Crude drugs

The term crude drugs is usually applied to plant or animal organs or whole organisms or exudations of these, either in the fresh state of dried and either ground or unground. Some crude drugs such as acacia, belladonna, and starch are official; for these, rigid specifications are available. Plant-derived crude drugs may come from cultivated sources or may be collected in the wild. Cultivation and collection are carefully planned to obtain drugs with the highest possible therapeutic activity or content of active constituents. The harvested drug plant must then be cleaned to remove matter such as sand and dirt. Next, unwanted plants or plant parts are carefully removed. Some crude drugs, such as belladonna, undergo curing, a process that consists either of slow drying or sweating, during which enzymes bring about chemical changes whereby the content of active ingredients is increased. Alternatively, as with cascara sagrada, the drug is carefully stored for a year, during which time unwanted constituents slowly decompose. The final stage in crude - drug production consists of drying, accomplished in air or with artificial heat. Drying aids preservation, stops various chemical reactions that might weaken or destroy the substance, facilitates subsequent grinding, and reduces weight and bulk. Drugs containing volatile constituents are dried at temperatures near freezing. After drying, some drugs (such as belladonna and ipecac) are reduced to a fine powder.

Known as «Hoffman’s drops», ether was first employed as an anesthetic in 1842; chloroform followed soon afterward in 1847. Alkaloid compounds were also isolated from plant sources during this period. Narcotine was obtained from opium by a French pharmacist in 1803 and was followed by morphine in 1806, emetine and strychnine (around 1817), brucine and piperine (1819), colchicines and quinine (1820), nicotine (1828), atropine (1833), cocaine (1860), and physostigmine (1867). Isolation of these potent compounds was a milestone in pharmaceutical progress for three reasons. First, accurate doses could now be administered; this had been impossible previously with crude drugs of unknown and variable composition. Second, toxic effects due to impurities in crude drugs could now be eliminated if pure compounds were used; and third, knowledge of the chemical structure of these drugs led to attempts at laboratory synthesis, whish led in turn to discovery of valuable related compounds.

The modern pharmaceutical industry began in the 19^th century with the discovery of highly active medicinal compounds that could most efficiently be manufactured on a large scale. As these compounds replaced herbal medicines of earlier times, the occurrence and severity of such diseases as pernicious anemia, rheumatic fever, typhoid fever, lobar pneumonia, poliomyelitis, syphilis, and tuberculosis were greatly reduced. Pharmaceutical industry research has greatly aided medicinal progress; of the 66 most valuable drugs introduced since aspirin in 1899, 57 were discovered and then produced in industrial laboratories.