Confocal Raman microscopy to probe content uniformity of a lipid based powder for inhalation: a quality by design approach.

In the present work confocal Raman microscopy was employed as a non-destructive tool to define the content uniformity and the polymorphic form of a drug substance distributed within a lipid based inhalable powder. Two spray dried powders with different active ingredient concentrations (1.55 and 7.

New insight into modified release pellets - Internal structure and drug release mechanism.

The aim of the study was to explore the drug release mechanism from pellets, coated with blends of poly(vinyl acetate) (PVAc) and polyvinyl alcohol-polyethylene glycol graft copolymer (PVA-PEG). Water influx and drug solubilization inside the pellets were investigated in correlation to drug release. The highly soluble drug Chlorpheniramine maleate (CPM) was used as a model compound.