Classification of drugs

classification of drugs from natural origin
alphabetical, morphological, pharmacological, chemical, taxonomical, chemotaxonomical, serotaxonomical classifications are included in the presentation

1. CLASSIFICATION OF DRUGS

2. Introduction IN ORDER TO FOLLOW THE STUDY OF THE INDIVIDUAL DRUGS, ONE MUST ADOPT SOME PARTICULAR SEQUENCE OF ARRANGEMENT, AND THIS REFERRED TO A SYSTEM OF CLASSIFICATION OF DRUGS. A METHOD OF CLASSIFICATION SHOULD BE : SIMPLE EASY TO USE FREE FROM CONFUSING

3. Overview BECAUSE OF WIDE DISTRIBUTION, EACH CLASSIFICATION HAS ITS OWN MERITS AND DEMERITS. ALPHABETICAL CLASSIFICATION MORPHOLOGICAL CLASSIFICATION CHEMI ICAL CLASSIFICATION PHARMACOLOGICAL CLASSIFICATION TAXONOMIC AL CLASSIFICATION CHEMOTAXONOMI CAL CLASSIFICATION SEROTAXONOMICAL CLASSIFICATION

4. ALPHABETICAL CLASSIFICATION Alphabetical classification is the simplest way of classification of any disconnected items. Crude drugs are arranged in alphabetical order of their Latin and English names (common names) or sometimes local language names (vernacular names) Amla Brahmi Coriander Datura Ergot Fennel Fenugreek Ginger Gokhru Henna Isabgol Jalap Kantakari Liquorice Mentha Nux vomica Opium Piper Psoralea Quassia Rauwolfia Sankhpushpi Senna Tragacanth Uncaria Vasaka Vinca Withania Xanthan gum Yam Yohimbine Zoranol

5. Indian pharmacopoeia Ayurvedic Pharmacopoeia of India British pharmacopoeia British herbal pharmacopoeia European pharmacopoeia United states pharmacopoeia and National Formulary Some pharmacopoeias and reference books which classify crude drugs according to alphabetical systems are as follows :

6. 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) Advantages Disadvantages It is simple method, in this system location, tracing and addition of the drug is easy. This method provides quick reference search of the crude drug.

7. 2. MORPHOLOGICAL CLASSIFICATION Here the crude drugs are arranged (Grouped) according to the part of the plant or animal represented into organized (Cellular) drugs and unorganized ( Acellular ) drugs. Organized : Drugs are the direct parts of the plant and having cellular structure. Examples of Organized drugs Entire : Shankhpushpi, Brahmi, Punarnava, Neem, Giloy Leaf : Vasaka, Digitalis, Mint Fruit : Fennel, Coriander, Amla, Capsicum Flower : Dhatakipushpa Root : Rauwolfia, Ashwagandha Seed : Mustard, Almond, Methi, Linseed Rhizome : Turmeric, Ginger Wood : Sandalwood, Red Sandalwood Bark : Cinnamon bark, Willo w Bark, Arjuna Bark, Ashoka Bark

8. UNORGANIZED DRUGS Drugs are the products of plant, animal and mineral sources like- dried latex, dried juice, dried extracts, gums, resins, fixed oils and fats, waxes, volatile oil, animal products, minerals (Solids, liquids, semi solids etc.) Latex: Opium Juice: Aloe, Amla, Giloy Gums : Acacia, Tragacanth Extract: Black Catechu, Pale Catechu Resin : Asafoetida, Guggul Wax : Bees wax Volatile oil : Cinnamon oil, Tea tree oil

9. Difference between organized and unorganized drugs : Organized drugs Unorganized drugs Part of plants or animals Obtained from parts of plants Well defined structure Not well defined structure Solid in nature It can be solid, semisolid or liquid in nature Morphology and microscopic study can be perform for evaluation Microscopy can not be performed, instead chemical tests can be performed Examples : Leaves – Senna, Mint Bark – Cinchona, Cinnamon Gum – Acacia, Tragacanth Dried juices - Aloe

10. Advantages This system of classification is more convenient for practical study especially when the chemical nature of the drug is not clearly understood. This type of classification is very useful in identifying the adulterants used. Disadvantages It does not give an idea about chemical constituents and therapeutic uses of drug. During collection, drying and packing morphology of the drug changes ,then they are difficult to study

11. CHEMICAL CLASSIFICATION Crude drugs are divided into different groups according to the chemical nature of their most important constituent present in the drug to which the pharmacological/therapeutic activity of drug is attributed. Alkaloids - Datura, Vasaka, Vinca, Lobelia, Tea Glycosides - Cascara, Senna, Digitalis, Aritha, Liquorice, Aloe Tannins - Catechu, Myrobalan, Ashoka, Amla, Volatile oil - Clove, Eucalyptus, Cinnamon, Fennel, Cumin, Tulsi, Ajowan Lipids - Castor oil, Beeswax, Arachis oil, Almond oil, Cocoa butter Carbohydrates and derived products - Acacia, Agar, Honey, Tragacanth, Starch, Gum and Resins -Colophony, Asafoetida, Cannabis, Ginger, Turmeric, Guggul, Acacia, Tragacanth Proteins and enzymes - Gelatin, Papain, Collagen, Casein

12. Advantages Disadvantages known chemical constituents are easy to study the drug. popular approach for phytochemical study This type of classification makes no proper placement of drugs containing two different types of chemicals. E.g.: Certain drugs are found to contain alkaloids and glycosides (Cinchona), Fixed oil and volatile oil (Nutmeg) of equal importance together and hence it is difficult to categorize them properly

13. 4. PHARMACOLOGICAL CLASSIFICATION Here, the crude drugs are grouped according to pharmacological activity of their main active constituent or therapeutic uses. This system of classification involves the grouping of crude drugs according to the pharmacological activity of their active constituents or their therapeutic uses, regardless of their morphology, taxonomical status, or chemical relationships. The drugs differing in mechanism of action but having same pharmacological effects are also grouped together, e.g. bulk purgatives, irritant purgatives, emollient purgative

14. Antidiabetic drugs : Methi seeds, Gymnema leaf, Bitter gourd Antihypertensive drugs : Rauwolfia Anti-inflammatory drugs : Boswellia gum resin, Guggul, Wintergreen oil, Eucalyptus leaf, Menthol, Capsicum CNS stimulants : Coffee, Tea, Cocoa Cardio tonics : Digitalis leaf, Squill Anti-malarial drugs : Cinchona bark, Artemisia Anti-cancer (antitumor) drugs : Vinca, Taxus, Curcumin Immunomodulatory agents : Ginseng, Ashwagandha(Withania), Giloy(Galo), Punarnava, Aloe, Tulsi Purgative drugs : Cumin seeds, Fennel, Mentha, Senna

15. The special advantage is that if even chemical constituents of the crude drugs are not known they can be classified properly on the basis of therapeutic or pharmacological effect Advantages : Disadvantages : Many herbal drugs possesses more that one pharmacological activity, in that case it’s difficult to classify one single drug into category. Example : leaves of neem used in skin disorders Fruits in diabetes Oil as anti-bacterial

16. 5. TAXONOMICAL CLASSIFICATION In this classification the crude drugs are classified according to kingdom, subkingdom, division, class, order, family, genus and species as follows : Example of Nuxvomica ( Strychnos nuxvomica) Kingdom – Plantae Subkingdom - Tracheophytes Division - Angiosperm Class – Dicotyledon Order – Gentiales Family – Loganiaceae Genus – Strychnos Species - Nuxvomica

17. It will provide proper idea about species and varieties of the organism. ADVANTAGES DISADVANTAGES This system does not correlate in between the chemical constituents and biological activity of the drugs.

18. 6. CHEMO TAXONOMICAL CLASSIFICATION This system of classification relies on the chemical similarity of a taxon, i.e. it is based on the existence of relationship between constituents in various plants. There are certain types of chemical constituents that characterize certain classes of plants. E.g. : Tropane alkaloids generally occur in most of the members of Solanaceae family. (Datura, Withania, Belladonna, Tobacco, Duboisia) E.g. : Volatile oils occur in the members of Umbelliferae (Fennel, Cumin, Dill, Caraway, Coriander, Anise)

19. 7. SEROTAXONOMICAL CLASSIFICATION The serotaxonomy can be explained as the study about the application or the utility of serology in solving the taxonomical problems. Serology can be defined as the study of the antigen–antibody reaction. Antigens are those substances which can stimulate the formation of the antibody. Antibodies are highly specific protein molecule produced by plasma cells in the immune system. Protein are carriers of the taxonomical information and commonly used as antigen in serotaxonomy. When foreign cells or particles (antigens) are introduced into an organism, antibodies are produced in the blood (antiserum).

20. The classification is based on similar plants by means of differences in the proteins they contain. It expresses the similarities and the dissimilarities among different taxa, and these data are helpful in taxonomy. It determines the degree of similarity between species, genera, family, etc., by comparing the reaction with antigens from various plant taxa with antibodies present against a given taxon. Serology helps in comparing nonmorphological characteristics, which helps in the taxonomical data. This technique also helps in the comparison of single proteins from different plants.