PROBLEMS SOLVED: INNOVATIVE ADVANCEMENTS IN WORKING WITH MINERAL UV FILTERS

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To combat these detrimental effects, consumers turn to sun care products. Indeed, sun care products are a $1.9 billion a year industry in the U.S., and skin care products featuring sun protection represent an additional $1.5 billion. Sales of premium products with SPF 40 or greater are the fastest growing segment, with sales rising some 30–40 percent a year.

But today’s consumers are also looking for products that are more natural. Sales of natural beauty and personal care products surpassed $7 billion in 2012 and are expected

to reach $13.2 billion by 2018, with a compound annual growth rate (CAGR) of 9.6 percent.1 Research reveals that more than half of U.S. female consumers are seeking natural products that do not contain unnecessary ingredients or chemicals.2

To meet the changing demands of today’s sun care product consumer, many formulators are turning to mineral UV filters. This paper provides an overview of current challenges in using these filters and explores the latest scientific advances that are improving their performance.

HALLSTAR PROBLEMS SOLVED: INNOVATIVE ADVANCEMENTS IN WORKING WITH MINERAL UV FILTERS 2

Visit almost any beach, park or backyard and it’s clear — people of all ages and types enjoy being out in the sun. But the public is also becoming increasingly aware of the dangers of prolonged sun exposure. Sunburns. Premature aging. Increased risk of skin cancer.

It’s not surprising that more sun care formulations are turning to mineral UV filters, such as zinc oxide (ZnO) and titanium dioxide (TiO2). These minerals are natural ingredients that provide broad-spectrum protection.

TiO2 is most often used for UVB protection (290–320nm), but also provides significant UVA (320–400nm) protection. ZnO is less effective than TiO2 for UVB protection, but is usually more effective in the long wavelength UVA part of the spectrum.

As desirable as mineral UV filters are, there are some definite challenges in integrating them into a successful formulation.

Aesthetic ChallengesConsumers may seek out personal care products that are more natural, but they are not willing to sacrifice aesthetics. There has been a shift in consumer expectations from function and efficacy benefits to sensory and emotional benefits. To ensure that their products meet these demands, manufacturers are increasingly using a variety of scientific methods to measure consumer responses to products based on the senses of sight, smell, touch, taste and hearing.3

This same attention to consumers’ sensory reactions in other personal care products is evident in the sun care market as well. Consumers now assume that the sun care products they buy will be effective, but they also want products that:

• Spread smoothly

• Feel good on the skin

• Dry smoothly

• Do not cause whitening

• Make them “feel good” and “happy”

Achieving these desirable sensory characteristics with a mineral UV filter can be challenging, but essential for a successful product. After all, the most effective sunscreen product is one that consumers will actually use on a regular basis.

Formulation ChallengesWorking with mineral powders is often less than desirable since they can pose health risks to workers, and it can be difficult to achieve even dispersion of the particles. Therefore, most formulators choose to formulate with dispersions featuring micronized TiO2 and ZnO particles.

These mineral dispersions can provide extremely effective broad-spectrum protection, but their effectiveness is dependent on particle size distribution and, to a lesser extent, on particle size. Unfortunately, mineral dispersions tend to form agglomerates, decreasing their efficacy — as well as decreasing their flowability and desirable skinfeel and increasing their whitening properties.

In addition, mineral dispersions, especially TiO2, tend to be photocatalytic, promoting the formation of reactive oxygen species and catalyzing the decomposition of organic materials.

Fortunately, new scientific breakthroughs are easing these challenges.

3

FULFILLING THE PROMISE OF MINERAL UV FILTERS

HALLSTAR PROBLEMS SOLVED: INNOVATIVE ADVANCEMENTS IN WORKING WITH MINERAL UV FILTERS

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The most effective sunscreen product is one that consumers will actually use on a regular basis.

Tightening Particle Size DistributionPutting UV mineral filters in a concentrated form in a dispersant not only eliminates the need to work with powered minerals, it also improves and tightens overall particle size distribution. This is essential since particle size distribution directly affects both the aesthetics and efficacy of a sun care product formulation. This tendency to form agglomerates appears in both TiO2 and ZnO formulations, although the issue is more severe in TiO2 formulations.

One successful way of tightening overall particle size distribution is to coat the mineral particles. An effective coating system consists of silica moieties (derived primarily from tetraorthosilicate), alkyl groups (derived from triethoxycaprylylsilane) and polydimethylsiloxane (derived from dimethiconol).

This combination forms a complete coating that surrounds the mineral particles and eliminates gaps. Chemical interactions between the particles are virtually eliminated and the particles no longer form clumps, but rather slide right over each other.

4

ADVANCED TECHNOLOGY TO IMPROVE PERFORMANCE

HALLSTAR PROBLEMS SOLVED: INNOVATIVE ADVANCEMENTS IN WORKING WITH MINERAL UV FILTERS

HALLBRITE® EZ-FLO ZDXZinc Oxide (non-nano) 60%, Butyloctyl Salicylate, Triceteareth-4 Phosphate, Trimethoxycaprylylsilane

HALLBRITE® EZ-FLO ZDX PLUSZinc Oxide (non-nano) 58%, Butyloctyl Salicylate, Ethylhexyl Methoxycrylene, Triceteareth-4 Phosphate, Trimethoxycaprylylsilane

Combining the benefits of a readily flowable Zinc Oxide dispersion with Hallstar’s patented Photoprotection expertise, Hallstar’s newest additions to our mineral dispersion line include HallBrite® EZ-FLO ZDX and HallBrite® EZ-FLO ZDX PLUS. These products combine the benefits of industry-leading ZnO performance with built-in Photoprotection technology.

HIGH PERFORMINGZINC OXIDEDISPERSIONS

ZnO (58%)

HallBrite®

BHB

Solastay® S1

Broad-Spectrum protection

Protected ZnODelivery System

Combine withAvobenzone

ZnO (60%)

Highly DispersedZnO

HallBrite® BHB

Increased SPF& PFA Results

ChinaApproved

Broad-Spectrumprotection

Polar Solvent

HallBrite ® EZ-FLO ZDX PLUS

Hal

lBrit

e® EZ

-FLO ZDX

HallBrite® BHB Eliminates Conglomeration

Before After

Easilypourable

Highly Stable(45°C)

Unique CoatingSystem

(Silica Based)

Creates nice, smooth lotionconsistency without any

particle perception

cGMP

HALLBRITE® EZ-FLO ZDXZinc Oxide (non-nano) 60%, Butyloctyl Salicylate, Triceteareth-4 Phosphate, Trimethoxycaprylylsilane

HALLBRITE® EZ-FLO ZDX PLUSZinc Oxide (non-nano) 58%, Butyloctyl Salicylate, Ethylhexyl Methoxycrylene, Triceteareth-4 Phosphate, Trimethoxycaprylylsilane

Combining the benefits of a readily flowable Zinc Oxide dispersion with Hallstar’s patented Photoprotection expertise, Hallstar’s newest additions to our mineral dispersion line include HallBrite® EZ-FLO ZDX and HallBrite® EZ-FLO ZDX PLUS. These products combine the benefits of industry-leading ZnO performance with built-in Photoprotection technology.

HIGH PERFORMINGZINC OXIDEDISPERSIONS

ZnO (58%)

HallBrite®

BHB

Solastay® S1

Broad-Spectrum protection

Protected ZnODelivery System

Combine withAvobenzone

ZnO (60%)

Highly DispersedZnO

HallBrite® BHB

Increased SPF& PFA Results

ChinaApproved

Broad-Spectrumprotection

Polar Solvent

HallBrite ® EZ-FLO ZDX PLUS

Hal

lBrit

e® EZ

-FLO ZDX

HallBrite® BHB Eliminates Conglomeration

Before After

Easilypourable

Highly Stable(45°C)

Unique CoatingSystem

(Silica Based)

Creates nice, smooth lotionconsistency without any

particle perception

cGMP

A Good Solubilizer Adds Stability and Eliminates Conglomeration

Before After

By tightening particle size distribution and restricting the formation of agglomerates, coating the mineral particles:

• Improves the effectiveness of the formulation by increasing the amount of light that is reflected and refracted away from the skin.

• Enhances the aesthetics of the formulation by eliminating perceptible particulates. The feeling of grittiness and tackiness is reduced and flowability is improved, leaving consumers with a pleasant experience and skin feel.

• Reduces skin whitening.

Using Coated Titanium Particles in a Concentrated Solution Dramatically Reduces Whitening Compared to Traditional Formulations

SolutionHallStar has developed UV filter dispersions highlighting both the benefits of photo-protected Titanium Dioxide and an

industry leading mineral UV filter aesthetic. Leveraging a patent-protected C3+ coating system consisting of Silica moieties

(derived primarily from Tetraorthosilicate), Alkyl groups (derived from Triethoxycaprylylsilane) and Polydimethylsiloxane

(derived from Dimethiconol) with our market leading photostabilizer technology, SolaStay® S1 (Ethylhexyl Methoxycrylene)

and HallBrite® BHB (Butyloctyl Salicylate), we’ve introduced to the market how mineral UV filters can be easy to work with

and also result in nice feeling, low whitening, high performance sunscreens for customers.

Drawdowns of dispersions diluted in C12-15 Alkyl Benzoate.

Drawdowns made using #4 Meyer rods on dark substrates.

The greater whitening effect of competitor products is very

apparent.

HallBrite®

EZ-Flo tDXHallBrite®

EZ-Flo tDX PlusCompetitorProduct A

CompetitorProduct B

introDuCtionMetal oxides with a wide band gap, such as Titanium Dioxide (TiO

2), or with a direct band gap, such as Zinc Oxide

(ZnO), absorb and reflect UV energy from the sun’s radiation. This makes them useful as UV filters and as pigments in

the cosmetic industry. Unfortunately, they are also photo-active, promoting the formation of reactive oxygen species

and catalyzing the decomposition of organic materials. This is not desired in personal care applications, where the

protective functions of these organic compounds are needed. Commercial surface modifications have not eliminated

this degradation, so a new means of protection was needed.

HallBrite® EZ-FLO TDX Plus

HallBrite® EZ-FLO TDX

Competitor A

Competitor B

Competitor C

Wavelenght (nm)

Ab

sorb

an

ce (

Att

en

uati

on

) 1

0,9

0,8

0,7

0,6

0,5

0,4

0,3

0,2

0,1

0

300 400 500 600 700 800 900 1000

Absorbance Spectra of UV Fi l ter Concentrates : 0.001% act ive TiO2

d i luted in C12-15 Alkyl Benzoate - 1 cm Path Length

Wavelenght (nm)

Perc

en

t Tra

nsm

itta

nce

100

90

80

70

60

50

40

30

20

10

0

300 400 500 600 700 800 900 1000

Transmittance Spectra of UV Fi l ter Concentrates : 0.001% act ive TiO2

d i luted in C12-15 Alkyl Benzoate - 1 cm Path Length

HigH PErForming titAnium DioXiDE DiSPErSionSleveraging a new patented coating system and pure photostability science

The HallStar Company - 120 S. Riverside Plaza, Suite 1620 - Chicago, IL 60606 - USA - +1-312-385-4494

hallstar.com

TiO2 (23%) TiO

2 (40%)

SolaStay® S1

HallBrite® BHB

Polar Solvent

HallBrite® BHB

Protected TiO2

Delivery System

Highly DispersedTiO

2

Increased SPFResults

Combine withAvobenzone

Broad SpectrumProtection China

Approved

High UVBProtection

EasilyPourable

Highly Stable(45°C)

No ParticlePerception

Minimal Whitening

Patented C3+ Coating(Silica moieties,

Alkyl groups,Polydimethylsiloxane)

HallBrite ® E

Z-F

LO

TD

X

Hal

lBri

te®

EZ

-FLO

TDX Plus

Wavelength (nm)

Ab

sorb

an

ce (

Att

en

uati

on

)

Perc

en

t Tra

nsm

itta

nce

Wavelength (nm)

1

0,9

0,8

0,7

0,6

0,5

0,4

0,3

0,2

0,1

0

100

90

80

70

60

50

40

30

20

10

0

300 400 500 600 700 800 900 1000 300 400 500 600 700 800 900 1000

Drawdowns made using #4 Meyer rods on dark substrate

Improving PhotostabilityTo mitigate the photcatalytic and oxygen species-generating activities of TiO2 and ZnO formulations, adding a photostabilizer, such as ethylexyl methoxycrylene, can improve stability and reduce harmful reaction upon exposure to sunlight. In addition, instead of a more

traditional solvent of C12-15 Alkyl Benzoate, adding butyloctyl salicylate to the solvent system will increase the polarity of your overall oil-phase. This further improves the photostability of the formulation, as well as improving aesthetics by imparting an elegant, moisturizing feel to the skin in an odorless, colorless, non-irritating liquid.

5HALLSTAR PROBLEMS SOLVED: INNOVATIVE ADVANCEMENTS IN WORKING WITH MINERAL UV FILTERS

Transmittance Spectra of Sunscreen Concentrates

® HallBrite® EZ-FLO TDX Plus HallBrite® EZ-FLO TDX

Competitor A Competitor B Competitor C

Absorbance Spectra of Sunscreen Concentrates: 0.001% Active TiO2 Diluted in Linear Alkyl Benzoate

1 cm Path Length

Wavelength (nm)

Abs

orba

nce

0.90.80.70.60.50.40.30.2

0300 400 500 600 700 800 900 1000

0.1

1

Transmittance Spectra of Sunscreen Concentrates: 0.001% Active TiO2 Diluted in Linear Alkyl Benzoate

1 cm Path Length

Wavelength (nm)

Perc

ent T

rans

mitt

ance

9080706050403020

0300 400 500 600 700 800 900 1000

10

100

® HallBrite® EZ-FLO TDX Plus HallBrite® EZ-FLO TDX

Competitor A Competitor B Competitor C

Absorbance Spectra of Sunscreen Concentrates: 0.001% Active TiO2 Diluted in Linear Alkyl Benzoate

1 cm Path Length

Wavelength (nm)

Abs

orba

nce

0.90.80.70.60.50.40.30.2

0300 400 500 600 700 800 900 1000

0.1

1

Transmittance Spectra of Sunscreen Concentrates: 0.001% Active TiO2 Diluted in Linear Alkyl Benzoate

1 cm Path Length

Wavelength (nm)Pe

rcen

t Tra

nsm

ittan

ce

9080706050403020

0300 400 500 600 700 800 900 1000

10

100

TAKING ADVANTAGE OF THE MINERAL UV FILTER OPPORTUNITY

The trends are clear. Consumers are:

• Looking for sun care and skin care products that provide both UVA and UVB protection.

• Seeking premium products that provide high levels of protection.

• Showing a preference for products that are more natural.

• Not willing to sacrifice aesthetics. They want products that flow well, spread smoothly, feel good on the skin, dry smoothly and are non-whitening.

Mineral UV filters can meet the first three consumer demands, and advances in science can help formulators meet the fourth. The challenges of working with mineral UV filters are now easily overcome with new scientific advances, including the coating of mineral particles and using specially formulated solvent systems.

Premium sun care products — and skin care products with UV protection — represent fast growing markets. With the right understanding of the science behind successful formulations, manufacturers can expand their market share and reap the rewards associated with mineral UV filters.

Hallstar has been successfully studying photoprotection and the stabilization of active ingredients for more than 20 years. The company holds more than 50 patents on photoprotection technology and is committed to maximizing the efficacy of active ingredients. As a leading global provider of specialty chemistry solutions, Hallstar takes a collaborative approach to every engagement, delivering technical support, chemistry expertise and industry knowledge that helps its customers make the most of their products, from concepts to the first production batches.

To learn more visit www.hallstar.com

© Hallstar, All Rights Reserved. 5/17

1 Penning, Abby. “Demand for beauty to grow over $13 billion by 2018, report says.” Cosmetics and Toiletries. Web. June 26, 2013. cosmeticsandtoiletries.com

2Trends 2025. Mintel Group Ltd. Web. mintel.com 3Stone, Herbert and Sidel, Joel L. Sensory Evaluation Practice (Third Edition), 2004