PURPOSE: To apply UV/Vis spectrometry for characterization of submicroscopic drug carriers, such as nanoparticles and lipid vesicles. METHODS: We first investigated theoretically, within the framework of the Rayleigh-Gans-Debye approximation (RGDA), parameters affecting turbidity spectrum, τ(λ), of nanosized light scatterers. We then analyzed, within the framework of the RGDA, experimental turbidity spectra (λ = 400-600 nm) of extruded unilamellar vesicle (70 nm ≤ 2r ≤ 110 nm) suspensions to derive vesicle size, using dynamic light scattering results for comparison. We similarly studied the preparations polydispersity and lamellarity and monitored vesicle size changes. RESULTS: Turbidimetry suffices for accurate, fast, and viscosity-independent characterization of submicroscopic particles. Analysis of turbidity spectra, or more precisely wavelength exponent spectra (derivatives of logarithmic turbidity spectra), yielded similar average radii (r = 54.2 ± 0.2 nm; 46.0 ± 0.2 nm; 35.5 ± 0.1 nm) as dynamic light scattering (r = 55.9 ± 1.5 nm; 46.1 ± 0.4 nm; 36.1 ± 0.4 nm). Both methods also revealed similar suspension polydispersity and cholate-induced vesicle size changes in a few nanometer range. CONCLUSION: Despite its experimental simplicity, the widely accessible turbidimetric method provides accurate size values and is suitable for (continuous) monitoring size stability, or sameness, of submicroscopic drug carriers.
PURPOSE: To apply UV/Vis spectrometry for characterization of submicroscopic drug carriers, such as nanoparticles and lipid vesicles. METHODS: We first investigated theoretically, within the framework of the Rayleigh-Gans-Debye approximation (RGDA), parameters affecting turbidity spectrum, τ(λ), of nanosized light scatterers. We then analyzed, within the framework of the RGDA, experimental turbidity spectra (λ = 400-600 nm) of extruded unilamellar vesicle (70 nm ≤ 2r ≤ 110 nm) suspensions to derive vesicle size, using dynamic light scattering results for comparison. We similarly studied the preparations polydispersity and lamellarity and monitored vesicle size changes. RESULTS: Turbidimetry suffices for accurate, fast, and viscosity-independent characterization of submicroscopic particles. Analysis of turbidity spectra, or more precisely wavelength exponent spectra (derivatives of logarithmic turbidity spectra), yielded similar average radii (r = 54.2 ± 0.2 nm; 46.0 ± 0.2 nm; 35.5 ± 0.1 nm) as dynamic light scattering (r = 55.9 ± 1.5 nm; 46.1 ± 0.4 nm; 36.1 ± 0.4 nm). Both methods also revealed similar suspension polydispersity and cholate-induced vesicle size changes in a few nanometer range. CONCLUSION: Despite its experimental simplicity, the widely accessible turbidimetric method provides accurate size values and is suitable for (continuous) monitoring size stability, or sameness, of submicroscopic drug carriers.
Authors: Desirée Magalhães Dos Santos; Camila Valesca Jardim Rocha; Elita Ferreira da Silveira; Marcelo Augusto Germani Marinho; Marisa Raquel Rodrigues; Nichole Osti Silva; Ailton da Silva Ferreira; Neusa Fernandes de Moura; Gabriel Jorge Sagrera Darelli; Elizandra Braganhol; Ana Paula Horn; Vânia Rodrigues de Lima Journal: J Membr Biol Date: 2018-02-08 Impact factor: 1.843
Authors: Khaled Almansour; Iman M Alfagih; Alhassan H Aodah; Fawaz Alheibshy; Raisuddin Ali; Turki Al Hagbani; Mustafa M A Elsayed Journal: Pharmaceutics Date: 2021-12-30 Impact factor: 6.321