Pharmacy and Dispensing.
Pharmacy and Dispensing are classified together under the heading of PHARMACOLOGY.
Pharmacy deals with the making of extcacts, tinctures, pills, tablets, etc., whilst DISPENSING deals with the mixing of these preperations and putting pills, tablets, etc., into suitable containers for the patient.
These are books of standard formulae. In Britain the ‘British Pharmacopea’ is the volume that lays down the standard for drugs prescribed by the accepted orthodox medical profession. You will find that most hospitals have there own pharmacopoeas, in which they list their own formulae. Within the medical profession it is found that prescriptions are written in Latin, but in the herbal profession, where the patient seldom handles his prescription, it is customary to dispense the medecine on the premises.
Prescriptions need to be built up intelligently and dispensed accurately. There is no room in modern herbal practice for a ‘handful of this or a handful of that’. Such practices may still be practiced by ordinary persons but are not the ways of the professional. It is necessary to prescribe individually for each patient. This prescription should be built up from the totality of the symptoms, the signs of the disease and your examination. However, for the beginning practitioner, he or she may use a general compound for the disease, to enable him or her, to carefully examine the diagnosis. On the second visit a properly formulated prescription should have been prepared. In a busy practice, such compound formulae, can be used for uncomplicated cases, i.e. For the common cold, mild cough, etc..
When the medicinal virtues to be extracted are soluble in water, slightly volatile, then boiling water is the menstruum. It is poured upon the herbs of which the infusion is required. The container is carefully covered and the contents are allowed to remain untouched for a short or long time, depending on the permeability of the herbs. Again, it is also dependent upon the strength of infusion desired.
If an infusion is required from dried leaves or flowers, they are first moistened with a small drop of boiling water. They are then allowed to moisten and swell for a short period of time, before adding the remaining boiling water. Infusions produced by adding all of the boiling water at once, are still frequently made, but they are deficient in both flavour and perfume.
The infusion of all herbal matter that does not exert a very powerful action upon the human economy, may be made by pouring on a pint of boiling water upon the roots, herb or bark, and allowing it to macerate for from one half hour to one full hour. The dose of the infusion is normally from one to two ounces (one or two wineglassfuls), three or four times a day.
It can be taken as a general rule, that for herbal substances that abound in woody fibre, and contain but little extractive matter, that a third or fourth part of 40% alcohol added is a sufficient quantity for their extraction and preservation. Those that abound in mucilage, or that really soften or become pulpy and gelatinous in weak spirit, Two or three parts of 40% alcohol is required.
The preperation of Decoctions.
Decoctions are solutions of the medicinal virtues of herbs that are obtained by boiling with water. It is often a more effective way or extracting the medicinal virtues than the simple infusion.
In the manufacture of decoctions, the herbs either roots, barks, leaves, stems etc., should be well bruised or ground into powder. Or, if they are fresh and soft, they should be sliced into very small portions.
If the herbs are dried and have been ground into powder, it should be sieved to remove any very fine dust. If not sieved, the very fine dust will compact making the decoction thick and very difficult to strain.
The container in which the boiling is to be conducted, must be fitted with a tight lid to exclude the air and to prevent the steam from escaping. The heat source should be regulated so that the brew is just simmering or gently boiling. If it boils violently, it will injure the medicinal virtues and the finished decoction will have lost its medicinal potency.
The resultant decoction should be strained whilst hot, but not boiling. This should be through a hair sieve or other filtering device. It will be found that as the decoction cools, a sediment forms. This is because, in a decoction the boiling water dissolves a greater amount of vegetable matter than an infusion.
This deposit is rich in the medicinal virtues and should not be rejected. It should be shaken vigourously when it is administered to the patient. You will see, that the practice of leaving the decoction to become cold before straining is an unwise one.
A decoction with a sediment is not attractive to look at, but its value is far superior to those that are clear and usually inert. Long boiling is unnecessary and should be avoided, especially in decoctions that are prepared from aromatic herbs, or those containing large quantities of extractive material.
Most decoctions should, in their formulas, include directions on the amount of time that they should be boiled, for instance: ‘to be boiled for a short time’, or for ‘ten minutes’ or they should stipulate ‘boil down to one pint and strain’. In the latter case, this method is employed where the drug does not suffer from boiling.
Distilled water (aqua dest) should be used in the preperation of decoctions, as any other water usually has impurities within it, and may contain large quantities of lime or chlorine, thus reducing its solvent action.
Decoctions of all herbal matter not exerting a powerful action upon the human economy may be made by boiling a specific amount of water, for say, fifteen to twenty minutes.
When the medicinal virtues of herbs are volatile or injured by strong heat, an infusion should be prepared in preference to a decoction. If however, a solution of the fixed constituents is sought, a decoction is preferable.
In the preperation of Compound decoctions, those ingredients should be boiled first which least readily impart their virtues. Those herbs that most readily impart their virtues are added afterwards. In most cases it would be better to infuse the more volatile and aromatic herbs and then add the strained infusion when cold. In this way, the properties of all the herbs will be retained, and the properties of the most delicate herbs will not be damaged or destroyed by the heat of the decoction.
A tincture is a solution of the active principles of any substance in rectified spirit, the spirit being the direct menstruum of the resin, essential oils, and vegetable matter of the substance. The virtues of many vegetables are extracted direct equally by water, but in the watery and spiritous tinctures of them, there is the difference that the active parts in the extraction are blended with a large proportion of inert gummy matter, on which there solubility in this menstruum in a great measure depends, while spirit extracts them almost free from gum. Tinctures are generally made in the strength of one or two ounces of drug to the pint of menstruum. Alcohol is used as a menstruum.
- When the solvent is not soluble or only sparingly soluble in water – such as resins.
- When the watery solution is extremely perishable – example, garlic.
- When the use of alcohol is indicated as well as that of the solvent.
As we cannot assist the solution by means of heat, we must facilitate by the mechanical division of the solvent. A coarse powder often answers best, when too fine, it is apt to settle agglutinate.
Please note at the commencement of this article on tinctures, in the first sentence we mentioned ‘rectified spirit’ this is spirit that is 95% pure alcohol.
Methods of Preperation of Tinctures.
The bruised material is allowed to remain in contact with the whole of the menstruum in a closed vessel for a period of seven days, agitating at intervals. The liquid is then poured off and the mush submitted to pressure, when more liquid is obtained. The two liquids are mixed and then filtered.
The bruised material is thoroughly moistened with a portion of the menstruum and is then packed in a percolator and exhausted by allowing the remainder to trickle slowly through. The marc is removed, submitted to pressure and the expressed liquid, which is necessarily weak in extraction, is mixed with the percolate, sufficient of the original menstruum being added to produce the volume required.
|Herb||% Alcohol||Ounces to pint||Dose|
|Asafoetida||70||4||10 to 60 drops|
|Aurantia||80||5||10 to 60 drops|
|Buchu||60||4||10 to 60 drops|
|Calumba||60||2||10 to 60 drops|
|Capsicum||80||6||1 to 3 drops|
|Hydrastis||60||2||10 to 60 drops|
|Limonis||90||4||10 to 60 drops|
|Myrrh||90||4||10 to 60 drops|
|Serpentaria||70||4||10 to 60 drops|
|Tolu||90||2||10 to 60 drops|
|Valerian||60||4||10 to 60 drops|
These, as the name signifies, contains several ingredients.
Tincture of Aloes Compound Tincture.
|Aloes crushed||0.5 ounce|
|Gentian No. 20 powder||0.5 ounce|
|Rhubarb No 20 powder||0.5 ounce|
|Alcohol (60%)||18 fluid ounces|
|Tincture of Myrrh||Q.S.
(This means sufficient quantity.)
Macerate the drugs in the alcohol for seven days with frequent aggitation, strain and press. Mix the liquids and make up the volume with the Tincture of Myrrh to 20 fluid ounces. Dose: 10 to 60 drops.
These preperations are somewhat hard and are midway between ointments and plasters. They are often spread upon linen and do not melt and run when applied to the skin. They are often made of wax or spermaceti in combination with lard or oils. The ingredients are melted together over a gentle heat. After they are combined they should be allowed to cool, but should be stirred all the time until set.
Take of resin, five ounces; lard, eight ounces; yellow wax, two ounces. Melt together with a gentle heat, and stir until cool. The common name for this cerate is Basilicon Ointment. It is used as a gentle stimulant and can be applied to blistered surfaces, indolant ulcers, burns, scalds and chilblains.
Compound Resin Cerate
Take of resin, suet and yellow wax, each a pound. Melt together, strain through linen and stir until cool. This was used in the same way as the resin cerate.
Take lard, eight ounces; white or yellow wax, four ounces. Melt together and stir till cool. Used for dressing blisters, wounds, etc., where it is desirable to keep the part moist and free of air.
Confections, Conserves and Electuartes
These are a soft solid base, in which medicinal articles are incorporated with sugar, syrup or honey. The Sugar, syrup or honey has a preservative effect and also masks the taste of the medicine, making it more palatable and also convenient to use.
Take of aromatic powder, five and a half ounces; syrup of orange peel, six ounces; clarified honey, two ounces. Rub the aromatic powder with the syrup and honey, and beat the whole together in a mortar until they are thoroughly mixed. This is a very useful remedy in debilitated conditions of the stomach or, as a vehicle for other medicines. The aromatic powder may be made from cinnamon, ginger and other pleasant spices. Mix one drachm of this with powdered herbs and take. Ideal for administering to children.
Confection of Senna. (Lenitive electuary).
Take of Senna, eight ounces; Coriander seeds, Four ounces; Bruised Licorice root, three ounces; Figs, one pound; Pulp of Prunes and Pulp of Tamarinds, of each ¾ of a pound; Refined Sugar, two pounds and a half; Water, four pints. Rub the Senna and Coriander together and seperate ten ounces of the powder with a sieve. Boil the residue with the licorice and figs, in the water, to one half; then press out the liquor and strain. Evaporate the strained liquor by the most gentle heat, to a pint and a half; then add the sugar to form a syrup. Lastly, rub the pulps with the syrup, and gradually, and having added the sifted powders, beat all together until well mixed. This is a pleasant and admirable laxative, being well adapted to the habitual costiveness of pregnant women, and those affected with piles.
These are generally prepared by dissolving one ounce of the essential oils of plants in one pint of alcohol. The oils of Lemon, Peppermint, Sassafras, etc., are made in this way, and their properties of course, are similar to the oils from which they were prepared. They are generally taken in a little sweetened water, in a dose of ten drops to a teaspoonful.
These are soft solids, obtained by evaporating the tinctures or solutions, of vegetable substances. The active principle of dried vegetables can only be extracted by some liquid; this, for preparing extracts, is either water or alcohol, or a mixture of the two. Those obtained by the use of water are called AQUAOUS, or watery extracts; those by means of alcohol, ALCOHOLIC extracts; and those by both alcohol and water, HYDRO-ALCOHOLIC extracts.
Pills are small spherical bodies. They are widely prescribed because they provide a convenient method for administering bitter or unpleasant substances, and they retain their activity for a long time. Being small in bulk they are conveniently carried.
There are four main requirements for a good pill and a fifth is also desirable.
The first requirement is solubility.
The pill should readily disintegrate in the alimentary or intestinal tract. This is most important. Most pills when freshly made accomplish this, but it is not always so. Some pills that are manufactured in large quantities fail to conform. In the manufacture of pills in large quantities, sugar or talc are used to coat the pill. If the coating is applied as soon as they are made, the pill is liable to shrinkage and the coating cracks and falls off. This can often be prevented by exposing the pills to heat while they are placed in shallow trays. When quite dry and hard they are then coated. Pills produced in this way are often dry and hard and can progress through the body without breaking down.
The second requirement is thorough mixing.
For the dosage to be accurate it is essential that the ingredients should be thoroughly mixed and evenly distributed throughout the pill mass.
The third requirement is uniform weight.
This is coupled with thorough mixing in order to ensure the correct dose.
The fourth requirement is a uniform shape.
This is essential so that the pill may be swallowed easily. To aid in swallowing, pills are manufactured round or oval. Theoretically the oval pill is the most advantageous. The shorter diameter enables entry more easily into the oesophagus.
The fifth requirement is tastelessness.
Pills should be coated preventing contact with the ingredients and the mucous membrane. If in direct contact with the mucous membrane the taste of the pill ingredients would be, in many cases, unpalatable. Sugar coating, varnishing or silvering, does not appreciably delay disintegration, as they are quickly washed off in the alimentary tract. Coating not only renders the pill tasteless but it also aids in the retention of the pill mass. It prevents oxidation and the loss of volatile constituents.
Pills are made from pill masses that derive their substances from several groups. Firstly, there is the active medicinal ingredients. Secondly, a diluent is needed when the quantity of active ingredient is very small. Thirdly, an excipient, which is a substance necessary to form the mass. It needs to be firm, elastic and adhesive, and of course soluble in the gastric juices. The excipient may be in the form of a binding agent which assists adhesion of the particles; or it can be an absorbing agent, as in pills containing oils; or it can be fluid or semi-solid to plasticize the mass. The excipient is probably one of the most important factors in manufacturing pills.
The following stages are necessary for the manufacture of pills:-
- Preperation of the pill mass.
- Rolling, Cutting and Rounding.
Preperation of the Pill Mass.
First, Thoroughly mix all the dry ingredients in the ascending order of quantity, all must be in very fine powder.
Secondly, Add any fluid ingredients and thoroughly mix by trituration.
Thirdly, Add the fluid excipient, a little at a time until a proper consistency is obtained.
Next, we come to the process of Rolling, Cutting and Rounding. The whole of the mass is then rolled on to a flat board to the length of the number of pills required. It is important that the cylinder of pill mass is uniform throughout. The cylinder is next severed through the length to produce equal portions of pill mass, of the size required for rolling into pills. Rolling is started with the fingers and is finished beneath a suitable piece of wood. To prevent the cutter adhering to the pills, it is dusted with powdered licorice root, in the case of dark pills, and kaolin for light coloured pills.
Coated pills are more stable than uncoated pills and of course have a much nicer appearance.
First, Make a mixture of icing sugar seven parts and starch one part.
Second, A mixture of equal quantities of mucilage of Acacia and syrup for moistening the pills.
A quantity of the first, sufficient to cover the bottom of a pot is placed within. The pills are moistened with the second, and the damp pills are dropped into the pot and rotated for a minute. They are then transferred to a clean pot and again rotated. This second rotation serves to detach any loose particles, leaving only a thin coat on the pills. They are allowed to dry for fifteen minutes, and a further coat should be applied in the same way. A further two coats should be applied in the same way, making four coats in all.
This is a soluble coating and is quite satisfactory for hard pill masses. The solution is twenty grams of gelatine and water to make up one hundred grams in weight. Soak the gelatin in sixty mils of water until softened, then beat until dissolved, the, add the remainder of the water.
A gelatin coating apparatus can be improvised by mounting long needles on a cork. The pills are impaled on the ends of the needles. He pills are then lowered into the gelatin for a few seconds. When they are withdrawn, they should be shaken to throw the surplus gelatin solution off of the pills. Rest the cork upon its side for a half hour and allow the coating to dry. The pills are then detached. Where the needles were inserted in the pills a small hole remains. With a piece of glass rod a drop of the gelatin solution is applied to the hole and sealed. Allow the gelatin to harden and then put the pills into pill containers.
Coating for Enteric Pills.
Certain substances are used as a protective coating for pills to enable the medication to be carried through the acid fluids of the stomach, so that the pills will not dissolve until they reach the alkaline fluids of the intestines. These coatings are used for substances that irritate the mucous membrane; substances that are decomposed or rendered inert by the gastric fluid; substances that are intended for action in the intestines.
Pills coated in this way are called enteric coated. Treatment of a gelatin coat with a solution of Formaldehyde. The gelatin coated tablets or pills are immersed in a solution of formaldehyde for ten minutes. This is the best method for the following reasons:-
- The pills are always correctly enteric.
- There is no danger of the coating cracking off by rough handling.
- The gloss appearance of the pills is uaffected.
- It requires no special apparatus.
- It is most convenient.
Pills are normally packed in screw capped bottles with a small piece of cotton wool within the neck to prevent motion from damaging the coating. Recently, the practice has been adopted of sending large quantities within polythene bags contained within cardboard boxes.
2nd Part to Follow.