In 780 AD, Pedanios Dioscorides, a Greek pharmaco-botanist, authored the book “De materia medica libre cinque,” which documented approximately 600 plants with medicinal properties.
Galen, a Greek pharmacist-physician, resided in Rome and detailed the process for creating formulas with plant and animal medications, leading to the origin of the term “galenical pharmacy”.
In the 19th century, there were different branches of material medica, which is the study of medical matter. These branches included pharmacology, which focused on drug actions, and pharmacognosy, which covered all aspects of drugs with less emphasis on action. C.A Seydler (Chr. Aenotheus), a medical student in Halle/Saale, Germany, came up with the term “pharmacognosy” by combining the Greek words “pharmakon” (drugs) and “gnosis” (knowledge). In 1815, he named his dissertation “Anaclectica pharmacognosthica”.
Fluckiger defines Pharmacognosy as the application of different scientific fields in order to acquire information about medications, resulting in a comprehensive comprehension of its range.
Pharmacognosy is the scientific study of natural drugs and their components obtained from plants and animals. It involves applying biological, biochemical, and economic principles to understand these substances.
In a recent historical research study, it was found that the book called Lerbuch der Materia medica used the term “Pharmacognosis”. This book was written by J.A. Schmidt and published in Vienna in 1811, with a primary focus on exploring medicinal plants and their attributes.
In the 19th century, chemists began producing various organic compounds with more intricate structures. Some of these compounds had medicinal value, leading to the development of three main drug-related fields: pharmacology, which studies the actions and effects of drugs.
The discussion revolves around two interconnected fields of study concerning medicines, which are pharmacognosy and medicinal chemistry. Pharmacognosy encompasses the understanding of medicines derived from natural sources like plants, animals, and microorganisms. On the other hand, medicinal chemistry is centered on the creation and synthesis of synthetic drugs.In the late 29th century, three significant events transformed the perspective of both the public and scientists towards pharmacognosy. Firstly, classical plant drugs were increasingly utilized to treat various ailments, particularly those that were self-limiting. Secondly, major pharmaceutical manufacturers acknowledged the value of plants known for their medicinal properties, recognizing them as exceptional sources of key constituents that could be used either as new drugs or as prototypes for future medications. Finally, the most groundbreaking development, still in its early stages of drug discovery, is known as recombinant DNA technology, genetic engineering, or more specifically, pharmacobiotechnology. This innovation involves transferring genetic material from one organism to another, enabling the latter to produce a useful drug component in large quantities.
The worth of natural products:
There are four crucial roles that natural sources play in modern medicine. Firstly, natural sources offer various drugs that have immense benefits but are difficult to produce on a large scale through artificial means.
Examples such as alkaloids of the opium poppy, ergot, solanaceous plants, cardiotonic glycosides, antibiotics, serum, and vaccines are all derived from natural sources. These natural compounds can be modified slightly to enhance their effectiveness or reduce their toxicity.
Examples:
Numerous variations of the morphine molecule have been developed, serving as prototypes or models for synthetic drugs that have physiological activities similar to the original morphine molecule. For instance, procaine and similar local anesthetics, such as cocaine, are examples of drugs created based on the morphine molecule’s structure and characteristics.
Natural products are compounds that exhibit little to no activity, but they can be modified through chemical or biological means to produce potent drugs.
Crude drugs are vegetable or animal drugs composed of natural substances and have only undergone collection and drying processes.
Classification: Composition – Botanical, Pharmaceutically, Pharmacological, Pharmacologically – Chemical
Natural substances refer to substances found in nature, including whole plants and their anatomical parts, without changes made to their molecular structure. These substances may come in the form of derivatives or extractives.
Solvent or menstruum refers to a single substance or mixture of substances obtained by the process of extraction, which are considered as the chief constituents. It is a liquid or liquid mixture that removes only those substances which dissolved by extraction.
Marc
?the remaining undissolved portion of the drug after the extraction process is finished.
Geographic source and Habitat
?region where the drug-producing plant or animal grows
Indigenous
?plants that grow in their original countries
Naturalized plants are plants that grow in a foreign land or in a locality other than their native homes.
Preparing rugs for the commercial market:
1. The collection of drugs from cultivated plants guarantees a genuine natural source and a trustworthy product. It is most beneficial to collect the drugs when the plant part containing the active ingredient is at its highest level and when it can dry to offer the best quality and appearance. This is typically the case with flower tops and leaves during active photosynthesis.
?flower should be collected prior to or just about the time of pollination. ?seed should be collected when fully matured. Gums and oleoresin should be gathered during dry weather.
Fruits should be collected near the ripening period.
2. Harvesting – the mode of harvesting varies with each drug produced and with the pharmaceutical requirements of each drug. Mechanical devices such as pickers, mowers, binders, swath, and steel can be used.
3. Drying
Advantages:
– Removes moisture,
– Prevents molding,
– Prevents action of bacteria,
– Fixes the constituents,
– Facilitates grinding and milling, and
– Prevents environmental hydrolysis.
The different types of drying include:
– Air drying
– Artificial Air Drying
For leaves and underground plant parts, they should be placed on screen trays and dried at a temperature of 40-60 degrees Celsius. For drugs containing volatile oil, air drying at a temperature of 35 degrees Celsius is recommended. Large and fleshly roots should be slit or sliced.
Bark, root, rhizome, seed, and some fruits should not be exposed to temperatures higher than 35 degrees Celsius.
Garbling is the final stage in the preparation of crude drugs. It involves removing extraneous matter such as other parts of the plant, dirt, and added adulterants. This process is carried out after the drug is dried but before it is baled or packaged.
5. Packaging, Storage, and Preservation:
- compressed bales
- bags
- paper boxes
- sacks
- barrels
- cans
- casks
- matting foam
The evaluation of drugs involves the identification and determination of their quality and purity. This evaluation can be done through various methods, including organoleptic evaluation, microscopic evaluation, and biologic evaluation. Organoleptic evaluation refers to using the organs of sense to evaluate drugs, including examining the macroscopic appearance of the drug. Microscopic evaluation is important for studying adulterants in powdered plants. Biologic evaluation involves assessing the pharmacological activity of certain drugs for their evaluation and standardization. In this process, organisms are used to evaluate drugs biologically.
The text outlines various organisms used for different experiments and tests, along with their corresponding purposes. Some of the uses include assaying vitamins in bacteria using a microbiological method, assaying yeast/molds for vitamins, and testing for living microscopic animals such as Daphnia using Digitalis. Other uses involve the standardization of goldfish, frogs, and young adult domestic chickens for ergot and diphtheria toxicity. Additionally, pigeons and cats are used in assaying digitalis, rabbits are used for curare alkaloid experiments, dogs are tested for Veratrum viride in antihypertension studies, and humans are observed to assess the effects of various drugs.
Chemical tests are used to identify the active components of natural drugs, involving color reactions and chemical assays. These tests determine the plant’s cellular and non-drug components that act as the active principle. Purification of the main principle can be achieved by determining the saponification number, iodine number, and acid value of fixed oil.
The analysis of drug’s active principle includes examining physical properties like solubility, specific gravity, optical rotation, congealing point, refractive index, melting point, and water content.
DRUG CLASSIFICATION:
1. Morphology deals with the classification of plants and animals.
2. Taxonomy focuses on the natural relationship or phylogeny between plants and animals.
3. Pharmacologic or therapeutic relates to the medicinal properties and therapeutic effects.
4. Chemical constituent involves the activity and therapeutic use of drugs based on their chemical composition.
Chemistry of natural drug products
The individuals – chemical compounds discovered in plants and animals. Active individuals – compounds responsible for the healing effect. 1. Medically active – induce chemical modifications in the medicinal formulation. For instance, a preparation containing tannic acid with iron causes pre-capitation.
The pharmacologically active components of a substance can be either single chemical substances (like sugars, starches, plant acids, enzymes, glycosides, steroids, alkaloids, proteins, hormones, and vitamins) or mixtures of chemical substances (such as fixed oils, fats, waxes, volatile oils, resins, oleoresins, oleo-gum-resins ,and balsams).
The inactive components like starch and coloring matter do not possess any distinct pharmacological effects. However, secondary plant substances that have been extracted, crystallized, and purified may contain inert matter which could impact the absorption or effectiveness of the active components.
The secondary components of medicinal plants are affected by three main factors: heredity (genetic makeup), ontogeny (developmental stage), and environment (soil, climate, accompanying flora, and cultivation method). The research on drug biosynthesis or biogenesis focuses on the biochemical pathways that create the secondary constituents utilized in medications. For instance, research has indicated that amino acids and their fundamental derivatives contribute as precursors in the synthesis of intricate alkaloids.
Below is a list of active constituents and their corresponding drugs:
CARBOHYDRATES AND RELATED COMPOUNDS
These compounds consist of carbon, hydrogen, and oxygen. They can exist as polyhydroxy aldehyde or ketone alcohols.
GLYCOSIDES are compounds that, when broken down through hydrolysis, yield one or multiple sugars.
TANNINS: a collection of intricate phenolic compounds that are able to bind with proteins.
The compounds known as lipids consist of fixed fats and waxes.
5. VOLATILE OILS: These are essential oils that contain the aromatic substances of plants.
1. RESINS AND RESIN COMBINATIONS: substances consisting of resins, oleoresins, oleo-gum-resin, and balsams.
ALKALOIDS are usually basic in character and can exist in nitrogenous crystalline or oily forms.
7. VITAMINS AND VITAMINS CONTAINING DRUGS: These are essential chemical compounds that support the normal growth and functions of animals.
1.7. BIOLOGICS: These are products derived from antigenic matter or antibody preparations that can activate immunity in patients.
1. HERBS AND HEALTH FOODS: These products originate from natural sources and are used by the general public for self-treatment of ailments or improving their overall health. It’s crucial to acknowledge that many of these products do not possess therapeutic benefits and certain ones may even be detrimental.
