Crude Drug - Quality Control Flashcards
General Monographs Def
Groupings based on substances with similar properties and uses eg herbal teas
Monograph Def
Attributes of a substance (eg liquorace root); description, function and chemical properties
Considerations when evaluating the quality, purity and authenticity of drugs
Ensure that material is correctly identified at each step of the process. Good agricultural practice and good manufacturing practice is important
Standards and Limits Tests
Chemical/Physical/Biological Assays, microscopical examinations, macroscopical and organoleptic properties
What is an indication of shelf life
Microbial Quality
Why are quality standards lower for natural products then allopathic
Due to natural variation both between species and within the same species chemical concentrations may not be as consistent. Additionally there are more chemicals present in natural products as they weren’t tailored for a specific function
Names of Standard and Limit Considerations
foreign matter, moisture content, ash values, volatile oil determination, crude fibre, tannin content, bitterness, swelling index, Rf values, microbial contamination and toxic values
Types of foreign matter
Related plant parts (eg leaf and root from the same plant) and parts of other plants (eg dandelion vs grass roots). There’s a risk of sample misidentification/contamination when collecting
Ways to prevent misidentification/contamination of foreign matter
Thin layer of sample is isolated and examined at 6x magnification, quantified and compared to literature
Reasons to minimise moisture content
promotes bacterial growth and degeneration of enzymes
2 methods of moisture content determination
water determination and drying loss
3 methods of water determination
Karl-Fischer titration, Dean-stark distillation (all volatile substances evapourated) and coulometric (electrochemical) titration
Loss on Drying Outline
Dry a weighed quantity of crude drug at 100-105 degrees C. Crude drug will begin to lose weight as volatile substances (may not be only water) are evapouratec off. Take weight of drug when it remains constant (no more loss). Substract values and get weight of volatile substances.
When do you use a dessiactor in loss on drying
Chamber that contains water specific drying agents. Other volatile substances aren’t lost
Ash Values Outline
Incineration of vegetable drugs at 450 degrees C burns all organic substances (including water) into inorganic ash that can then be weighed. Imprecise as the exact organic content varies even within species
Total Ash Contents
CO3^2-, PO4^3-, Silicates and Silica
Example of ash value used in healtcare
Determine contents of surgical dressing
Methods of isolating specific contents from ash
treat with dil. H2SO4 befor ignition = sulphates isolation, treat total ash with dil. HCl = silica and adding water
Volatile Oil Determination
Meek Savin appartus seperates oil from water by distillation. For oils with same density as water xylene must be added to separate them out and for oils more dense then water modifications must be made to apparatus
Crude Fibre Determination Outline
Fibre is typically insoluble. Determined by chemical analysis and filtration
Tannin Content Determination Outline
Compared in an assay with pyrogallol (standard)
Tannin Effects in Human Body
Tightening of muscle
Bitterness Determination Outline
Only taste test left valid in pharmacopeia. Dilute sample until bitter taste is gone. Compare number of dilutions necessary for sample to number of dilutions necessary for quinine (standard)
Swelling Index Outline
Volume (ml) taken up by 1g of a drug when in an aqueous solution for a 1 hr
Rf Values
Thin layer chromatography. Separates out individual chemical components. Ratio of how far a chemical moves / how much it solvent moves (polarity mmeasurement)
Microbial Contamination Outline
Total viable aerobe and mold count
Toxic Residue Determination Outline
Tests for presence of pesticides, fumigation residue, alflatoxins and radioactivity
Crude Drug Assay Outline
Measures a single or multiple compounds expression of activity. Chemical and physical prefered (biological/animal are viewed as inhumane)
Biological Assay Example
Brine Shrimp Assay
Spectroscopic Assay Techniques
UV, Visible, IR and Fluorescence (depends on properties of drug)
Immunoassay techniques
Radioimmunoassays and ELISA (enzyme linked immunoabsorbant assay)
Macroscopial Technique Outline
Qualitative - appearance to naked eye. Evalutes processing quality, storage quality and infestation
Organoleptic Technique Outline
Colour/odour/taste of substance. Swelling due to water. Brown paper test (oil presence) and frothing when agitated with water (froth = presence of soap)
Microscopical Techniques Outline
Maesurement of CFUs on substances with constant area/length characteristics. Magnification necsaary = no of micrometers substance covers. Reference substances may be used
Types of Microscopical Measurements
Stomatal Measurements and veins measurement. Distinguish closely related species
Advanced microscopical techniques
Camera lucida (how much light is needed to permeate sample), photomicrographs (drawings/photos of microscope image), UV microscopy, phase contrast microscopy and electron microscopy
Stomatal Number (stomata measurement)
Average no of stomata per mm^2 of epidermis
Palisade Ratio (stomata measurement)
Average no. of palisade cells under an upper epidermal cell
Stomatal Index (stomatal measurement)
% proportion of regions of epidermis that are stomatal
Vein-Islet Number (vein measurement)
no of veins per mm^2 calculated from 4 contiguous of mm^2 of central lamina
Vein Termination No (vein measurement)
no. of veinlet terminations per mm^2 of leaf surface
Phloroglucinol Staining
Stains red/pink in presence of ligin (positive) and blue in it’s absence (negative)
Iodine Staining
Blue/black in presence of starch, orange-yellow in absence
Sudan Red Staining
Red in the presence of cuticle components
