Di-µ(2)-chlorido-bis-[aqua-(2,2'-bipyridine-4,4'-dicarboxylic acid-κN,N')(nitrato-κO)copper(II)].

In the title compound, [Cu(2)Cl(2)(NO(3))(2)(C(12)H(8)N(2)O(4))(2)(H(2)O)(2)], which consists of a chloride-bridged Cu(II) dimer, the Cu atom is in a distorted octa-hedral environment defined by two N atoms from the 2,2'-bipyridine-4,4'-dicarboxylic acid ligand (H(2)bpdca), two bridging chlorido ligands, and two O atoms from an equatorial water mol-ecule and an axial nitrate anion, respectively. The two halves of the dimeric unit are related by an inversion centre at the midpoint between the two Cu atoms. Both carboxylic acid groups in the H(2)bpdca ligand remain protonated, as confirmed by the two sets of C-O bond lengths. The dinuclear mol-ecules are linked into a three-dimensional network via inter-molecular hydrogen bonds.

[In vitro transdermal permeation of lidocaine-dodecanol binary eutectic system].

AIM: To study the effect of lidocaine-dodecanol binary eutectic system on the transdermal permeation of lidocaine. METHODS: Binary eutectic mixture of different proportions of lidocaine and dodecanol were prepared and the patch containing the binary eutectic mixture was developed. The solubilities of pure lidocaine and lidocaine from the binary eutectic system were determined in pH 7.9 phosphate buffer. The transdermal flux of lidocaine from the patches containing the binary eutectic system and pure lidocaine were measured using Franz-type single diffusion cell. RESULTS: The melting point of the lidocaine-dodecanol binary eutectic system was markedly lower than that of pure lidocaine. The steady state transdermal flux of lidocaine from the patch of the binary eutectic system was six times as much as that of pure lidocaine patch. CONCLUSION: The lidocaine-dodecanol binary eutectic system could produce high thermodynamic activity of the drug and the high driving force for transdermal permeation of lidocaine.

[The UV-Vis spectra and substituent effect of organoimido derivatives of polyoxometalates].

In the presence of a carbodiimine, i.e. DCC, a series of organoimido derivatives of polyoxometalates have been synthesized via the reaction of [alpha-Mo8O26]4- with aromatic amines and its hydrochloride salt. Elemental analysis, IR, 1H-NMR and UV-Vis spectra were used to characterize those hybrids, in particular their UV-Vis spectra have been studied. The results show that typical metal-ligand charge transfer (MLCT) transitions occur in the organic-inorganic hybrid molecules. There is a good linear relationship between the shift of UV-Vis absorptions (delta lamda max) and conjugation effect of the p-substituted group (sigmaR).

A new layered zinc phosphate templated by protonated isonicotinate, [Zn2(C6H5NO2)2(HPO4)2].

An organic-inorganic hybrid compound, poly[bis[(pyridine-4-carboxylato)zinc(II)]-di-mu3-phosphato], [Zn2(C6H5NO2)2(HPO4)2], has been hydrothermally synthesized and structurally characterized. The crystal structure consists of two types of two-dimensional layers of zinc hydrogenphosphate templated by protonated isonicotinate (ina) (or 4-pyridinecarboxylic acid), which contain two crystallographically independent centrosymmetric [Zn2(ina)2(HPO4)2] dimers as basic building units. The layers are interconnected via hydrogen-bonding and heterocyclic ring interactions.

In vitro and in vivo characterization of a newly developed clonidine transdermal patch for treatment of attention deficit hyperactivity disorder in children.

The aim of this study was to characterize a newly developed clonidine transdermal patch, KBD-transdermal therapeutic system (TTS), for the treatment of attention deficit hyperactivity disorder in children. In vitro release, penetration, and in vivo pharmacokinetics in rabbits were investigated. The smaller size of KBD-TTS (2.5 mg/2.5 cm2) showed a similar in vitro penetration to those of Catapres-TTS (2.5 mg/3.5 cm2, a clonidine transdermal patch used for the treatment of hypertension, Alza Corporation, U.S.A.). The transdermal penetration rate of clonidine was mainly controlled by the ethylene vinylacetate membrane used in the patch. The skin layer may be only a minor rate-limiting barrier after the topical skin layer at the dosing site is saturated with penetrating clonidine in the initial phase (0 to 12 h). A sensitive liquid chromatography-mass spectrometry method for the quantification of clonidine in rabbit plasma was developed using solid-phase extraction and gradient elution on LC combined with the selected-ion monitoring (SIM) mode. A single dose of clonidine transdermal patch (KBD-TTS) or Catapres-TTS was transdermally administered to rabbits (n=6 each) and removed after 168 h. The average half-life, Tmax, Cmax and Css values of clonidine in rabbits following administration of KBD-TTS were 19.27+/-4.68 h, 52.56+/-25.77 h, 27.39+/-9.03 ng/ml, and 25.82+/-9.34 ng/ml, similar to those of Catapres-TTS, respectively. The clonidine plasma concentration of KBD-TTS reached a steady state at 24 h through 168 h. The in vitro release rate of the clonidine from KBD-TTS significantly correlated with the in vivo absorption rate (p<0.001).

[Determination of clonidine in rabbit plasma by HPLC-MS].

AIM: To determine clonidine in rabbit plasma by LC-MS. METHODS: The LC-MS system consisted of Waters Alliance 2790 HPLC and Micromass ZQ-4000 MS. The HPLC was performed by using XTerra C18 (150 mm x 2.1 mm ID, 5 microm). The mobile phase, consisting of acetonitrile/ammonium hydrogen carbonate solution, was maintained to a flow-rate of 0.2 mL x min(-1) and the linear gradient elution was adopted. Mass spectrum was obtained by using electrospray ionization interface and the m/z of SIM was 230. RESULTS: The average recovery was high and the method was reproducible. The calibration curve showed good linearity in the range of 1 - 80 microg x L(-1), the lowest limit of detection was 0.05 microg x L(-1). The Cmax, AUC0-t, and Tmax value of the pharmacokinetics parameter were (27 +/- 9) microg x L(-1), (5,352 +/- 1,121) microg x L(-1), (79 +/- 17) h. CONCLUSION: The results demonstrated that the method had high sensitivity, good selectivity, accuracy and precision. It is used to determine the clonidine concentration in plasma. The transdermal patch can deliver clonidine to the surface of rabbit skin stably for periods of up to 1 week after a single application.