Skip to main content

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

Post a Comment

Popular posts from this blog

Erythropoietin: definition, structure, synthesis in vivo

Definition: EPO: = erythropoietin   A glycoprotein hormon-like structure, a sialoglycoprotein, which is an important factor in the survival, growth and proliferation of erythroid precursor cells (EPC) and it improves the de novo creation, differentation and growth of red blood cells (RBC). Thus, EPO controls the erythropoiesis = production of RBC. EPC: these are cells that are located in the bone marrow, will eventually form the RBC. RBC: cells responsible for the transport and distribution of oxygen throughout the body. Structure: Built out of 165 aminoacids (AA). They are all connected and form 1 polypeptide chain.  Although, within the chain, there are 2 disulfide bonds.  Respectively on positions: Cys7-161 and Cys29-33  Cys = cystein and the numbers indicate the positions these AA are located. Cystein structure. Available  sulfide  group for bonding There are also 4 positions where there is a possibility for glycosylation  Namel...
Post a Comment
Read more

Alkylhalides: Substitution reactions 6 (Sn1)

Alkylhalides: Substitution Nucleophile substitution reaction ( Sn1 reaction ) Sn1 side reactions I will now discuss some side reactions that can occur when a Sn1 reaction takes place. Carbocation shift Illustrated in the scheme below: Benzyl- and allylhalides  Benzyl- and allylhalides can undergo Sn1 AND Sn2 reactions. How to distinct them? Sn1 conditions: protic solvent and by adding a weak attacking nucleophile. Note: Benzyl- and allylhalides easily undergo Sn1 reactions, because their carbocations are very stable. Sn2 conditions: aprotic solvent and by adding a strong attacking nucleophile. Note: tertiary benzylhalides and tertiary allylhalides will NOT undergo a Sn2 reaction because of the steric effects (see chapter Sn2 reaction blogposts). Sn2 reaction examples Sn1 reaction examples Sn1 and Sn2 reactions in biology, nature and medicines S-Adenosyl methionine This is a biological methylating agens, also known as SAM . It is a frequen...
1 comment
Read more

Alkanes and radicals 1: Introduction

Alkanes and radicals Introduction Let's start with one of the most complex compounds consisting of alkanes and cycloalkanes (naftenes) that can be separated by distillation: Petroleum . Some tips when writing reactions with radicals, have a look on these reactions below, when an heterolytic bond gets cleaved, the arrowhead gets two barbs. When there is a homolytic bond that gets cleaved the arrowhead that shows the direction of the radical, gets one barb, have a look: Alkanes are little reactive, they will not react fast and heavily, because they only contain strong  sigma  σ bindings (single bonds). They also only have non-partial charged atoms. Although, alkanes DO react with Cl2 and Br2. The reactions are listed below, have a look, first the actual reaction, then shown in detail with different steps : 
Post a Comment
Read more