4. When the rider on the scale is used, return it to zero after each weighing.
5. Recheck the “balance” of the instrument after each substance is weighed.
6. Clean and properly secure the balance when weighing is completed.
Care of the Balance
1. Never add or remove items from the balance unless the balance is locked. It is the small knob at the bottom front of the balance. When this knob is turned all the way to the right, the balance beams will not move and are referred to as “locked.” When this knob is turned all the way to the left, the balance beams will move to give the operator a reading. This position is referred to as the “unlocked” position.
2. Keep in a closed case in a dry, protected place.
3. Never leave the balance unlocked when not in use.
4. Handle weights with forceps to avoid collection of foreign matter that can cause inaccuracy.
5. Clean only with a dry rag. Never use any liquid on the balance.
6. Always protect the pan with paper. Waxed paper is best.
7. If the balance is to be moved for any distance, consult Remington’s Pharmaceutical Sciences for instructions on how to secure the balance to prevent damage.
PHARMACEUTICAL PREPARATIONS
SYRUPS
Syrups are concentrated aqueous solutions of sucrose, containing flavoring or medicinal substances.
Methods of Preparation
In preparing syrups, the sucrose may be dissolved with the aid of heat, by agitation, or by percolation. The process to be used depends upon the ingredients of the syrup and the time available for completing its manufacture.
USES: Many of the syrups are used as vehicles. Their sweet taste causes them to be a preferred form for the administration of drugs.
EXAMPLES: Simple Syrup; Syrup of Orange
ELIXIRS
Elixirs are aromatic, sweetened hydroalcoholic solutions containing medicinal substances. They are liquids having an aromatic odor and a pleasant taste. The color of elixirs varies according to the nature of the ingredients; some are artificially colored.
Methods of Preparations
Simple solution is the general process employed in preparing elixirs. Many are prepared, however, by adding the medicinal substances directly to aromatic elixir, which is an elixir-base. While elixirs are very simple to mix, it should be noted that most elixirs are very difficult to filter, and since most elixirs require filtration, suction filtration is the recommended method.
USES: Used internally. Their uses vary according to their ingredients.
EXAMPLE: Elixir of Terpin Hydrate
LOTIONS
Lotions are liquid preparations, usually aqueous, containing the insoluble substances intended for external application. The insoluble ingredients must be in very fine particles to prevent irritation to the skin. They are dispensed with “Shake Well” labels and “External Use Only” labels.
USES: The use of each lotion is determined by its respective ingredients.
EXAMPLE: Calamine lotion
SUSPENSIONS
Suspensions are coarse dispersions comprised of finely divided insoluble material suspended in a liquid medium. In order to keep the insoluble material in suspension, a third agent, called a suspending agent, is required.
Method of Preparation
There are no general methods for the preparation of suspensions; however, in order for the insoluble ingredients to remain in suspension, they