728 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS of constituents of sticks, standard cocoa butter and an interesterified hy- drogenated palm oil were studied first. Although this paper is concerned primarily with suppositories, the data presented here are also applicable to sticks and pencils. The use of sup- positories in pharmacy is widespread. It may be recalled that they are generally obtained from a base mass (mixtures of fatty substances and ac- tives) by melting and pouring into molds of different types. On removal from the mold, the suppository is smooth and bright. Although it is de- sirable to retain this appearance, different surface defects become apparent after more or less prolonged storage. These defects may include spots, excrescences, exudates, circinate forms, bloom, etc., all of which may be due to different causes. Description of Surface Defects Two simple cases, which can be easily remedied, will be examined first., The third case, mentioned below, is the major concern of this presentation. 1. An almost complete coating of crystals on the suppository can some- times be found. These crystals are chemically not related to the fatty substances comprising the bulk of the suppository. Such a case is repre- sented in Fig. 1, which shows the appearance of the surface of a suppository containing caffeine. This sublimable substance, which originally was distributed throughout the mass, diffused to and crystallized on the sur- face. This behavior is not necessarily a characteristic of sublimable substances. Such a phenomenon can also occur if one of the components of the sup- pository is soluble in a solvent, as is the case with essential oils. This de- fect can often be avoided by enclosing the suppository in a hermetically sealed film which also touches the surface of the suppository, (e.g., alu- minum foil). 2. When the suppository contains aqueous solutions or extracts emulsi- fied or dispersed in the fatty substance, the surface defect might be either dull white spots (Fig. 2) or gray spots (Fig. 3). This defect is caused by mold, and the odor is always characteristic. The addition of an antifungal agent to the preparation generally corrects this condition. 3. Aside from the foregoing easily explained phenomena, there are more complex surface anomalies. They are excrescences due to the fatty substance itself, generally called bloom or liquid exudate. The formation of bloom (which is not necessarily white at the outset) is well known in chocolate manufacture. It has also been observed in cos- metic products, such as eyebrow pencils and lipsticks. The formation of surface defects is increased by the use of cocoa butter as the base (or of fatty substances or mixtures of fatty substances with analogous properties) and by storage at high constant temperature.

THE STUDY OF SURFACE ANOMALIES OF FATTY SUBSTANCES 729 Figure 1.--Surface of suppository with Figure 2.--Suppository with white surface crystallized caffeine (12X). mold (12X). Figure &--Suppository with gray surface mold (12X). These defects are also more likely in the presence of small quantities ot very finely powdered substances in dispersion in the fatty phase. Under these various conditions, defects appear rapidly and abundantly. Surface anomalies of this type appear to be due to changes in crystalline structure however, is just one or are several phenomena involved? Chocolate bloom has been the subject of considerable research (1-6), and a general review by Andersson (7) summarizes the theories of these authors. Not only were theories formulated, but remedies were proposed and solutions were found which considerably diminish chocolate bloom. Today good quality chocolate remains bright at 25øC and forms no bloom,