Aids to practical dispensing / by C.J.S. Thompson.

  • Charles Thompson
Date:
1902
Catalogue details

Licence: In copyright

Credit: Aids to practical dispensing / by C.J.S. Thompson. Source: Wellcome Collection.

    39/108 (page 27)
    to remove an ugly precipitate or resinous deposit to improve the appearance of a mixture, the dispenser is not justified in doing so, and depriving it perhaps of an active ingredient. A mixture should be strained only when it is desired to remove any substance that should not be present. Drops and Draughts.—The term ‘drops’ is usually applied to a liquid medicine that is ordered to be taken in doses of from one drop to a teaspoonful. ‘ Drops ’ generally consist of a tincture or other spirituous pre- paration undiluted with water. They rarely cause the dispenser any difficulty, and are generally dispensed in glass-stoppered bottles and sent out capped with skin or leather. ‘ Drops ’ intended for application to the eyes require very careful preparation, and great exactness should be exercised in weighing and measuring. Minute quantities of such alkaloids as eserine or cocaine are frequently prescribed by oculists, and when the amount ordered is unweighable on the dispensing scale, a solution of definite strength should be made, and the exact quantity can then easily be calculated and measured off. Eye drops should be neutral, and tested with litmus paper before sending out. It is customary to dispense them in special bottles, the stopper of which forms a dropper by which they may be applied. If any of the ingredients used are affected by the action of light, the bottle should be covered with paper, or one of coloured glass used. The ‘ draught ’ is the term applied to a liquid medicine usually of from i to 2 ounces in quantity, the whole of which is to be taken for a dose. At one time this was a very popular form for administering medicine, and it was customary formerly to dispense mixtures in the shape of draughts, six, eight, or twelve, as ordered, each bottle containing one dose. The compounding of draughts seldom presents any special difficulty. When several are to be prepared, the best method is to mix the whole quantity required in a glass measure instead of making each draught separately, and when complete fill up the requisite number of bottles. In cases when more than one dose is dispensed in a bottle, an equal division should be accurately marked on a slip of paper and pasted up the side of the bottle.