Sapo Durus

A prescription which turns up periodically, and which hails from Buxton, is-

This is really a cipher prescription : what the prescriber wishes the patient to get is lin. potass, iodidi c sapone.

Thymol should only be combined in a state of solution. A good way of compounding is to add about its own weight of camphor and rub them together. These form an uncrystal-lisable fluid. Crystals of thymol are exceedingly irritating.

In this case dissolve the thymol in the lard by the aid of a gentle heat, and mix with the lanoline and other ingredients, previously incorporated.

Tinctures and other spirituous substances are not easily combined with fat. Ordinary soft lard will take up one-fifth, hard lard will take up one-sixth, of its weight of tincture. To mix them, the lard or other fatty substance should be spread evenly on the bottom and sides of the mortar, and the tincture added gradually. A little soap-powder, if permissible, greatly facilitates the combination,

To compound this without alteration of the formula, place the ointment in a mortar, add the liniment drop by drop, and stir constantly. The ammonia in the liniment combines with the fat of the ointment to form a soap, thus greatly assisting the compounding. This method requires considerable care.

Unguentum Domesticum is the name given by Unna to a mixture of yolk of egg, 2 parts, and almond oil, 3 parts, 1 per cent of Peruvian balsam being added as a preservative.

This is particularly adapted for balsam, tar, and ichthyol preparations, with or without additional fatty matter, especially when watery ingredients have to be added. The vehicle has great water-absorptive power.

Vasogen

The commercial product is an ointment-basis. See C.& D., 1906,1.514, and 'Pharmaceutical Formulas,'p. 819.

Sending Out Ointments

If the patient can afford it, always send out ointments in covered pots. If not, use chip boxes, preferably flat shape, previously dipped in melted hard paraffin. Tins are now largely used for ointments; those with rounded bottoms are best. The dispenser must use his discretion as to what he puts into them. They are not suited, for example, for ointments containing active chemical substances or much water. It is customary to cover with 'waxed paper.'Preference should be given to paraffined paper: wax or stearin paper is often rancid, and affects the ointment. When ointments are of a semi-fluid character, or if very volatile ingredients are present, a wide-mouth stoppered bottle should be used. Very poisonous ointments should be labelled 'Poison' on the pot as well as on the lid.