On the Preparation of Suppositories.
By ROBERT F. FAIRTHORNE.
Having noticed in the journals recently quite a number of articles on the above mentioned subject, and finding that the experience of the writers differs from mine in some respects, I thought that I would add to the general fund by giving the method which is employed in Mr. Shinn's store for preparing suppositories. The following plan has proved satisfactory in every respect:
The moulds (made of white metal and of the usual form) are suspended in ice water by means of a perforated tray, which is supported on the surface of the water. These are placed in the water a minute or two before using, so as to become thoroughly chilled, thereby preventing the suppositories from sticking.
The requisite quantity of butter of cacao having been weighed, is cut into thin slices by means of a knife. If an extract or other substance, soluble in water, is employed as the medicating ingredient, it is rubbed up with a small quantity of that liquid and reduced to the consistence of syrup. When this is accomplished, mix it with all the butter of cacao by trituration. Transfer the mixture to a capsule and heat it over a spirit lamp, constantly stirring with a spatula. When it is scarcely melted and about as thick as cream, pour into the moulds. So much heat should not be applied as thoroughly to melt the butter, but only just sufficient to render it thin enough to pour.
The suppositories must be allowed to remain at least fifteen minutes in the moulds surrounded by ice water, after which they may easily be removed by tapping the mould on the counter. They will be found when thus made to be hard and smooth. They keep well for several months, and if placed in a moderately cool place, such as a cellar, will remain unchanged even in the hottest weather.
The several points deserving special attention are, that butter of cacao alone will produce suppositories sufficiently hard for the purposes to which they are applied (except when camphor or other essential oil is introduced as the medicating ingredient, in which case the addition of a little wax or spermaceti is necessary), that the extract or other substance used is, by this process, first uniformly disseminated through the butter of cacao whilst cold, that substance being reduced to powder by trituration; that the cacao butter, &c., are kept constantly stirred when being heated, and that the mixture is only reduced to the consistence of cream by carefully regulating the amount of heat applied, so as to avoid the danger of deposition of extract, which always occurs when it becomes too thin from the use of too much heat.