Getting under your skin

We’ve all bought a jar of ‘wrinkle be gone’ cream after being impressed by its ‘sounds impressive’ ingredients and we have all dutifully slapped it on, thickly. After a few days of this manic love-affair we have all stood next to our ‘magnify me’ mirror, took a deep breath and surveyed the landscape looking for the new us.  Was our money well spent? Do we look 10 years younger?  Maybe…..

Being a complete science nerd all I want to know is ‘how did THAT hydroazoliposome wotsit get into MY face?

Well I must say that is not an easy question to answer as getting stuff under your skin is a bit of a scientific  and biological challenge. You see the thing is this,  believe it or not your skin is designed to keep things out so it is actually quite difficult to get things under it. Yes if we rub garlic on our feet we can smell it on our breath within a few minutes and yes an aromatherapy massage can reach the parts that an ordinary rub down just can’t touch but it’s not like that for everything.  All that your average skin cream can hope to do is serve as a moisture trap or a barrier cream, working at or on the surface to prevent or modify moisture loss. To get actives in takes a little giggery pokery!

Firstly the actives have to be very small so that they can get through the little nooks and crannies of the skin – things like collagen and elastin are often way too big to get through under normal circumstances. Secondly the physical conditions must be right with regards to formulation pH, melting point and solubility of the active – all chemistry and all important but often difficult to balance in a cost-effective and cosmetically acceptable formulation.  After that you may still need other chemicals to help the active to penetrate through the skin or even need to use another gadget to help it on its way (electric current, heat or light).

Ok, so let’s assume that the cosmetic chemists and brand owners have thrown everything at their formulation and got everything right on paper. What next?

Well the guys at Monash University’s Pharmacy department are experts at measuring skin penetration and I have just been reading a great little study that I want to share with you.  Anita Schneider and Barrie Finnin set about investigating the  penetration powers of three common actives in vivo (living tissue) after noticing that many cosmetic actives are only tested in vitro (in test-tube or laboratory conditions).  They looked at  Niacinamide, Genistein and a tripeptide using real human skin gathered from abdominal surgery and tracked their journey through the skin samples, nice!

So what happened?

Well, first of all the actives were tested in a saturated solution rather than a real-time formulation meaning that the odds should be stacked in the favour of skin penetration. Then the active solution was placed under an occlusive barrier on the skin meaning a) it can’t  go anyway and b) the skin will start sweating making it easier for the active to get through.  So, with perfect conditions the testing got underway!

Results.

The test showed that Niacinamide did penetrate quite easily through the stratum corneum making it a very useful and powerful antioxidant for skincare use.  Genistein only penetrated the skin to a small degree and the tripeptide got nowhere near to penetrating at levels that could stimulate collagen synthesis.

So where does that leave us?

Well, I love the fact that people like this are taking the time to do this type of work as there is nothing better than real life evidence. The fact that only one out of these three common actives got through in high enough levels to do any good was not that surprising as it really is hard to get stuff into the skin. However this doesn’t make me any less likely to give products a go. Why? Well, cosmetic chemists are cleaver people and where there is a will there is a way! I am sure that the rise of nanotechnology, high-tech delivery systems, novel emollients and electric currents will help stack the odds in our favour.

And after all, the proof is in the pudding, if you think you look and feel better then go for it!

The study was published in the Australian Journal of Cosmetic Science Vol 23, No 6, pages 18-24 and Anita from the university can be contacted here: anita.schneider@pharm.monash.edu.au