Bayer including pneumonia and tuberculosis. Bayer scientists were not the first to make heroin, but the company led the way in commercializing it. "Heroin" was a Bayer trademark until after World War I. In 1903 Bayer licensed the patent for the hypnotic drug diethylbarbituric acid from its inventors Emil Fischer and Joseph von Mering. It was marketed under the trade name Veronal as a sleep aid beginning in 1904. Systematic investigations of the effect of structural changes on potency and duration of action at Bayer led to the discovery of phenobarbital in 1911 and the discovery of its potent anti-epileptic activity
Drug delivery to the brain permeability was known and labeled them either CNS+ or CNS- for compounds that easily transverse the barrier and those that did not. They then set out to analyze the above factors to determine what is necessary to transverse the blood–brain barrier. What they found was a little surprising; lipophilicity is not the leading characteristic for a drug to pass through the barrier. This is surprising because one would think that the most effective way to make a drug move through a lipophilic barrier is to increase its lipophilicity, it turns out that it is a complex function of all of