The Future of Bran Control

The Future of Dandruff Control Introduction Zinc Pyrithione (Zinc Pyrithione) is one of the most frequently used ingredients in dandruff control. The prospect of its ban in the European cosmetics market1 is significantly altering the hair care market. Dandruff preventative product manufacturers around the world face the challenge of finding suitable alternatives that meet growing consumer awareness as well as changing regulatory requirements. Dandruff is a common scalp problem affecting more than one-third of the world's population. From China to Germany to Brazil, from Generation Z to Generation Y to those over 55 (Baby Boomers), regardless of gender, dandruff significantly impacts consumer confidence. Representative market research2 shows that the vast majority of people with dandruff problems seek natural solutions and remedies that leave hair smooth without irritating the scalp. In this article, we wish to discuss how dandruff forms and present forward-looking appropriate solutions for keeping dandruff under control.

Dandruff Formation

There are various reasons for the flaky appearance of the scalp. Dandruff, which is not always easy to distinguish from a dry scalp, is typically a result of oily scalp that causes excessive proliferation of Malassezia, a fungal species fed by excess sebum production (Figure1). Malassezia naturally is part of the scalp microbiome in most healthy individuals.4 To date, it has not been fully researched why dandruff develops in some people but not in others. In addition to genetic factors, environmental factors such as pollution, intensive cleansing routines, stress, and cold weather appear to play a role. The first choice for treating dandruff symptoms is typically the use of antifungal actives. This is based on the conclusion that a healthy microbial balance is disrupted in flaky scalp due to overgrowth of certain microorganisms. On the other hand, the cause of flaky scalp may not always be related to Malassezia and excess sebum production. In this case, formulation effects should focus on combining with anti-dandruff activity.

Crinipan® AD (climbazole), A Traditional Antimicrobial Solution

Antimicrobials control excessive proliferation of microorganisms in the scalp, particularly Malassezia, which is linked to dandruff formation. Among these alternatives, the best known are climbazole (Crinipan® AD), zinc pyrithione (ZPT), and piroctone olamine (PO), widely used and known for their effectiveness in reducing dandruff. Legislation effective from 1 March 2022 that bans ZPT use in the EU has halted the use of this ingredient in the European market, and with the global decline in ZPT, it is expected to impact the global market in the coming years. In this context, the number of products launched with zinc pyrithione over the past three years has been examined (Figure 2). According to current European legislation, climbazole in rinse-off anti-dandruff6 shampoos can be used up to 2% (Annex III/310), but lower usage levels apply to other applications (Annex V/32).7 These usage limits have been in effect since 2019. In the past, a maximum usage rate of 0.5% widely accepted in all cosmetic applications was common practice. This rate still applies today in some countries, such as China. Symrise conducted several in vivo studies comparing the effectiveness of three traditional anti-dandruff actives. One of these studies compares the effectiveness of 0.5% climbazole with 0.5% ZPT in the same shampoo base. Both dandruff score (1 [no dandruff] to 6 [excessive]) and hair oiliness (1 [not oily] to 6 [excessive]) were evaluated by three experts. This 6-week evaluation was conducted on 30 subjects; half used a shampoo containing climbazole, the other half used one with ZPT. The study results showed that climbazole significantly reduced dandruff within the 42-day treatment period and had a similar effect to ZPT as shown in Figure 3. Additionally, climbazole more strongly reduced oiliness on the scalp compared to ZPT and also prevented new dandruff formation (Figure 1 and Figure 3).  

SymClariol®, A Globally Compatible, Multi-Functional Ingredient

SymClariol® (decylene glycol) is used globally as a cosmetic active ingredient addressing many aspects of personal hygiene. The lipophilic nature of this humectant and its antimicrobial profile make it an ideal, multi-functional ingredient for cosmetic hygiene products from scalp to toenails. The recommended usage rate for hair and scalp care applications is 2%. The molecule's performance on the scalp was demonstrated in a study by Beauty Hi-tech Innovation Co., Ltd. showing that it helps reduce sebum and dandruff.8 In a study conducted by Symrise on 13 subjects, 1% SymClariol® (decylene glycol) used in combination with low-dose climbazole (0.1%) confirmed shampoo effectiveness. Subjects washed their hair three times per week with the test shampoo. After 42 days of use, dandruff levels were significantly reduced and subjects reported that the shampoo helped reduce itching on the scalp (Figure 4).9 This data shows that manufacturers can use decylene glycol in combination with a commonly used anti-dandruff ingredient like climbazole, or even rely on SymClariol® alone. In fact, combining different anti-dandruff ingredients in cosmetic formulations is very common practice. For example, L'Oréal's current market products in India contain salicylic acid and zinc pyrithione, and Unilever in China uses a combination of climbazole and salicylic acid. 10,11 To enhance the anti-dandruff effectiveness of hair care products, combinations of ingredients can be utilized. This was demonstrated in a study conducted at Beiersdorf showing that a combination of 0.5% climbazole and 0.5% piroctone olamine in a shampoo completely eliminated dandruff compared to a shampoo containing 1.0% zinc pyrithione alone.12  

Crinipan® PMC green, A Natural-Derived, Easy-to-Use Solution

Crinipan® PMC green (propanediol caprylate) is a naturally sourced new-generation anti-dandruff ingredient launched in 202013. This ester represents a new mechanism of action through targeted release of a substance: Malassezia cannot produce fatty acids necessary for growth and cell membrane construction. The yeast releases lipases (enzymes) to break down triglycerides found in scalp sebum into alcohols and fatty acids. Instead of scalp sebum, Malassezia breaks down the ester into caprylic acid and propanediol (Figure 5). Caprylic acid exhibits direct antifungal activity, while the use of propanediol in the ester masks the strong odor of caprylic acid and provides different beneficial properties. When Crinipan® PMC green was used at 0.5%, it was found to significantly reduce dandruff compared to climbazole.14 To demonstrate the comparative effectiveness of propanediol caprylate with piroctone olamine in reducing dandruff, a 28-day shampoo study was conducted on 21 volunteers with oily scalps. Non-adherent and adherent dandruff were evaluated by a dermatologist across the entire scalp using a score between 0 (no dandruff) and 5 (excessive dandruff amount). Therefore, the resulting total dandruff score (adherent + non-adherent) is evaluated between 0 and 10. The shampoos contained either 0.5% propanediol caprylate or 0.5% piroctone olamine and were used three times per week. After 28 days, a significant reduction in total dandruff amount was observed in both shampoos. No significant difference was found between the two shampoos, clearly demonstrating the excellent effectiveness of Crinipan® PMC green. In addition to significantly reducing dandruff, additional research has shown that Crinipan® PMC green supports a healthier scalp microbiome and also provides various other benefits such as a healthier scalp, shinier hair, ease in detangling hair, and assistance in reducing sebum. 15 The recommended use of Crinipan® PMC green in cosmetic applications is up to 1.0%. A major advantage of this product is that its liquid form provides ease of use and does not require excessive energy in the cosmetic product manufacturing process. No heating or vigorous stirring is required to dissolve the product.

Crinipan® ADS, An All-in-One Liquid Solution

The difficulty faced by some formulators is that antimicrobial ingredients such as ZPT, PO, and Climbazol come in solid form. To dissolve these ingredients in a formulation, heating or at least a long mixing time is usually required. To overcome such difficulties, formulators may prefer to use Crinipan® ADS, a liquid mixture containing climbazole along with phenoxyethanol, decylene glycol, and 1,2-hexanediol. This multi-functional product succeeds in providing complete protection when used at a 1.5% rate in a shampoo, while its contained climbazole anti-dandruff active limits excessive proliferation of Malassezia.16,17 Conclusion The ban on zinc pyrithione has already hit the European market and is expected to gradually impact the global market. A wide variety of alternative anti-dandruff solutions are available for formulators. From the most traditional antimicrobial solution like Crinipan® AD to easier-to-use ingredients like Crinipan® ADS that also provide the advantage of complete shampoo protection in a single step... On the other hand, Crinipan® PMC green clearly represents the future of dandruff control: a naturally derived, easy-to-use solution that supports a healthy scalp microbiome with a completely new and innovative mechanism of action. SymClariol® (decylene glycol) is an alternative option particularly for applications targeting global markets due to China compliance. The combination of multiple technologies remains a common practice aimed at enhancing the performance of hair care formulations, providing multiple benefits. References 1 COMMISSION REGULATION (EU) 2021/1902 of 29 October 2021 amending Annexes II, III and V to Regulation (EC) No 1223/2009 of the European Parliament and of the Council as regards the use in cosmetic products of certain substances classified as carcinogenic, mutagenic or toxic for reproduction and published in the Official European Journal on Nov 3, 2021. It took effect in March 1st, 2022: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32021R1902 2 Symrise CICS database 2016, 2018, 20-22 countries; Scalp Care Exploration Study 2020, 5 countries 3 American Academy of Dermatology Association. Accessed 11.04.2022 https://www.aad.org/public/everyday-care/hair-scalp-care/scalp/dry-scalp-conditions 4 Findley K., Oh J., Yang J., Conlan S., Deming C., Meyer J., Schoenfeld D., Nomicos E., Park M. (2013). Topographic diversity of fungal and bacterial communities in human skin; Nature, 498 (7454) 5 Mintel. Accessed January 2022 https://www.gnpd.com/sinatra/shared_link/b9cb7b39-8f45-46b2-b181-aaeec7ee40e5 6 Anti-dandruff from a European point of view; subject to differing legislation depending on the region: I.e. propanediol caprylate, climbazole and piroctone olamine are not approved as anti-dandruff actives by the US FDA drug monograph. 7 COMMISSION REGULATION (EU) 2019/698 of 30 April 2019 amending Annexes III and V to Regulation (EC) No 1223/2009 of the European Parliament and of the Council on cosmetic products. https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A32021R1902&qid=1635933838171 8 Lin X., Nomachi A. and Yang J., (2019). Rise to the Top: decylene glycol for Scalp Health and Care; Cosmetics & Toiletries, June 3rd, 2019 9 Schmaus G., Lange S. (2007). EP20638553B1, Use of c10-c14-alkanediols in the preparation of a composition for the prophylaxis and/or treatment of malassezia-induced dandruff formation and compositions comprising c10-c14-alkanediols. 10 Mintel, L'Oréal anti-dandruff shampoo, L'Oréal Paris. July 2022 - https://www.gnpd.com/sinatra/recordpage/8905265/from_search/pAr7fUjaCH/?page=1 11 Mintel, Clear anti-dandruff shampoo, Unilever. July 2022 - https://www.gnpd.com/sinatra/recordpage/5544185/from_search/1a0BGGdCbL/?page=1 12 Schmidt-Rose T., Brarcn S., Fölster H., Hillemann T., Oltrogge B., Philipp P., Weets G., Fey S. (2011). Efficacy of a piroctone olamine/climbazole shampoo in comparison with a zinc pyrithione shampoo in subjects with moderate to severe dandruff; International Journal of Cosmetic Science, 33, 276-282 13 Genrich F., Koch C., Lange S., Bugdahn N., Schmaus G. Next Generation Dandruff Control. SOFW-Journal 146 8-13. December 2020 14 Genrich, F., Nordzieke, S. (2021). Shaping the Future with Green Dandruff Control; Euro Cosmetics 29, 16-18. 15 Genrich F., Koch C., Massironi M., Thomaz F. Propanediol caprylate: Shifting the Microbiome, Sebum Levels and Classic Approach to Dandruff. Cosmetics & Toiletries Vol 136; No. 6, 44-51. June 2021 16 Genrich F., Pungitore S., Lange S., Pesaro M. (2018). Modern protection for shampoos; Pharmaceutical & Cosmetic review Vol 45; no. 2, 15-17 17 EP2589291B2, CN103083196A, (2012). Synergistically active ternary anti-microbial mixtures; Symrise Translated and Compiled by: Tuğba Bayazıt Technical Application Specialist / Africa, Middle East, Turkey Team Leader Symrise Authors: Laura Meunier, Dr. Florian Genrich Cosmetic Ingredients Division, Skin Care Category Symrise AG, Germany Dr. Steffen Nordzieke Global Innovation Cosmetic Ingredients Microbiology Research Symrise AG, Germany