King Saud University
  Help (new window)

تحميل الدليل التدريبي

أسئلة شائعة


II- Detection of foreign matters:

Foreign organic matter refers to any other part of the plant or animals except that constituting the drug, and to any other vegetable or animal tissues or substances. The Permissible percentage of foreign matter in a drug is usually specified  in its official monograph.

A- determination of ash:

Ash is inorganic residue left when vegetable drug is incinerated. Analysis of plant ash shows that it contains Ca, Mg, K, Na, Si, P and Fe.

The amount and composition of ash varies according to some factors:

1-   The part and age of the plant: in the young leaves, the ash may constitute about 5% while in mature leaves reaches about 15%. The ash content of the wood (5%) is usually much lower than that of the bark (20%).

2-   Culture treatment: type of soil and elements present in it.

3-   The constitution of the ash varies wih the time of collection.

In the Pharmacopeia a maximum of 2% of cid insoluble ash is permitted unless otherwise stated in the monograph.

The total ash and acid insoluble ash are determined by the official method.

This consists of incinerating and weighting the total ash, then boiling the total ash with dilute hydrochloric acid, filtering, igniting and weighting the acid insoluble ash.


Acid insoluble ash consists of sand, silicates and other dirties and is an indication of the amount of dirty present in the sample. It is called foreign inorganic matter.

B- Moisture is normally present to the extent of 5-10% in all dried drugs. An excess of moisture is considered as an adulterant.

Excessive moisture is considered an adulterant because a- its added weight,

b- excess moisture is conductive to the promotion of mold and bacterial growth and subsequently to deterioration and spoilage of the drug.


Moisture is usually determined in one of FOUR ways, the specific method often being stated in the drug monograph.

1-   Gravimetric method:

a-   If the drug contains no volatile material, a weighed sample is heated at 100c to constant weight, the loss in weight being the water content.


b-  If volatile constituents are present, these must first be determined by the volatile ether-extractive method and their weight deduced from the loss in weight by drying, before the water content can be determined.

2-   Volumetric (Toluene distillation) method:

It is applies in either of the above cases. The water is distilled from the drug with toluene in a continuous distillation apparatus. The water is caught in the trap and is determined by direct measurement of the volume.

3-   Titrimetric (Karl Fischer) method:

It is applicable for expensive drugs and chemicals containing small quantities of moisture. This method of water determination is based on the stoichiometric reaction of the solution of sulfur dioxide, pyridine in dry methanol and iodine. this is titrated against a sample containing water which cause loss of brown color untill the end point where the color of iodine persist.

4-   Determination of moisture by spectroscopic methods:

Water can absorb energy at various wavelength throughout the electromagnetic spectrum and this can be made a basis for the quantitative determination. Measurments can be made in both the infrared and ultraviolet regions. The NMR spectroscopy also employed for the determination of moisture in plant products.


C- Detection of filth:

In quality control procedures the pharmacopoeias stated: drugs containing appreciable quantities of foreign organic matter, animal excreta, insects or mould should however be rejected even though the percentage of such substances be insufficient to cause the rejection of the drug.

1- Insects, insect parts, rodent hairs and feces may be separated from the drug by means of liquids of varying specific gravity.

Most drug material will float on chloroform, but rodent pellets will sink in this liquid.

2- Insect parts can be separated by boiling the drug with water, cooling and then vigorously stirring in a small amount of mineral oil.


The mineral oil rises to the top carrying with it the insect fragments.  Floating strata may be separated by mean of Wildman trap flask and sinking strata by means of a percolator equipped with two corks at either end of the stem.

The recovered impurities are then identified microscopically.


Methods of controlling insect in crude vegetable drugs:

Most common methods are:

1- Heat treatment, which consists of exposing the drug to a temperature of 60-65C is often effective especially for insect eggs that are not penetrated rapidly by insecticides.

The duration of the exposure is determined by the volume of drug to be treated. It may vary from a few minutes to several days. Prolonged exposure to high temperature may inactivate enzymes.


2- Drugs may be fumigated by the use of various volatile insecticidal agents in closed areas e.g., CCl4, CH3Br or mixture of ethylene oxide and carbon dioxide.

- Most fumigants do not kill the eggs of insects and therefore it is common to repeat fumigation at intervals of two week, to give better chance of eliminating all insects, since time is permitted for eggs to hatch and larvae are killed.

- Stored drugs that are susceptible to insect attacks should be fumigated routinely every 3or 4 months.

- If medicinal plants are to be fumigated in greenhouse, it is desirable to fumigate at night, since the plant are more sensitive to such poisonous in the daytime then their stomata are fully open than at night when the stomata are partially closed.

3- liming, a procedure used for a few drugs e.g., ginger, nutmeg.

4- Low temperature storage is preferred than above methods. Exposure to subfreezing temperatures of 10-15C for 12-18hrs will destroy even eggs.

5- Exposure to alternate periods of low and high temperature frequently is more effective for killing insects than a prolonged period of low temperature exposure.









III- Safety measures:

Drug adulteration

Adulteration involves a number of different conditions: inferiority, spoilage, deterioration, admixture, sophistication and substitution.


From the standpoint of present day commerce, inferior, spoiled or deteriorated drug represent the greatest percentage of cases of drug adulteration.


1- Inferiority: 

Inferiority refers to any substandard drug or substance. The more restricted definition as applied to foods, drugs and materials produced by nature indicates a naturals substandard condition.


The dried, ripe seeds of Strychnos nuxvomica containing less than 1.15% of strychnine would be an inferior or substandard drug. If, on the other hand, this drug had originally contained the required 1.15% of strychnine had been partially abstracted with a solvent, the drug would be considered as adulterated or deteriorated. 

Milk, offered for sale at retail, is usually required to contain not less than 3% of butterfat. If milk containing 4% of butterfat has water added to it to reduce the butterfat to 3%, it is considered adulterated, but if the same milk has all the butterfat separated from it in the form of cream and then just enough of this cream is restored to the milk to give the required 3% of butterfat, it is not considered adulterated.

The standard for powdered opium is not less than 10% and not more than 10.5% of anhydrous morphine. Powdered opium containing a higher percentage of alkaloids may be admixed with inferior or exhausted powdered opium to bring the amount of alkaloids in the mixture to the stated percentage. Such an admixture is not constructed as adulteration.

The official compendia permit this practice to be followed for powdered extracts and they list the permissible diluents that may be used.

 2- Spoilage:

Spoilage refers to a form of substandard drug in which the quality or value or usefulness of the article has been impaired or destroyed by the action of fungi and bacteria as to render the article unfit for human consumption.

Many examples of spoilage are found in the food industry, particularly in fresh fruits, vegetables, meats, fish and seafood.

All drugs which are unfit for human or animal consumption are legally considered as adulterated.

3- Deterioration:فساد

It is applied to any impairment of the quality or value of an article by the abstraction or destruction of valuable constituents by distillation, extraction, aging, moisture, heat, fungi, insects.

1- Whole cloves from which part of the volatile oil has been removed by distillation "spent cloves".

2- Ground linseed from which part of the fixed oil has been expressed "linseed cake".

3- Lard in which the fats have to some extend decomposed to form fatty acids" rancid lard".

4- Powdered squill that has hardened through absorption of moisture.

5- Coffee that has largely lost its caffeine through over roasting.

6- Ergot that is moldy and rhubarb that has become "wormy" are examples of deterioration.

4- Admixture: مزيج

It is the addition of one article to another through accident, ignorance or carelessness. If the admixture is done intentionally to defraud, it is sophistication. Buchu containing a few stem or root with some adhering soil would be classed as admixtures. If, however, an admixture exceeds the established standard, it legally becomes an adulteration.

5- Sophistication:

It is addition of a spurious or inferior material to any article with intent to defraud. The addition of wheat flour to powdered ginger, with enough capsicum to restore or enhance the pungency and enough curcuma to maintain the color, would represent a typical example of sophistication (which is sometimes referred to as true adulteration).

6- Substitution:

It is occur when an entirely different article is used or sold in place of the one required or requested. A complete substitution, even through intentional and fraudulent, is none of the true article is present. All types of substitution are considered legally as adulteration. Cottonseed oil sold as olive oil and American saffron sold as Spanish saffron are examples of substitution.

Too often we hear the expression: “Since herbal products are natural, they are safe”. Unfortunately, this is not always true, due to a many factors including the following:


1- Factual information about many herbs is often lacking.


2- A portion of the information available about many herbs currently on the market may be exaggerated or misleading. This is especially true of some individuals and organizations that are mainly interested in marketing their products only for profit, with little regard for the consumer.


3-The lack of adequate quality control present in some herbal product companies around the world leads to variability in the quantity and quality of the products’ content. Added to this is the practice of mislabeling some herbal supplements, making the use of these products confusing, risky, or simply ineffective.


4- Fortunately, situation is now changing, as some herbal organizations that include competent technical staff are now establishing good manufacturing practices (GMP).  

 5- Some of the multilevel marketing schemes involving herbal products and other supplements tend to foster self-diagnosis, as well as self-medication, both of which can be potentially dangerous to the consumer.


6- Some herbal products which are new to the Western market, originating in Asia, Africa or South America, for example, have not been adequately tested for purity, safety or efficacy, prior to their introduction into the United States.


7- Some plants have not been adequately studied with respect to their use by special populations, including pregnant or lactating women, small children and the elderly, for example.


8- Interactions between herbal products and conventional medications can sometimes be serious. Much still needs to be learned about this important topic.







What are the risks of using natural herbs during pregnancy?

Although herbs are natural, not all herbs are safe to take during pregnancy. The FDA urges pregnant women not to take any herbal products without talking to doctors first and to consult a trained and experienced herbalist if they want to take herbs during their pregnancies. 

Herbs may contain substances that can cause: miscarriage, premature birth, uterine contractions, or injury to the fetus.


Herbs to avoid during pregnancy

 Rosemary is considered Likely Safe when used orally in amounts typically found in foods. (Rosemary has a Generally Recognized as Safe (GRAS) status in the US.) But in pregnancy, Rosemary is considered Possibly UnSafe when used orally in medicinal amounts. Rosemary might have uterine and menstrual flow stimulant effects. avoid using.


Garlic, Sage, Ginger and Tumeric, All of these herbs could be contraindicated in pregnancy when used in large or concentrated doses, but are considered safe when used in amounts found in food.

Saw Palmetto - when used orally, has hormonal activity

Goldenseal - when used orally, may cross the placenta

Dong Quai - when used orally, due to uterine stimulant and relaxant effects

Blue Cohosh - when used orally; uterine stimulant and can induce labor

Roman Chamomile - when used orally in medicinal amounts


Are there any herbs that are recommended in pregnancy?

Choosing to use herbs during pregnancy is a personal choice, but to ensure the best outcome for you and your baby, you should be well educated on

1-  the types of herbs,

2-  parts of the herb (root, leaf, etc…) and

3-  the way that they could be used (caplet, tonic, tea). 

The herbs that are considered safe to use during pregnancy are often food or tonic herbs. These often will be found in either tablet form, tea, or infusion form.


Herbs used in Pregnancy

The following herbs have been rated
Likely Safe or Possibly Safe for use during pregnancy:

1- Red Raspberry Leaf - Rich in iron, this herb has

- helped tone the uterus,

- increase milk production,

- decrease nausea, and

- ease labor pains.

Some studies have even reported that using red raspberry leaf during pregnancy can reduce complications during birth. 

Pregnancy teas that are made from red raspberry leaf to help promote uterine health during pregnancy.

There is some controversy about whether this should be used throughout pregnancy or just in the second and third trimester, so many health care providers remain cautious and only recommend using it after the first trimester.


2- Peppermint Leaf - Helpful in relieving nausea/morning sickness and flatulence

3- Ginger root - Helps relieve nausea and vomiting

4-Slippery Elm Bark - (when the inner bark is used orally in amounts used in foods) Used to help relieve nausea, heartburn, and vaginal irritations

5-Oats & Oat Straw - Rich in calcium and magnesium; helps relieve anxiety, restlessness, and irritated skin

6-Garlic - when used orally in amounts commonly found in foods

7-Capsicum (hot pepper) - when used topically and appropriately.


The following herbs have been rated as having Insufficient Reliable Information Available by the Natural Medicines Database, although many are recommended by homeopathic physicians, herbalists, and midwives who treat pregnant women. 

1-  Dandelion - Rich in Vitamin A, calcium, and iron; dandelion root and leaf can also help relieve mild edema and nourish the liver


2-Chamomile (German) - High in calcium and magnesium; also helps with sleeplessness and inflammation of joints

3-Nettles (Stinging Nettles) - High in vitamins A, C, k , calcium, potassium, and iron. Used in many pregnancy teas because it is a great all around pregnancy tonic.


1, 2, 3 Natural Medicines Database

4 Women's Health Series: Herbs of Special Interest to Women. J Am Pharm Assoc 40(2):234-242, 2000.

5 Raspberry leaf in pregnancy: its safety and efficacy in labor. J Midwifery Womens Health. 2001 Mar-Apr;46(2):51-9. PMID: 11370690

6 Belew, C Herbs and the childbearing woman: guidelines for Midwives. J Nurse-Midwifery 1999;44:231-252

An outline of Quality Control Techniques


1-GC – MS: is a very powerful analytical equipment which measures chemical constituents which are volatile or can be made volatile such as Fatty acids, Phytosterols, Terpenoids etc.

The equipment is very sensitive and even a very small amount of active component can be identified and quantified.


2- Atomic Absorption Spectrometer (AAS)
To ensure quality and safe products. AAS is a very popular analytical instrument for the low level analysis of different heavy metals (Lead, Arsenic, Cadmium & Mercury) / and any trace elements upto part per billion (ppb) level.


3-Standardization & Quality Control Of Herbal Ingredients
An essential factor in the assembly of any herbal product is the availability of qualitatively standardised herbal ingredients.




4-Identification and authentication of plant material

Preserve and maintain Specimen and Database containing full information on all plant species of our interest. Every herbal ingredient is authenticated by experts, involving macroscopic and biochemical examination of each plant material. Complete phytochemical fingerprinting is obtained and compared with the respective standards.



Safety measures
It has established procedures for ensuring that contaminants do not enter in the product during cultivation and processing.

We ensure that no adulterant is present in raw herbs. Material is stored in dry and clean conditions to avoid any fungal/bacterial infestation.


Batches of herbs are checked for pesticidal residues and heavy metals, to avoid any possibility of their contamination from adjacent fields.





King   Saud University. All rights reserved, 2007 | Disclaimer | CiteSeerx