On Benzoating Ointments Extemporaneously.
By CHARLES F. BOLTON.
An Inaugural Essay.
The subject of benzoin in ointments has for some time past attracted the attention of the profession, and there is nothing in the whole range of Pharmacy that gives more satisfaction than a perfect ointment, not only to the druggist who dispenses it, but also to the physician who prescribes, and the patient who uses it. There is nothing that reflects more credit on the Pharmacist than an elegant and well dispensed ointment. To accomplish this requires not only experienced manipulation, but something more; it needs that the unctuous matter should be fresh and free from the least trace of rancidity; it should not only be this way when dispensed, but if possible should be made in such a manner that it would remain in a perfectly sweet condition for a considerable length of time, thus affording the patient an opportunity of using the whole of the ointment in a sweet state. This can be effected in many instances by using the officinal unguentum benzoini as the base of the ointment, but often the physician directs the ointment to be prepared and benzoated extemporaneously. To benzoate the ointment by the officinal process involves time, but by the plan that I suggest it can be accomplished in a very short time without the aid of heat, thus saving a great deal of time and trouble. In many instances time is quite an important object. The formula that I have decided upon, after making several experiments, is as follows
|Rx||Benzoin pulv. (select.)||℥ij.|
Introduce the benzoin into an eight ounce bottle, add the ether, macerate for twenty-four hours with frequent agitation, pass through a filter, to the filtrate add ol. ricini, and shake until dissolved; then transfer to a shallow vessel in order to allow the ether to evaporate spontaneously; lastly, when the ether has entirely disappeared, place in a wide-mouthed bottle ready for use. With a view to economy I experimented with alcohol and benzine as solvents; the former of the specific gravity .817 gave moderate satisfaction, the result being of a much darker color, owing to the foreign matter in the benzoin being more soluble in alcohol than in ether; this I considered a serious objection, as it discolored the ointment considerably, while that made with the ether did not, at least not more than if it were benzoated by the officinal process. The benzine experiment, however, was a complete failure, it extracting from the benzoin only a very small amount of benzoic acid, leaving entirely undissolved the resin, cinnamic acid, and volatile oil. The result from the formula that I have given is of the consistency of a soft extract, one ounce of the extract fully representing an ounce of the benzoin in a state that is perfectly miscible with unctuous substances. I benzoated several ointments with this extract in the early part of last April, and allowed them the greater portion of the time to be exposed to the atmosphere, and when I examined them in the fall I could find none of them oxidized in the least, and in the case of ung. hydr. oxidi rubri the bright orange color was perfectly preserved. I also used it in several prescriptions and it always gave perfect satisfaction. I used it in the proportion of half dram to the ounce of ointment; it call also be used very advantageously in preparations for the hair, it being very soluble in alcohol and perfectly miscible with Ol. ricini in combination with alcohol, but insoluble in the fixed and volatile oils in a free state. It is also freely soluble in chloroform.