Investigations on residual elimination of altrenogest oral solution in pigs and the withdrawal time.

The residual elimination of altrenogest in swine was investigated, preparing for the determination of withdrawal time. The residues of altrenogest in sebum, muscle, liver and kidney were extracted by optimized methods and further analyzed by UPLC-MS/MS. Under experimental conditions, the LOD and LOQ of altrenogest in sebum, muscle, liver and kidney were 0.5 and 1.0 µg/kg, respectively. The recoveries were in the range of 65 and 95% and the inter- and intra-RSD were less than 15%. The established method for the extraction, purification and detection of altrenogest is suitable for the determination of the residue of altrenogest in edible tissues of pigs. It was showed that altrenogest had the highest residual concentration level in liver, followed by kidney, sebum and muscle. Then withdrawal time was set at 9 days. The study provides an effective basis for elimination of altrenogest in swine.

Comparative pharmacokinetic study of two kinds of altrenogest oral solutions for sows.

This study was to compare the pharmacokinetic characteristics of domestic altrenogest oral solution (DAOS) or imported altrenogest oral solution (IAOS) in healthy sows. A single administration (1 mg/kg body weight) of DAOS or IAOS was performed in sixteen healthy sows according to a two-period crossover design. Plasma concentrations of altrenogest (AT) were measured by high performance liquid chromatography coupled to a tandem mass spectrometer (HPLC-MS/MS) and the concentration-time data of AT was analyzed by WINNONLIN 5.2. It was suggested that the main pharmacokinetic parameters of DAOS and IAOS were as follows: Cmax was 227.59 ± 83.35 ng/mL and 152.83 ± 80.34 ng/mL, Tmax was 1.16 ± 0.52 h and 1.58 ± 0.85 h, t1/2 was 3.63 ± 0.72 h and 3.45 ± 0.63 h, MRT was 5.02 ± 0.79 h and 5.21 ± 0.87 h, AUC0-t was 1050.23 ± 409.80 h·ng/mL and 778.22 ± 397.84 h·ng/mL, and AUC0-∞ was 1060 h·ng/mL and 786 h·ng/mL, respectively. The relative bioavailability of DAOS was 134.9%. Above results indicated that oral DAOS was better absorbed than IAOS, Cmax of DAOS was higher than that of IAOS (p < 0.05). However, there was no significant difference in the main pharmacokinetic parameters between oral DAOS and IAOS (p > 0.05). Our data confirmed that the absorption, fast elimination and bioavailability of DAOS in sows were better than those of IAOS.

(Naphthalene-1,4-di-yl)dimethyl dibenzoate.

In the title compound, C(26)H(20)O(4), the complete molecule is generated by a crystallographic 2-fold axis and the naphthalene ring system is planar within 0.05 (4) Å. The dihedral angles between the -COO plane, the benzene ring and naphthalene ring system are 12.83 (3) and 12.93 (1)°, respectively. The -COO plane and the benzene ring are almost coplanar, forming a dihedral angle of 2.59 (8)°.

(E)-3-(3-Chloro-phen-yl)-N-(4-hy-droxy-3-meth-oxy-benz-yl)acryl-amide.

In the title compound, C(17)H(16)ClNO(3), the 4-hy-droxy-3-meth-oxy-benzyl group is planar [maximum atomic deviation = 0.0138 (16) Å] and is nearly perpendicular to the chloro-benzene ring, making a dihedral angle of 84.67 (4)°. The chloro-benzene and amide groups are located on the opposite sides of the C=C bond, showing an E configuration. The relatively long C=O bond distance of 1.2364 (19) Šand the short C-N bond distance of 1.341 (2) Šsuggest electron delocalization in the amide fragment. Inter-molecular O-H⋯O, N-H⋯O and weak C-H⋯O hydrogen bonding is present in the crystal structure.

N-(4-Hydr-oxy-3-methoxy-benz-yl)benzamide.

In the mol-ecular structure of the title compound, C(15)H(15)NO(3), the two benzene rings are twisted with respect to each other, making a dihedral angle of 75.11 (10)°. In the amide fragment, the C=O and C-N bond distances are 1.248 (3) and 1.321 (3) Å, respectively, indicating electron delocalization. A partially ovelapped arrangement between parallel hydroxy-methoxy-benzene rings is observed in the crystal structure, and the face-to-face distance of 3.531 (16) Šsuggests the existence of weak π-π stacking. N-H⋯O and O-H⋯O hydrogen bonding is also present in the crystal structure.

N'-[(E)-3-Indol-3-ylmethyl-ene]isonicotino-hydrazide monohydrate.

Crystals of the title compound, C(15)H(12)N(4)O·H(2)O, were obtained from a condensation reaction of isonicotinylhydrazine and 3-indolylformaldehyde. The mol-ecule assumes an E configuration, with the isonicotinoylhydrazine and indole units located on the opposite sites of the C=N double bond. In the mol-ecular structure the pyridine ring is twisted with respect to the indole ring system, forming a dihedral angle of 44.72 (7)°. Extensive classical N-H⋯N, N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonding and weak C-H⋯O inter-actions are present in the crystal structure.