Lecture 5. Adulteration, evaluation & plant tissues.pdf

Adulteration Presented by: Marwa Saeed Galaa Goda Department of Pharmacognosy, Faculty of Pharmacy, SCU  Objectives Definition Different types of adulteration Evaluation of drugs  Ad...

Adulteration Presented by: Marwa Saeed Galaa Goda Department of Pharmacognosy, Faculty of Pharmacy, SCU  Objectives Definition Different types of adulteration Evaluation of drugs  Adulteration I. Definition It means debasement of any article. An adulterant is a substance which is cheap and available in large amount. The term 'adulteration' of an article covers a number of conditions, which may be intended or by accident, usually in crude drugs, this practice includes substitution of the original crude drugs partially or fully with other substances which is either free from or inferior in therapeutic and chemical properties.  Adulteration II. Types 1- Sophistication (true adulteration): Addition of an inferior material intentionally (Partial replacement). e.g. 1 - addition of wheat flour/starch + capsicum + curcuma to ginger. e.g. 2 - addition of invert sugar (resulted from hydrolysis of sucrose and consists of glucose and fructose ) to honey. e.g. 3 - Paraffin wax coloured yellow has been used to adulterate the more expensive beeswax.  Adulteration II. Types 2- Substitution: An entirely different article is used instead of the drug (Total replacement) e.g. Arabian senna or dog Senna instead of genuine senna e.g. Supply of cheap cottonseed oil in stead of olive oil.  Adulteration II. Types 3- Admixture: Addition of one article to another by ignorance or carelessness. Admixture may occur through faulty collection i.e. collection of another part of the same plant e.g. Stems, stalks and aerial parts with leaf drugs, or inclusion of soil on an underground organ e.g. Collection of other plants by mistake or as a result of ignorance of collectors, or the co-collection of two similar species.  Adulteration II. Types 4- Deterioration OR spoilage: Destruction of a valuable constituent due to improper storage by moisture, heat, fungi, or insect. So, the drug is rendered unsuitable for human consumption.  Adulteration II. Types 5- Inferiority: Any drug not conforming to standards (containing less amount of active constituents). A natural substandard condition (e.g. where a crop is taken whose natural constituent is below the minimum standard for that particular drug). e.g. volatile oil containing materials like clove, fennel etc., where the dried exhausted material resembles the same like original drug.  Adulteration II. Types 6- Addition of worthless heavy materials: e.g. lead (Pb) shot has occurred in pieces of opium etc (adulterated marijuana). e.g. Addition of powdered olive stones to powdered liquorice and gentian.  Adulteration III. Evaluation of drugs It means determination the quality and purity of the drug. This is done by the following methods: 1- Organoleptic method. 4- Chemical method. 2- Microscopic method. 5- Chromatographic methods. 3- Physical methods. 6- Biological methods.  Adulteration III. Evaluation of drugs 1. Organoleptic method By means of the organs of sense. This includes the macroscopic appearance of the drug (shape, size, color, external markings and fracture), taste and the touch of the drug. 2. Microscopic method By microscopic examination of the histology of powdered drugs. By detecting the key elements as fibers, starch, hairs, Ca ox crystals, ….  Adulteration III. Evaluation of drugs 3. Physical methods: By measuring physical contents/constants such as solubility, optical rotation, refractive index, melting point. Occasionally, specific gravity is of interest. e.g. in case of Clove and Galls, which are considered of good quality if they sink in water 4. Chemical methods: Drugs are usually exposed to strict chemical tests for identification of their active principles. Examples are the color reaction of alkaloids with the Dragendorff’s reagents and the reducing effect of sugars with the Molisch’s and Fehling tests.  Adulteration III. Evaluation of drugs 5. Chromatographic methods: Chromatography refers to a number of sensitive techniques for the separation and identification of drugs (TLC, GC, HPLC,…). 6. Biological methods: By checking the pharmacological activity of certain drugs. Assays on living animals can indicate the strength of the drug. Plant cell types & contents Presented by: Marwa Saeed Galaa Goda Department of Pharmacognosy, Faculty of Pharmacy, SCU  Objectives Plant tissues Cell contents  Flower Plant tissues Plants, like multicellular animals, Leaf Shoot system have organs composed of different tissues, which in turn are composed of cells. Stem Root system Plant tissues are classified into 1. Dermal tissue: 2. Ground tissue 3. Vascular tissue  Plant tissues 1. Dermal Tissues Outer layer of cells which protect the plant from water loss and from fungi and bacteria and regulate gas exchange Dermal tissue includes 1. Epidermis 2. Stomata 3. Epidermal outgrowth (trichomes)  Plant tissues 1. Dermal Tissues The epidermis is coated on the outer side with a waxy cuticle that prevents water loss. The epidermis is covered with pores called stomata that regulate the exchange of gases and water vapor between the outside air and the interior of the leaf. Typically, the stomata are more numerous over the lower epidermis than the upper epidermis. Some leaves have hairs, which are extensions of epidermal cells (Trichomes). pores subsidiary cells  Plant tissues 1. Dermal Tissues Stoma (pl. stomata) The pore is bordered by a pair of specialized parenchyma cells known as guard cells which regulate the size of the opening. There are 4 basic types of stomata, these types are distinguished on the basis of the subsidiary cells surrounding the stomata & their arrangements. A) Anomocytic type B) Anisocytic type C) Paracytic type D) Diacytic type  Plant tissues 1. Dermal Tissues Stoma (pl. stomata) 1. Anomocytic type The surrounding epidermal cells have no special arrangement,, so all the cells are normal epidermal cells without any modification. 2. Anisocytic type The stomata is surrounded by 3 or more subsidiary cells, one of them is distinctly smaller than the others.  Plant tissues 1. Dermal Tissues Stoma (pl. stomata) 3. Paracytic type Each stoma is surrounded by 2 subsidiary cells that have their long axis parallel to the axis of pore. 4. Diacytic type Each stoma is surrounded by 2 subsidiary cells having their long axis perpendicular to the pore.  Plant tissues 1. Dermal Tissues Hairs Hairs are a natural projections outside the epidermal tissues with various shapes, size and characters. They are either glandular or non-glandular. Hairs They are used for the identification of drugs. Non glandular Glandular hairs hairs  Plant tissues 1. Dermal Tissues Non glandular hairs Unicellular Multicellular branched Non branched Branched Non branched uniseriate Simple Stellate biseriate Peltate pluriseriate  Plant tissues 1. Dermal Tissues Glandular hairs External secretory structures Unicellular (rare) Multicellular Branched stalk Non branched stalk  Plant tissues 1. Dermal Tissues Non branched stalk unicellular multicellular Unicellular Uniseriate stalk head with unicellular head Bicellular head biseriate stalk with biseriate head Multiicellular head pluriseriate stalk with multicellular head  Internal secretory structures: 1- Ducts : They may contain gums, resins, mucilage or oil, They may be: Schizogenous ,lysigenous or schizolysigenous. a.Schizogenous: The duct is lined with epithelial cells. The cavity is smooth and regular  b. Lysigenous: The duct is formed by disintegration of cells leaving a space. The cavity is rough and irregular c. Schizolysigenous: The duct is formed by partial disintegration of cells, i.e.. some of the epithelial cells remain intact. 2- Laticifers : These are structures containing latex which are formed of a single elongated (latex cell ) cell or formed by a combination of many cells after breakdown of the separating cell walls (latex vessel), e.g. opium.  Plant tissues 2. Ground Tissues Tissues that are neither dermal nor vascular are ground tissue. They are usually storage, photosynthetic or support cells. Ground tissue includes: Parenchyma tissue Collenchyma tissue Sclerenchyma tissue  2. Ground Tissues 1- Parenchyma cells: They are simple living tissues, having thin cellulosic walls, with intercellular spaces. 2- Collenchyma cells: Simple living tissue with thick cellulosic walls. 3- Sclerenchyma (fibers and sclereides): They are dead cells when mature, e.g sclerides or fibers that have thick lignified secondary walls to provide a mechanical support.  Plant tissues 3. Vascular Tissues These tissues transport water, sugars and other materials through the plant Vascular tissue includes Xylem: It transports H2O & minerals from root to other parts of the plant. Phloem: It is a food conducting tissue.