Handbook of solubility data for pharmaceuticals , Handbook of solubility data for pharmaceuticals , کتابخانه دیجیتال جندی شاپور اهواز

http://chemistry-chemists.com/chemister/Spravochniki/handbook-of-solubility-data-for-pharmaceuticals-2010.pdf

Handbook of Solubility Data for Pharmaceuticals

The microsponge delivery system of benzoyl peroxide: preparation, characterization and release studies.

Distance measurement in the nanometer range by electron paramagnetic resonance spectroscopy (EPR) in combination with site-directed spin labeling is a very powerful tool to monitor the structure and dynamics of biomacromolecules in their natural environment. However, in-cell application is hampered by the short lifetime of the commonly used nitroxide spin labels in the reducing milieu inside a cell. Here, we demonstrate that the Gd(III) based spin label Gd-PyMTA is suitable for in-cell EPR. Gd-PyMTA turned out to be cell compatible and was proven to be inert in in-cell extracts of Xenopus laevis oocytes at 18 °C for more than 24 h. The proline rich peptide H-AP10CP10CP10-NH2 was site-directedly spin labeled with Gd-PyMTA at both cysteine moieties. The resulting peptide, H-AP10C(Gd-PyMTA)P10C(Gd-PyMTA)P10-NH2, as well as the model compound Gd-spacer-Gd, which consists of a spacer of well-known stiffness, were microinjected into Xenopus laevis oocytes, and the Gd(III)-Gd(III) distances were determined by double electron-electron resonance (DEER) spectroscopy. To analyze the intracellular peptide conformation, a rotamer library was set up to take the conformational flexibility of the tether between the Gd(III) ion and the Cα of the cysteine moiety into account. The results suggest that the spin labeled peptide H-AP10C(Gd-PyMTA)P10C(Gd-PyMTA)P10-NH2 is inserted into cell membranes, coinciding with a conformational change of the oligoproline from a PPII into a PPI helix.

Gd(III)-PyMTA Label Is Suitable for In-Cell EPR

Determination of gadolinium-based MRI contrast agents in biological and environmental samples: a review.

Handbook of pharmaceutical manufacturing formulations , Handbook of pharmaceutical manufacturing formulations , کتابخانه مرکزی دانشگاه علوم پزشکی تهران

Handbook of Pharmaceutical Manufacturing Formulations

Saturated solubility and reaction rate constants for the decomposition of benzoyl peroxide in solution and suspension were determined for use in formulation development. The solvents studied included ethanol, propylene glycol, and cosolvent mixtures of PEG 400 and water. The solubility of benzoyl peroxide was inversely related to the solvent polarity, with greater solubility occurring with semipolar solvents. The stability of benzoyl peroxide in solution was dependent on the solvent, concentration of benzoyl peroxide, and temperature. The compound was least stable in PEG 400. Stability was improved when water was added to PEG 400. Similar solvent effects were observed in suspension. In benzoyl peroxide suspensions of PEG 400 and PEG 400/water blends, benzoyl peroxide stability was dependent on solubility, with improved stability occurring in blends where the benzoyl peroxide was least soluble. Thus, solution formulations of benzoyl peroxide in pharmaceutically acceptable solvents are unlikely to show good stability; however, suspension formulations should be reasonably stable if the vehicle is selected to provide low benzoyl peroxide solubility.

Eric M. Chellquist

Papers

Benzoyl peroxide solubility and stability in hydric solvents.

The effect of mobile phase modifiers on the simultaneous LC elution of a gadolinium complex and free ligand

An LC method for measuring complex formation equilibria by competitive chelation.

Binding constant determination of WIN 22169, a novel polymeric ligand.