Downstream processing of spray-dried ASD with hypromellose acetate succinate – Roller compaction and subsequent compression into high ASD load tablets 

Here at Gamlen we are highlighting some of the fascinating and ground-breaking research that has been carried out by our customers in our Paper of the Month posts.

This month’s paper of the month demonstrates how a Gamlen Powder Compaction Analyser can be used as part of the formulation development process. Here the authors are investigating the roller compaction and tablet compression of a formulation with a high ASD (amorphous solid dispersion) content. ASD methods are used to improve the solubility of BCS class II drugs.

An Image showcasing Downstream processing spray-dried HPMCAS ASD
  • In this instance, the ASD was produced by spray drying the API (Nifedipine) with a carrier polymer, HPMCAS (hypromellose acetate succinate). This process transfers the API into an amorphous state increasing its solubility.
  • Two formulations were prepared, one using microcrystalline cellulose/croscarmellose as the binder/disintegrant and the other using MCC/low-substituted hydroxypropyl cellulose.
  • The formulations were subjected to roller compaction and the resultant granules were analysed using the Gamlen and a number of additional material physical property tests.
  • Tablets were manufactured using a rotary tablet press and the final tablets were evaluated.


A tablet formulation was successfully developed containing a high level of spray dried ASD. This was facilitated by careful selection of the roller compaction compression pressure and the binder/disintegrant system.