anti-acne active
ingredients include but are not limited to one or more additional
antibiotics, salicylic acid, azelaic acid, niacinamide, urea peroxide, and
retinoids such as tretinoin, adapalene and tazarotene.
Preferably, the topical acne medication is photostable and does not
increase the incidence of adverse reactions to sun exposure, such as
occurs commonly with sulfonamides and tetracycline. In topical
compositions containing such medications, such as ROSAC.RTM. Cream (Stiefel
Laboratories, Inc., Coral Gables, Fla.), a sunscreen is included to
prevent the deleterious effects of the sun's radiation in combination with
a sulfonamide. This is in contrast to the present invention in which a
sunscreen is utilized for its effect in preventing damage to an individual
caused by exposure to the sun and in which the anti-acne medication in the
composition is not degraded by the sun and does not induce adverse effects
to an individual when exposed to the sun. Therefore, medications that
degrade due to sun exposure or that result in injury to an individual upon
exposure to the sun, such as sulfonamides and tetracycline, are expressly
excluded from the scope of the present invention.
Additionally, certain skin care compounds, such as benzoyl peroxide, are
reactive and degrade due to exposure to sun. For that reason, these
compounds may be combined in a composition with a sun filter. See
Bouillon, et al, U.S. Pat. No. 4,671,956. Compositions containing benzoyl
peroxide are expressly excluded from the scope of the present invention.
The amount and concentration of sunscreen in the composition will vary
depending on the particular sunscreen present but is an amount and
concentration which is effective to protect an individual from the UV
radiation. Similarly, the amount and concentration of the anti-acne
medication will vary depending on the particular anti-acne medication in
the composition but is an amount that is effective to treat, prevent, or
reduce the symptoms of acne vulgaris.
For an optimally effective sunscreen formulation, two or more active
sunscreen ingredients may be combined in a composition in order to attain
both the breadth of sunscreen protection (UVB and UVA) as well as to
achieve sufficient SPF. There are a great many sunscreen ingredients
listed in the FDA's OTC monograph of approved sunscreen active ingredients
in addition to the sunscreens that are described herein. However, as
described above, it is preferred that the composition of the invention
contain a broad spectrum sunscreen effective against both UVA and UVB. It
is further preferred that the sunscreen is photostable.
Further, there are a multitude of anti-acne ingredients that may be used
in the topical treatment and prevention of acne. The anti-acne
ingredients, such as salicylic acid, azelaic acid or an antibiotic, may be
used singly in the formulation of the invention or in combination with one
or more other anti-acne ingredients, such as those listed above. One
important factor in utilizing the compositions and methods of the present
invention is the selection of anti-acne ingredients and sunscreen
ingredients that are compatible with and that are stable within the
selected vehicle. There can be physical and chemical incompatibilities
wherein one active ingredient adversely affects another or the vehicle.
The present invention involves stable formulations in which each active
ingredient is compatible within the formulation. This means that the
formulation is physically and chemically stable, that is the physical
properties of viscosity, odor, and color of the formulation remain
substantially unchanged upon storage for a period of 12 months at
25.degree. C. and there is no more than a 10% loss of any active
ingredient (sunscreen agent or anti-acne medication) when the formulation
is stored for this period of time at this temperature. Making such
formulations is described herein, and methods for the manufacture and
testing of such formulations for stability are known to those skilled in
the art.
Many anti-acne medications and many sunscreens are capable of causing skin
irritation. Therefore, if a potentially irritating anti-acne medication is
included in the composition of the invention, it is preferred that a
non-irritating sunscreen or one with a low irritation potential, such as
titanium dioxide, be included. Likewise, if a potentially irritating
sunscreen is included in the composition, it is preferred that the
anti-acne medication in the composition not be irritating or be only
mildly irritating.
An additional benefit of the invention to persons suffering from acne is
sun protection, and avoidance of exacerbating the condition when using a
product based on this invention. As a result of using the combined
product, patients exposed to the sun may be effectively treated by the
anti-acne component and be protected from sun exposure.
As previously stated, individuals in the typical acne age group is
generally not motivated to use sunscreen products, yet are highly
motivated to use products to prevent, treat, and manage their acne. Acne
patients under the care of physicians are most commonly given multiple
medications as part of their over all treatment regimen. Often, patient
compliance is a problem in managing such patients because the young
patients do not consider protection from the sun to be of great importance
even though they typically place great importance on treating their acne.
According to the invention, the sunscreen is combined in the same
formulation as the anti-acne medication. This results in an increased
compliance for the use of sunscreen products because the patients are
motivated to use the anti-acne medication which is in combination with the
sunscreen.
The formulation is preferably a semi-solid dosage form, but it may be a
liquid including a spray, also. Among the most preferred semi-solid dosage
forms, gels are the most preferred, followed by foams, lotions, and
creams. Foams, lotions, and creams preferably have a low ratio of oil
phase, if present, to water phase. Cosmetic elegance and spreadability of
the vehicle are important aspects of this invention in order to obtain
patient compliance and uniform and complete application of the sunscreen
component to the skin.
By increasing the routine use of sunscreens by adolescents and young
adults, multiple health benefits are obtained, including: An effective
method of having adolescents regularly use sunscreens on exposed facial
areas, Reduced long-term risk of skin cancer, Minimization of the visible
signs of skin aging, Preventing the photo-exacerbation of acne that occurs
with sun-exposed acne patients, thus obtaining improved efficacy with the
anti-acne component of the combination, and Establishing the habit in
these young people of protecting the skin from daily sun exposure and of
being responsible for the maintenance of healthy skin.
Claim 1 of 21 Claims
1. A method for increasing the compliance
in the use of topical sunscreens comprising providing to an individual in
need thereof a photostable, chemically stable, and physically stable
formulation for topical application to the skin for treating acne vulgaris
and protecting skin from harmful effects of chronic exposure to the sun
comprising a vehicle, one or more sunscreen agents dissolved or suspended
in the vehicle, which sunscreen agent is selected from the group
consisting of titanium dioxide, zinc oxide, bisoctrizole, anisotriazine,
para-aminobenzoic acid (PABA) and derivatives, anthranilates,
benzophenones, cinnamates, salicylates, camphor derivatives, benzene
1,4-di(3-methylidene-10-camphosulfonic) acid, drometriazole trisiloxane,
and dibenzoylmethanes, and an antibiotic medication that is effective in
treating or reducing the signs of acne vulgaris, which antibiotic
medication is dissolved or suspended in the vehicle.
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