FRAGRANCE JOURNAL 2007/July

Characteristic of hydrophobically-modified hydroxypropyl methylcellulose,
and application of hair cosmetics.
Abstract : Hydrophobically-modified hydroxypropyl methylcellulose (HM-HPMC) is athickener which has hydrophobic long chain alkyl group in molecular side chain.
Because of the interaction of hydrophobic group in water, HM-HPMC has a good viscosity
increase and thixotropic characteristics in comparing with hydroxypropylcellulose (HPC)
and hydroxyethylcellulose (HEC).
By formulating HM-HPMC in hair care product, it was possible to develop the productwhich is excellent in the growth to hair, pliability, slide property, and freshness.
This paper describes the result of basic physical properties of HM-HPMC for hair careproduct and one of applying HM-HPMC to hair treatment, and manufacturing notes.
KeywordHydrophobically-modified hydroxypropyl methylcellulose ; HM-HPMC ;thickener ; hair care ; hair treatment

1.

Introduction
Cellulose derivatives have been applied to various cosmetic areas including

viscosity adjustment, thickening, gelatinization, dispersion stabilization, water retention,emulsion stabilization, adhesion and film formation depending on their characteristics.
Particularly, hydroxypropylcellulose (HPC) and hydroxyethylcellulose (HEC) have been
preferably used in the areas, such as viscosity adjustment, thickening and gelatinization, inthe system in which carbomer, a typical thickener, cannot be used (compounding withcationic components, etc.).

However, thickening efficiency is limited with thesecellulose derivatives because of their molecular weights; therefore, it is necessary to add
them in a considerable quantity to obtain desired viscosity.

Moreover, in comparison

with carbomer, solutions prepared from the cellulosed derivatives show poor thixotropicity,
giving unsatisfactory results with respect to the sense of use as cosmetic preparations.
On the other hand, it has been tried to improve thickening efficiency and sense ofuse by introduction of hydrophobic functionalities such as C12 to C18 side chains into
existing cellulose derivatives.

For example, derivatives have been prepared byintroduction of C12 to C16 side chains into HEC (hereinafter, referred to as HM-HEC),
and an application of such derivatives to shampoo has been reported.1)

HM-HEC has

been positioned as a surfactant rather than a thickener because of the points that
low-molecular weight HEC is used as a raw material for structural modification, and thatits molecular structure has been designed so that the degree of substitution of the1

FRAGRANCE JOURNAL 2007/Julyhydrophobic group becomes relatively high.
Moreover, a study of the use as gelatinizing agents for pharmaceutical products byintroduction of hydrophobic groups into macromolecular cellulose derivatives has also
been reported.2) In the reported study, hydrophobic HPMC (hereinafter, referred to as
HM-HPMC) was synthesized for evaluation by introduction of a C18 hydrophobic groupusing high-molecular weight HPMC (hydroxypropylmethylcellulose) as a cellulose
derivative.

The limiting viscosity and apparent viscosity of the aqueous solutions of

HM-HPMC and its raw material HPMC were measured for comparison, showing nodifference in the limiting viscosity that reflects the size of pure macromolecules, while theapparent viscosity that affects the dispersion of macromolecules and interactions between
them in the measurement system was found to be markedly higher in the HM-HPMC
solution than that in the HPMC solution.

Based on this finding, it was discussed that the

thickening efficiency of HM-HPMC might be related to the formation of aninter-molecular network by molecular association among the hydrophobic groups in water.
In addition, it has also been reported that thixotropic fluidity similar to carbomer is
exhibited by formation of the network like this.
HM-HPMC is marketed under the INCI name of “Hydroxypropylmethylcellulose
Stearoxy Ether”, and it has become to be used in various cosmetic areas commencing withskin care and hair care.
2.

Viscosity Characteristics of HM-HPMC
The relationship between the quantity of addition of HM-HPMC aqueous solution

and its raw material, HPMC, and viscosity is shown in Figure 1.

Despite no great

difference in the length of the main macromolecular chain between HM-HPMC and
HPMC, HM-HPMC shows thickening efficiency superior to HPMC.

Similarly,

the relationship between the shear rate and viscosity of the 2 types of aqueous solutions
was examined (Figure 2).

It was revealed that HM-HPMC showed a greater decrease inapparent viscosity with increase in shear rate, forming a more thixotropic aqueous solution
compared to HPMC.

It is considered from the above findings that preparation of aformulation with better sense of use may become possible by use of HM-HPMC as athickener by addition to cosmetic preparations in a smaller quantity.

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FRAGRANCE JOURNAL 2007/July

Viscosity (mPa•s/25 ℃)

100,00 0

10,00 01,00 0

10 0

10
0 .0

0.5

1.0

1.5

2.0

Added Quantity (%)

Figure 1: Re lationship betwee n the Quantity of Addition of
Ce llulose Derivatives and Viscosity
B-Type viscometer, 6 rpm (25℃ )○ HPMC (viscosity grade: 100,000)△ HPMC (viscosity grade: 10,000)● HM-MPMC (viscosity grade: 100,000)▲ HM-MPMC (viscosity grade: 10,000)℃)
Viscosity(mPa•s/25
粘度（ mPa･s/25 ℃）

100 ,0 00

10 ,0 00

1 ,0 00

1 00
1

10

1 00
-1- 1

S harerate （ ss ））ず り速度（Figure 2: Relationship betwe en Shear Rate of Cellulose
図 2 セルロース 誘導体 ずり速度と粘度
Derivatives and Viscosity
E型粘度計
（25℃）
セルロース誘導体添加量
1.0%E-Type viscometer(25℃); quantityof addition of cellulose
derivatives: 1.0%
○ HPMC（粘度グレード100,000）
grade: 100,000)○ HPMC (viscosity● HM-HPMC（粘度グレード100,000使用）● HM-MPMC (viscosity grade: 100,000)

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FRAGRANCE JOURNAL 2007/July3.

Anticipated Functions Obtained by Introduction of HM-HPMC into Hair Care

Products
Negative senses of use such as tangling of the hair and friction or bad passing of thefingers through the hair at washing due to the sense of bundling, or sense of
stiffness/roughness at drying are associated in many macromolecular thickeners that arecompounded in hair care products, when they are excessively adsorbed.

The majority of

consumers tend to desire the natural texture (sense of smoothness or cohesiveness) that thehair originally has.

HM-HPMC exhibits very high thickening efficiency at a low

concentration, with which viscosity is easily adjustable, while the texture of the naturalhair is being retained; therefore, its compounding in hair care products is considered
useful.
Moreover, not only the functions as a thickener, it is also expected for HM-HPMC
that it may be effective in protecting hair and imparting good sense of use to hair careproducts. The lipid layer called F-layer is present in the outermost surface of the cuticle
covering the hair surface, making the hair surface hydrophobic.

At the same time,

18-methyleicosanoic acid contained in the lipid layer has the function to impart a smoothtexture to the hair surface.

The hydrophobic F-layer that has originally been present in

the hair surface is lost partly or fully by repeated chemical treatments such as coloring andpermanent waving, through which hair surface becomes hydrophilic.

Like this, friction

and hair tip tangling may occur at hair washing and drying, respectively, byhydrophilization of hair surface.

The hydrophilic part in the HM-HPMC molecule has anaffinity to the hydrophilic damaged area of the F-layer, while frictional resistance isreduced by hydrophobization of the hair by the presence of a hydrophobic long-chain
alkyl group, through which the effects, such as good passing of the fingers through thehair and the smoothness of hair surface, etc., can be expected.

Furthermore, since

HM-HPMC possesses an amphiphilic property, it exists in the vicinity of the interface
between lipid and water in emulsified bulk, through which the interfacial film is hardened.
Thus, it is expected that stability of lipid particles may be heightened by HM-HPMC, andthat it may function as an auxiliary emulsifying agent.

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FRAGRANCE JOURNAL 2007/July

4.

Characteristics in the Use for Hair Treatment
The characteristics of HM-HPMC in the use for hair treatment were examined.

4-1. Properties of Aqueous Solution of HM-HPMC and Sense of Use
The appearance of 1% aqueous solution of HM-HPMC is a light yellow and clear
gel.

The gel is not hard, while it having elasticity, being well spread on the palm.

4-2. Texture
Evaluation Method: An aqueous solution of 1% HM-HPMC and aqueous solutionsof other thickeners were prepared, and 40 g each of the solutions was applied to the wholehead in 10 study subjects of 20’s to 50’s in age having middle-damaged hair, and their hair
was washed after standing for 5 minutes, then the hair was set using a hair dryer.
Sensory evaluation was made by 5-ranked rating (Table 1) at wetting and drying.
Table 1: Criteria for Sensory Evaluation
Spread on the hair

Hair elasticity

Hair slide property

Hair freshness

5 Points

Good

Soft

Good

Good

4 Points

Slightly good

Slightly soft

Slightly good

Slightly good

3 Points

NormalNormalNormalNormal2 Points

Slightly bad

Slightly hard

Slightly bad

Slightly bad

1 Point

Bad

Hard

Bad

Bad

Evaluation Results: HM-HPMC was well spread at both wetting and drying, giving
an excellent sense of use with its distinctive gel property.

Furthermore, it was found that

HM-HPMC was effective in imparting high elasticity and natural slide property to the hairthrough hair surface hydrophobization by its hydrophobic functional group (Tables 2 and
3).

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FRAGRANCE JOURNAL 2007/July

Table 2: Results of Sense of Use and Hair Sensory Evaluation at Wetting
SpreadElasticity

Slide property

1% HM-HPMC

4.3

4.6

4.3

1% HEC

2.4

2.4

2.9

1% Highly polymerized PEG

4.0

1.4

1.4

1% Guar gum

2.4

2.6

3.0

1% Carrageenan

3.0

2.6

3.0

1% Konjac mannan

3.1

3.0

3.0

Elasticity

Slide property

Freshness

1% HM-HPMC

4.6

4.6

3.6

1% HEC

1.4

2.9

1.4

1% Highly polymerized PEG

1.4

1.4

1.4

1% Guar gum

3.0

3.0

2.7

1% Carrageenan

3.1

3.0

2.7

1% Konjac mannan

3.0

3.0

2.6

Table 3: Results of Hair Sensory Evaluation at Drying

4-3. Observation at the Time of Application to Damaged Hair
The hair of a Chinese was treated as described below, and it was examined by ascanning electron microscope (Model TSM-6701F, JEOL Ltd.).
Method for Treatment of Damaged Hair: The hair was bleached in a mixture of 10%hydrogen peroxide and 10% ammonia water (1:1) for 50 minutes, then it was washed withwater and dried using a hair dryer (Figure 3).
Treatment with HM-HPMC: An appropriate amount of 1% aqueous solution of
HM-HPMC was applied homogeneously to the damaged hair described above, and then it
was washed with water and dried using a hair dryer (Figure 4).
In accordance with the results obtained by the sensory evaluation, an improvementin the state of hair surface could be found by treatment with HM-HPMC.

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FRAGRANCE JOURNAL 2007/July

Figure 3: Electron Microscopic Picture of Damaged Hair

Figure 4: Electron Microscopic Picture of Damaged Hair Treated with HM-HPMC

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FRAGRANCE JOURNAL 2007/July

4-4. Stability
Multiple thickeners are occasionally used for the purpose of improvement in productstability, etc.; thereby, when HM-HPMC is used in combination with other thickeners, it isnecessary to design the formulation with caution because the combination use may affectwater solubility of HM-HPMC.

Particularly, when it is used in combination with guar

gum, HEC, etc., it is desirable to carry out product stability test with caution, becausesome cases of separation were found with time.

Moreover, when it is used in

combination with polyhydric alcohol components, such as higher alcohols and glycerin,etc., or certain antiseptics, there are occasionally cases of separation and decrease inviscosity; therefore, it is necessary to decide compounding conditions with adequate
precaution.
4-5. Irritancy to the Scalp
A patch test was performed to confirm irritancy of HM-HPMC to the scalp.
Test Method: A 24-hour occlusive patch test of the upper inner arm was performed using
Finn Chamber®.
Test Samples:i)

1.2% Aqueous solution of HM-HPMC

ii)

Purified water (negative control)iii)

0.5% Sodium lauryl sulfate (positive control)

Judgment Method: Sin reaction was judged by visual inspection 2 hours after
application.
Calculation Method: Primary irritation index (P.I.I.) was calculated by dividing thetotal sum of the larger value of skin reaction either 2 or 24 hours after application by the
number of study subjects using the following equation:
Skin irritation index =å (Larger value of the skin reaction either 2 or 24 hours after applicatio n)
Number of study subjects
Evaluation Criteria: Skin irritancy was rated by scoring the safety categories (Table 4).

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FRAGRANCE JOURNAL 2007/July

Table 4: Skin Irritation Index and Safety Category
Primary Irritation Index (P.I.I.)

Safety Category0 ～ 0.5

Not irritating

0.5 ～ 2.0

Mildly irritating

2.1 ～ 5.0

Irritating to a comparable degree

5.1 ～ 6.0

Strongly irritating

6.1 ～ 8.0

Corrosive

Evaluation Results: The safety category of HM-HPMC was rated as a non-irritating
substance, being judged not to be problematic in the irritancy to the scalp (Table 5).
Table 5: Irritancy Evaluation Results
Judgment Time

1.2% HM-HPMC

Purified Water

0.5% Sodium Lauryl Sulfate

After 2 hour

0.0

0.0

0.6

After 12 hours

0.1

0.0

0.8

5.

Application of HM-HPMC to Hair Treatment
Operational performance, sense of use, issues, etc., at application of HM-HPMC tohair treatment, including comparisons with other macromolecular thickeners, are reported
here.
Examinations were made for the 2-agent treatment systems in which an insoluble
product is formed by complexation of an anionic polymer and a cationic surfactant (Table
6).
Table 6: Formulation For Evaluation of Treatment Agents 1 and 2<Treatment Agent 1>
1-A

1-B

1-C

HM-HPMC

0.50

－

－

HPC

－

1.10

－

HEC

－

－

1.00

Polyglutamic acid

0.55

0.55

0.55

Paraben

0.22

0.22

0.22

Purified water

Residue

Residue

Residue

Viscosity (mPa•s)

16,70017,20016,300Viscosity: B-Type viscometer, 12 rpm, 25°C

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FRAGRANCE JOURNAL 2007/July<Treatment Agent 2>
Stearyl trimethyl ammonium chloride

2.00

Cetyl alcohol

5.00

Isopropyl myristate

4.50

Purified water

Residue

Polyglutamic acid was compounded as an anionic polymer in the treatment agent 1. In
addition, a macromolecular polymer was used as a thickener to adjust viscosity so that theagent can easily be applied to the hair.

A cream formulation consisting mainly of acationic surfactant was prepared as the treatment agent 2 aimed at formation of an ioniccomplex by mixing with the agent 1.
Using these trial products, effects of difference in the type of thickener on theproperty related to sense of use were assessed by the sensory test (Table 7).
Table 7: Sensory Evaluation Results of Hair Treatment<At wetting>Spread(Operational performance)

Elasticity

Slide property

1-A

1.3

3.5

3.8

1-B

3.0

2.7

2.5

1-C

3.6

2.5

2.1

Elasticity

Slide property

Freshness

1-A

3.5

4.2

3.8

1-B

2.3

2.7

2.1

1-C

2.0

2.5

1.9

< At drying >It was possible to obtain comparable viscosity by addition of HM-HPMC in a smaller
quantity compared to other 2 types of thickeners.

Moreover, it was revealed with respect

to the sense of use that HM-HPMC was superior to other 2 types of thickeners in the
points that it showed better slide property and lower tendency in hardening of the hair atwetting, and that a better texture in elasticity/moisture retention could be imparted to thehair with its better slide property at drying.

However, although issues remained unsolved

with respect to the operational performance at spreading on the hair and covering power atapplication, because of the excessive hardness of the gel from the characteristic as hairtreatment product (brushing) when HM-HPMC is used as it is, the issues could be

10FRAGRANCE JOURNAL 2007/July

improved by combination use of an emulsion, through which gel hardness could be
reduced.

In addition, it became also possible to impart emollient property by

combination use of an emulsion.

Examples of the combination use were shown in Table

8, and the sensory evaluation results were shown in Table 9.
Table 8: Examples of Formulation by Combination with an Emulsifying System
HM-HPMC

0.40

Polyglutamic acid

0.05

Cetyl alcohol

2.00

Behenyl alcohol

1.00

Octyl dodecanol

2.00

Cetyl ethylhexanoate

5.00

Decaglyceryl tris-stearate

0.80

Polyoxyethylene cetyl alcohol (30 E.O.)

1.20

Purified water

Residue

Table 9: Sensory Evaluation Results of Hair Treatment by Compounding of anEmulsifying System<At wetting>Spread(Operational performance)

Elasticity

Slide property

3.7

3.5

4.2

Elasticity

Slide property

Freshness

3.5

4.2

3.8

1-A’

< At drying >1-A’

Since it was difficult to impart emollient property with the other 2 types of thickeners
from the stability aspect, the finding may suggest an important characteristic of
HM-HPMC.
Assuming actual production, precautions for compounding of HM-HPMC were
described in the following.
Although HEC and HPC are marketed, which are claimed to be soluble at ordinary
temperatures, they tend to form an insoluble mass when they are added to water atordinary temperatures, being difficult to dissolve.

For complete dissolution, it isnecessary to add and disperse in water that has previously been heated to a temperature(75 to 80°C) at which it is insoluble, and then cool it to 25°C; therefore, the relevant
operational time becomes additionally necessary in the manufacturing process.

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FRAGRANCE JOURNAL 2007/July

Occasionally, complete dissolution may become difficult in the presence of other highly
water-soluble components at addition of HM-HPMC; therefore, it is necessary to take it inmind that the operation may become tedious when heating and cooling processes arenecessary for emulsification like as the present example, in addition to heating and coolingin the process for dissolution of thickeners.

The differences in finish by difference inmanufacturing process were shown in Table 10.
Table 10: Differences in Finish by Manufacturing Process of the Formulations Shownin Table 8
Phase A: HM-HPMC, purified water (50% of the compounded quantity)
Phase B: Cetyl alcohol, behenyl alcohol, octyl dodecanol, cetyl ethylhexanoate, decaglyceryl tris-stearate,polyoxyethylene cetyl ether (30 E.O.)
Phase C: Polyglutamic acid
<Manufacturing Method 1>
1)Preparation of A-Phase: Add HM-HPMC to purified water that has previously been heated to 80°C with stirring,and disperse it in water. Then, cool the mixture to 25°C to dissolve HM-HPMC.

2)

Separately, mix the B-phase that has been heated to 80°C in another tank by a homogenizing mixer, and stop thehomogenizing mixer after emulsification. Then, gradually add the remaining purified water that has beenheated to 80°C and used for preparation of the A-phase with stirring by a paddle mixer.

3)

Stop the homogenizing mixer, and add the prepared A-phase to the mixture. Mix adequately, and cool the
mixture to 25°C.

4)

After cooling, add the C-phase to obtain the formulation of cream for evaluation.

<Manufacturing Method 2>
1)

Modify the method for preparation of the A-phase described in the above manufacturing method 1 as follows:
omit the process of cooling to 25°C after dispersion of HM-HPMC at 80°C (Add it in the process 3) at thetemperature of 80°C).

Processes of 2), 3), 4) are the same as in the manufacturing method 1.
<Results>
The formulation prepared according to the “manufacturing method 1” became a slightly hard cream.

On the other

hand, the formulation prepared according to the “manufacturing method 2” formed a precipitate of insoluble
HM-HPMC.

As described above, although there are some points to consider, it is possible todesign products having unique characteristics in both physical property and sense of use at
the same time by application of HM-HPMC to hair treatment.

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FRAGRANCE JOURNAL 2007/July

6.

Conclusions
Carbomer has been the main stream of cosmetic thickeners to date.

Moreover,although various cellulose derivatives or natural macromolecules have been used in thesystems in which carbomer cannot be used, those having satisfactory properties not only inthickening efficiency but also in the sense of use have been available little.
It was revealed by the present study that HM-HPMC might be advantageous in the
points not only that it exerted excellent thickening efficiency, but also that various
functions were imparted to hair care products by its structural characteristic.

It isconsidered that HM-HPMC may be a raw material with which further applications can be
expected in the future.

HM-HPMCINCI name : Hydroxypropylmethylcellulose Stearoxy Ether

Trade name : SANGELOSE
Manufacturing company : DAIDO CHEMICAL CORPORATION (Japan)
Contact[ North America]
UNIGLOBE KISCO., INC
707 Westchester Avenue, Suite 207
TEL. +1-914-397-1150

FAX. +1-914-397-1155

6292 San Ignacio Avenue #A, San Jose, CA 95119
TEL. +1-408-224-6500

FAX. +1-408-224-6530[ Europe]
KISCO (DEUTSCHLAND) G.m.b.H.
Business Campus Muenchen Parkring 11
TEL. +49-89-30748140

FAX. +49-89-307481429

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