A nonirritating, nonionic detergent surfactant composition suitable for application to and cleaning of sensitive tissue, including periocular and ocular tissue, having a low cytotoxicity and high cleaning ability includes a principal nonionic surfactant and at least one auxiliary nonionic surfactant present in the surfactant composition in sufficient amounts to increase the cleaning ability of the principal non-ionic surfactant.

The present invention generally relates to detergent surfactant 
compositions suitable for application to and cleaning of sensitive 
tissues. More particularly, the present invention relates to nonirritating 
detergent surfactant compositions, comprised of a combination of 
nonirritating surfactants, especially suitable for lid hygiene in the 
treatment of chronic blepharitis. 
The blepharitis, or inflammation of the eyelid, is a frequently encountered 
ocular disease. In addition to causing red and itching eyes, blepharitis 
may also interfere with the fitting of contact lenses, as well as 
aggravate the treatment of keratitis sicca, endanger intraocular surgery, 
or lead to corneal complications, such as toxic ephitheal keratitis 
catarrhal ulceration or phlycetnlosis. 
One common symptom of blepharitis is a heavy deposition of oily debris 
called scurf on the eyelashes and lid margins. The oily debris is the 
secretion (meibum) of meibomian glands. In the blepharitis patients, it is 
often found that their meibomian glands suffer from oversecretion and/or a 
thickened meibum. As a result, the glands are engorged, clogged and 
inflamed. 
The meibum is composed of various classes of lipids including a fatty 
wax/sterol ester fraction of up to sixty percent. This lipid component can 
enhance the accumulation of debris and crusting which further exacerbates 
inflammation associated with the blepharitis. 
Lid hygiene is currently the most accepted treatment for blepharitis. In 
addition, a number of oral and topical medications may be utilized to 
augment the primary lid hygiene therapy as may be prescribed on an 
individual basis. Effective cleaning agents for removal of meibomian 
secretions associated with debris have been anionic surfactants having 
high foaming characteristics. See, for example, U.S. Pat. No. 5,000,868. 
Unfortunately, such anionic surfactants tend to be irritating to sensitive 
ocular tissue and because of their ionic nature, may be chemically 
incompatable with other formulation ingredients such as, for example, 
buffers, preservatives and medicaments. 
Consequently, surfactant compositions, specifically formulated for lid 
hygiene, have required the presence of surfactants capable of reducing the 
irritant properties of the anionic surfactant or reducing their chemical 
incompatability. 
The composition of the present invention, effective for use on periocular 
and ocular surface tissues includes no component necessary for reducing 
irritating characteristics of other surfactant components. 
SUMMARY OF THE INVENTION 
The present invention is a nonirritating detergent surfactant composition 
suitable for application to and cleaning of sensitive tissues which is 
especially effective for cleaning of ocular and periocular tissue. 
The composition comprises a principal nonionic surfactant present in the 
nonirritating detergent surfactant composition in a sufficient amount to 
clean the sensitive tissue. More particularly, the cleaning ability may be 
defined in terms of the lipid cleaning efficiency of the surfactant. 
In addition, at least one auxiliary nonionic surfactant is present in the 
composition in a sufficient amount to increase the cleaning ability of the 
principal nonionic surfactant. It is important to appreciate that no 
irritating surfactants such as anionic surfactants are present in the 
composition of the present invention. Hence, there is no component of the 
composition of the present invention which is added to overcome or 
suppress the irritating activity of a component. This results in a 
naturally inherent nonirritating surfactant composition. 
Importantly, the auxiliary surfactants present in the composition are 
effective for enhancing the cleaning ability of the principal auxiliary 
nonionic surfactant. In the instance where one auxiliary surfactant is 
used in conjunction with the principal nonionic surfactant, the cleaning 
ability of the resultant composition is greater than the cleaning ability 
of either the principal surfactant or the auxiliary surfactant taken 
alone. More particularly, this occurs when both the principal and 
auxiliary nonionic surfactants comprise block polymers of polyoxyethylene 
and polyoxypropylene. Specifically, this enhanced cleaning activity occurs 
when the principal nonionic surfactant comprises Pluronic.RTM. P85, (CTFA 
name: poloxamer 235) and the auxiliary nonionic surfactant comprises 
Pluronic.RTM. F87 (CTFA name: poloxamer 237). 
The nonirritating detergent surfactant composition of the present invention 
further has extremely low irritation potential to ocular and periocular 
tissue. The low irritation potential of the composition of the present 
invention may be demonstrated with in vitro Chinese hamster ovary cell 
cytotoxicity test. Specifically, when the principal and auxiliary nonionic 
surfactants are present in the nonirritating detergent surfactant 
composition in a combined amount of at most ten percent by weight, and the 
composition applied to Chinese hamster ovary cells at a tenfold dilution, 
more than eighty percent of the cells survive.

DETAILED DESCRIPTION 
It has been well established that a surfactant which cleans better is 
usually more damaging to cells. For example, anionic surfactants are 
generally more efficient in removing grease and dirt but are also more 
irritating and have a high cytotoxicity profile. 
Nonionic surfactants are known to be milder than anionic surfactants but 
heretofore have not demonstrated detergent activity on a par with anionic 
surfactants. 
As hereinbefore briefly discussed, prior art formulations for lid hygiene 
have utilized anionic surfactants which have high cytotoxicity and 
irritation to sensitive surfaces. In combination with such ionic 
surfactants, a number of components have been utilized in an attempt to 
reduce the irritant properties of the ionic surfactants. Because of the 
inherent irritant activity of anionic surfactants, compositions 
incorporating such surfactants, even though compensating components are 
present, require complete and thorough rinsing of the compositions from 
ocular and periocular tissue due to the possibility of anionic surfactant 
remaining in contact with such tissue after use of surfactant and thereby 
causing high irritation. 
In view of the fact that no component of the composition of the present 
invention is inherently irritating to periocular or ocular tissue, no 
rinsing of the composition following lid cleaning is required. 
While the following description of the present invention is directed to use 
as cleansers for ocular and periocular tissue, because of its 
nonirritating and low cytotoxicity profile, the composition of the present 
invention is also suitable for the cleaning of skin, mucous membranes, 
wounds, contact lenses, and removal of makeup for eyes and facial tissue. 
In addition, its use may be extended to the cleaning of hands and fingers 
which would subsequently be in contact with eyes, wounds, or other 
sensitive areas. 
The principal nonionic surfactant present in the composition of the present 
invention is a block copolymer of polyoxyethylene and polyoxypropylene 
which are available under the trade name Pluronic.RTM. marketed by BASF. 
Specifically, the principal nonionic surfactant is Pluronic.RTM. P85. A 
first auxiliary nonionic surfactant is also a block copolymer of 
polyoxyethylene and polyoxypropylene and specifically comprises 
Pluronic.RTM. F87. The principal surfactant is present in the composition 
in an amount from about four percent to about nine percent by weight. 
The first auxiliary surfactant is added to enhance the cleaning ability of 
the principal surfactant which may be effected through better 
solubilization, emulsification, or wetting power. The preferred auxiliary 
surfactant, in accordance with the present invention, Pluronic.RTM. F87 is 
present in the composition in an amount from about 0.5 percent to about 
two percent by weight. 
Preferably, a second auxiliary nonionic surfactant, such as ethoxylated 
octyl phenol, may be combined with the principal and first auxiliary 
surfactants. Specifically, the second auxiliary surfactant may be 
Igepal.RTM. CA 897 (CTFA name: octoxynol 40) marketed by Rhone-Poulenc. 
Preferably, the total amount of surfactants in the composition of the 
present invention is ten percent or less of the total composition with the 
remaining component being water. It should be appreciated that the 
composition of the present invention may be buffered by any common buffer 
system such as phosphate, borate, acetate, and citrate with the pH and 
osmolarity adjusted in accordance with well-known techniques to proper 
physiological values. 
In addition, if a preservative is desired, the compositions may be 
preserved with any well-known system such as benzyl alcohol with/without 
EDTA, benzalkonium chloride, chlorhexidine, Cosmocil.RTM. CQ, or 
Dowicil.RTM. 200. 
Importantly, because of the nonionic nature of the surfactants of the 
present invention, no chemical incompatability is encountered even if a 
positively or negatively charged preservative is incorporated, such as 
quaternary ammonium salts. This also applies to buffers and other 
medicaments that may be used in combination with the composition of the 
present invention. 
In addition, depending upon the use of the cleanser, amino acids, minerals, 
vitamins, or the like may be added to provide nutrition to skin or 
tissues. Further, moisturizers or emollients such as aloglycerine 
propylene glycol, hyaluronic acid, hydroxic propyl cellulose, or carboxy 
methyl cellulose may be added to soothe the skin. Specifically, when the 
composition is to be used in connection with cleaning wounds, medications 
may be added, such as antibiotics, antimicrobiocidal agents, 
anti-inflammatory agents, local anesthetics, anti-acne agents, etc., 
depending upon the specific activity desired. 
A clear advantage of the present invention resides not only in its 
extremely low toxicity risk but also in its minimal chemical 
incompatibility with other ingredients (such as preservatives, buffers, 
medications, etc.) incorporated in the formulations. The minimal 
chemically incompatible risk is attributed to the position of no ionizable 
functional groups in the surfactants chosen in the present invention. 
The cleaning ability, specifically the lipid cleaning ability, of the 
composition of the present invention is diagrammatically presented in FIG. 
1 so as to illustrate the synergistic effect of nonionic surfactant 
combinations which, in the case of Pluronic.RTM. F87 and Pluronic.RTM. 
P85, results in a greater cleaning ability than the cleaning ability of 
either the Pluronic.RTM. F87 or P85 taken separately. In addition, as will 
be hereinafter demonstrated, the combination of the principal surfactant, 
Pluronic.RTM. P85, and auxiliary surfactants, Pluronic.RTM. F87 and 
octoxynol 40, provide lipid cleaning ability on a par with anionic 
surfactants but with no irritating properties and significantly less 
cytotoxicity. 
The diagram as shown in FIG. 1 will be discussed in more detail after the 
following description of the protocol in determining the cleaning ability 
of the detergent surfactant in accordance with the present invention. 
In order to show lipid cleaning ability of the composition of the present 
invention, an artificial lipid mixture was utilized which comprised thirty 
percent cholesteryl stearate, thirty-five percent lanolin, and thirty-five 
percent Miglyol.RTM. 810 (CTFA name: caprylic/capric triglyceride). 
This mixture was supported on a polymacon (38/0) lens (Hydron) with the 
convex surface of the lens coated with the artificial lipid mixture by 
lightly touching the surface to the melted lipid and leaving the coated 
lens on a slide (convex surface facing up), for between ten to thirty 
minutes. 
Thereafter, the composition to be tested was placed, five drops at a time, 
on the palm of a hand and the lens, with the convex surface facing down, 
rubbed in a circular motion in the composition for twenty seconds. 
Thereafter, the lipid remaining on the lens was officially observed. 
The cleaning efficacy scoring system was as follows: 
______________________________________ 
CLEANING EFFICACY TEST 
VISUAL OBSERVATION 
SCORE (after rubbing lens with tested composition) 
______________________________________ 
0 Lens is totally coated with lipid 
1 1/6 of the lens is not covered by lipid 
2 1/3 of the lens is not covered by lipid 
3 1/2 of the lens is not covered by lipid 
4 2/3 of the lens is not covered by lipid 
5 5/6 of the lens is not covered by lipid 
6 All lipid on the lens is gone 
______________________________________ 
The cleaning score, between 1 and 6, is plotted for various surfactant 
compositions in FIG. 1 for percentages of principal surfactant from 0 to 
10%, first auxiliary surfactant from 0 to 10%, and second auxiliary 
surfactant from 0 to 10%. The remaining composition is water. 
These number scores appear in FIG. 1, which is diagrammatically presented 
in order to show the increased cleaning ability of the composition when 
the primary surfactant Pluronic.RTM. P85 is between about 2% to about 9%, 
the first auxiliary surfactant Pluronic.RTM. F87 is present in the amount 
of between 0.5% to about 2%, and the second auxiliary surfactant octoxynol 
10 is present in the amount of about 0.5% to about 5%. Each of the points 
displayed in FIG. 1 include a total surfactant weight of about 10%. To 
compare the composition of the present invention with the prior art lid 
hygiene formulations, the cleaning efficacy test, as hereinabove 
described, was performed on I-Scrub, distributed by Spectra. The results 
are shown hereinbelow: 
______________________________________ 
TEST SOLUTION OBSERVED SCORE 
______________________________________ 
Spectra's I-Scrub 4.67, 5.33, 5, 4.67, 5.33 
Mean = 5.0, CV = 6.6% 
The optimized 5.3, 5 
formulation 
______________________________________ 
These results demonstrate that the optimized formulation of the present 
invention has the equivalent cleaning ability as that of I-Scrub, which is 
an anionic surfactant-based formulation. 
The ingredients of I-Scrub are generally known as follows: 
______________________________________ 
I-SCRUB 
______________________________________ 
Disodium monolaureth 
anionic surfactant (mild, 
Sulfosuccinate high foaming) 
PEG-200 Glyceryl Mono- 
nonionic surfactant (emul- 
tallowate sifier, anti-irritant) 
PEG-78 Glyceryl Mono- 
nonionic surfactant (emul- 
cocoate sifier, anti-irritant) 
Cocoamidopropylamine 
nonionic surfactant (foam 
Oxide booster, anti-irritant) 
Benzyl Alcohol, EDTA, 
preservative 
Purified Water USP 
______________________________________ 
An important feature of the composition of the present invention is its low 
cytotoxicity profile. The cytotoxicity was evaluated as follows to 
quantify chemically-induced toxicity. Chinese hamster ovary cells used 
(CHO) are a well-characterized cell line and are widely used in 
cytotoxicity assays as has been well-documented in the literature. 
The materials and methods of the present assay are as follows: 
MATERIALS 
A. CHEMICALS AND MEDIA 
1. Ham's F-12 medium (1X, with sodium bicarbonate) 
2. Heat inactivated fetal bovine serum (lots tested using SOP TC-003) 
3. L-glutamine solution (200 mM) 
4. Dulbecco's phosphate buffered saline (PBS) 
5. Trypsin-EDTA solution (1X) 
6. Sodium chloride 
7. Sodium phosphate (monobasic and dibasic) 
8. .beta.-nicotinamide adenine dinucleotide phosphate (NADP) 
9. Glucose-6-phosphate (Glc-6-P) 
10. Potassium chloride 
11. Magnesium chloride 
12. Calcium chloride 
13. Aroclor 1254 induced rat liver S9 
14. Methanol 
15. Giemsa stain 
B. Tissue Culture Supplies and Cell Lines 
1. Tissue culture dishes (6-well clusters) 
2. Chinese hamster ovary (CHO) cells, clone K.sub.1 -BH.sub.4 (originally 
from Oakridge National Laboratory) 
METHODS 
A. Preparation 
1. Media for cell growth (Ham's F-12) 
.a. Add 50 ml of heat inactivated fetal bovine serum per 500 ml Ham's F-12 
medium. 
b. Add 2.5 ml of glutamine per 500 ml medium. 
2. Liver 59 - cofactors mix 
a. Prepare stock solutions of: 0. M sodium phosphate, pH 8.0; 0.1M NADP; 
1.0M glc-6-P; 1.5M potassium chloride; 0.5M magnesium chloride; and 0.5M 
calcium chloride. 
b. Prepare sterile 8.8 ml cofactor mix aliquots containing: 5.45 ml double 
distilled water; 2.5 ml sodium phosphate; 0.4 ml NADP; 0.05 ml glc-6-P; 
0.2 ml potassium chloride; and 0.2 ml magnesium chloride. These aliquots 
can be stored frozen at -70.degree. C. 
c. Prior to use, thaw aliquot cofactor mix and add 0.2 ml calcium chloride. 
A white precipitate will form. 
d. Add 1 ml of liver S9 (-30 mg/ml) to the cofactor mix and store on ice. 
B. Cytotoxicity Assay 
1. Trypsinize CHO cells using the procedures described in Research 
Microbiology SOP TC-001. 
2. Determine cell concentration using one of the procedures outlined in 
Research Microbiology SOP TC-002. 
3. Dilute the cell suspension to a final concentration of 100 cells per ml 
in complete growth media. Maintain the cell suspension on ice until cells 
are plated to minimize cellular attachment to the surfaces of the 
container. 
4. Pipet 2 ml of the cell suspension into each well (200 cells/well). Shake 
the dish in two directions immediately after filling all of the wells in 
the dish. This is critical to ensure even distribution of cells throughout 
the entire surface area of the dish. 
5. Allow the cells to attach for 3 hours at 37.degree. .+-.1.degree. C. in 
a humidified incubator with an atmosphere of 5% CO.sub.2 in air. 
6. At the time of treatment, change medium to 2 ml Ham's F-12 medium (with 
glutamine, without serum). 
7. For assays designed to measure the effect of metabolic activation, add 
0.4 ml of S9-cofactors mixture to 1.6 ml of Ham's F-12 (with glutamine, 
without serum) at the time of treatment. 
8. Add test compound in 20 .mu.l of ethanol, acetone or DMSO (1% v/v final 
concentration of solvent) depending on solubility. Note: DMSO also 
facilitates cellular uptake. if the test compound is a suspension (such as 
liposomes) they can be added in up to 100 .mu.l of PBS. Three wells are 
used per dose. 
9. Each assay must include positive and negative controls. The equivalent 
volume of the solvent alone serves as the negative control. Any known 
cytotoxic agents at cytotoxic doses can be used as positive controls 
(e.g., cyclohexamide, mitomycin C, benzo (a) pyrene). 
10. Return dishes to the incubator for 3 hours. Do not stack the dishes 
more than two high as it is important for sample cultures to stabilize at 
37.degree. .+-.1.degree. C. at the same time. This is even more critical 
for experiments involving S9 since the reaction kinetics for the enzymes 
involved in metabolic activation are temperature dependent. 
11. Remove medium containing test compound out of each well and rinse 
surface with 1 ml of PBS per well. 
12. Pipet 2 ml of complete growth medium (Ham's F-12, with serum and 
glutamine) into each well. 
13. Return dishes to incubator and allow cells to grow for 7-8 days. Do not 
handle dishes as this minimizes colony splitting. 
14. Fix, stain and score colonies as described in Research Microbiology SOP 
TC-005. 
15. Express cytotoxicity data as cloning efficiency (C.E.) and relative 
survival (R.S.). 
##EQU1## 
The results of the cytotoxicity assay or cytotoxicity profile are shown in 
FIG. 2, which shows the relative survival of the Chinese hamster ovary 
cells as a function of concentration of the formulation tested. 
The hereinabove-described CHO clonal assay was used to establish the 
cytotoxicity profiles for the present invention preserved by five 
different preservative systems. Ten to one hundredfold dilutions of these 
solutions were tested, with all dilutions being made in distilled water. 
The unpreserved present invention was also tested. The vehicle, water in 
this case, was used as a positive control. The relative cell survival is 
calculated by comparing the cells surviving from a formulation with the 
cells surviving from water. Disodium monolaureth sulfosuccinate, a "mild" 
anionic surfactant commonly used in baby shampoos and lid hygiene 
products, was used as a negative control. The solutions tested were as 
follows: 
1. Pluronic.RTM. P85/Pluronic.RTM. F87/octoxynol 40 (7:1:2 ratio) 10% 
solution 
2. Pluronic.RTM. P85/Pluronic.RTM. F87/octoxynol 40 (7:1:2 ratio) 10% 
solution+Benzyl Alcohol (0.5%) 
3. Pluronic.RTM. P85/Pluronic.RTM. F87/octoxynol 40 (7:1:2 ratio) 10% 
solution+Benzyl Alcohol (0.5%)+EDTA (0.05%) 
4. Pluronic.RTM. P85/Pluronic.RTM. F87/octoxynol 40 (7:1:2 ratio) 10% 
solution+Benzyl Alcohol (0.5)+Germall 115 (0.3%) 
5. Pluronic.RTM. P85/Pluronic.RTM. F87/octoxynol 40 (7:1:2 ratio) 10% 
solution+Dowicil.RTM. 200 (0.03%)-Phosphate Buffer 
6. Disodium monolaureth sulfosuccinate 
The results dramatically show the low cytotoxicity of the formulations in 
accordance with the present invention. For example, at concentrations of 
up to 10% of the unpreserved formulation in accordance with the present 
invention, an 80% relative survival is shown, which is roughly 100 fold 
less cytotoxic than the "mild" surfactant, disodium monolaureth 
sulfosuccinate. The preserved formulations, depending on the preservatie 
system used, may be 30 to 100 fold less cytotoxic than disodium 
monolaureth sulfosuccinate. Therefore, because of the low cytotoxicity of 
the formulations in accordance with the present invention, the formulation 
need not be rinsed, or flushed, from the eye after instillation. This is 
to be compared with prior art products comprising anionic surfactants 
which must, because of their relatively high cytotoxicity, be rinsed, or 
removed, from the eye after instillation because residual anionic 
surfactant will cause eye irritation. 
Hence, it can be readily appreciated that the low cytotoxicity of the 
formulation of the present inventions eliminates the criticality of 
rinsing. 
That is, if some, or all, of the formulation of the present invention 
remains in the eye, little, if any, irritation occurs, due to the nonionic 
surfactants therein. 
In addition, it is shown that a formulation in accordance with the present 
invention which is preserved with benzyl alcohol exhibited a cytotoxicity 
profile similar to the unpreserved solution at 10% of formulation. Also, 
the addition of EDTA did not significantly alter the cytotoxicity profile 
of the formulation at 10%. 
Other formulations of various preservatives exhibited a lower cytotoxicity 
profile. 
The formulation of the present invention may be produced in any 
conventional manner by combining the surfactants in the proportions 
hereinabove recited. 
Although there has been hereinabove described a nonirritating detergent 
surfactant composition suitable for application in cleaning of sensitive 
tissues such as periocular and ocular tissues, in accordance with the 
present invention, for the purpose of illustrating the manner in which the 
invention may be used to advantage, it should be appreciated that the 
invention is not limited thereto. Accordingly, any and all modifications, 
variations, or equivalent arrangements which may occur to those skilled in 
the art, should be considered to be within the scope of the present 
invention as defined in the appended claims.