Pharmacognosy PDF

PHARMACOGNOSY _,..__...,.....______~,.,_._,_ Points to be covered in this topic ---..: □ DEFINITION ---..: □ HISTORY ----.: □ SCOPE AND DEVELOPMENT ---..: □ SOURCES OF DRUGS ---...: □ ORGANIZED DRUGS...........: □ UNORGANIZED DRUGS ...

PHARMACOGNOSY _,..__...,.....______~,.,_._,_ Points to be covered in this topic ---..: □ DEFINITION ---..: □ HISTORY ----.: □ SCOPE AND DEVELOPMENT ---..: □ SOURCES OF DRUGS ---...: □ ORGANIZED DRUGS...........: □ UNORGANIZED DRUGS  INTRODUCTION TO PHARMACOGNOSY (□ DEFINITION l Pharmacognosy is defined as the scientific study of the structural, physical, chemical and biological characters of crude drugs along with their history, cultivation, collection, preparation for the market and preservation. Thus Pharmacognosy literally means to acquire knowledge about drugs. [□ HISTORY l The oldest lmown herbal docum.e nt of China i Pen Tsao written by Shen Nung. 3000BC Pen-t-Sao It believed that Pen Tsao is the oldest document and contain 365 drugs in which 120 emperor, 120 minister and 125 servant drugs. It consists of ma of as many as 800 formulae 1500BC Papyrus and about 700 crude drugs of the plant and Ebers mineral origin. Books were written in Egypt The great Greek physician known as 460 - Hippocrates 'Father of Medicine' deals with the 360BC anatomy & physiology of human beings. The renowned philosopher is well known Aristode for his studies on animal kingdom. (Recorded 500 plants) The ~reek philosopher known for his writings 372 - 37 BC on the plant kingdom.  The Greek physician in 78 AD described OIOAD Dloacorldes several plants of medicinal importance in 'De Materia Medica'. (600 medicinal plants) The Greek pharmacist describes various 131 - 200AD Galen methods of extraction & preparation containing active constituents of crude drugs. 1707-1778 SWede The great syst.ematist classified the plants Linnaeus and introduced the system of naming the plants known as the binomial system which is still followed. (d) DIOICOfdlN (I).... &.--. (MO OIOAO) (1ffl 1771AD) [ □ SCOPE AND DEVELOPMENT l There is continuous increase in the demand of herbal products in many countries due to safe use. India's have introduced Herbal pharmacopoeia's which contains regulatory requirement. Pharmacognosy should posses the basic knowledge of botany and zoology. The knowledge of plant taxonomy, plant breeding and plant genetics is helpful in the development of cultivation technology for medicinal plants. Chemotaxonomy - Based on modern ideas of classification. Plant tissue culture, biogenetic pathway, biochemistry, biochemical engineering put new development in pharmacology. Pharmacognosy is an vital link between· pharmacology and medicinal chemistry.  Pharmacognosy is also an important link between ayurvedic a nd allopathic medicine. The use of herbal drugs is increasing day by day and new plant drugs are fin ding their way into medicine as purified phytochemicals... l Pla:r,.ts- Plant source is the oldest source of drugs. Most of the drugs in ancient times were derived from plants. Almost all parts of the plants are used i.e. leaves, stem, bark, fruits and roots etc. For example leaves of Digitalis purpurea are the source of Digitoxin and Digoxin, which are cardiac glycosides. s. I SOURCES I NO. OF DRUG EXAMPLE Alkaloids:- Nuxvomica, Opium, Cinchona, Ergot, Rauwolfia Glycosides :- Digitalis, Senna, Liquorice Lipid :-Castor oil, Kokum butter 1. PLANT Volatile oil :- Clove, Fennel Tannins :- Myrobalan, Pale catechu Resins:- Colo phony, Jalap, Balsam of tolu Carbohydrate :- Acacia, Guar gum, Pectin Animals- Pancreas is a source of Insulin, used in treatment of Diabetes. Sheep thyroid is a source of thyroxin, used in hypertension. Cod liver is used as a source of vitamin A and D. Cochineal (dried full grown female insects) consists of carminic acid used as colouring agent for foods, drugs and for cosmetic products. s. NO. I SOURCES I OF DRUG EXAMPLE Hormone 1- Thyroid, Conjugated Oestrogen, Insulin, Oxytocin, Vasopressin, Gonadotropins Enzymes ,. Pancreatin, Trypsin, Chymotrypsin, Fibrinolysin, 2. ANIMAL Pepsin, Hyaluronldase Vitamins 1 Cod liver oil,Sharkliver oil 111 Carbohydrate :- Honey Marine Sources- The greater part of the earth surface is covered by seas and ocean, which contains about 5,00,000 species of marine organisms. Many of these compounds have shown pronounced biological activity s. SOURCES I NO. j OF DRUG EXAMPLE Antimicrobial agents:- Cephalosporins, Thelpin, Holotoxin, Variabilin Antiviral Agents :- Ara-a, Avarol, Eudostomin-a, Oppositol AntiparasiticAgent :- DomoicAcid, a-kainic Acid, Bengamide-f, Anticancer agent :- Sinularin, Crassin Acetate, Halitoxin, 3. Marine Asperidol Anticoagulant :- Carrageenan, Fucoidan Cardiovascular Agent :- Eledoisin, Octopamine, Tetramine Saxitoxin, Laminine Anti-inflammatory agent :- Manoalide ,Flexibility, Tetradoxin Plant Tissue Culture- It is in-vitro cultivation of plant cell or tissue under aseptic and controlled environmental conditions, in liquid or on semisolid well defined nutrient medium for the production of primary and secondary metabolites or to regenerate plant. Applications are Production of Phytopharmaceuticals, Biochemical Conversions Clonal Propagation (Micro- propagation), Production of Immobilized Plant Cell and Sources of drugs of natural origin. "' Uid&reniwed r e Bud ~. -· 1.e.. ~ TiIISUct umpo ~ Catus bmed Caius (· ·i CabNpl,fll l ~..t..-CIII F'\dlefa,!l.lnng atu ed ~~iar.w:dnew pbndct (□ Organized and unorga~ized drugs ] Organized drugs Unorganized drugs They are the sources from plants They are the sources of plants and ani1nals. ,animals and minerals. They procured directly from the They are products of plants and above Sources. animals and obtained by extraction, distillation, incision methods. They have proper cellular structures They do not have well defined like, leaves, flowers, fruits, barks, cellular structure like gum, mucilage, roots, woods etc resin etc. They are identified by They are identified by organoleptic morphological characters properties. They are solid in nature. They are solid, semi-solid and liquid in nature. To study their characters, transverse To study their characters, physical section is used for drugs under parameters like density, optical microscope. rotation, viscosity, refractive index, chemical tests are important. ! EXAMPLES OF ORGANIZED DRUGS :- Leaves - Digitalis, Eucalyptus, Mint, Senna, Spearmint, Squill, Tulsi, Vasaka, Coca, Buchu, Hyoscyamus, Belladonna, Tea. Fruits - Fennel, Coriander Hyoscyamus Belladonna Barks - Cascara, Cassia, Cinchona, Cinnamon, Cascara Cinnamon Root -Aconite, Ipecac Aconite Seed - lsapghula, Nux-Vomica Flowering parts Clove, Pyrethrum, Chamomile Pyrethrum Nux-Vomica : EXAMPLES OF UNORGANIZED DRUGS :- ► Dried latex Latex is the milky sap of many plants that coagulates on exposure to air. It is an emulsion or suspension in which the aqueous phase is composed of mineral salts, proteins, sugars, tannins & alkaloids. The oily phase is composed of oils, resins, etc. ✓ Latex is usually produced in laticiferous tissues which may be: Laticiferous cells Laticiferous tubes. Laticiferous vessels (originate from many cells); e.g. Opium ► Dried juices These juices are got from fresh fruit. Mixing these juices with water, milk or soda you'll have unforgettable refreshing drink ► Dried extracts This group includes drugs whi ch are prepared by evaporati ng the aqueous decoction from parts of certain pJ.u1t s or arnnwls. Examples of dried extracts are the following drugs: 1. Agar 2. Gelatin 3. Ga1nbar or catechu Extraction Emulsions Flaxseed Oil Cake Extract (FOCE) Flaxseed Oil Cake Spray drying 180°C Flaxseed oil (10%/20°/o)+Maltodextrin + starch Oil stability PV and TBARS Color Storage time: 4 weeks ALA content Antioxidant activity: ABTS, DPPH... I Total Polyphenolics Content Total Free Amino Acids Content FTIR ► Gums and mucilage Gums and mucilage have similar constitutions and on hydrolysis yield a ; ,.· --- :"' »:,.,.... l. # -~ mixture of sugars and uronic acids..,4I·· "I , It Gums are considered to be pathological ~~... products, while mucilage is formed by ·...... normal metabolism. "4 ~.,.  ► Oleoresins These are found in abundance in the trunk of the trees in the resin ducts or in rhizomes (ginger), fruits ( capsicum) and other parts of the plants. They are insoluble in water, may be semi- solid or solid. Many times they get associated with gums or volatile oils. Example - Copaiba, ginger ► Oleo-gum-resins Oleogum resins are naturally occurring mixtures of resin, volatile oil and gum. The example includes gum myrrh, asafoetida, gamboge, etc. Oleogum resin ooze out from incisions made in a bark and harden.  UNIT-I I ~LA:SSIFICATION (()F DRUGS Points to be covered in this topic..........: □ ALPHABETICAL..........: □ MORPHOLOGICAL......---.: □ TAXONOMICAL - -----.: □ CHEMICAL - -----.: □ PHARMACOLOGICAL ---~: □ CHEMO AND SEROTAXONOMICAL  [ CLASSIFICATION OF DRUGS ) □ ALPHABETICAL In Alphabetical classification, the crude drugs are arranged in the alphabetical order of their English and Latin names. a. Indian pharmacopeia IP 1955 {Latin) b. Indian pharmacopeia IP 1966 (English) c. British pharmacopeia BP (English) d. United States of pharmacopeia USP (English) e. European pharmacopeia (Latin) E..g. for alphabetical order of crude drugs- l "lo l>I.\ 'lo PIIAR \ 1 \I ( )PO f:I. \ 211,.. A - Acacia, Agar, Amla, Ashoka, Aconite. Atjuna. B - Benzoin, Bahera, Bentonite, Beeswax. C - Cinchona, Chirata, Cinnamon, Cumin. D - Dill, Datura, Digitalis E - Ergot, Ephedra, Eucalyptus. ! Advantage - A simple and useful method for books and references like I.P; B.P; U.S.P. Tracking of crude drugs in easy way. Any addition of crude drug is very easy. This system is handling by any person. No need for technical person. ! Disadvantage - 1.This system does not provide any information for the scientific nature of crude drugs. 2. In this classification original source is not clear. 3. Nature of drug is not clear either it is organized or un-organized. □ MORPHOLOGICAL Morphological classification is based on the morphological or external characters of the crude drugs. In this system the drugs are arranged according to the morphological or external characters of the parts of the plants, which is used as a drug like leaves, barks, fruits, seeds, flowers, etc. In this system the crude drugs are further divide as- 1. Organised drug 2. Un-organized drug ► Organised drug- These drugs contains direct plant parts. These drugs represent any part of plant with cellular structure like leaves, roots, bark, seeds etc. ► Un-organized drug - These drugs are not direct parts of the plants but they are prepared from plants. These drugs does not represents any part of the plant without cellular structure like gums, resins, fat, waxes etc. Example of Crude drugs under morphological classification: Seeds - Nux-vomica, Isabgol Leaves - Senna, Digitalis, Vasaka Barks - Cinchona, Kurchi, Cinnamon Roots - Rauwolfia, Aconite, Ipecac Rhizomes - Turmeric, Ginger Flowers - Clove, Saffron Fruits - coriander, fennel Gums - Acacia, Tragacanth Plant's exudates- Black catechu,Aloe.  ! Advantage - This system is easy for the classification of crude drugs. Without knowing the chemical constituents, drugs are classified properly. This type of classification is useful in identifying the adulterants ! Disadvantage - 1. This system does not provide any information regarding chemical constituents and therapeutic use of crude drugs. 2. It is difficult to recognize the organized or un-organized nature of crude drugs. □ Taxonomical Taxonomical classification is purely a botanical classification and is based on the principles of natural relationship among organisms. The drugs are grouped in Kingdom, phylum, order, family, genus and species. Example: Phylum - Spermatophyta Class - Dicotyledons Sub-class - Sympetalae Order - Tubiflorae Family- Solanaceae Genus - Atropa, Hyoscyamus ! Advantage This system provide information about scientific nature of drugs. Majority of characters are easily studied. ! Disadvantage Drugs obtained from non living origin are not classified in this system  □ Chemical Classification In this system of classification, drugs are arranged according to the chemical nature of active constituents of the drugs. This classification is based on the chemical nature of the active constituents or chemical constituents of drugs. CHEMICAL CONSTITUENTS DRUG Alkaloids Vinca, Datura, Lobelia Resins Colophony , Benzoin Tannins Catechu, Ashoka Volatile oils Clove, Eucalyptus Lipids Castor Oil, Beeswax Proteins and enzymes Gelatin, Papain ! Advantage This type of classification is very easy for the study of chemical constituents. On behalf of chemical constituents, medicinal use also studied. ! Disadvantage In this type of classification there is no proper placement for drugs containing two different types of chemical constituents. The drugs of different origin are placed under similar chemical titles.  - - -- ----- □ Pharrnacological This type of classification is based on the therapeutic effect or pharrnacological action of crude drugs. This system of classification can be used for suggesting substitutes of drugs if they are not available at a particular place or point of time. PHARMACOLOGICAL ACTION DRUGS Anti-inflammatory Turmeric, Mint, Aloe Anti-amoebic Kurchi Bark, Ipecac Anti-asthmatic Ephedra, Vasaka, l.obelia Astringent Ashoka, Myrobalan Anti-cancer Vinca, Taxus DRUG ACTING ON G.I.T Carminative Fennel, Cardamom, Mentha Emetic Ipecac Laxative Agar, Isabgol, Banana Purgative Senna, Castor oil RESPIRATORY SYSTEM Expectorant Vasaka, Liquorice, Ipecac Antitussive codeine ! Advantage In this classification if the chemical constituents of the drugs are not lmown they can be classified properly on the basis of therapeutic effects or pharmacological uses. Drugs with differ in mechanism of action but similar in pharmacological action fall in same group. ! Disadvantage This classification is not provide information regarding morphology, taxonomical status, chemical constituents of drugs. Does not provide any information regarding sources of drugs.  □ Chemotaxonomic This system of classification applies Chemistry to systematics. It includes systematic study of the chemical variation between different plant truca. It helps to understand the relationship between constituents in various plants and the trucon they belong to. Certain plant families are even characterized by the presence of certain chemical compounds. Example - Tropane alkaloids are found in Solanaceae, rutin in Rutaceae etc. ! Advantages: It is simple method, in this system location, tracing and addition of the drug is easy. No technical person is required for handling the system. ! Disadvantages: Scientific nature of the drug cannot be identified by this method, whether they are organized or unorganized drug. This system does not help in distinguishing the drugs of plant, animal and mineral source. ( Original source is not clear) □ Serotaxonomical classification Serology is defined as that portion of biology, which is concerned with the nature and interactions of antigenic material and antibodies. Smith (1976) defined it as "the study of the origins and properties of antisera" When foreign cells or particles (antigens) are introduced into an organism, antibodies are produced in the blood (antiserum).  ! Advantages: It is simple method, in this system location, tracing and addition of the drug is easy No technical person is required for handling the system. ! Disadvantages: Scientific nature of the drug cannot be identified by this method, whether they are organised or unorganised drug. This system does not help in distinguishing the drugs of plant, animal and mineral source.  UNIT-I. ~,,--- Ir ," ' , I II j I ', I I!:, il - - I.. ,DRUGS OF NATURAL ORIGIN' Points to be covered in this topic.......... □ ADULTERATION OF DRUG.......... □ EVALUATION ► Organoleptic method ► Microscopic method ► Physical method ► Chemical method ► Biological method.......... □ QUANTITATIVE MICROSCOPY........... □ LYCOPODIUM SPORE METHOD.......... □ LEAFCONSTANTS......... □ CAMERA LUCIDA.  QUALITY CONTROL OF DRUGS OF NATURAL ORIGIN □ ADUtTERATION OF DRUGS Adulteration is broadly defined as admixing or substitution of original or genuine drugs with inferior, defective or otherwise useless, worthless or harmful substance. It is a practice of substituting original crude drug in part or whole with other similar looking substances. It also occurs due to spoilage and deterioration of drugs. The drug is said to be adulterated if it fails to confirm to the compendia! standards of quality, purity and strength. Adulteration means deterioration, admixture, sophistication, substitution, inferiority and spoilage. ! Deterioration : It refers to the change caused in drug quality. ! Admixture : It refers to addition of one or more items to the drug either due to ignorance or carelessness. ! Sophistication : Intentional adulteration meant for material gains e.g Crocus sativus is adulterated with Carthamus tinctorius. ! Substitution : Some other drug is presented as the original drugs e.g Strychnos nux blanda and S. potatorum instead of S. nux vom ica. ! Inferiority : It Refers to any substandard drug and spoilage is due to the attack of microorganisms. Deterioration · e  Admixttle Inferiority Sophistication ~~ ' , Com substitution 1----.-~ Altentic ctUtJ.__._.. lmpirmeM '--iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii.;;;;;t/ ~!!!!!!!!!!!!!!!!!!!!!!~ 1 of qualify adutteration) " { Spoilage Md deterioration Substaxlard'aj(jterated d1JJ ► TYPE OF ADULTERATION ✓ Substitution with substandard commercial varieties: The adulterants used here may resemble original crude drug by morphological, chemical or therapeutic characters, but are substandard in nature and hence cheaper in cost. ✓ Substitution with superficially similar inferior drugs: These inferior drugs used may or may not have any chemical or therapeutic value as that of original natural drug. Due to their morphological resemblance to authentic drug, they are marketed as adulterants. ✓ Substitution with artificially manufactured substances: It has been also observed that substances artificially prepared to resemble original drug are used as substitutes. Generally, this practice is followed for much costlier drugs. ✓ Substitution with exhausted drugs: In this type, the same drug is admixed but is devoid of any medicinally active constituents as they are already e~acted out.  This practice is more common in case of volatile oil containing drugs like fennel, clove, coriander, caraway etc. Sometimes, naturalcharacters of exhausted drugs like colour and taste are manipulated by adding other additives and then it is substituted. ✓ Besides these common practices: sometimes other methods are employed like use of synthetic chemicals to enhance the natural character ✓ Presence of vegetative matter from the same plant: Sometimes, the other miniature plants growing along with medicinal plant are mixed with drug due to their resembling colour, odour and in some cases constituents. ✓ Harmful adulterants: Several times, the wastes from market are collected and admixed with authentic drugs. This is particularly noticed for liquids or unorganized drugs. ✓ Adulteration of powders: Besides the entire drugs, the powdered forms are frequently found to be adulterated. □ DRUG EVALUATION Drug evaluation means confirmation of its identity, determination of its purity and quality and detection of nature of adulteration. It has been established that chemical constituents of a plant species vary with respect to climatic and seasonal changes. Different methods used are - 1. Organoleptic evaluation 2. Microscopic evaluation 3. Physical evaluation 4. Chemical evaluation 5. Biological evaluation  ! Organolep tic evaluation It refers to the evaluation of drug through gross morphology like size and shape of leaves, flower, bark, seed, fruits, woods etc and sensory profile like colour, odour, taste, touch and texture of plant. Organoleptic evaluation means conclusions drawn from impressions on organs of senses. ► leaves Type of leaves. Simple and compound leave _ __..-=--=--=--=--=-.---- ------- -- Shape of leaves Oval, Oblong, Round, Cordate, Linear, Lanceolate, Ovate, Obovate. Type of leaf apex Acute, Acuminate, Obtuse, Recurred Type of leaf margin Entire, Serrate, Crenate, Sinuate, Dentate Type of leaf base symmetrical , Asymmetrical, Cordate, Decurrent Type of venation of Parallel, Reticulate, Palmate, Reticulate L.___4'1.--.. ~f/ ~~ ' ~ ~ Stcu-ahas,.cl O al Elliptical Deltoid Fig. Shape of leaves 8 J t Photo1 Photo 2 Simple leaf Compound leaf ' Fig. Type of leaves ► Flowers Type of inflorescence :- Solitary, Cymose, Raceme, f w Solitary Raceme Corymb Spike.r c.[ ~ - T. Capitulum ~, Spadix Spike, Corymb, Capitulum.... -~... T r.... ~ ~ p ·V Umbel Compound umbel Unlparous cyme Dichasial cyme ► Bark a z Shape of bark.·- Flat, Curved, Recurred, Channeled quill, Double quill, Compound quill m e J ~ F\\ Flat Curved Recurved Channelled Quill Double quill Compound quill ► Seed Type of seed :- Globular, Spherical, Oval, Planoconvex, Reniform t- -~ ~1 ,# ,~ ·~-,-- FenugrNk Cilantro/ corlan~, ~inut Kabull chkkp~.a/ Corn pr!Nnzo be.an ,. -E-...~. Yellow musurd ~ Cumin Cow~.1 --~.. "~..... Sorshum Field pea C.r w v C.nol..-4' J$ ~ G1Hn1ram/.., ~dpepper c.,om muna be n Rice Wild sunflowef ~ --~t ~.i}:,~ ·1.v· WhltepoPP'f ~ Blackc.umln ~~ Wheat Bladeye oowpea Chk pea  ► Odour and taste of somedrugs Camphor-aromatic odour, Ginger, capsicum-pungent odour Cardamom- green colour fruit Cinnamon- brown color bark Fractured surface- cinchona Lemon-sour taste Honey-sweet ! Microscopic evaluation This evaluation is also known as anatomical evaluation or histological evaluation of crude drugs. This method can be used to identify the organized drug in powdered form by their histological characters or anatomical cell or tissue arrangements. This evaluation also covers study of the constituents by application of chemical method to small quantities of powdered drug. Microscopic evaluation include ✓ Leaf constants ✓ Types of stomata ✓ Calcium oxalate crystals ✓ Trichome ✓ Stomata: Stomata are the minute epidermal opening present in the aerial part of the leaves. Mainly it helps in gaseous exchange. It consists of two kidney shaped cells with middle tiny pore. Broadly four types of stomata viz. stomoos:,en Moss type, Gymnospermous, Gramineous type and Dicotyledonous type. e.g. - Paracytic- Senna, Coca Diacytic- Spearmint, Peppermint Anomocytic - Buchu, Clove, Opium Anisocytic - Vinca, Belladonna Actinocytic - Blue berry, Sunken -ephedra ✓ Trichome: Trichomes are hair-like components, found on the epidermis of several types of plant stems and leaves. Sometimes in seeds also observed (Nuxvomica). Generally they are colorless under microscope but lignified in case of Nux von1ica. Covering trichomes (Unicellular and multicellular), glandular and hydathodes. Multicellular covering trichomes are two types namely branched and unbranched. Glandular trichomes: They are two types namely Unicellular and multicellular Examples: Unicellular covering trichomes: Senna, Nuxvomica, Cannabis, Lobelia Multicellular unbranched trichomes: Datura, Digitalis, Belladonna Multicellular Branched trichomes: Artemisia, Pyrethrum Unicellular glandular trichomes: Betel, Vasaka, Piper Multicellular glandular trichomes: Digitalis Hydathodes: Present in Piper betal ! Chemical evaluation It involves both qualitative and quantitative determinations of their active principles. In this method characteristic qualitative chemical tests are employed to identify crude drugs and their constituents. Quantitative chemical assays are used to determine their quality and purity This method of evaluation is now widely used in the examination of crude drugs for its accuracy and reliability Generally it is completed in two parts - 1. Preliminary phyto-chemical screening 2. Particular chemical test for different phyto-constituen Examples For alkaloids- Dragendroff's test, Mayer's test, Wagner's test For cardiac glycosides- Legal test, Baljet test, Killer Killiani test For steroids- Liebermann- Burchard reaction For carbohydrates- Molish test, Fehling solution test etc. ! Biological evaluation This Biological evaluation of crude drugs is very useful in determining the potency of drug sample. In this type of evaluation the extent of pharmacological activity of the drug or its constituents is taken as the basis of quality. Since living organisms or their isolated living tissues are used, this method is also called the biological method or bioassay. Many drugs, particularly the antibiotics, toxins and toxoids and also vitamins are assayed by this method. Examples 1. Analgesic activity is evaluated by Hot plate method, Tail flick method 2. Antipyretic activity is evaluated by Yeast induced pyrexia method 3. Anti-inflammatory activity is evaluated by Carageenan induced rat paw edema ! Physical Evaluation The Physical evaluation of crude drugs is accomplished by the determination of various physical constants using various physicochemical techniques. The common physical constants used to evaluate crude drugs and their extracted chemical principles include specific gravity (particularly of the fats and volatile oils and some crude drugs as Nutgalls), optical rotation (of some alkaloids in solution and of volatile oils), refractive index (particularly of the volatile and fixed oils), melting points (of isolated alkaloids and their derivatives), ash values (of most crude drugs) and extractive values (of most crude drugs). Moisture content Limit for moisture content:  ALOES Not more than 10% DIGITALIS Not more than 05% ERGOT Not 1nore than 08% ACACIA Not more than 15% STARCH Not more than 15% Ash content Physiological ash : Derived from plant tissue itself Non physiological ash : Consist of residue of extraneous matter sand , soil etc. adhering to the herb itself Total ash: Physiological Ash+ Non physiological Ash Fluorescence analysis HERBAL DRUG NATURE OF FLUORESCENCE CINCHONA Purple blue GENTIAN ROOT Whitish blue IPOMOEA Deep purple-violet QUASSIA Whitish blue RHUBARB Violet □ QANTITATIVE MICROSCOPY OF CRUDE DRUGS ► Lycopodium spore method: This method is use to identify the crude drugs when the chemical and physical methods ar~ inapplicable. This method is also useful to detect the adulteration present in the crude drugs containing starch grains. Examples: The percentage purity of an authentic powdered ginger is calculated using the following equation: % purity= N x W x 94000 x 100 / S x M x P Where, N = Number of characteristic structures (starch grain) in 25 fields. W = Weight in mg oflycopodium taken. S = Number oflycopodium spores in the same 25 fields. M = Weight in mgof the sample, calculated on the basis of sample dried at 105°C. P = 2,86,000 in case of ginger starch grains powder. Significance: Determination of foreign organic matter. Determination of percentage purity of drugs. Detection of adulterant ► Leaf constants: 1. Stomal Index: It is the percentage proportion of the number of stomata to the total number of epidermal cells. Stomata} number varies considerably with the age of the leaf but stomatal index is relatively constant for a given species. Example: Atropa- 20.0-23.0 Oower epidermis) 2. Stomata number Stomata! number is defined as the average number of stomata per sq mm of epidermis of the leaf. 3. Palisade ratio Numbers of palisade cell under each epidermal cell 4. Vein islet number Number of vein islet per sq. mm of the leaf surface between midrib and margin 5. Vein-termination Number ofveinlettermination per sq. mmof the leaf between midrib and margin ► Camera Lucida: It is an optical device or instrument in which rays oflight are reflected by a prism to produce an image on a sheet of paper, from which a drawing is made. It works on simple optical principle reflecting beam of light through a prism and a plane mirror. There are two types of camera lucida namely Swift Ives and Abbe model camera lucida. The Abbe camera lucida consists of a prism fitted over the eyepiece of the microscope. A side arm is carrying a mirror that supported vertical over the tracing paper In Swift Ives Camera lucida the plane mirror is replaced by a small right angled prism. It is a small size and fitted over the eyepiece of the microscope with a screw. Principle: During use, the light from the drawing board is reflected by the plane mirror into the prism and further reflected into the observer's eye that is seeing the drawing paper and the pencil in the direction of the stage of the microscope. The prism has a small opening through which the observer is seeing the image of the object. As a result, the superimposed image then conveniently traces the microscopic object