Sunscreen SPF 50 - Chemists Corner

Formulating

Sunscreen SPF 50

Posted by Shubh123 on June 23, 2025 at 4:15 am
I am trying the below formulation of chemical sunscreen spf 50. Trying to make it ultra matt, not sticky, non oily. Tried several trials but unable to achieve desired sensorial effect. Please see the below formulation.

1. Water- 42.6

2. Allantoin- 0.5

3. Sodium Gluconate-0.2

4. Sepinov EMT 10-0.8

5. Sepimax Zen- 0.1

6. Pentylene Glycol- 1

7. Bemotrizinol-8

8. Univul A plus-8

9. Ethylhexyl Triazone-5

10. Isododecane-10

11. Dicaprylyl Carbonate- 2

12. C13-C15 Alkane-2

13. Olivem 1000-1

14. Peg 100 stearate & Glyceryl stearate- 2

15. Cetyl alcohol- 1

16. Dimethicone 350 cst- 2

17. Dimethicone & Vinyl Dimethicone crosspolymer - 6

18. Silica Dimethyl silylate- 0.7

19. Tapioca Starch - 2.5

20. Magnesium Stearate- 0.5

21. Ectoin-1

22. Phenoxyethanol-0.5

23. Ethylhexyl Glycerine-0.5

Any help would be highly appreciated.

Thank you!
- This discussion was modified 4 weeks ago by Shubh123.
Fekher replied 4 days, 10 hours ago 4 Members · 8 Replies
8 Replies

Aniela

Member
June 24, 2025 at 5:18 am

I do not make them, but silicone or acrylate polymers used to enhance water resistance can have a greasy or sticky feel. Personally, I would “play” with the 2 above, and see how it goes. Also, the %s of the sunscreen-agents can lead to that. This might help with the latter https://www.reddit.com/r/SkincareAddiction/comments/ls706p/percentages_of_uv_filters_for_european_sunscreens/

PS- Does your benchmark use the same emulsifier system? I find it a bit odd, but again, I’m not familiar with making sunscreens.
- Shubh123
  
  Member
  June 27, 2025 at 4:20 am
  
  Thanks! The link you shared is helpful.
  
  The bechmarks have different emulsifier system. I tried with that system also but it didnt work so that’s why I changed the system. Now we achieved the sensorial part as per our requirement but still struggling with stability.
Fekher

Professional Chemist / Formulator
June 28, 2025 at 4:11 am
Formulation seems quite good just may:
1*Three uv filters will not protect as well if they are more ( i know that yours are broad spectrum however all sun screen seen contain more then three filters)
2* Oil phase is more then 40 % so it is really not easy to have stable emulsion .
3* Even with Sepinov EMT 10-0.8 Sepimax , Zen- 0.1 the level of Olivem 1000-1 ,Peg 100 stearate & Glyceryl stearate- 2 seems low .
- This reply was modified 3 weeks, 2 days ago by Fekher.
- Shubh123
  
  Member
  July 1, 2025 at 12:14 am
  
  Thanks! Can you suggest any emuslfiers. As i tried few but none of them work.
  - Fekher
    
    Professional Chemist / Formulator
    July 1, 2025 at 3:47 am
    
    i guess you should work on the level of use before then changing your emulsifiers .As i know yours can be fine . Make some researchement for free sunscreen formulations and you will find many emulsifiers systems .
cosmetic_chemist_vietnam

Pharmacist
July 2, 2025 at 4:51 am

If you want your sunscreen is ultra matte, you should use W/O or W/Si system. O/W or Si/W is usually not matte enough.
- Shubh123
  
  Member
  July 14, 2025 at 4:01 am
  
  Thanks! We are trying both ways i.e. W/O and O/W. However we now achieved O/W emlusion with matt finished. Now working on the stability part as its losses its viscosity after 8 days on 45 degree C/75% RH.
Fekher

Professional Chemist / Formulator
July 17, 2025 at 5:56 pm

Even your SPF will be low as predicted will not may reach 30.