Martin A. Erickson III, RPh
Your Compounding Questions Answered
I have an Rx for compounded rectal suppositories, but the drug is thermolabile at 45°C, which is cooler than melted suppository vehicles. What should I do?
Cold-rolling, or compressing, suppositories is a valuable technique that is rarely used today. The following processes must be performed quickly. It is wise to practice with “blanks” for technique and to help with density measurements.
1) Heat a ceramic or Wedgwood mortar in hot water, dry thoroughly.
2) Add the active ingredient, and triturate to a fine powder. Add a small amount of ethanol, if needed, and some shaved or flaked fatty acid blend suppository vehicle.
3) Continue triturating to a uniform mass—the friction and warm mortar will soften the vehicle—and then geometrically add more of the vehicle with trituration until it is worked into the mass. A small amount of lanolin may be helpful, depending upon characteristics of the active ingredient.
4) Form the material into a rough ball with a spatula while it is still in the mortar, then remove the mass onto a piece of parchment paper. Fold the paper over the mass, and roll the mass to a uniform, compressed ball using the hands.
5) Transfer the ball to a clean pill tile with a hard surface, cover with the parchment paper. Using a smooth board and compression, form a “pipe” by rolling the suppository mass back and forth between the board and the pill tile.
6) If you have confidence the pipe is not hollow, and provided your pill tile has hash marks previously calibrated to yield a uniform dose, use a spatula to cut the pipe into equal lengths. (If you have access to an aluminum suppository mold, the soft pipe can be rolled sufficiently to fit into the warmed mold’s suppository cavities.)
7) When the suppositories have cooled, a pointed or rounded end can be formed on each with the fingers, using a piece of parchment paper to separate the fingers from the suppository.
The prepared suppositories must be wrapped individually before dispensing. The suppositories are friable and the patient must be cautioned to handle them carefully. Prepared compressed suppositories should also be labeled to refrigerate. PT
Mr. Erickson is director of professional affairs at Gallipot Inc.