Application of UV dissolution imaging to pharmaceutical systems.

UV-vis spectrometry is widely used in the pharmaceutical sciences for compound quantification, alone or in conjunction with separation techniques, due to most drug entities possessing a chromophore absorbing light in the range 190-800 nm. UV dissolution imaging, the scope of this review, generates spatially and temporally resolved absorbance maps by exploiting the UV absorbance of the analyte. This review aims to give an introduction to UV dissolution imaging and its use in the determination of intrinsic dissolution rates and drug release from whole dosage forms. Applications of UV imaging to non-oral formulations have started to emerge and are reviewed together with the possibility of utilizing UV imaging for physical chemical characterisation of drug substances. The benefits of imaging drug diffusion and transport processes are also discussed.

Design and development of a novel fused filament fabrication (FFF) 3D printed diffusion cell with UV imaging capabilities to characterise permeation in pharmaceutical formulations.

The present work aimed at designing and developing a novel 3D printed diffusion cell capable of UV imaging using the fused filament fabrication (FFF) method. UV imaging has proven to be very versatile in the area of pharmaceutics giving insights into various phenomena including the dissolution behaviour of dosage forms, intrinsic dissolution rates and the drug precipitation processes. A 3D printed diffusion cell in the similitude of a Franz cell was successfully printed using polylactic acid (PLA) filaments equipped with quartz for the imaging area. A model ibuprofen (IBU) gel formulation was tested by introducing the dosage form through the 3D printed donor compartment. The drug concentration permeated through the skin mimic (silicone membrane) was determined from the 3D printed receptor compartment using UV imaging in real-time. The results showed successful UV imaging of the permeation of IBU gel in the novel diffusion cell potentially negating further analytical testing such as the HPLC process required for Franz cell tests thereby reducing costs. Potential interactions between the drug and filament used in the 3D printed process suggests although this concept can be moved towards commercialisation, care should be taken with choice of filament used in the 3D printing process.