Quantification of cyproheptadine in human plasma by high-performance liquid chromatography coupled to electrospray tandem mass spectrometry in a bioequivalence study

A rapid, sensitive and specific method to quantify cyproheptadine in human plasma using amitriptyline as the internal standard (IS) is described. The analyte and the IS were extracted from plasma by liquid‐liquid extraction using a diethyl‐ether/dichloromethane (70/30; v/v) solvent. After removing and drying the organic phase, the extracts were reconstituted with a fixed volume of acetonitrile/water (50/50 v/v) + 0.1% of acetic acid. The extracts were analyzed by high performance liquid chromatography coupled to electrospray tandem mass spectrometry (LC‐MS/MS). Chromatography was performed isocratically using an Alltech Prevail C18 5 µm analytical column, (150 mm x 4.6 mm I.D.). The method had a chromatographic run time of 4 min and a linear calibration curve ranging from 0.05 to 10 ng/mL (r2 > 0.99). The limit of quantification was 0.05 ng/mL. This HPLC/MS/MS procedure was used to assess the bioequivalence of cyproheptadine in two cyproheptadine + cobamamide (4 mg + 1 mg) tablet formulations (Cobactin® [cyproheptadine + cobamamide] test formulation supplied from Zambon Laboratórios Farmacêuticos Ltda. and Cobavital® from Solvay Farma (standard reference formulation)). A single 4 mg + 1 mg [cyproheptadine + cobamamide] dose of each formulation was administered to healthy volunteers. The study was conducted using an open, randomized, two‐period crossover design with a 1‐week washout interval. Since the 90% CI for Cmax and AUCs ratios were all within the 80‐125% bioequivalence limit proposed by the US Food and Drug Administration, it was concluded that the cyproheptadine test formulation (Cobactin®) is bioequivalent to the Cobavital® formulation for both the rate and the extent of absorption of cyproheptadine. Copyright © 2011 John Wiley & Sons, Ltd.     

Effects of vitamin d treatment on skeletal muscle histology and ultrastructural changes in a rodent model

Vitamin D is well known for its role in maintaining calcium and phosphorus homeostasis and in promoting bone mineralization; however, more of its pleiotropic effects have been described recently. The aim of the present investigation was to study the effect of vitamin D treatment on skeletal muscles changes under different dietary conditions using an animal model. Four groups of C57BL/6J mice (n = 11 each) were maintained on either low fat diet (LFD) or high fat diet ??(HFD) with and without 1α,25-dihydroxyvitamin D3 (calcitriol) for 16 weeks. Animal weigh was recorded at baseline and then regular intervals, and at the end of the study, skeletal muscle tissues were harvested for the evaluation of the histopathological and ultrastructural changes. When control C57BL/6J mice were fed high-fat diet for 12 weeks, body weight gain was significantly increased compared with mice fed a LFD. (30.2% vs. 8.4%, p < 0.01). There was a significant gradual decrease in the weight of HFD fed mice that were treated with vitamin D as compared with a steady increase in the weights of controls (6.8% vs. 28.7%, p < 0.01). While the LFD group showed some ultrastructural changes, HDF fed on mice showed great muscle structural abnormalities. The whole sarcosome along with its membrane and cristae were severely damaged with scattered myocytes in HFD group. Furthermore, the mitochondria appeared weak and were on the verge of degenerations. The bands were diminished with loss of connections among myofibrils. These changes were attenuated in the HFD group treated with vitamin D with tissues have regained their normal structural appearance. The current findings indicate an important effect of vitamin D on skeletal muscle histology under HFD conditions.     

Sinapic Acid Ameliorates Acetic Acid-Induced Ulcerative Colitis in Rats by Suppressing Inflammation,Oxidative Stress,and Apoptosis

Background: Ulcerative colitis (UC) is a long-term condition which results in inflammation and ulcers of the colon and rectum. The key indications of active disease are abdominal pain and diarrhea mixed with blood. Aims: We explore the underlying colon protective mechanism of sinapic acid (SA) against acetic acid (AA) induced ulcerative colitis in rats. The implications of inflammation, oxidative stress, and apoptosis are studied. Methodology: Twenty-four rats were distributed into four categories, normal control (NC), ulcerative colitis (UC), ulcerative Colitis with SA 40 mg/kg (SA 40 mg/kg + AA), and ulcerative colitis with prednisolone (PRDL 10 mg/kg + AA), and were pretreated orally with saline, saline and SA (40 mg/kg/day) or PRDL (10 mg/kg/day) respectively, for 7 days. UC was prompted by trans-rectal administration of 4% AA on the 5th day, colon tissues were surgically removed for gross morphology and histological inspection, oxidative stress, and inflammatory markers and immunoblot analysis of Bax, caspase-3, and Bcl-2. Results: Macroscopic and histological inspection demonstrated that both SA 40 mg/kg and PRDL (10 mg/kg/day) significantly ameliorates colonic injuries. In addition, both pretreatments significantly ameliorates AA-induced UC, oxidative stress, as indicated by suppressed malondialdehyde (MDA), nitric oxide (NO) levels and restoring antioxidant/oxidant balance as indicated by catalase and glutathione levels, suppressed inflammation via inhibiting cytokines TNF-α, IL-6, inflammatory markers MPO, PGE₂, COX-2 and NF-κB and inhibiting the protein expression of Bax and caspase-3 apoptotic protein and increasing the anti-apoptotic protein, Bcl-2 thereby inhibiting apoptosis. Conclusion: Sinapic acid significantly ameliorates AA induced UC in rats by suppressing inflammation, oxidative stress, and apoptosis in colonic tissues which exhibits its potential for the management of UC.     

A host-guest optical sensor for aliphatic amines based on lipophilic cyclodextrin

A host-guest optical sensor for the determination of aliphatic amines as exemplified by octylamine is proposed. It is based on the reversible fluorescence enhancement of heptakis(2,6-di-O-isobutyl)-β-cyclodextrin(DOB-β-CD) hosting tetraphenylporphyrin (TPP) immobilized in poly(vinyl chloride) (PVC) membrane by aliphatic amine extracted from aqueous phase into membrane phase. The optimum membrane contained 1.15 wt % TPP, 6.15 wt % DOB-β-CD as sensing reagent and other membrane materials. The fluorescence enhancement of the membrane resulted from the formation of a stable three-component complex among DOB-β-CD, TPP, and aliphatic amines. With the optimum conditions described, the fluorescence response of the sensor to octylamine shows a good correlation with the theoretically derived equation in the range 1.0 × 10^–6 to 8.0 × 10^–4 mol/L. The response characteristics including reversibility, response time, reproducibility and lifetime and selectivity of this optical device are also discussed in detail. This sensor has also been applied for the determination of octylamine in water samples containing interferents with satisfactory recovery. Received: 21 November 1999 / Revised: 10 January 2000 / Accepted: 15 January 2000     

Preferred conformations of enol ethers in solution: Detection of an equilibrium by kinetic nuclear overhauser effects

n.O.e. difference spectra reveal that the preferred solution conformation of methyl enol ethers has the methyl group $\text{syn}$-periplanar to the double bond; n.O.e kinetics in a methoxy—heptatriene demonstrate the presence of both possible periplanar conformations, the energy difference being $\text{ca}$ 1 kcal/mole.