A rapid in-process control (IPC) test to monitor the functionality of taste masking polymer coatings using Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS).

Monitoring of the coating end-point of functional coatings during the coating application process is desirable. Since currently available PAT methods require expensive test equipment, there is a need for a rapid test that can easily be applied without major investment. BARDS is a novel technique that has the potential to economise the production process of these kinds of pellet and tablet formulations. The thickness of a controlled release coating is a key factor that determines the release rate of the drug in the gastro-intestinal tract or other targeted functionalities such as taste masking or moisture protection. Correspondingly, the amount of drug per unit mass of pellets decreases with increasing thickness of the functional coating. In this study, the functional polymer loading of the coating process is investigated by testing pellets via BARDS technology (Broadband Acoustic Resonance Dissolution Spectroscopy). The technique offers a rapid approach (<200 s) to characterising functional coatings at-line during their manufacture. Measurements are based on reproducible changes in the compressibility of a solvent during dissolution which is monitored acoustically via associated changes in the frequency of induced acoustic resonances. In case of enteric coatings a steady state acoustic lag time is associated with the erosion of the enteric coatings in acidic dissolution test media. This lag time is indicative of the coating layer thickness, assuming that the quality of the film coating is high. BARDS represents a possible future surrogate test for IPC testing, as a PAT method and possibly also for conventional USP dissolution testing. BARDS data correlate directly with the thickness of the functional coating, its integrity and also with the drug loading as validated by UV-Vis spectroscopy.

Increased compactibility of acetames after roll compaction.

A common technique for manufacturing granules in a continuous way is the combination of roll compaction and subsequent milling. Roll compaction can considerably impact tableting performance of a material. The purpose of this study was to investigate the influence of roll compaction/dry granulation on the compaction behavior of acetames, a class of active pharmaceutical substances, which are mainly used for the treatment of central nervous diseases. Some representatives of acetames were roll compacted and then compressed into tablets. Compactibility of granules was compared with the compaction behavior of the directly compressed drug powders. In contrast to many other materials, the roll compaction step induced an increase in compactibility for all investigated acetames. Specific surface areas of the untreated and the roll compacted drugs were determined by nitrogen adsorption. The raise in compactibility observed was accompanied by an increase in specific surface area during roll compaction.