Lactose suppositories

The suppositories contain sulfanilamide 15.0% in a water-miscible, nonstaining base made from lactose, propylene glycol, stearic acid, diglycol stearate, methylparaben, propylparaben, trolamine, and water, buffered with lactic acid to an acid pH of approximately 4.3. Each suppository contains sulfanilamide 1.05 g with lactose in a base made from polyethylene glycol 400, polysorbate 80, polyethylene... 

In suspension suppositories, the active substance is processed as small particles that are prone to form agglomerates. The effective dispersion of the agglomerates (see Sect. 29.3) is a prerequisite for a sufficient content uniformity. Lactose may be used in pharmacy preparations to disperse the agglomerates and to maintain separation of the primary particles. This is most important with low dosed active substances, which do not easily lead to a good content uniformity. If 50 mg or less of active substance(s) is used per suppository, as a standard 100 mg lactose may be added to each suppository, as illustrated by chlorpromazine suppositories in Table 11.4. The added lactose should not be considered as a filler only as it is in tablets or capsules, but its main function in suppositories is the dispersing of the active substance. 

In large-scale preparations of suppositories lactose may be added for another purpose. Sometimes a high dose analgesic suppository has a good structure, while a low dose suppository is brittle. In such case another suppository base may be used. More easily, the volume of the suspended active substance may be increased by adding lactose. This provides a good suppository too. In this case the lactose only acts as filler. Other fillers used in suppositories are sucrose and microcrystalline cellulose [8h],... 

The uniformity of content of suppositories with morphine hydrochloride 20 mg in a fat base is considerably improved by triturating the morphine hydrochloride first with 100 mg of lactose or mannitol [28]. It is likely that the agglomerates of morphine hydrochloride are ground between the crystals of lactose or mannitol into smaller primary particles. 

The result may be in this case Diclofenac sodium suppositories 12.5 mg, followed by a list of the excipients, for example hard fat and lactose... 

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