Evaluation of Anhydrous α-Lactose, A New Excipient in Direct Compression

Abstract

AbstractDifferent forms of lactose are available for direct compression of tablets. The use of spray-dried lactose, which has good flow and compressibility characteristics, is limited by its stability when stored under humid conditions. Sieved crystalline fractions of α-lactose monohydrate such as the 100 mesh fraction, have very good flow properties and an outstanding stability, but the compressibility is so poor, that it can be used only in combination with other filler-binders, like microcrystalline cellulose. A third form of lactose, increasingly used in direct compression is anhydrous lactose. The commercially available products generally consist of an excess of β next to α-lactose. They both have good binding and stability characteristics, but a flowability which is less than optimum. The latter is caused by the rather irregular particle shape and the relatively high amount of fines. A newly developed form of lactose is anhydrous α-lactose. It is prepared by dehydration of α-lactose monohydrate. Bin...