If the content of HPMC exceeds a 20 % rate in a formulation the tablets do not disintegrate but gelatinise. The dissolution of the active is retarded. As an example the figure shows the dissolution profiles of a formulation containing Theophylline. The dissolution of Theophylline with RetaLac^® is quite similar to the physical blend or when using wet granulation and can be easily modified by inclusion of further excipients [as an example purple curve RetaLac^® plus FlowLac^® 90 2:1]. Due to RetaLac^®’s flow and compaction properties RetaLac^® can be used for sustained release formulations by using direct compression technology.