clonidine hydrochloride is an antihypertensive agent used for migraine prophylaxis, attention deficit hyperactivity disorder, menopausal flushing and tourette syndrome. the quantity of the active substance in pharmaceutical preparations must be within specific limits, in agreement with the respective label claim. therefore, the aim of this study was to establish the conditions for two spectroph...

Three rapid spectrophotometric methods were developed for the determination of sunitinib based on the formation of ion-pair complex in acidic medium with bromocresol purple, bromothymol blue, and bromophenol blue. The formed ion-pair complexes, extractable with chloroform, were measured at 422 nm for bromocresol purple, 425 nm for bromothymol blue and 427 nm for bromophenol blue. All these meth...

Three rapid spectrophotometric methods were developed for the determination of sunitinib based on the formation of ion-pair complex in acidic medium with bromocresol purple, bromothymol blue, and bromophenol blue. The formed ion-pair complexes, extractable with chloroform, were measured at 422 nm for bromocresol purple, 425 nm for bromothymol blue and 427 nm for bromophenol blue. All these meth...

MP2/aug'-cc-pVTZ calculations have been carried out to investigate the halogen-bonded complexes formed when CO and CS act as electron-pair donors through C to ClF, ClNC, ClCl, ClOH, ClCN, ClCCH, and ClNH₂. CO forms only complexes stabilized by traditional halogen bonds, and all ClY molecules form traditional halogen-bonded complexes with SC, except ClF which forms only an ion-pair complex. Ion-...

Lipophilic ion-pair complexes of 3-dl-alpha-tocopherylcarbonyl-1-n-alkyl-pyridinium-cromolyn (TAP-CG) were designed to enhance the percutaneous absorption of cromolyn (CG), and the effect of n-alkyl chainlength of the ion-pair complexes on the CG permeation through hairless mouse skin was evaluated in vitro. The permeation rates of CG were examined in isopropyl myristate (IPM) suspension using ...

the ion-pair association constant values, related to the reaction +  were determined by means of the nmr spectroscopy. the values of the thermodynamic functions of the ion pairing process were calculated on the basis of the nmr results. in addition, the association entropy was found to be dependent on the temperature. comparing the experimental data and the fuoss theory it is found that  ion-pa...

The spin dynamics of radical pairs from ion-pair complexes between viologen and tetraarylborate compounds have been investigated in the presence microwave (μw) radiation, using steady-state electron paramagnetic resonance to follow pair dynamics.

using the mixed solvents, (water +ethanol + propanol), the solubility of cdf2 was determined byevaporating method at 25° c. the results showed that the sollbility, s, of cdf2 decreases bydecreasing the dielectric constant of the mixed solvent .once the solubility of cdf2 was determined,the concentration solubility product, ksp(c)=4s3, was calculated .furthermore ,by estimating the meanactivity ...

The second-generation poly(ethylene imine) dendrimer (L), based on ammonia as the initiating core molecule, forms anion and ion-pair complexes in aqueous solution. Speciation of the complex species formed and determination of the relevant stability constants were performed by means of potentiometric titration in a 0.10 M NMe4Cl solution at 298.1 K. Protonated forms of L interact with NO3(-), SO...