Dissolution Testing Using Fiber Optics— A Regulatory Perspective

Influence of Particle Size on the Ultraviolet Spectrum of Particulate-Containing Solutions: Implications for In-Situ Concentration Monitoring Using UV/Vis Fiber-Optic Probes

“…Other studies detail the use of different probe designs (e.g. transmission versus transflectance probes, or probes with variable path length) (14)(15)(16)(17)(18)(19)(20)(21)(22)(23) as well as the validation efforts necessary to implement the technology in pharmaceutical settings (24)(25)(26). A number of clear advantages can be associated with the use of in situ fiber-optics.…”

Miniaturized Rotating Disk Intrinsic Dissolution Rate Measurement: Effects of Buffer Capacity in Comparisons to Traditional Wood’s Apparatus

“…Some of the challenges of traditional dissolution testing methods which use external sampling of the test solutions (e.g., sampling errors due to filter clogging, mechanical sipper malfunction, sample contamination, adsorption of compound to tubing) were avoided by the use of the in situ fiber opticdip probe UV apparatus, since the concentration measurements are performed directly in the dissolution media, with processed results plotted in "real time." Interference due to background turbidity is minimized by a spectral second derivative method (23)(24)(25)(26)(27)(28)(29). Spectral scans (200-720 nm) of all eight channels takes less than one second.…”

“…Turbid solutions are traditionally filtered during external sampling in order to read the UV spectra reliably. Newer in situ fiber optic dip-probe methods require neither filtration nor external sampling of the dissolution media (23)(24)(25)(26)(27)(28)(29).…”

Reply: Is oil red-O staining and digital image analysis the gold standard for quantifying steatosis in the liver?

“…An alternative approach consists of using a sampling probe permanently inserted in the dissolution medium and continually measuring the drug concentration as the solid dosage form dissolves. Studies have appeared in the literature describing different sampling probe designs, their advantages, limitations, and the effect of several variables on their performance 1–23…”