521-15-3Relevant articles and documents
Testosterone- and vitamin-grafted cellulose ethers for sustained release of camptothecin
Qui?ones, Javier Pérez,Mardare, Cezarina Cela,Hassel, Achim Walter,Brüggemann, Oliver
, p. 641 - 652 (2018/11/26)
Camptothecin (CPT), a potent anticancer drug with known antiviral activity, is halted of clinical use. Few drug delivery systems of CPT are approved for therapy. Hereby, we propose the encapsulation of hydrophobic CPT in the inner core of cellulose nanoaggregates for sustained release with retaining of antiproliferative activity. Cellulose conjugates were synthesized by esterification of methyl cellulose, hydroxyethyl cellulose and (hydroxypropyl)methyl cellulose with testosterone, ergocalciferol and DL-α-tocopherol hemisuccinates. The degree of substitution attained ranged from 0.004 to 0.025 and no depolymerization was observed by size exclusion chromatography. ATR-FTIR and NMR spectroscopies confirmed grafting of testosterone and vitamins to celluloses. According to dynamic light scattering, it resulted in their self-assembly in aqueous medium as stable and slightly negatively charged nanoaggregates of 213 to 731 nm. Nanoaggregates formation was also assessed using transmission electron and atomic force microscopies. CPT was encapsulated in the cellulose nanoaggregates, achieving a content of 1.7–13.0 wt %. Sustained release of camptothecin over 150 h was observed in simulated physiological conditions. CPT-loaded cellulose nanoparticles appeared to be possible candidates for chemotherapy, according to observed cytotoxicity against MCF-7 cancer cells.
ELISA and LC-MS/MS method for detecting 19-nortestosterone residue in animal tissues
Jiang,Yang,Fan,Wu,Huang,Liu,Wang,Yang,Zhao
experimental part, p. 1503 - 1507 (2012/08/28)
Two different analytical methods for the detection of 19-nortestosterone (NT) residue in bovine have been developed and the comparison was also performed. For this purpose, EDC method was employed to synthesize the artificial antigen of NT-17-BSA. The results of IR and UV-visible spectra indicated that the artificial antigen was synthesized successfully and the conjugation ratio was 18:1. Based on the checkerboard titration results, an icELISA standard curve was established. The linear range was from 0.04 to 86 ng/mL, with LOD and IC50 value of 0.02 ng/mL and 1.2 ng/mL, respectively. For LC-MS/MS analysis, analytes were separated using a mobile phase solution of 1 % formic acid in water/acetonitrile/methanol (60:20:20, v/v/v) at a flow rate of 0.2 mL/min. The ultraviolet detector was operated at 242 nm and the injection volume was 10 μL. Positive chemical ionization mode was used and the relative collision energy was optimized to 28 %. When applied in spiked bovine samples, the correlation coefficients (R2) of the icELISA and LC-MS/MS data were 0.9963 in muscle, 0.9988 in liver and 0.9984 in kidney, respectively. The results suggest that it was an advantage through coupling of icELISA as screening method and LC-MS/MS as confirmatory method for detecting 19-nortestosterone residues in animal edible tissues.
Drug latentiation. Synthesis and preliminary evaluation of testosterone derivatives.
Kupchan,Casy,Swintosky
, p. 514 - 524 (2007/10/07)
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