Multidisciplinary Approach on Characterizing a Mechanochemically Activated Composite of Vinpocetine and Crospovidone

Enhanced Oral Bioavailability of Vinpocetine Through Mechanochemical Salt Formation: Physico-Chemical Characterization and In Vivo Studies

“…The use of a fiber optic apparatus (HELLMA, Milano, Italy), connected to a spectrophotometer (ZEISS, Germany, wavelength 270.19 nm), permitted the determination of VIN concentration without perturbing the release environment (each release test lasted 120 min). Moreover, this methodology, previously successfully employed for coground systems containing VIN (15), allowed for easily overcoming the problem connected to drug concentration measurements in the presence of a dispersion of solid particles. Indeed, whilst the maximum VIN absorption occurred at 270.19 nm, the maximum citric acid absorption was at 220.49 nm, and the scattering effect due to polymeric particles uniformly occurred at every wavelength.…”

“…The first 5 μl of the filtrates were discarded, while the subsequent was collected. Then, an appropriate amount of the filtrate was diluted with acetonitrile and assayed by a validated high pressure liquid chromatographic (HPLC) with mass spectrometry (MS) detection method (24) already used in our previous work (15).…”

“…Recently, our group has successfully increased the oral absorption by cogrinding VIN with micronized crospovidone in a planetary mill using an optimized mechanochemical activation process (15). In that experience, the mechanical loading has caused particles' comminuting and disordering of lattice structure, so that the solid has gained an activated state more prone to dissolution (e.g.…”

Drug Nanocrystals: Theoretical Background of Solubility Increase and Dissolution Rate Enhancement

“…7 This base-type drug (pKa = 7.1) 8 was chosen as a model drug because it is practically insoluble in water (1.6 mg mL -1 in pH = 7.4 at 37 °C). 9 Vinpocetine melting temperature (T m∞ = 149.6 °C), melting enthalpy (DH m∞ = 94600 J kg -1 ) and DC p (difference in specific heat capacity at constant pressure between the liquid ( ) was evaluated according to the group contribution approach 10,11 implemented by the Breitkreutz software. 12 Determination of the solid vinpocetine -vapor surface tension ( …”

Improvement of the water solubility of tolfenamic acid by new multiple-component crystals produced by mechanochemical methods

“…In these experiments, the solution was kept homogeneous using an impeller (rotational speed 200 rpm) and the determination of HTA concentration was performed using fibreoptic apparatus (HELLMA, Milano, Italy) connected to a spectrophotometer (ZEISS, Germany,). 21 Measurement was 25 performed at 286.9 nm (HTA maximum absorption, supporting information). Each sample was tested in triplicate.…”