PHARMA FOCUS: EXCIPIENTS
A unique multifunctional lactose grade for DC formulations While direct compression or DC has been known for many years, it has only recently become more established. This is thanks to the introduction of excipients specifically designed for DC. The advantages of DC include fewer processing stages and the elimination of heat and moisture effects.1 Pauline Janssen and Marly Bastiaansen of DFE Pharma discuss SuperTab 24AN as an ideal excipient choice to support formulators in expanding the use of DC.
L
actose is one of the most commonly used tablet diluents for DC, especially grades that are modified to improve flow and compaction. Besides the importance of good flow and compactibility, the ability of excipients to achieve good drug content uniformity in final tablets is key. It has been speculated that the ability of certain excipients to achieve good drug content uniformity may be a result of excipient morphology whereby the active ingredient can be distributed into crevices in the excipient structure.² Anhydrous lactose is modified by granulation to create a structure with crevices that enhance mixing potential to achieve good drug content uniformity, while at the same time increasing the flow and compaction properties (see Figure 1b). SuperTab 24AN as multifunctional excipient enables pharmaceutical manufacturers to extend the potential use of DC.
MANUFACTURING PROCESS The manufacturing process for granulated anhydrous lactose is both unique and patented, providing enhanced functionality. As the name already indicates, granulated anhydrous lactose is produced using a combination of processes. Anhydrous lactose (Figure 1a) is produced by roller drying and subsequent comminution and sieving. Evaporation is done at temperatures above 93.5°C, resulting in predominant crystallisation of anhydrous β-lactose, typically 70% to 80%. For the production of granulated anhydrous lactose, a sieved fine particle size fraction of anhydrous lactose is agglomerated on a fluid bed agglomerator with an aqueous lactose solution as a binder. This granulation step modifies the morphology of the excipient to a granular porous structure (see Figure 1b), which has a positive effect on flow and compactibility, and maintains disintegration time. Robustness of the process is proven by evaluating and monitoring
Figure 2: Consistency data of functional related characteristics of SuperTab 24AN
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MARCH 2021 // WWW.PHARMACOS.CO.ZA
Figure 1a: SEM picture SuperTab 21AN
Figure 1b: SEM picture SuperTab 24AN
