Caffeine is a nitrogenous organic compound of the alkaloid group, (1,3,7-trimethylpurine-2,6-dione) a methyl xanthine alkaloid which is consumed as a beverage, administered as a medicine or applied for cosmetic purposes. However, caffeine does not possess the properties of an ideal skin penetrant as it is a hydrophilic material with a Log P of -0.07. Caffeine also exhibits unusual solubility behaviour in non-aqueous solvents and forms aggregates in aqueous solutions.
IS IT SAFE? ARE THERE SIDE EFFECTS?
You have a cup of coffee daily, don't you?
EFFECTS ON HAIR LOSS
Caffeine increases cAMP levels in cells and therefore promotes proliferation by stimulating cell metabolism; a mechanism which would counteract (DHT) induced miniaturization of the hair follicle. Encapsulated in Niosomes, which are liposomes containing a non-ionic surfactant, and transferosomes (ultraflexible vesicles) this hydrophilic drug showed significantly greater penetration into the skin and permeation across the stratum corneum. Dose-response experiments showed that a concentration of 0.15%was stimulatory in male skin organ culture model. .High concentrations may cause an over-stimulation of hair follicle metabolism resulting in extensive consumption of energy reserves, exhaustion of the proliferation capability and finally lack of hair shaft elongation. Recent study in Identical female Twins showed less consumption of caffeine as an exogenous factor associated with increased vertex hair loss
STRUCTURE & SYNTHESIS
Can be found naturally in tea, coffee, guarana, maté, kola nuts, and cacao. Pure caffeine (trimethylxanthine) is a white powder or could look as silky needles.Caffeine is recommended as a test substance by the OECD because it has been studied extensively in vitro and in vivo.
MECHANISMS OF ACTION
Caffeine inhibits the phosphodiesterase enzyme and has an antagonistic effect on central adenosine receptors. It is a stimulant of the central nervous system and may produce wakefulness and heightened mental activity. The molecule also increases rate and depth of respiration but it is a weaker bronchodilator than theophylline, with a direct effect against apoptosis.
DIRECT SCALP DELIVERY
Topical delivery of active compounds to different compartments of the skin and its appendages is the prerequisite for the efficient treatment of skin diseases.The absorption of topically applied compounds and their levels in the blood vary considerably in the different regions of the human body. The density of hair follicles significantly contributes to this effect by an increase in surface area and a disruption of the epidermal barrier towards the lower parts of the hair follicle. Hereby, the human hair follicle serves not only as a reservoir, but also as a major entry point for topically applied compounds. Hair follicles are the only pathway for fast caffeine absorption during the first 20 min after application.