Anti-dandruff shampoo, how does it work?

Anti-dandruff

Dandruff

What is dandruff? Also called "roos" in dutch, are dead skin cells of the scalp, which are formed by a pathological process, caused by an acceleration of keratinization (also known as hyperkeratosis).

These dead cells will stick to eachother, together with tallow these compounds of cells will form to the dandruff as we know it. In some cases, due to the tallow, these 'flakes' can look yellowy, vivacious.

Most common cause is just a dry skin type, and by a yeast, living on the human skin, named Pityrosporum ovale (now known as Malassezia globosa). The exact mechanism how the yeast produces more dandruff is not fully known, but probably it's caused by a metabolisation of triglycerides into oleic acid. Fact is, reduce the yeast in population and dandruff will reduce significantly. N.B.: it has been proven that the colonization of the yeast is almost the double of normal population on people with more dandruff than other people.

Get rid of the yeast, get rid of the dandruff

The handle dandruff, the most commonly first-used solution is an anti-dandruff shampoo.

The shampoo is often a mild shampoo with antibacterial, antimycotical and keratolytic agents.

Most used agents: Zn/Na-pyrithione, Se-Sulfide (however contested due to toxicity, only used if really needed), coal tar, salicylic acid, nystatin, ...

Most preferred: Zn/Na-pyrithione, or Pyrithione Zinc, Pyrithione Sodium.

These molecules get rid of the yeast and thus the dandruff.

Structure of Pyrithione Zinc (source: Wiki)

For example: Procter & Gamble's "Head and Shoulders" shampoos contain about 1% of Pyrithione Zinc as an anti-dandruff shampoo.

One last thing that is very important to note, that not many people consider: allow these shampoos to rest on the scalp for a relatively long time! (1-2 minutes atleast), since these molecules need time to penetrate into the skin to get to the yeast! Thus, do not immediately rinse of the shampoo after application.

Comments

Alkynen: Elektrofiele additie

Elektrofiele additie: Waterstofhaliden op alkynen Voorbeeld van waterstofhaliden: HCl, HBr, HF, HI Gebruik van één equivalent waterstofhalide met alkyn (dus 1:1 geen overmaat geen tekort) Bij een overmaat aan het waterstofhalide zal een tweede reactie plaatsvinden op het gehalogeneerde alkyn, ter vorming van een geminaal regioisomeer.

Coca-Cola: Life - myth or truth?

"Coca-Cola Life" Recently the Coca-Cola company released a new beverage: the Coca-Cola Life drink. It should contain less sugar than the normal Coca-Cola drink; a part of the sugar is replaced with the recently approved sweetener from the Stevia plant (stevioglycosides). It's being sold as a 'natural' drink, but those stevioglycosides are as natural as the chemical sweetener aspartame found in Light and Zero drinks. However it is true that the amount of sugar is much lower (being reported as 33%, some say it's around 20%); yet approximately still 3-4 sugar cubes / 33 cl can (5-6 in a normal can). I bought it myself and found that the flavor has not really changed from the original Coca-Cola, however it does taste more "flat" - but definitely true it yourself. The outside of the can has the colour green. I personally do not associate this "healthy - natural" colour with Coca-Cola, but it's growing on me. In sum

Alkanes and radicals 4: Additionreactions of radicals

Alkanes and radicals Addition of radicals on an alkene Look at the two reactions below, the first reaction is in normal circumstances, which will result in a normal Markovnikov reaction ( with the addition of a protic acid HX to an alkene , the acid hydrogen (H) becomes attached to the carbon with fewer alkyl substituents , and the halide (X) group becomes attached to the carbon with more alkyl substituents). In the second reaction, peroxide is used as condition, this will result in an anti-Markovnikov reaction. The peroxide will generate Br radicals in small amounts (this is the initiation for this anti-reaction). Let's see the peroxide mechanism in detail. As stated above, an alkyl peroxide is a radical initiator. The electrophile will add on the sp2 carbon which carries the most hydrogens (where also the radical with most alkyl groups will be formed). The termination reactions will have several other outcomes. In the major outcome, the radical will not b

Pharmacist Blog about what I encounter and find useful/interesting

Search This Blog