بسم الله الرحمن الرحيم

Mai Mohammed Al-Oqail مي محمد العقيّل Email: maioqail@hotmail.com Site: faculty.ksu.edu.sa/11982

Evaluation of crude drugs

Crud drugs : Vegetable or animal drugs that consist of natural substances that have undergone only the processes of collection and drying. Natural substances: 1- Plant origin: leaves, flowers, seeds and barks. Or vegetable saps, extracts and secretions. 2- Animal origin: whole animals, glands or organs, extracts and secretions.

1- Identity 2- Quality and Purity To evaluate a crude drug: Importance of evaluation of crude drugs: 1- Biochemical variation in the drugs 2- Deterioration due treatment and storage 3- Substitution and adulteration, as result of carelessness, ignorance and fraud

1- Identity Can be established by actual collection of the drug from plants → +ve identified. How to determine the origin of the samples: 1- "Drug gardens' established by institutions engaged in pharmacognostical research. 2- Comparing unknown sample with A- Published description drug B- Authentic drug samples.

2- Quality and Purity How obtain high grade of quality? It is refers to the intrinsic value of the drug, i.e., the amount of medicinal principle or active constituents present. How obtain high grade of quality? I- Collection of the drug from the correct natural source at the proper time and in proper manner. e.g1., Opium e.g 2., clove II- Preparation of the collected drug by proper cleaning, drying and garbling III- Proper preservation of the cleaned, dried, pure drugs against contamination with dirt, moisture, fungi, filth and insects.

Several problems not applicable to synthetic drugs influence the quality of herbal drugs: 1-Herbal drugs are usually mixtures of many constituents. 2-The active principle(s) is (are), in most cases unknown 3-Selective analytical methods or reference compounds may not be available commercially. 6- The methods of harvesting, drying, storage, transportation, and processing (for example, mode of extraction and polarity of the extracting solvent, instability of constituents, etc.) have an effect 4-Plant materials are chemically and naturally variable 5-The source and quality of the raw material are variable.

1- Organoleptic evaluation The evaluation of a drug involves a number of methods: 1- Organoleptic evaluation Definition: The entire description of official crude drug monographs. = Organs of sense = Macroscopic appearance of drug. The majority of information on the identity, purity and quality of the material can be drawn from these observations, they are of primary importance before any further testing can be carried out Authentic specimen of the material under study and samples of pharmacopoeial quality should be available to serve as a reference. This evaluation procedure provides the simplest and quickest means to establish the identity and purity and thereby ensure quality of a particular sample

1- Shape and size (for entire drugs not powdered). Flowers: Floral parts: stigmas, corollas, anther, ovary, receptacle. Leaves and leaflets: Length, width, apex, margin, base, venation, the texture of the leaf and the hairs in upper and lower surface. The feel of the surface described as soft, hairy smooth. .

The bark: i- The barks occur in three shapes: Flat or curved pieces. Single quill. Double quills. ii- Barks have two surfaces, an outer and inner. iii- The inner surface is usually lighter in color than the outer surface 2- Odor and taste. Odor: 1- distinct 2- indistinct [Depend on the amount of volatile constituents present in drug]. General terms used in describing odor are: 1-aromatic, 2-balsamic, 3- spicy

Taste: General terms used in describing taste are: 1- Acid (sour) 2- Saccharine (sweet): indicates sugar or sugar like substances e.g., liquorice. 3- Saline (salty) 4- Alkaline 5- Bitter: indicates presence of substances such as bitter principle e.g., glycoside, alkaloids. 6- Tasteless (all substances insoluble in the salive). 7- Distinctive sensations to the tongue: a- mucilaginous and oily (soft feeling) e.g., linseed. b- astringent (contraction of the tissues of the mouth) indicates presence of tannin. c- pungent (warm biting sensation) e.g., ginger. d- acrid (irritant sensation) e.g., Aconite, coca. e- nauseous (those tending to excite vomiting), Ipeca.

3- Color and external markings. May help in revealing the nature of the herb. 1- White: e.g., starch, flours, gums) 2- Pale yellow (yellowish white) e.g., ginger, squill, white pepper. 3- Deep yellow: e.g., peeled liquorice, calumba, hydrastis. 4- Light pale brown e.g., nux vomica, fennel, coriander, anise. 5- Dark brown: e.g., cloves. 6- Dark reddish brown: cinchona, nutmeg. 7- Red: Kamala. 8- Pale green e.g., lobelia. 9- Greenish brown: most of the leaf herbs. 4- Fracture and internal color.

2- Microscopical evaluation Dealing with microscopic appearance of the herb in sectional view and in powdered form. Microscopical evaluation is useful in the study of: 1- Histologic elements of herbs. 2- Detection of adulterant. 3- Quantitative microanalysis of admixed or adulterated powders.

Histology: refers to the character and arrangement of these tissues as they are present in the herb. Histologic studies : 1- Very thin transverse (radial) section 2- Longitudinal (tangential) sections (entire organ) Powdered herbs posses very few macroscopic features of identification outside of color, odor and taste.

Keys For the identification of powdered crude drugs: 1- leaves: a- Trichomes (glandular and nonglandular) b- Crystals of calcium oxalate c- Stomata d- Epidermis cells, palisade, e- Vessels 2- flower: a- Trichomes (glandular and nonglandular) b- Epidermis, stigma, anther. c- Pollen grain d- Volatile oil

3- Fruits and seeds: Starch Aleurone Sclerenchyma Vitta Endocarp Bark & wood: Phloem, xylem Trachedes, Parenchyma, wood Parenchyma Fibers, medullary rays, cork, cambium.

In some cases, the drug may have the same diagnostic element, they are known as closely related species. So, microscope is not the method of choice

Microscopical numerical value: It is used to identify closely related species. 1-Microscopical linear measurement Used only in Root Rhizomes Bark E.g1., Different between Cinnamon القرفه السيلانيه as quill and Cassiaالقرفه الصينيه as flat [Both have same diagnostic element]. So differentiate between both by: Microscopical linear measurement Cinnamon Cassia 1- Diameter of starch granules < 8 μm > 10μm 2- Width of phloem fiber 30 μm 30-45 μm

Rio Ipecacuanha Cartagena Ipecacuanha 15 μm 17-20 μm Active constituent Cinnamon Cassia Volatile oil 0.7-1% v/w 1-2%v/w Cinnamic aldehyde 60-75% Not less than 85% Phenolics 4-10% - Eugenol 10% Tast Astringent More astringent Cost Cheap Cheaper E.g2., Ipecacuanha Starch granule Rio Ipecacuanha Cartagena Ipecacuanha 15 μm 17-20 μm Why we need to differentiate between Rio and Cartagena Ipeca? Because Rio Ipeca contains more emetine alkaloid.