Knowledge of drugs or pharmaceuticals



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Pharmacognosy, which literally means a knowledge of drugs or pharmaceuticals, has been part of the healing arts and sciences since mankind first began to treat illnesses.

  • Pharmacognosy, which literally means a knowledge of drugs or pharmaceuticals, has been part of the healing arts and sciences since mankind first began to treat illnesses.

  • Today, pharmacognosy is a highly specialized science that represents one of the major disciplines of pharmaceutical education.

  • During the past few years, as a result of the intense concern with all aspects of ecology, there has been a renewed interest in so-called `natural` foods and drugs. The availability of an extremely wide variety of these products, ranging from fenugreek tea to ginseng chewing gum, has stimulated the public to learn more about them.



*From this humble beginning, medicine and pharmacy gradually emerged along separate paths: the physician diagnosed the ailment and prescribed the remedy,

  • *From this humble beginning, medicine and pharmacy gradually emerged along separate paths: the physician diagnosed the ailment and prescribed the remedy,

  • and the apothecary or pharmacist specialized in the collection, preparation, and compounding of the substance.

  • *The term materia medicia, meaning medicinal materials, was synonymous with the substances and products derived from natural sources and was employed by the physicians of that era.

  • * The term pharmacognosy was introduced by C.A.Seydler, a medical student in Halle/Saale, Germany, in 1815 (A small work by Seydler entitled Analecta Pharmacognostica)

  • * This name is formed from two Greek words, pharmakon, drug!, and gnosis, knowledge.



* Pharmacognosy may be defined as `an applied science that deals with the biologic, biochemical, and economic features of natural drugs and their constituents.` It is a study of drugs that originate in the plant and animal kingdoms. Modern aspects of the science include not only the crude drugs but also their natural derivatives.

  • * Pharmacognosy may be defined as `an applied science that deals with the biologic, biochemical, and economic features of natural drugs and their constituents.` It is a study of drugs that originate in the plant and animal kingdoms. Modern aspects of the science include not only the crude drugs but also their natural derivatives.

  • 1-Digitalis leaf (Digitalis lanata folium) and its isolated glycoside, digitoxin,

  • 2-Rauwolfia root (Rauwolfia serpintina radix) and its purified alkaloid, reserpine,

  • 3-Thyroid gland with its extracted hormone, thyroxin, are all part of the subject matter of pharmacognosy.

  • *Natural and Synthetic Substances :

  • Distinguished by chemical and physical tests.

  • In some instances drug constituents have been partially replaced in commerce by synthetic

  • compounds of identical chemical structure and therapeutic properties;



1-For example, natural camphor is obtained from the camphor tree by steam distillation; it is

  • 1-For example, natural camphor is obtained from the camphor tree by steam distillation; it is

  • dextrorotatory in its reaction to polarized light. In contrast, synthetic camphor may be

  • manufactured by either of two methods: by total synthesis from vinyl chloride and

  • cyclopentadiene (a completely synthetic process) or by semi synthesis from pinene derived from

  • pine sumps (not entirely a synthetic process but a chemical modification of a natural product).

  • Synthetic camphor is racemic and can be differentiated easily from the natural form.

  • 2- Epinephrine, caffeine, codeine, ephedrine, menthol, penicillin, and other chemicals may also

  • be partial or total synthesis. They are considered a definite part of pharmacognosy.





The term crude, as used in relation to natural products, means any product that has not been advanced in value or improved in condition by shredding, grinding, chipping, crushing, distilling, evaporating, extracting, artificial mixing with other substances or by any other process or treatment beyond what is essential to its proper packing and to the prevention of decay or deterioration pending manufacture.

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