Botany Semester 4 extraction process.pptx

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1. Extraction process

2. Extraction : It defined as the treatment of the plant or animal tissues with solvent , whereby the medicinally active constituents are dissolved and most of the inert matter remains undissolved. The solvent used for extraction is known as “ menstruum.” And the inert insoluble material that remains after extraction is called “marc”.

3. 1. Infusion 2. Decoction 3. Maceration 4.Percolation 5.Digestion Various processes for extraction

4. 1. Water : Water is a solvent for protein , colouring matter, gums, glycosides, sugars, alkaloidal salts, enzymes, many organic acids and most of the organic salts. Waxes ,fats ,fixed oils and most alkaloids are insoluble in water. Solvent used in extraction process

5. It is cheap. Is has a wide solvent action. It is non-toxic. It is non-inflammable . Disadvantages: Water helps in growth of moulds and bacteria. Hence ,some preservative is needed during extraction of crude drugs. Water causes hydrolysis of many substances. Advantages of water:

6. Large amount of heat is required to concentrate the aqueous preparation than non-aqueous preparation. 2 . Alcohol : Alcohol is solvent for alkaloids , glycosides, volatile oils and resins. Alcohol does not dissolve albuminous matter ,gums ,waxes, fats, fixed oils and sugar.

7. The mould and bacteria cannot grow in a solution in which alcohol concentration is 20% or more. It is neutral and hence extraction products obtained from it are compatible with other products. A small amount of heat is required to concentrate the alcoholic preparation. It is non-toxic in the concentration mostly present in the preparations. Disadvantages : The preparation becomes costly when alcohol is used as solvent for extraction of API. Advantages

8. Infusion : It consist of pouring water over the drugs and Then allowing it to keep in contact with water for the stated period ,usually 15 minutes ,with occasional stirring and finally filtering off the liquid. Processes used for extraction

9. Drug is placed at the bottom of the pot. Water is added and it is well stirred 3 or 4 times. Infusion can also be prepared by enclosing the drug in a muslin bag and then suspending it just below the level of the water in a beaker. Stirring is not required bcz water slowly circulate due to increase in specific gravity of water near the drug. When water comes in contact with the drug ,it dissolves API and become heavier. Apparatus :

10. Heavier layer come down and their place is taken by fresh water. As a result ,there is slow circulation of water & hence stirring is not required. Special pots known as ‘ infusion pot’ used for preparation of infusion . There are two type of infusion: 1. Fresh infusion 2. Concentrated infusion

11. A fresh infusion is an aqueous solution of active constituents of a vegetable drug prepared by the process of infusion . e.g fresh infusion of Quassia. Coarse powder is used Water is used as menstruum bcz it has more penetration power & dissolves the API. Pharmacopoeia states that fresh infusion should be used within 12 hrs after its preparation bcz it gets spoiled due to fungal or bacterial growth. Fresh infusion :

12. It is prepared by double or triple maceration process. Conc. Infusions are 8 times stronger than fresh infusion. Alcohol in the conc of 20-25 % is used as menstruum. Hence these preparation can be stored for longer period due to preservatives action of alcohol. E.g conc infusion of Quassia & conc compound infusion of chirata. Concentrated infusion

13. Drug is boiled with water for stated period usually 10 minutes. After boiling ,the liquid is strained and water is passed through the content of the strainer to make the required volume. This process is mainly used for vegetables drugs of hard and woody nature having thermostable water soluble constituents. Decoction process:

14. Various types of maceration process: 1 . A process for tincture made from organised drug e.g. roots,stem,leaves etc. This process is called ‘ Simple Maceration’. 2 .A process for tincture made from unorganised drugs such as oleo resins and gum resins. This process is known as ‘ Maceration with Adjustment’. 3. Process for concentrated preparations which includes both ‘ Double maceration’ and ‘Triple maceration’. Maceration process :

15. Apparatus: A wide mouth bottle or any other container which can be well stoppered is used for maceration process. A closed container is essential to prevent the evaporation of menstruum which is mostly concentrated alcohol. No adjustment in volume is made. 1. Maceration process for tincture made from organised drugs (Simple Maceration).

16. Drug is placed with the whole of the menstruum in a closed vessel for seven days. During this period shaking is done occasionally. After seven days ,the liquid is strained and marc is pressed. The expressed liquid is mixed with strained liquid . It is then filtered to make a clear liquid. The final volume is not adjusted. Method:

17. 1. Tincture of Orange . 2 .Tincture of Lemon. 3 .Tincture of Squill. 2. Maceration process for Unorganised Drugs or Maceration with Adjustment. Method : Unorganised drug is placed with 4/5 th of the menstruum in a closed vessel for period of 2-7 days. Shaking is done occasionally. After stated period ,liquid is filtered and final volume is made up by passing remaining 1/5 t h of mentruum. The marc is not pressed. Example :

18. 1 . Tincture of tolu 2. compound tincture of benzoin 3 . Maceration process for Concentrated Preparation or Multiple Maceration process. Maceration process is carried out in the same way as simple maceration process , but the menstruum used is divided into two parts in double maceration process and into three parts in triple maceration process. Example

19. PHYSICAL EVALUATION

20. Evaluation of the drugs on the basis of important physical properties or physical characteristics of the active constituent is known as physical evaluation. Physical standards are constant for crude drugs and help in evaluation of crude drugs. The characteristics studies involved in physical evaluation are given in following table.

21. No. Class Method 1. Foreign material Moisture content Foreign organic matter Microbial contamination Loss on drying 2. Ash values Total ash Acid insoluble ash Water soluble ash Sulphated ash 3. Extractive values Water soluble extractives Ethanol soluble extractives Petroleum ether soluble extractives Ether soluble extractives Alcohol soluble extractives

22. 4. Physical constants Melting point Boiling point Optical rotation Rf value Solubility in different solvents Bitterness value Swelling index Viscosity Specific gravity pH value Density 5. Chromatographic Methods Thin layer chromatography (TLC) High performance liquid chromatography (HPLC) Gas liquid chromatography (GLC) High performance thin layer chromatography (HPTLC) Column chromatography Gel permeation chromatography( Gel filteration) Affinity chromatography

23. 6. Spectroscopical Methods UV and visible spectroscopy Infra-red spectroscopy NMR spectroscopy Mass spectroscopy X-ray spectroscopy Radio immune assay (RIA) Fluorescence analysis

24. FOREIGN MATERIAL : A) Moisture content : An excess water in medicinal plant material will lead to deterioration through microbial growth or enzyme mediated hydrolysis in glycoside containing plants. Therefore limits for the amount of water should be set for every plant material. The moisture content of a drug should be minimized to prevent decomposition of crude drugs either due to chemical change or microbial contamination. Moisture content is determined by following methods: Loss on Drying (dry in oven at 100-105 °C) Azeotropic (toluene distillation) distillation method Karl Fischer method

25. Foreign organic matter: The parts of the organs other than the crude drugs are defined as foreign organic matter. The maximum limit for the foreign organic matter is given in monographs of crude drugs. If the limit exceeds, it indicates deterioration in quality of crude drugs. Microbial contamination: The drugs such as Acacia, Agar, Tragacanth, powdered Digitalis etc. should be free of E. coli microorganisms. The crude drugs to be taken internally, should be free from bacteria and mold contamination. Loss on drying: The loss in weight of crude drugs due to drying of water and volatile oil.

26. 2. Ash values : The residue remaining after incineration of drug is the Ash content of the drug, which simply represents inorganic salts, naturally occurring in drug or adhering to it or deliberately added to it, as form of adulteration. It varies in cases of many crude drugs and its study gives an idea about the quality and purity of the drug during evaluation. Total Ash: The test is designed to measure the amount of material remaining after ignition. Carbon and organic matter present in the drug is converted to ash at the 450˚C or above. It contains carbonates, phosphates, silicates and silica. Many a time, the crude drugs are admixed with various mineral substances like sand, soil, chalk powder or other drugs with different inorganic contents.

27. Acid insoluble ash: Acid-insoluble ash is the residue obtained after treating the total ash with dil. HCl. This determination measures the presence of silica and excessive earthy material. Water soluble ash : It is the calculated difference in weight between the total ash and the residue remaining after treatment of total ash with water. Incinerator

28. EXTRACTIVE VALUES: The crude drugs have their biological activity due to chemical constituents. These constituents are soluble in different solvents. It is the amount of active constituents extracted with solvents from a given amount of medicinal plant material. Water soluble extractive: This method is applied to drugs which contain water soluble active constituents of crude drugs, such as tannins, sugars, plant acids, mucilage, glycosides etc.

29. (b) Ether soluble extractive: The types of ether soluble extractives values determined for evaluation of crude drugs are volatile and non-volatile ether extractives. The volatile ether-soluble extractive represents volatile oil content of the drug. Non-volatile ether soluble extractives represent resin, fixed oils, or coloring matter present in the drugs. (c) Alcohol soluble extractive: Alcohol is an ideal solvent for extraction of various chemicals like tannins, resins, etc. 95% ethyl alcohol is used for determination of alcohol soluble extractive.

30. 4. Physical constants Melting Point: Melting point is used to judge the purity of crude drug. In case of pure chemicals or phytochemicals, melting points are very sharp and constant. The drugs from animals and plants origin contain the mixed chemicals; they give certain range of melting point. The purity of crude drugs can be ascertained by determining their melting points in the range. Boiling point: This parameter is applicable to all liquid phytoche micals like oils or few alkaloids. Shift in boiling p oint range helps in determining purity of phytochemicals.

31. (c) Refractive index: When a ray of light passes from one medium to another of different density, the ray is bent from original path. The ratio of the velocity of light in air to its velocity in the substance (drug) is termed as refractive index of the substance. Refractive index is constant for liquid depending upon purity and it is considered for its standardization. Refractive index of a compound varies with light, temperature and pressure.

32. (d) Optical rotation: Many volatile oils and other substances show the ability to rotate the plane of the polarized light to right or left side and likewise they are called dextrorotatory or levorotatory respectively. This detection of optical rotation and its magnitude is an important criteria for evaluation of drugs. (e) R f value: The active constituent present in the crude drugs when subjected to thin layer chromatographic study , move on the TLC plates according to their affinity with the solvent. The quality control employs TLC for assessing the quality and purity of the drug. R f value is the ratio of distance moved by the solute divided by the distance moved by the solvent front. It varies from zero to one.

33. (f) Solubility in different solvents: The presences of adulteration in the drug could be identified by solubility studies. e.g. Castor oil is soluble in 90% alcohol. Balsam of Peru is soluble in chloral hydrate solution. Asafoetida is soluble in carbon disulphide. Alkaloidal bases are soluble in chloroform, while alkaloidal salts are soluble in polar solvents. Colophony is freely soluble in light petroleum. (g) Bitterness value: Medicinal plant materials that have a strong bitter taste. Bitter substances can be determined chemically. However, since they are mostly composed of two or more constituents with various degrees of bitterness, it is first necessary to measure total bitterness by taste. The bitterness value is determined organoleptically by comparison with a Q uinine hydrochloride solution which acts as the standard.

34. (h) Swelling index: Many medicinal plant materials are of specific therapeutic or pharmaceutical utility because of their swelling properties, especially gums and those containing an appreciable amount of mucilage, pectin or hemicellulose. Swelling index is defined as the volume in ml occupied by swelling of 1 gm of a drug, under specified condition. The mixing of whole plant material with the swelling agent is easy to achieve, but cut or pulverized material requires vigorous shaking at specified intervals to ensure even distribution of the material in the swelling agent.

35. ( i ) Viscosity: Viscosity of a liquid is constant at a given temperature. Viscous natural drugs like gums, mucilage or pectin like compounds should be evaluated for its viscosity. Hence it can be used as a means of standardizing liquid drugs. (j) Density and Specific gravity: All liquid phytochemicals have to be evaluated for its density and specific gravity. This parameters is very essential for volatile oil standardization. specific gravity, is the ratio of the density of a substance to the density of a given reference material.

36. Chromatography is  a separation technique for separating components of a mixture . The different components of the mixture travel through the stationary phase at different speeds, causing them to separate from one another. Separation depends on the differential in affinities of the solute between two immiscible phases. A stationary phase and mobile phase. The stationary phase is a fixed bed of large surface area which may be porous of finely divided solid or liquid that has been coated as a thin layer on inert support material. The mobile phase is moving phase over stationary phase. Mobile phase may be a pure liquid or a mixture of solutions or it may be gas or mixture of gases.

37. TYPES OF CHROMATOGRAPHY Paper chromatography Thin layer chromatography (TLC) High performance thin layer chromatography (HPTLC) High performance liquid chromatography (HPLC) Gas chromatography Gas liquid chromatography (GLC) Column chromatography

38. SPECROPHOTOMETRY UV-visible spectrophotometry Mass spectrometry Nuclear magnetic resonance spectroscopy Infrared spectroscopy Radio immune assay Fluorescence analysis

39. 1. Ultraviolet – visible spectroscopy Ultra-violet (UV) and visible absorption techniques contain analytical methods based on measurement of light absorption by substances in the wavelength region from 180 to 780 nm. The Principle of UV-Visible Spectroscopy is based  on the absorption of ultraviolet light or visible light by chemical compounds , which results in the production of distinct spectra The region from 180 to 390 nm is known as the UV region and from 390 to 780 nm. the visible region of the spectrum. Absorption in the UV visible region arises from electronic transitions within the molecule.

40. 2. Infra red spectroscopy Infrared spectroscopy is a very powerful technique which uses electromagnetic radiation in the infrared region for the determination and identification of molecular structure as well as having various quantitative applications within analytical chemistry. Wavelength range from 700 nm to 1 mm atoms can absorb energy from electromagnetic radiation ; this absorbed energy alters the state of the atoms within the molecule . These changes are usually manifest in alterations to the frequency and amplitude of molecular vibrations, which may be measured and plotted to produce an infrared spectrum . Infrared spectroscopy is one of the most useful and widely used methods to perform structural analysis, since it is helpful to identify functional groups. IRS is used for the identification of drugs, polymorphic modifications, excipients and raw materials , due to its sensitivity.

41. 3. Nuclear magnetic resonance (NMR) Spectroscopy NMR is the branch of spectroscopy dealing with the absorption of radio frequency radiation by substances held in a magnetic field. Absorption results from interaction of radiation with magnetic movement of nuclei in the sample at it occurs at different frequencies for nuclei with chemically different environments within a molecule. NMR is important for elucidation of molecular structure, especially the stereochemistry and configuration. The process reveals position of protons in a complex molecule. This is useful for determination of Hydrogen bonding (Intermolecular and intramolecular) and Carbon bonding. It determinates impurities and minor components in mixtures as comfort, speed and specificity of analysis. It is used to identify structural isomers

42. 4. Mass spectrometry In mass spectrometry, molecules in gaseous state under the pressure between 10 -7 to 10 -5 mmHg are bombarded (attacked) with beam of energetic electrons using tungsten or rhenium filament . The molecules are ionized and broken up in fragments , which can further break up into smaller ions. All these ions are accelerated by an electric field , sorted out according to their mass to charge ratio. T he mass-to-charge ratio (symbols: m/z, m/e) of a  cation is equal to the mass of the cation divided by its charge . The mass of the molecular ion is equal to the molecular weight of the compound. Thus, the mass-to-charge ratio of the molecular ion is equal to the molecular weight of the compound. The mass spectral data of compound indicates the molecular ion, peak and other major and minor fragments which helps to establish the structure of compound, by giving exact molecular weight, molecular formula and an idea about its structural type. E.g m/e ratio of toluene is 91

43. 5. Fluorescence analysis The organic molecules absorb light over a specific range of wavelength and many of them give out such radiations. Fluorescence is a process of re-emission of radiant energy absorbed in the form of visible light. In this process light emitted is always of higher wavelength than that absorbed. In fluorescence, absorption and emission of light takes place in very short time (10 -12 to 10 -9 seconds.) If there is delay in the emission of light then the phenomenon is called as phosphorescence . The delay period may range from fraction of second to few days . Both the process called as luminescence. The drugs like belladonna leaf and root, wild cherry bark, gambier catechu, aloes, jalap etc. show fluorescence in visible range.