A SEMINAR ON COMPENDIAL METHODS FOR EVALUATION OF CRUDE DRUG AND HERBAL FORMULATION: A SEMINAR ON COMPENDIAL METHODS FOR EVALUATION OF CRUDE DRUG AND HERBAL FORMULATION Guided by: Prepared by: MRS: V.V.Karkhanis Nishit Patel A.R College of Pharmacy M.Pharma (Q.A) IInd Sem. ID 07PH909 PowerPoint Presentation: GENERAL INFORMATION: The test procedures being described are mostly related to starting materials used in herbal drug preparation. Starting materials are usually dried powdered or some are fresh used in herbal preparations. Quality control of starting material, play a major role in the production of phyto Pharmaceuticals of standard quality. The great importance for the pharmaceutical industries is in the evaluation of crude drugs. This involves the determination of identity, purity and quality. Purity depend upon the absence of foreign matter whether organic or inorganic. Based on the concentration and nature of the constituents through, a crude drug may conform to all the official standard of purity and be of good quality. PowerPoint Presentation: It is virtually impossible to avoid some naturally occurring inorganic or organic contaminants. While collecting crude drug from the field. e.g Inorganic contaminants: Sand, Soil, Stone. Organic contaminants : Pesticides, neighbouring plant of different species Also molds, insects, animal excreta etc. These affects the purity of any crude drugs which needs proper assessments and detection based on different phytochemical parameters. They are described in subsequent sections. And evaluation of this parameters give clear idea about the specific characteristics of crude drugs. PowerPoint Presentation: PARAMETERS FOR STANDARDIZATION: (A) DETERMINATION SOLVENT EXTRACTIVE VALUE: Definition of Extractive value: “The crude drugs have their biological activity mainly due to active chemical constituents. These constituents may be soluble in different polar, semipolar, or nonpolar solvent. Total soluble constituents of the drug in any particular solvent or mixture of solvents may be called as its extractive value.” This method determines the amount of active constituents in given amount of medicinal plant material when extracted with solvents, it is employed for that material for which no biological or chemical assay method exist. PowerPoint Presentation: The extraction of any crude drug with a particular solvent yields a solution containing different phytoconstituents. The composition of these phytoconstituents in that particular solvent depends upon the nature of the drug and solvent used. The use of a single solvent can be the means of providing preliminary information on the quality of particular drug sample. Methods For Determination of Solvent Extractive Value: 1. Determination of water soluble extractive (As per IP’ 96) The water soluble extractive value play an important role for the evaluation of crude drugs. E.g water soluble extractive of ginger is expected to be in the range of the 10% with respect to air dried material, lowering of this extractive value indicates the addition of exhausted material with the original drug. PowerPoint Presentation: Method-I:- Take 5 gm of air dried powder Macerated with 100 ml of chloroform water for 24 hours Shaking frequently during the 1st 6 hours and allow to stand for 18 hours Thereafter filter rapidly Evaporate 25 ml of the filtrate to dryness in a tared flat-bottomed shallow dish, dry at 105°C and weight Calculate the % of water soluble extractive with reference to the air dried drug has to be calculated. PowerPoint Presentation: Method-II Take 5 gm of air dried powder in 50 ml water Heated at 80°C in stopper flask Shake well and allow standing for 10 min Cool, add 2gm of kieselguhr and filter Transfer 5 ml of the filtrate to a tared evaporating dish Evaporate solvent on a water bath Continue drying for 30 minutes, finally dry in steam oven for 2 hours and weigh the residue Calculate the % of water soluble extractive with reference to the air dried drug has to be calculated. PowerPoint Presentation: 2. Determination of Alcohol Soluble Extractive: Introduction: The alcohol soluble extractive value is also indicative for the same purpose as water soluble extractive. The solvent strength of alcohol varies from 20-95% v/v. The solvent strength has to be chosen depending on the nature of drugs to be extraction. The extractive value varies depending on the strength of alcohol used for extraction. Eg. Ginger when extracted with 90% alcohol gives an alcohol soluble extractive value of approximately 4.5 % v/v, which includes the oil and resins present in it. And in case of rhubarb, 45% v/v alcohol strength is suitable to extract the anthraquinone present in it. PowerPoint Presentation: Method as per IP’96 ( ethanol soluble extractive) Take 5 gm of air dried powder, coarsely powdered drug. Macerated with 100 ml of ethanol of specified strength in closed flask. Shaking frequently during the 1st 6 hours and allow to stand for 18 hours Thereafter filter rapidly Evaporate 25 ml of the filtrate to dryness in a tared flat-bottomed shallow dish, dry at 105 C and weight Calculate the % of ethanol soluble extractive with reference to the air dried drug has to be calculated. PowerPoint Presentation: 3. Hexane soluble extractive value: (Non Pharmacopoeia) Extract completely about 2 gm of the powdered drug by subjecting it to the action of solvent Hexane in a continuous extraction apparatus for 20 hrs Transfer the Hexane solution to a tared porcelain dish and allow evaporating spontaneously. Then dry it over phosphorus pentoxide for 18 hours and weigh. Calculate the % of Hexane soluble extractive with reference to the air dried drug has to be calculated. PowerPoint Presentation: 4. Volatile Ether soluble extractives: (Non Pharmacopoeial) Extract completely about 2 gm of the powdered drug by subjecting it to the action of solvent anhydrous Ethyl Ether in a continuous extraction apparatus for 20 hrs Transfer the Ether solution to a tared porcelain dish and allow evaporating spontaneously. Then dry it over phosphorus pentoxide for 18 hours and weigh the total Ether extract. Heat extract gradually and dry it at 105°C. The loss in Wt. represents the volatile portion of the extract. ` PowerPoint Presentation: 5. Non volatile ether soluble extract: (Non Pharmacopoeial) Proceed as directed under volatile ether soluble extract. Weigh the extract after drying in a dessicator at 105°C to constant weight represents the non volatile portion of the extract. In the determination of all extractive values, the % has to be determined with respect to the air dried material. PowerPoint Presentation: (B) DETEMINATION OF ASH VALUES: Ash Value: “Remnant of the crude drugs after incineration contains mostly inorganic salts and non-volatile inorganic components known as Ash” This value varies within fairly wide limits and is therefore an important parameter for the purpose of evaluation of crude drugs. In certain drugs, the % variation of the weight of Ash from sample to sample is very small and any marked difference indicates a change in quality. More direct contamination, such as by sand or earth, is immediately detected by the ash value. Ash value can be determined by three different methods: Total Ash Acid insoluble Ash Water soluble Ash PowerPoint Presentation: 1. Determination of total Ash: Intoroduction: Ashing involves an oxidation of the component of the product. A high ash value is indicative of contamination, Substitution, adulteration or carelessness in preparing the crude drug for marketing. Total Ash is designed to measure the total amount of material produced after complete incineration of the ground drug at as low temperature as possible (about 450°C) to remove all the carbons. At higher temperature, the alkali chloride may be volatile and may be lost by this process. The total Ash usually consist of Carbonates, Phosphates, Silicates and Silica which includes both: Physiological Ash: Which is derived from the plant tissue itself Non – physiological Ash: Which is the residue of the adhering material to the plant e.g Sand and soil. PowerPoint Presentation: Method For Determination of Total Ash: (As per IP’96) Take a 2-3 gm of the air dried crude drug in the tared platinum or silica dish and incinerate at temp. not exceeding 450°C If carbon free Ash can not be obtained Then Until Free from carbon, cool and Weigh Collect the residue on ash less filter paper Incinerate the residue and filter paper until the Ash is white. Calculate the % of Ash with Reference to air dried drug. PowerPoint Presentation: Determination of Acid Insoluble Ash: Introduction: Acid insoluble Ash is frequently necessary to evaluate the crude drugs, which indicates the residue obtained after treating the total Ash with dilute HCl and weighing residue. This Ash value particularly indicates contamination with silicious material. E.g. earth and sand. The value for this Acid insoluble Ash varies from 0.5% (Agar) to as much as 12% (Hyoscymus) If no figure is stated in the individual monograph, it is assumed that the acid insoluble Ash value should not exceed 2%. PowerPoint Presentation: Method for determination of acid insoluble Ash: (As per IP’96) There are two methods for acid insoluble Ash determination. Method – I Boil the Ash obtained in Total Ash with 25 ml of 2 M HCl for 5 min. Collect the insoluble matter on an Ashless filter paper. Wash with hot water, ignite, and cool in dessicator and weigh. Calculate the % of Acid insoluble Ash with Reference to air dried drug. PowerPoint Presentation: Method – II Boil the Ash obtained in Total Ash with 10 ml of 2 M HCl for 10 min. Collect the insoluble matter on an Ashless filter paper. Wash with hot water until filtrate is neutral, ignite to dull redness Cool in dessicator and weigh. Calculate the % of Acid insoluble Ash with Reference to air dried drug. PowerPoint Presentation: Determination of Water Soluble Ash: Introduction: Water soluble Ash is that part of the total Ash content which is soluble in water. Water soluble Ash value is the difference in wt between the Total Ash and the residue obtained after treatment of total Ash with water. PowerPoint Presentation: 3. Method for determination of water soluble Ash: (As per IP’96) Boil the Ash obtained in Total Ash with 25 ml of water 5 min. Collect the insoluble matter on an Ashless filter paper. Wash with hot water, ignite for 15 min. at a temperature not exceeding 450°C. Subtract the Wt. of the insoluble matter from the Wt. of the Ash taken. Calculate the % of water soluble Ash with Reference to air dried drug. PowerPoint Presentation: (C) DETERMINATION OF TOTAL SOLID: The term Total Solid is applied to the residue obtained when the prescribed amount of the preparation is dried to constant Wt. under the specified conditions. PowerPoint Presentation: Method for the determination of Total Solid:(As per IP’96) Take an accurate quantity of substance being examine stated in individual monograph. Place in tared dish Evaporate at as low temperature as possible until solvent is removed. Heat on a water bath until the residue is apparently dry. Transfer to an oven and dry to constant Wt. at 105°C. The hygroscopic nature of the certain residues, it may be necessary to use dishes provided with well fitting covers. Cool in dessicator, Wt. and calculate the % of Total solid to compare air dried substance. PowerPoint Presentation: (D) DETERMINTION OF CRUDE FIBRE: Introduction: Estimation of crude fibre denotes the measurement of the content of cellulose, lignin and cork cell in the plant tissue. The material is defatted and boiled with dilute acids to eliminate the soluble material, washed, dried and weighed. Excess of the crude fibre indicates adulterated with woody tissue like kernels. The quality determination of the crude drugs may not be as useful with this estimation as it varies 20-30%. The crude fibre consists of the material other than Ash which can not be dissolved in water and can not be digested by boiling with H 2 SO 4 or with NaOH. It represents more resistant part of the plant cess as well as some less resistant cell wall component like cellulose and pectin. PowerPoint Presentation: Method for determination of crude fibre: (As per USP XX) Take 2 gm of drug sample. Extracted with ether. Add 200 ml of 1.25% H2SO4 Extracted drug and whole mixture boil for 30 min. under reflux in a 500 ml flask. Mixture is then filtered through a hardened filter and residue washed with boiling water until free of acid. PowerPoint Presentation: All the residue rinsed back into the flask with 200 ml of boiling 1.25 % of NaOH solution and again boil under reflux for 30 min. The liquid is then quickly filtered through a tared filter and the residue on the filter is washed with boiling water until neutral. Dried at 110°C to constant Wt. and incinerated, like wise to constant Wt. The difference between the Wt. of the dried residue and that of the incinerated residue represent the Wt. of the crude fibre. PowerPoint Presentation: (E) DITERMINATION OF MOISTURE CONTENT: Introduction: Moisture is expected component of crude drug, which must be eliminated as far as practicable. Moisture triggers the enzymatic activity or facilitates growth of microbes which leads to crude drug destruction. The preparation of crude drug from the harvested drug plants involves cleaning to remove soil or other extraneous material followed by drying which plays a very important role in the quality as well as purity of the material. The objectives of drying fresh material are: To aid in their preservation. to ‘fix’ their constituent i.e. to check enzymatic or hydrolytic reactions that might alter the chemical composition of the drug. to facilitate subsequent comminution (grinding into a powder). to reduce their weight and bulk. PowerPoint Presentation: Insufficient drying favors spoilage by molds and bacteria and makes possible the enzymatic destruction of active principles. The moisture requirement for the active growth of some of the common molds and bacteria that may be found in or on drugs are relatively low. Therefore, the drying process should reduce the moisture content of the drug below this critical or threshold level. It is difficult state a precise upper limit of moisture that can be permitted in the crude drug. Drug may be stored safely if the moisture content is reduce to 6% or less, except agar for which USP permits as much as 20 % moisture. Drying should be accomplished as rapidly as is possible with good practice. A weighed sample of the crude drug is dried at 100 C and weighed periodically until no more than 0.25% is lost in 1 hour drying. The total weight loss is expressed as a % of the initial weight of the sample. The residual moisture (if any) which can not be driven off in this way is called ‘bound water’. PowerPoint Presentation: 1. Loss on drying. The test for loss on drying determines both water and volatile matter in crude drug. Loss on drying is the loss of mass expressed as % w/w and can be determined by following procedure. Method: (As per IP’96) Place a prescribed quantity of the substance to be examined in a weighing bottle. Dry the substance to constant mass or for the prescribed time by one of the following procedure. In a dessicator: The drying is carried out over diphosphorus pentoxide at atmospheric pressure and at room temperature. In vacuo The drying is carried out over diphosphorus pentoxide, at a pressure of 1.5 kpa to 2.5 kpa and at room temperature. PowerPoint Presentation: In vacuo within a specified temperature range: The drying is carried out over diphosphorus pentoxide, at a pressure of 1.5 kpa to 2.5 kpa within the temperature range specified in the monograph. If the drying is carried out at a temperature above 100°C the temperature range within which the desiccant is to be maintained is also specified. In an oven within a specified temperature range: The drying is carried out in an oven within the temperature range specified in the monograph. PowerPoint Presentation: 2.Azeotropic volumetric method: (As per IP’96) Introduction: The azeotropic method gives a direct measurement of water or other volatile constituents present in crude drug being examined.When sample is distilled together with an immiscible solvent, such as toluene to xylene, the water present in the sample is absorbed by the solvent. The water and solvent is distilled together and separated in the receiving tube on cooling.If the solvent is anhydrous, water may remain absorbed in it leading to false result. It is therefore advisable to saturate the solvent with water before use. This method is based on the fact that water and benzene, toluene, or xylene will form a binary azeotropic mixture. PowerPoint Presentation: Design of apparatus: The apparatus (DEAN STARK) consists of a glass flask (F) connected by a tube to a cylindrical tube fitted with a graduated receiving tube (RT) and a reflux condenser. The receiving tube is graduated in 0.1 ml division to minimize the error of reading which does not exceed 0.05 ml. Heat may be supplied by an electric heater. PowerPoint Presentation: Procedure: An appropriate quantity of ground crude drug placed in flask(F), toluene is added, and the apparatus is connected as shown in fig. The graduated receiving tube (RT) is filled with toluene, and then the flask is heated until no more water is distilled over. Both toluene and water distilled over, but the water being heavier than toluene, sinks to bottom of the receiving tube(RT) displaying toluene which flows back into the flask(F). When the apparatus has cooled and the toluene and the water in tube (RT) have separated completely, the volume of water distilled over can be read and the % initially present in the sample can be calculated as % using the formaula % = 100 x N/W Where, W = Wt. in gm of the material examined. N = Number of ml of water obtained. PowerPoint Presentation: 3. Karl Fischer Method: Karl fischer method is one of the most extensively used chemical methods for determination of total moisture as it can be applicable to very small quantities of moisture. The reagent containing a solution of iodine, sulphar dioxide and pyridine in dry methanol constitutes Karl Fischer reagent. Iodine is reduced by SO2 in the presence of water causing the loss of dark brown colour of the reagent. This reaction endpoint is measure by Platinum electrode. PowerPoint Presentation: Method (As per IP’96) Primary standardisation of the reagents. Place 36 ml of dried methanol in titration vessel Add Karl Fischer reagent To give end-point (using Platinum electrode) Add quickly 150 – 350 mg of Sodium Tartrate. Titrate with Karl Fischer Determine the accurate volume of KF required. Calculate the Water equivalent factor. Weight in mg of sodium tartrate X 0.1566 F = ------------------------------------------------------- Ml of KF reagent PowerPoint Presentation: Test for Sample: 20 ml of Dried Methanol in titration vessel Add KF reagent To give end-point Transfer quickly Prescribed amount of substance being examine Stir for 1 min Titrate and determine endpoint Calculate % water content. Volume of KF X Factor = ----------------------------------------- Weight of sample PowerPoint Presentation: Determination of essential (Volatile) oils in crude drugs: The volatile oils (or essential oils) are liquid components of plant cells which, like the lipids are immiscible with water and volatile at ordinary temperature. Although many of the volatile oils are sufficiently soluble in this medium to impart to it their characteristics odour and taste. Many of the volatile oils are used as carminatives, as diuretics, as anthelmintics, as local stimulants and mild antiseptic, as parasiticides or local irritants. The quality of an essential oils containing drug is expressed primarily in terms of the percentage of oil present . PowerPoint Presentation: Method for determination of essential (volatile) oils: In order to determine the volume of oil, the plant material is distilled with water and distillate is collected in graduate tube. The aqueous portion is separated automatically and is returned to the distillation flask. If the volatile oils posses a mass density higher than or near to that of water and difficult to separate from the aqueous phase due to the formation of emulsion, a solvent with low mass density and suitable boiling point may be added to the measuring tube. Xylene is used most frequently. The dissolved volatile oil then flats on the top of the aqueous phase. Yield is effected by the following factor Weight of the drug taken Condition of when distilled Time of distillation.