On the Use of Wax, Tallow, Etc., in Suppositories, part 2.
By CHARLES L. EBERLE.
(Concluded from last number.)
Slow manipulation with a mixture of wax and cacao-butter before hardening, we can readily understand, would cause a granulation of the wax, and produce a cone in which the heat to which it is to be subjected would act only upon the cacao-butter, to the exclusion of the wax, which would then remain unchanged, causing irritation and difficulty; but we are only supposed to be dealing with mixtures which have been well stirred to the time of their introduction into the mould, which mould has been thoroughly chilled, and the suppository likewise. Under such circumstances the mixture is uniform and perfect, and shows no disposition to separate on fusion, if the heat be maintained at that point.
The difficulties in a proper understanding of the preparation of suppositories without the addition of a hardening ingredient in connection with cacao-butter have been solely those of manipulation.
Experience is leading many to prepare the excipient with a smaller proportion of wax, spermaceti, &c., than they at first thought necessary, until the quantity used by some is so trifling as to practically amount to little or no use.
Of the various mixtures, those of one-eighth spermaceti or one-fourteenth or less of wax are least objectionable. Tallow suet or paraffine produced no results not secured by the first-mentioned, while there were some objections to be attached to their use not present in the others.
Now while some have discovered points of manipulation to make these suppositories of cacao-butter alone, rapidly and well (and how much often hangs upon a very slight thread in this respect), far exceeding in value those I am about to offer to you, I will simply state the mode which gives me the most satisfactory result.
The mould is of brass; a clamp hinged at one extremity and handled at the other, held firmly in place by a ring slipped over said handles; the cones are turned from the interior face of the clamps, as in an ordinary bullet-mould. It should mould at least one dozen, and be improved by the addition of a loose clamp, to be attached firmly in the centre and it the bottom of so long a tool, to prevent the loss of the fused mass before congealing, by running from between the plates.
This mould should, so far as possible, be thoroughly chilled and ready for use. To place the fused butter in the mould while it is warm, and cool both by the same operation, almost invariably results in the contraction of the metal upon the cool cone to a degree that upon the attempted separation of the matrix every cone will be split in two. When the mould is thoroughly cooled, the butter sets rapidly, and in fifteen or twenty minutes the suppositories will drop from the matrices by their own gravity.
The deductions I draw from a close observance of this subject for the past two years axe, that the addition of a substance such as wax, spermaceti, &c., to cacao-butter produces a mixture requiring a higher point of heat for its fusion, and in proportion to the amount of such addition; and that when such addition is made, if it should not be sufficient to prevent the fusing of a suppository at animal temperature, no irritating or harmful effect is produced either upon the vagina or urethra. Where a larger quantity than that mentioned above is added, the annoyance produced requires the removal or ejection of the suppository before any harm may be done.—Proc. Amer. Pharm. Assoc., 1870.