Pharmacog 2

• Pharmacognosy, which literally means a knowledge of drugs or pharmaceuticals, has been a part of the healing arts and sciences since mankind first began to treat illnesses.
• Pharmacognosy is an applied science that deals with the biologic, biochemical, and economic features of natural drugs and their constituents.
• Crude drugs are vegetable or animal drugs that consist of natural substances that have undergone only the processes of collection and drying.
• Crude drugs are used infrequently as therapeutic agents; more often, their chief principles are separated by various means and are employed in a more specific manner.
• These principles are known as derivatives or extractives.
• Regardless of whether the derivative or extractive is a single substance or a mixture of substances, it is considered the chief constituent of the drug.
• The process of drug extraction is a generally accepted method of obtaining these active principles.
• Extraction removes only those substances that can be dissolved in the liquid or liquid mixture referred to as the solvent, or, more specifically, as the menstruum.
• The undissolved portion of the drug that remains after the extraction process is completed is called the marc.
• The product of the extraction process is known as the extractive and is usually a mixture of substances.
• Active constituents are compounds that are responsible for the therapeutic effect.
• Semi-synthetic drugs are derived from chemical modification of a natural constituent, for example, Camphor from pinene in pine trees.
• An Official Drug is listed in pharmacopeia.
• Drying also removes bulk, converting the drug to a form that is more convenient for handling.
• Naturalized plants are those that grew in foreign lands other than their native countries.
• A Non-official Drug has never appeared in official pharmacopoeia.
• Indigenous plants are those that grow in their native countries.
• Preparation of crude drugs involves collection, which is the process of selecting the species to cultivate.
• Harvesting is the process of gathering the samples at a specific and proper period or season, which can be done manually or mechanically.
• Natural drugs are obtained from nature, for example, Camphor from Camphor Plants.
• Natural substances are found in nature that comprise whole plants and herbs.
• Drying is the removal of moisture, which prevents bacterial and fungal growth and facilitates milling and grinding.
• Totally synthetic drugs are manufactured from chemical synthesis.
• Pharmacopeia is a book containing directions for the identification of samples and the preparation of compound medicines and publishing by the authority of a government or medical or pharmaceutical society.
• Chemical evaluation of crude drugs involves isolation, purification, and identification.
• Physical evaluation of crude drugs includes moisture contents, specific gravity, optical rotation, refractive index, melting point, viscosity, and solubility.
• Garbling is the final step in the preparation of crude drugs, a physical process of removing extraneous material.
• Curing is a special drying process that enhances the properties of the active ingredient, for example, Cascara sagrada reduced glycosides.
• Packaging, storage, and preservation are for the protection and marketability of crude drugs.
• Organoleptic or morphological evaluation of crude drugs includes color, odor, taste, size, shape, and special features like touch and texture.
• Preservation of crude drugs can be done by exposing the drug to 65 ° C temperature, which is the simplest form in preventing insect attacks and other forms of destruction.
• Methyl Bromide and Chloroform (Carbon Tetrachloride) are used in the fumigation of large lots of crude drugs.
• Pharmacologic classification of drugs is based on therapeutic activity, for example, Hallucinogens, Anticholinergic.
• Chemical classification of drugs is based on the chemical class of the constituents.
• Morphologic classification of drugs is based on the part used, for example, Root crop, seed gums, etc.
• Biological evaluation of crude drugs assesses antifertility activity and anti ulcers activity.
• Taxonomic classification of drugs is based on the natural relationship or phylogeny, for example, Plant Families: Rutaceae.
• Microscopic evaluation of crude drugs detects cellular tissues, trichomes, stomata, starch granules, and calcium oxalate crystals.
• Secondary Constituents: Influenced by heredity, ontogeny, and environmental factors, they can produce variations in secondary plant constituents.
• History: Papyrus Ebers, Hippocrates, Aristotle, Theophrastus, Dioscorides, Galen, Shen Nung Pen Ts’ao, Scheele, Serturner, Pelletier & Caventou are important figures in the history of pharmacognosy.