United States Patent [19J
`Cardin et al.
`
`111111111111111111111111111111111111111111111111111111111111111111111111111
`US005104645A
`5,104,645
`[11] Patent Number:
`[45] Date of Patent: Apr. 14, 1992
`
`[75]
`
`[54] ANTIDANDRUFF SHAMPOO
`COMPOSITIONS
`Inventors: Caroline W. Cardin; Joyce I. Davis;
`Judi L. Hart; Diane G. Schmidt
`[73] Assignee: The Proctor & Gamble Company,
`Cincinnati, Ohio
`
`[21] Appl. No.: 472,041
`Feb. 2, 1990
`[22] Filed:
`[51]
`Int. Cl.s ................................................ A61K 7/75
`[52] U.S. Cl •............................... 424/70; 424/DIG. 4;
`252/DIG. 13; 252/106; 252/174.21;
`252/174.22; 252/174.17; 252/174.15; 514/852
`[58] Field of Search ..................... 424/70, DIG. 4, 78;
`252/106, 174.15, 174.17, 174.21, 174.22, DIG.
`13; 514/852
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`2,809,971 10/1957 Bernstein et al. ....................... 546/6
`3,236,733 2/1966 Karsten et al. ...................... 514/188
`3,753,916 8/1973 Parran ................................. 252/107
`3,761,417 9/1973 Parran ................................. 252/106
`3,761,418 9/1973 Parran ................................. 252/106
`4,166,845 9/1979 Hansen .................................. 424/70
`4,185,106 2/1980 Dittman ........................ 424/DIG. 4
`4,323,683 4/1982 Bolich et al. ............................ 546/6
`4,345,080 8/1982 Bolich Jr ................................ 546/6
`4,379,753 4/1983 Bolich ................................. 252/106
`4,405,645 9/1983 Rothlisberger ....................... 424/70
`4,470,982 9/1984 Winkler ............................... 514/188
`4,492,646 1/1985 Welch ............................ 252/174.21
`
`4,557,928 12/1985 Glover .......................... 424/DIG. 4
`4,559,227 12/1985 Chandra ....................... 424/DIG. 4
`4,631,187 12/1986 Padden .................................. 424/70
`4,711,775 12/1987 Dittman ........................ 424/DIG. 4
`4,801,447 1/1989 Gum ...................................... 424/70
`4,898{725 2/1990- Hoeffkes ............................... 424/70
`4,935,224 6/1990 Rosso .................................... 424/65
`
`FOREIGN PATENT DOCUMENTS
`285388 10/1988 European Pat. Off ..
`57-80644 11/1983 Japan .
`
`OTHER PUBLICATIONS
`Babar et al., In-Vitro Release Of Zinc Pyrethhione
`From A Shampoo Base And The Effect Of Various
`Additives On Its Release Rate, Drug Development and
`Industrial Pharmacy, 11(8), 1507-1522 (1985).
`R. L. Goldemberg, Advances In Cosmetic Technology,
`vol. 1, pp. 70-71 (1978).
`
`Primary Examiner-Thurman K. Page
`Assistant Examiner-Susan S. Rucker
`Attorney, Agent, or Firm-John M. Howell; Goldstein,
`Steven J.; Leonard W. Lewis
`
`[57]
`ABSTRACf
`Antidandruff shampoos comprising a surfactant, plate(cid:173)
`let zinc pyridinethione active of specific particle size, a
`suspending agent, water, and a synergizer for the active.
`Said compositions have superior efficacy when com(cid:173)
`pared with antidandruff shampoos known in the art.
`
`23 Claims, No Drawings
`
`1
`
`

`
`1
`
`5,104,645
`
`ANTIDANDRUFF SHAMPOO COMPOSffiONS
`
`TECHNICAL FIELD
`The present invention relates to antidandruff sham-
`poos. These shampoos exhibit excellent antidandruff
`activity.
`
`5
`
`2
`(d) from about 0.5% to about 6% of a suspending
`agent; and
`(e) the remainder water.
`These antidandruff shampoos are effective in cleans(cid:173)
`ing the hair, as well as effectively treating dandruff.
`These compositions may also include additional an(cid:173)
`tidandruff actives and/or silicone polymers to condi(cid:173)
`tions the hair without interrupting the treatment of said
`dandruff. The lotion form is particularly preferred for
`the shampoos.
`All ratios, percentages and parts given herein are "by
`weight" unless otherwise specified.
`
`15
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`The essential components of the present invention as
`well as optional components, are set forth in the follow(cid:173)
`ing paragraphs.
`
`BACKGROUND OF THE INVENTION
`Antidandruff shampoos are well known in the art and 10
`rely upon various actives for their antidandruff effec(cid:173)
`tiveness. Such compositions are not only designed to
`relieve the dandruff condition, but also to effectively
`clean the hair.
`U.S. Pat. No. 3,917,817, Vanlerberghe et al., issued
`Nov. 5, 1975, discloses a shampoo composition compris(cid:173)
`ing a piperazine based cationic polymer active, 10%
`sodium alkyl sulfate, 4% lauryl monoethanolamide and
`3% glycol distearate. U.S. Pat. No. 4,013, 787, Vanier- 20
`berghe et al., issued Mar. 22, 1977, discloses similar
`compositions.
`Pyridinethione slats are known for use as dandruff
`control actives. Specifically, 1-hydroxypyridinethione
`salts have been taught as antidandruff actives in lotion 25
`form shampoos. Included in this group is 2-zinc pyrith(cid:173)
`ion (ZPT) as disclosed in U.S. Pat. No. 2,809,971, Bern(cid:173)
`stein, issued Oct. 15, 1957; U.S. Pat. No. 3,236,733,
`Karsten, issued Feb. 22, 1966; U.S. Pat. No. 3,753,916,
`Parran, issued Aug. 21, 1973; Japanese Published Appli- 30
`cation 60810, published May 19, 1977 (Lion Fat and
`Oil); U.S. Pat. No. 4,323,683, Bolich et al., issued Apr.
`6, 1982; U.S. Pat. No. 4,345,080, Bolich, issued Aug. 17,
`1982; U.S. Pat. No. 4,379,753, Bolich, issued Apr. 12,
`1983; U.S. Pat. No. 4,470,982, Winkler, issued Sept. 11, 35
`1984; and European Published Patent Application No.
`285,388, published Oct. 5, 1988 abandoned.
`In the present invention it has been surprisingly found
`that when a pyridinethione metal salt in platelet form,
`with a specified particle size, is combined with any of a 40
`group of specific synergizers in a shampoo matrix, an
`unexpected substantial improvement in antidandruff
`efficacy is realized. Such compositions are stable, safe
`and effective in cleaning the hair while treating the
`scalp for dandruff.
`
`SURFACTANT
`An essential component of the present compositions
`is a synthetic surfactant. The surfactant, which may be
`selected from any of a wide variety of synthetic anionic,
`amphoteric, zwitterionic and nonionic surfactants typi(cid:173)
`cally used in shampoos, is present at a level of from
`about 5% to about 70%, preferably from about 10% to
`about 30%, most preferably from about 10% to about
`22%, of the composition.
`Synthetic anionic surfactants can be exemplified by
`the alkali metal salts or organic sulfuric reaction prod(cid:173)
`ucts having in their molecular structure an alkyl radical
`containing from 8-22 carbon atoms and a sulfonic acid
`or sulfuric acid ester radical (included in the term alkyl
`is the alkyl portion of higher acyl radicals). Preferred
`are the sodium, ammonium, potassium or triethanol(cid:173)
`amine alkyl sulfates, especially those obtained by sulfat(cid:173)
`ing the higher alcohols (Cs-Cts carbon atoms), sodium
`coconut oil fatty acids monoglyceride sulfates and sul(cid:173)
`fonates; sodium or potassium salts of sulfuric acid esters
`of the reaction product of 1 mole of a higher fatty alco(cid:173)
`hol (e.g., tallow or coconut oil alcohols) and 1 to 12
`moles of ethylene oxide; sodium or potassium slats of
`alkyl phenol ethylene oxide ether sulfate with 1 to 10
`units of ethylene oxide per molecular and in which the
`alkyl radicals contain from 8 to 12 carbon atoms, so(cid:173)
`dium alkyl glyceryl ether sulfonates; the reaction prod(cid:173)
`uct of fatty acids having from 10 to 22 carbon atoms
`esterified with isethionic acid and neutralized with so(cid:173)
`dium hydroxide; water soluble salts of condensation
`products of fatty acids with sarcosine; and others
`known in the art.
`Zwitterionic surfactants can be exemplified by those
`which can be broadly described as derivatives of ali(cid:173)
`phatic quaternary ammonium, phosphonium, and sulfo(cid:173)
`nium compounds, in which the aliphatic radicals can be
`straight chain or branched, and wherein one of the
`aliphatic substituents contains from 8 to 18 carbon
`atoms and one contains an anionic water-solubilizing
`group, e.g., carboxy, sulfonate, sulfate, phosphate, or
`phosphonate. A general formula for these compounds
`is:
`
`wherein R2 contains an alkyl, alkenyl, or hydroxyalkyl
`radical of from about 8 to about 18 carbon atoms, from
`
`45
`
`SUMMARY OF THE INVENTION
`The present invention relates to shampoo composi(cid:173)
`tions comprising:
`(a) from about 5% to about 70% of a synthetic surfac- 50
`tant·
`(b) fr~m about 0.3% to about 2% of pyridinethione
`metal salt in platelet particle form having a mean
`particle size of from about 2 microns to about 15
`microns;
`.
`(c) from about 0.5% to about 5% of a synergizer
`selected from the group consisting of polyethylene
`glycols containing from about 6 to about 22 ethyl(cid:173)
`ene oxide units, polypropylene glycols containing
`from about 6 to about 22 propylene oxide units, 60
`polyoxamer block polymers, polyethylene oxide
`fatty glycerides, polyethylenimines containing
`from about 6 to about 22 imine groups, polyethox(cid:173)
`ylated polyethylenimies, polyethylene oxide carbo(cid:173)
`hydrates, ethoxylated nonylphenols, ethoxylated 65
`alcohols, and mixtures thereof (preferred synergiz(cid:173)
`ers include the polyethylene glycols, particularly
`PEG-12);
`
`55
`
`2
`
`

`
`5,104,645
`
`3
`0 to about 10 ethylene oxide moieties and from 0 to 1
`glyceryl moiety; Y is selected from the group consisting
`of nitrogen, phosphorus, and sulfur atoms; R3is an alkyl
`or monohydroxyalkyl group containing 1 to about 3
`carbon atoms, x is 1 when Y is a sulfur atom and 2 when
`Y is a nitrogen or phosphorus atom; R 4 is an alkylene or
`hydroxyalkylene of from 1 to about 4 carbon atoms; and
`Z is a radical selected from the group consisting of
`carboxylate, sulfonate, sulfate, phosphonate, and phos(cid:173)
`phate groups.
`Examples include:
`4-[N,N-di(2-hydroxyethyl)-N-octadecylammonio](cid:173)
`butane-1-carboxylate;
`5-[S-3-hydroxypropyl-S-hexadecylsulfonio]-3-hydroxy(cid:173)
`pentane-1-sulfate;
`3-[P,P-diethyl-P-3,6,9-trioxatetradexocylphosphonio]-
`2-hydroxypropane-1-phosphate;
`3-[N,N-dipropyl-N-3-dodecoxy-2-hydroxypropylam(cid:173)
`monio ]-propane-1-phosphonate;
`3-(N,N-dimethyl-N-hexadecylammonio)propane-1-sul(cid:173)
`fonate;
`3-(N,N-dimethyl-N-hexadecylammonio)-2-hydroxy(cid:173)
`propane-1-sulfonate;
`4-[N,N-di(2-hydroxyethyl)-N-(2-hydroxydodecyl)am(cid:173)
`monio ]-butane-1-carboxylate;
`3-[S-ethyl-S-(3-dodecoxy-2-hydroxypropyl)sulfonio ](cid:173)
`propane-1-phosphate;
`3-[P,P-dimethyl-P-dodecylphosphonio]-propane-1-
`phosphonate; and
`5-[N,N-di(3-hydroxypropyl)-N-hexadecylammonio]-2-
`hydroxypentane-1-sulfate.
`Other zwitterionics, such as betaines, are also useful
`in the present invention. Examples of betaines useful
`herein include the high alkyl betaines such as coco
`dimethyl carboxymethyl betaine, lauryl dimethyl car- 35
`boxymethyl betaine, Iaury) dimethyl alphacarboxyethyl
`betaine, cetyl dimethyl carboxymethyl betaine, Iaury)
`bis-(2-hydroxyethyl) carboxymethyl betaine, stearyl
`bis-(2-hydroxypropyl) carboxymethyl betaine, oleyl
`dimethyl gammacarboxypropyl betaine, and Iaury) bis- 40
`(2-hydroxypropyl) alphacarboxyethyl betaine. The sul(cid:173)
`fobetaines may be represented by, for example, coco
`dimethyl sulfopropyl betaine, stearyl dimethyl sulfopro(cid:173)
`pyl betaine, lauryl dimethyl sulfoethyl betaine, and Iau(cid:173)
`ry) bis-(2-hydroxyethyl) sulfopropyl betaine. Amido 45
`betaines · and
`amidosulfobetaines, wherein
`the
`RCONH(CH2)3 radical is attached to the nitrogen atom
`of the betaine, are also useful in this invention.
`Examples of amphoteric surfactants which can be
`used in the compositions of the present invention are 50
`those which can be broadly described as derivatives of
`aliphatic secondary and tertiary amines in which the
`aliphatic radical can be straight chain or branched and
`wherein one of the aliphatic substituents contains from
`about 8 to about 18 carbon atoms and one contains an 55
`anionic water solubilizing group, e.g., carboxy, sulfo(cid:173)
`nate, sulfate, phosphate, or phosphonate. Examples of
`compounds falling within this definition are sodium
`3-dodecyl-aminopropionate, sodium 3-dodecylamino(cid:173)
`propane sulfonate, N-alkyltaurines such as the one pre- 60
`pared by reacting dodecylamine with sodium isethion-
`ate according to the teaching of U.S. Pat. No. 2,658,072,
`N-higher alkyl aspartic acids such as those produced
`according to the teaching of U.S. Pat. No. 2,438,091,
`and the products sold under the trade name "Miranol" 65
`and described in U.S. Pat. No. 2,528,378.
`Nonionic surfactants, which are preferably used in
`combination with an anionic, amphoteric or zwitter-
`
`4
`ionic surfactant, can be broadly defined as compounds
`produced by the condensation of alkylene oxide groups
`(hydrophilic in nature) with an organic hydrophobic
`compound, which may be aliphatic or alkyl aromatic in
`5 nature. Examples of preferred classes of nonionic sur(cid:173)
`factants are:
`1. The polyethylene oxide condensates of alkyl phe(cid:173)
`nols, e.g., the condensation products of alkyl phenols
`having an alkyl group containing from about 6 to 12
`10 carbon atoms in either a straight chain or branched
`· chain configuration, with ethylene oxide, the said ethyl(cid:173)
`ene oxide being present in amounts equal to 10 to 60
`moles of ethylene oxide per mole of alkyl phenol. The
`alkyl substituent in such compounds may be derived
`15 from polymerized propylene, diisobutylene, octane, or
`nonane, for example.
`2. Those derived from the condensation of ethylene
`oxide. with the product resulting from the reaction of
`propylene oxide and ethylene diamine products which
`20 may be varied in composition depending upon the bal(cid:173)
`ance between the hydrophobic and hydrophilic ele(cid:173)
`ments which is desired. For example, compounds con(cid:173)
`taining from about 40% to about 80% polyoxyethylene
`by weight and having a molecular weight offrom about
`25 5,000 to about 11,000 resulting from the reaction of
`ethylene oxide groups with a hydrophobic base consti(cid:173)
`tuted of the reaction product of ethylene diamine and
`excess propylene oxide, said base having a molecular
`weight of the order of 2,500 to 3,000, are satisfactory.
`3. The condensation product of aliphatic alcohols
`having from 8 to 18 carbon atoms, in either straight
`chain or branched chain configuration, with ethylene
`oxide, e.g., a coconut alcohol ethylene oxide condensate
`having from 10 to 30 .moles of ethylene oxide per mole
`of coconut alcohol, the coconut alcohol fraction having
`from 10 to 14 carbon atc.ms.
`4. Long chain tertiary amine oxide corresponding to
`the following general formula:
`
`30
`
`wherein R1 contains an alkyl, alkenyl or monohydroxy(cid:173)
`alkyl radical of from about 8 to about 18 carbon atoms,
`from 0 to about 10 ethylene oxide moieties, and from 0
`to 1 glyceryl moiety, and R2 and R3 contain from 1 to
`about 3 carbon atoms and from 0 to about 1 hydroxy
`group, e.g., methyl, ethyl, propyl, hydroxyethyl, or
`hydroxypropyl radicals. The arrow in the formula is a
`conventional representation of a semipolar bond. Exam(cid:173)
`ples of amine oxides suitable for use in this invention
`include dimethyldodecylamine oxide, oleyldi(2-hydrox(cid:173)
`yethyl) amine oxide, dimethyloctylamine oxide, dime(cid:173)
`thyldecylamine oxide, dimethyltetradecylamine oxide,
`3,6,9-trioxaheptadecyldiethylamine oxide, di(2-hydrox(cid:173)
`yethyl)-tetradecylamine oxide, 2-dodecoxyethyldime(cid:173)
`thylamine oxide, 3-dodecoxy-2-hydroxypropyldi(3-
`hydroxypropyl)amine oxide, dimethylhexadecylamine
`oxide.
`5. Long chain tertiary phosphine oxides correspond(cid:173)
`ing to the following general formula:
`
`RR'R"P.....O
`
`wherein R contains an alkyl, alkenyl or monohydroxy(cid:173)
`alkyl radical ranging from 8 to 18 carbon atoms in chain
`length, from 0 to about 10 ethylene oxide moieties and
`from 0 to 1 glyceryl moiety, and R' and R" are each
`alkyl or monohydroxyalkyl groups containing from 1 to
`
`3
`
`

`
`5
`3 carbon atoms. The arrow in the formula is a conven(cid:173)
`tional representation of a semipolar bond. Examples of
`suitable phosphine oxides are: dodecyldimethylphos(cid:173)
`phine oxide, tetradecyldimethylphosphine oxide, tet(cid:173)
`radecylmethylethylphosphine oxide, 3,6,9-trioxaoc- 5
`tadecyldimethylphosphine oxide, cetyldimethylphos(cid:173)
`phine oxide, 3-dodecoxy-2-hydroxypropyldi(2-hydrox(cid:173)
`yethyl)phosphine oxide, stearyldimethylphosphine ox(cid:173)
`ide, stearyldimethylphosphine oxide, cetylethylpropyl(cid:173)
`phosphine oxide, oleyldiethylphosphine oxide, dodecyl- 10
`diethylphosphine oxide,
`tetradecyldiethylphosphine
`oxide, dodecyldipropylphosphine oxide, dodecyldi(hy(cid:173)
`droxymethyl)phosphine oxide, dedecyldi(2-hydroxye(cid:173)
`thyl)phosphine oxide,
`tetradecylmethyl-2-hydroxy(cid:173)
`propylphosphine oxide oleyldimethylphosphine oxide, 15
`2-hydroxydedecyldimethylphosphine oxide.
`6. Long chain dialkyl sulfoxides containing one short
`chain alkyl or hydroxyalkyl radical of 1 to about 3
`carbon atoms (usually methyl) and one long hydropho(cid:173)
`bic chain which contains alkyl, alkenyl, hydroxyalkyl, 20
`or keto alkyl radicals containing from about 8 to about
`20 carbon ·atoms, from 0 to about 10 ethylene oxide
`moieties and from 0 to 1 glyceryl moiety. Examples
`include octadecyl methyl sulfoxide, 2-ketotridecyl
`methyl sulfoxide, 3,6,9-trioxaoctadecyl 2-hydroxyethyl 25
`sulfoxide, dodecyl methyl sulfoxide, oleyl 3-hydroxy(cid:173)
`tetradecyl methyl sulfoxide, 3-
`propyl sulfoxide,
`methoxytridecyl methyl sulfoxide, 3-hydroxytridecyl
`methyl sulfoxide, 3-hydroxy-4-dodecoxybutyl methyl
`sulfoxide.
`Many additional nonsoap surfactants, useful herein,
`are described in McCutcheon's Detergents and Emulsifi(cid:173)
`ers, 1979 Annual, published by Allured Publishing Cor~
`poration, which is incorporated herein by reference.
`The above-mentioned surfactants can be used alone 35
`or in combination in the shampoo compositions of the
`present invention. The anionic sur.factants, particularly
`the alkyl sulfates, the ethoxylated alkyl sulfates and
`mixtures thereof, as well as the isethionates, are pre(cid:173)
`ferred for use herein. Most preferred.are the mixtures of 40
`alkyl sulfate and ethoxylated alkyl sulfate, wherein the
`ratios of the former to the latter are from. about 1:5 to
`about 5:1. Most preferred contains ammonium lauryl
`sulfate and ammonium laureth sulfate.
`When these surfactants are introduced into the com- 45
`position it is preferred they be introduced as mixtures
`having a surfactant concentration of about 28% in the
`case of ammonium Iaureth sulfate and about 25% in the
`case of ammonium Iaury! sulfate. These concentrations
`allow for optimum processing of the shampoo composi- 50
`tions.
`
`30
`
`ANTIDANDRUFF ACTIVE
`In the present invention, the antidandruff active is a
`1-hydroxy-2-pyridinethione salt in platelet particle 55
`form, wherein the particles have an average size of from
`2 microns to about 15 microns, preferably from about 5
`microns to about 9 microns. The active is used at a level
`of from about 0.3% to about 2%, preferably about 1%,
`of the shampoo composition. The 1-hydroxy-2- 60
`pyridinethione salts are disclosed for use in antidandruff
`shampoos in U.S. Pat. No. 2,809,971, Bernstein, issued
`Oct. 15, 1957; U.S. Pat. No. 3,236,733, Karsten eta!.,
`issued Feb. 22, 1966; U.S. Pat. No. 3,753,196, Parran,
`issued Aug. 21, 1973; U.S. Pat. No. 3,761,418, Parran, 65
`issued Sept. 25, 1973; U.S. Pat. No. 4,345,080, Bolich,
`issued Aug. 17, 1982; U.S. Pat. No. 4,323,683, Bolich et
`al., issued Apr. 6, 1982; U.S. Pat. No. 4,379,753, Bolich
`
`5,104,645
`
`6
`issued Apr. 12, 1983; and U.S. Pat. No. 4,470,982, Wink(cid:173)
`ler, issued Sept. 11, 1984; all incorporated herein by
`reference.
`The pyridinethione salts useful herein can generally
`be defined as water-insoluble salts of 1-hydroxy-2-
`pyridinethione which has the following structural for(cid:173)
`mula in tautomeric form, the sulfur being attached to
`the No. 2 position in the pyridine ring.
`
`0
`
`I 0'"
`
`The salts result from substitution of the hydrogen of
`one of the tautomeric forms by the appropriate salt
`cation. Depending, of course, on the valence of the salt
`cation involved there may be more than one of the
`pyridinethione rings in the compound.
`Preferred slats are formed from metals such as zinc,
`tin, cadmium, magnesium, aluminium and zirconium.
`The most preferred metal herein is zinc which forms
`2-zinc pyrithione or ZPT. Other cations such as sodium
`are also suitable.
`The pyridinethione salts useful herein take the form
`of water-insoluble flat platelet particles which have a
`mean sphericity of less than about 0.65, preferably from
`about 0.20 to about 0.54, and a median particle size of
`from about 2 1-L to about 15 ,_.,, preferably from about 5
`1-L to about 9 ,_.,, the particle size being expressed as the
`median equivalent diameter of a sphere of equal vol(cid:173)
`ume. The median diameters are on a mass basis with
`50% of the mass of particles falling on either side of the
`value given.
`.
`The diameter of a sphere of equivalent volume for a
`particle can be determined by a variety of sedimentation
`techniques which are based on Stokes' Law for the
`settling velocity of a particle in a fluid. Such techniques
`are described in Stockham, J. D. and Fochtam, E. G.,
`Particles Size Analysis, Ann Arbor Science, 1978, incor(cid:173)
`porated herein by reference. An approach for determin(cid:173)
`ing the median equivalent spherical diameter based on
`volume, dv, is shown in U.S. Pat. No. 4,345,080, Bolich,
`issued Aug. 17, 1982, Example II, incorporated herein
`by reference.
`The sphericity of a particle is also described by
`Stockham and Fochtman, supra, at page 113, as (dv/d5)2,
`where dv is the diameter of a sphere of equivalent vol(cid:173)
`ume, supra, and ds is the diameter of a sphere of equiva(cid:173)
`lent area. As used herein, however, the mean sphericity
`is (dv/d5)2 or the surface are of spheres having equiva(cid:173)
`lent volume distribution divided by the actual surface
`area of particles as measured. A technique for determin(cid:173)
`ing actual surface area is shown in the examples using
`the BET technique described by Stockham and Foch(cid:173)
`tam, supra, at page 122.
`From the viewpoint of antidandruff efficacy, the
`BET surface area herein preferably falls in the range of
`from about 0.5 to about 3.5 m2fg, more preferably from
`about 1.0 to about 3.0 m2/g.
`The platelet 2-zinc pyrithione crystals preferred
`herein are made in the manner disclosed in U.S. Pat. No.
`4,323,683, Bolich eta!., issued Apr. 6, 1982; U.S. Pat.
`No. 4,345,080, Bolich, issued Aug. 17, 1982; and U.S.
`Pat. No. 4,379,753, Bolich, issued Apr. 12, 1983; all of
`which are incorporated herein by reference.
`
`4
`
`

`
`5,104,645
`
`H(OCHz-CHz).OH
`
`wherein n is from about 6 to about 22; preferably from
`about 6 to about 18. Most preferred is PEG-12 wherein
`n has the average value of 12, available as Carbowax
`600, from Union Carbide; Polyglycol E-600, from Dow
`Chemical U.S.A.; and Pluracol E-600, from HASP(cid:173)
`Wyandotte.
`The PPG used in the present invention has the for(cid:173)
`mula
`
`8
`No. 4,885,107, Wetzel, issued Dec. 12, 1989, all incorpo(cid:173)
`rated herein by reference, discloses selenium disulfide as
`the active ingredient in antidandruff shampoo composi(cid:173)
`tions.
`The pyridinethione/selenium disulfide mixtures spec(cid:173)
`ified herein are generally used at levels of from about
`1.25% to about 3% of the composition. The ratio of
`pyridinethione salt to selenium disulfide is generally
`from about 1:4 to about 2:1, preferred is about 1:1.
`
`7
`In addition to the 1-hydroxy-2-pyridinethione salts,
`the shampoo composition disclosed herein may include
`other known antidandruff actives. Such antidandruff
`actives, when used, are included at levels of from about
`0.1% to about 1% of the composition, and are selected 5
`from the group consisting of hydroxypyridone salts,
`selenium disulfide, and mixtures thereof.
`Hydroxypyridone salts are known antimicrobials. See
`Cosmetics and Drug Preservation, Principles and Practice,
`p 742 (edited by J. Kabura, 1984), incorporated herein 10
`SYNERGIZER
`by reference. The hydroxypyridone salts used herein
`When a synergizer component, defmed below, is
`can generally be described as 1-hydroxy-4-methyl-(lH)-
`combined with the specified size platelet pyridinethion
`pyridones having an aliphatic or aromatic moiety (R) at
`the 6 position thereof, wherein R has a 1r factor of at
`salts in a shampoo, the shampoo's antidandruff efficacy
`least 1:3, preferably from 2 to 6, more preferably from 3 15 is unexpectedly enhanced. These synergizers are used at
`to 5.5. The 1r factor is a measure of the lipophilicity!hy-
`levels from about 0.5% to about 5%, preferably from
`drophilicity of the substituent and is defined in detail in
`about 1% to about 3% and most preferably about 2%,
`of the composition, and are selected from the group
`the paper by W. Dittmar, E. Druckrey and H. Urbach,
`J. Med. Chern. 17(7), 753-6(1974) and references cited
`consisting of specific polyethylene glycols (PEG), poly-
`therein; all of which are incorporate~ herein by refer- 20 propylene glycols (PPG), polyethoxy/polypropoxy
`ence.
`copolymers (polyoxamers), polyethylenimines, polye-
`In structural terms, preferred R substituents are se-
`thoxylated polyethylenimines, polyethylene oxide fatty
`lected from linear and branched C3-Cu, preferably
`glycerides, ethoxylated nonylphenyol, ethoxylated al-
`C6-Cu, alkyl and alkenyl groups, Cs-Cs cycloalkyl
`cohols, polyethylene oxide carbohydrates, and mixtures
`groups, and Cs-Cs aryl groups. The cyclic moieties, 25 thereof. Preferred synergizers herein are the polyethyl-
`ene glycols containing from about 6 to about 22 ethoxy
`discussed above, can also be substituted with one or
`more alkyl or alkenyl groups up to C4. The R groups
`groups, particularly those having a molecular weight
`can further be substituted with halogen atoms. Of the
`from about 280 to about 1000. An especially preferred
`synergizer is PEG-12, with a molecular weight of about
`above, preferred R moieties are cyclohexyl and 2,4,4-
`30 546.
`trimethyl pentyl, the latter being highly preferred.
`The above mentioned compounds can be used both in
`PEG and PPG are known for use in shampoos as
`the free form and as salts, for example, salts with or-
`viscosity modifiers. See Goldemberg, Advances in Cos-
`ganic bases or inorganic cations. Low molecular weight
`metic Technology, Vol. 1 p. 70-71 (1978), incorporated
`alkanolamines are especially preferred organic bases.
`herein by reference.
`The preferred hydroxypyridone salt for use herein is 35
`The PEG for use in the present invention has the
`monoethanolamine slat known as piroctone olamine or
`formula
`Octopirox; see Cosmetic and Drug Preservation, supra.
`Piroctone olamine is described for use in deodorant
`compositions in Japanese Patent Application Sho
`57-104,313, published Dec. 23, 1983; Japanese Patent 40
`Application Sho 58-127,893 published Feb. 5, 1985
`(both to Lion) and U.S. patent application Ser. No.
`314,627, Melanson and Sturm, filed Feb. 23, 1989. Japa(cid:173)
`nese Patent Application Sho 57-080,644 (Lion), pub(cid:173)
`lished Nov. 18, 1983, discloses the use of a broad group 45
`of hydroxypyridone compounds for dandruff control.
`·
`All above cited references are incorporated herein by
`reference.
`The combination of pyridinethione and hdyroxypyri(cid:173)
`done compounds for use in antidandruff shampoos is 50
`known in the art. Japanese Patent Application Sho
`58-198, 413 (Lion), published Nov. 18, 1983, incorpo(cid:173)
`rated herein by reference, discloses antidandruff sham(cid:173)
`poo compositions which include a combination of zinc
`pyridinethione and piroctone olamine at a level from 55
`0.05 to 5% by weight, wherein the ratio of zinc pyri(cid:173)
`dinethione to piroctone olamine is from 9:1 to 1:9.
`The pyridinethione!hydroxypyridone mixtures spec(cid:173)
`ified herein are generally used at levels of from about
`0.4% to about 3% of the compositions. The weight ratio 60
`of pyridinethione salt to hydroxypyridone is generally
`from about 1:1 to about 5:1, preferably from about 2:1 to
`about 3:1, most preferred is about 2.5:1.
`Selenium disulfide is a medicine used in medicated
`shampoos for treatment of seborrhea. U.S. Pat. No. 65
`2,694,668, Baldwin et al., issued Nov. 16, 1954; U.S. Pat.
`No. 3,152,046, Kapral, issued Oct. 6, 1984; U.S. Pat. No.
`4,089,945, Brinkman, issued May 16, 1978; and U.S. Pat.
`
`H [OCHzyH J OH
`
`CH3
`
`n
`
`wherein n is from about 6 to about 22, preferably from
`about 6 to about 18. Most preferred is PPG-12wherein
`n has the average value of 12, available as Pluracol
`P-710, from BASF-Wyandotte.
`Polyoxamers are polyoxyethylene/polyoxypropy(cid:173)
`lene block polymers, which are useful herein as syner~
`gizers. An example of such a block polymer has the
`formula
`
`HO(CHzCH20)x (CHCHzO)y (CHzCHzO)zH
`I
`CH3
`wherein the total of x + z is from about 38 to about 156,
`and y is from about 30 to about 54. The block polymers
`
`5
`
`

`
`9
`also include polymers which have the propoxy, ethoxy,
`propoxy chain orientation. These synergizers are avail(cid:173)
`able from BASF-Wyandotte as Pluronics. Preferred for
`use herein is Pluronic F-68.
`Other synergizers useful herein include polyethyleni(cid:173)
`mines which are disclosed in U.S. Pat. No. 3,761,417,
`Parran, issued Sept. 25, 1973; incorporated herein by
`reference. These polyethyleneimines generally have the
`forumla
`
`5,104,645
`
`10
`factants and suspending agents, include the polysor(cid:173)
`bates available from ICI Americas as Tween. Preferred
`is Tween-20.
`Lastly, ethoxylated straight chain alcohols synergize
`5 the antidandruff actives disclosed herein. Said synergiz(cid:173)
`ers have the formula
`
`10 wherein R represents ·a blend of cetyl and stearyl radi(cid:173)
`cals n is from about 20 to about 55. These compounds
`are available from BASF Wyandotte as Plurafacs. Pre(cid:173)
`ferred is Plurafac A-39.
`
`H2(N-CH2-CH2)n-NH2
`wherein n is from about 6 to about 22, preferably from
`about 6 to about 18. Examples of these are PEl 7 and
`PEl 15.
`Ethoxylated polyethylenimies are also useful herein 15
`as synergizers. Such compounds are disclosed in Parran
`cited supra. These synergizers have the formula
`
`wherein y is from about 6 to about 22 and the ethoxylate
`groups x are independently from about 10 to about 30.
`An example of this is ethoxylated tetraethylene pent-
`amine.
`Ethoxylated nonylphenols are also useful herein as
`synergizers. These synergizers are nonionic surfactants
`having the formula
`
`wherein n is from about 1 2to about 50. Said synergizer
`is also known are nonoxynol. Preferred for use herein is
`Nonoxynol 40.
`Polyethylene oxide fatty glycerides also synergize
`the actives in the shampoo compositions disclosed
`herein. Said synergizers have the formula
`
`25
`
`35
`
`SUSPENDING AGENTS
`The compositions of the present invention contain a
`suSpending agent. Examples of suitable suspending
`agents include xanthan gum, long chain (C16-C22) acyl
`derivatives, long chain (C16-C22) amine oxides, and
`20 mixtures thereof, as are disclosed by U.S. Pat. No.
`4,704,272, Oh et al., issued Nov. 3, 1987, incorporated
`herein by reference.
`The preferred suspending agents are the ethylene
`glycol esters as disclosed in U.S. Pat. No. 4,885,107,
`Wetzel, issued Dec. 5, 1989; incorporated herein by
`reference. Most preferred are the diesters comprising a
`mixture of palmitate and stearate. The amount of stea(cid:173)
`rate should be in the range of about 10% to about 42%
`or in the range of about 55% to about 80% with palmi-
`30 tate accounting for the remainder. The amount of stea(cid:173)
`rate is preferably from about 60% to about 75%.
`The amount of the ethylene glycol diester useful in
`the present invention is from about 0.5% to about 6%,
`preferably from about 1% to about 4%.
`Water
`Water is the last essential component of the present
`invention and forms the remainder of the composition.
`It is generally present at a level of from about 20% to
`40 about 9<;!%, preferably from about 60% to about 85%,
`of the fmal composition.
`
`CH2-CH-CH2
`I
`I
`I
`0
`0
`0
`I
`I
`I
`(EO)nH (EO)nH (EO)nH
`wherein EO represents -(CH2-CH2-0-)- and 45
`each n is independently from about 0 to about 9 with no
`fewer than one ethoxy group in the compound. Such
`ethoxylated glycerides are available from ICI Americas
`~:~~~~:e~ted as Arlatone G or PEG-40 Sorbitan 50
`Polyethylene oxide carbohydrates may also be used
`to synergize the actives herein. Said synergizers have
`the formula
`
`OPTIONAL COMPONENTS
`T