DETERMINATION OF 5H-BENZO[2,3][1,4]OXAZEPINO[5,6-B]INDOLES IN RAT PLASMA BY REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC-ULTRAVIOLET METHOD: APPLICATION TO PHARMACOKINETIC STUDIES

Objective: Recently, we reported newly synthesized 5H-benzo[2,3][1,4]oxazepino[5,6-b]indole) derivatives and proved their cytotoxicity against hepatocellular carcinoma specific Hep-G2 cell lines. We attempted herein to describe a reversed-phase high-performance liquid chromatographic method for the determination of three most active compounds 6a, 10a, and 15a in rat plasma to predict their pharmacokinetics parameters before in vivo study.Methods: A rapid and sensitive reversed-phase high-performance liquid chromatographic was employed for the determination of 6a, 10a, and 15a in rat plasma. Each compound was separated by a gradient elution of acetonitrile and water with 1 mL/min flow rate. The detector was set at 270, 285, and 275 nm for 6a, 10a, and 15a and the recorded elution times were 2.00, 2.87, and 1.88 min, respectively.Results: The calibration curve was linear with R2 of 0.938, 0.875, and 0.923 over the concentration range of 0.1–50 μg/mL. The inter- and intra-day variations of the assay were lower than 12.26%; the average recovery of 6a, 10a, and 15a was 97.31, 92.56, and 95.23 % with relative standard deviation of 2.12%, 3.25%, and 2.28%, respectively. The Cmax and Tmax were ~ 46.34, 18.56, and 25.65 μg/mL and 2.0, 4.0, and 4.0 h for 6a, 10a, and 15a, respectively, which indicate a robust method of detection in the present experiment.Conclusion: The study suggests that all of the three compounds have a lower rate of absorption, higher volume of distribution, and lower clearance rate, indicating good therapeutic response for in vivo activity.Â

Comparative Evaluation of Dexmedetomidine and Magnesium Sulphate on Propofol Consumption, Haemodynamics and Postoperative Recovery in Spine Surgery: A Prospective, Randomized, Placebo Controlled, Double-blind Study

Purpose: Dexmedetomidine and magnesium sulfate have been used in anesthesia as adjuvant to provide hemodynamic stability and anesthetic agents sparing effect. We compared these effects of dexmedetomidine and magnesium sulfate in spine surgeries. Methods: Ninety patients were randomly assigned to three groups. Group D received dexmedetomidine loading dose 1 µg/kg over a period of 15 minutes and maintenance 0.5 µg/kg/h throughout the surgery. Group M received magnesium sulfate loading dose 50 mg/kg over a period of 15 minutes and maintenance 15 mg/kg/h throughout the surgery. Group C received same volume of normal saline. Heart rate (HR) and blood pressure values were recorded at various intervals. The induction and maintenance doses of anesthetics and recovery parameters were also recorded. Results: Heart rate in group D and group M were significantly decreased (p<0.05) during the whole intraoperative period compared to preoperative values. There was a significant difference in HR values between group C, D and M, during the whole intraoperaive period (p<0.05). Blood pressure values were statistically significantly lower in the group D and group M compared to group C after intubation and all time observations of surgery (p<0.05). Both drugs reduced the anesthetic agent’s requirement during surgery. However, the recovery parameters were statistically significant increase with magnesium sulphate compared to dexmedetomidine and control groups. Conclusion: Dexmedetomidine is more effective than magnesium sulfate for maintaining the hemodynamic stability in spine surgeries. Both these drugs also reduce the requirements of anesthetic agents. Recovery from dexmedetomidine is as rapid as control group compared to magnesium sulfate

A METHOD FOR DETERMINING 1,4-BENZOTHIAZINE DERIVATIVES IN RAT PLASMA BY HPLC AND ITS APPLICATION TO A PHARMACOKINETIC STUDY

Objective: The objective of the study was to develop, optimize and validate of a new reverse-phase high-performance liquid chromatography (RP-HPLC) method for the determining 1,4-benzothiazine derivatives (AR13 and AR15) in a biological sample of rat plasma. The 1,4-benzothiazine derivatives are produced by the synthetic reactions.Methods: RP-HPLC separation was performed using an ODS-2 Hypersil column with gradient elution mobile phase consisting of water-acetonitrile for AR13 and AR15 (1:9 v/v, 3:7 v/v) at room temperature 1 ml/min flow rate, and interfaced with photodiode array detector (PDA) detector, 233 nm, 235 nm respectively.Results: A linear response was obtained between (range from 0.100-10.00 mg/ml) AR13 and (range from 0.096–9.88 mg/ml) AR15 with correlation coefficient 0.999 and 0.998. The linearity range of both AR13 and AR15 was 101.65±1.5 and 98.78±1.7.Conclusion: It was concluded that the method was simple, accurate, sensitive, accurate and reproducible and has been successfully applied to the pharmacokinetic study of AR13 and AR15 in rat plasma

Hydrophilic Composites of Chitosan with Almond Gum: Characterization and Mechanical, and Antimicrobial Activity for Compostable Food Packaging

To enhance the characteristics of the biocomposite film, solution cast was used to incorporate almond gum at different concentrations (10.0, 30.0, and 50.0%). The functional groups and morphology were determined using FTIR and SEM. The thermal property of chitosan and its composites materials were determined via TGA. In this study, the incorporation of almond gum into the chitosan matrix resulted in good mechanical strength, film thickness, and low barrier and solubility characteristics. Water vapor transmission rate (WVTR) and oxygen transmission rate (OTR) of the composites films was also investigated. The WVTR and OTR values for the chitosan/almond gum (CSA) composite film values are 11.6 &plusmn; 1.62 (g/m2/day) and 32.9 &plusmn; 1.95 (cc/m2/24 h), respectively. The obtained composites show significantly improved antimicrobial activity against Gram-negative (E. coli) and Gram-positive (S. aureus) food-borne pathogenic bacteria. The results suggest that the CSA composites may serve as a promising candidate for antimicrobial food packaging materials. After an observation of the test results, it is inferred that the CSA composites bear good mechanical and antimicrobial activity and also show enhanced morphological characteristics

The Thermo-Mechanical and Dielectric Properties of Superhydrophobic Pbz/TiO₂ Composites

Polymer composites display the synergistic property of the polymer (matrix) and inorganic particles (filler material), when their combination is properly utilized. In the present work, polymer composites possessing a superhydrophobic property are fabricated by imposing the combination of both surface free energy and surface roughness. Polybenzoxazine (Pbz) is a choice of low surface free energy material and TiO2 particles contribute to create surface roughness. Thus, Pbz/TiO2 composites were fabricated by varying TiO2 contents to produce superhydrophobicity. The hydrophobicity increased from 94° for Pbz to 140° for Pbz/T5. The advantage of molecular design flexibility is also utilized to synthesize benzoxazine monomer (Bzo), which then undergoes thermally induced self-polymerization with different contents of TiO2 to produce Pbz-TiO2 composites. The structure analysis and curing behavior of the Bzo monomer was examined using FT-IR, NMR and DSC techniques. Whereas the properties of the Pbz/TiO2 composites were analyzed by WCA, SEM, DMA, TGA, and dielectric techniques

The Thermo-Mechanical and Dielectric Properties of Superhydrophobic Pbz/TiO2 Composites

Polymer composites display the synergistic property of the polymer (matrix) and inorganic particles (filler material), when their combination is properly utilized. In the present work, polymer composites possessing a superhydrophobic property are fabricated by imposing the combination of both surface free energy and surface roughness. Polybenzoxazine (Pbz) is a choice of low surface free energy material and TiO2 particles contribute to create surface roughness. Thus, Pbz/TiO2 composites were fabricated by varying TiO2 contents to produce superhydrophobicity. The hydrophobicity increased from 94&deg; for Pbz to 140&deg; for Pbz/T5. The advantage of molecular design flexibility is also utilized to synthesize benzoxazine monomer (Bzo), which then undergoes thermally induced self-polymerization with different contents of TiO2 to produce Pbz-TiO2 composites. The structure analysis and curing behavior of the Bzo monomer was examined using FT-IR, NMR and DSC techniques. Whereas the properties of the Pbz/TiO2 composites were analyzed by WCA, SEM, DMA, TGA, and dielectric techniques

Ipsilateral simultaneous fracture of the trochlea involving the lateral end clavicle and distal end radius: a rare combination and a unique mechanism of injury

【Abstract】Isolated trochlea fracture in adults is a rare surgical entity as compared to its capitellar counterpart. It has been only mentioned sporadically in the literature as case reports. Fracture of the trochlea is accompanied by other elbow injuries like elbow dislocation, capitellum fracture, ulnar fracture and extraarticular condylar fracture. Here we report a unique case of isolated displaced trochlea fracture associated with fractures of the lateral end clavicle and the distal end radius. We propose a unique mechanism for this rare combination of injuries: typical triad of injury, i.e. fracture of the distal end radius with trochlea and fracture of the lateral end of the clavicle. Nonoperative treatment is recommended for undisplaced humeral trochlea fractures; but for displaced ones, anatomical reduction and internal fixation are essential to maintain the congruous trochleacoronoid articulation and hence to maintain the intrinsic stability of the elbow. Key words: Isolated trochlea fracture; Clavicle; Radius fracture

Morphological, Mechanical, and Antimicrobial Properties of PBAT/Poly(methyl methacrylate-<i>co</i>-maleic anhydride)–SiO₂ Composite Films for Food Packaging Applications

A poly(methyl methacrylate-co-maleic anhydride) P(MMA-co-MA) copolymer was synthesized via radical polymerization. The synthesized P(MMA-co-MA) copolymer was identified by 1H- and 13C-nuclear magnetic resonance spectroscopy (1H-NMR), (13C-NMR), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The poly(butylene adipate-co-terephthalate) (PBAT)/P(MMA-co-MA)–SiO2 composites were developed using a solution-casting method. The PBAT to P(MMA-co-MA) weight ratio was kept at 70:30, while the weight percentage of SiO2 nanoparticles (NPs) was varied from 0.0 to 5.0 wt.%. SiO2 was used for PBAT/P(MMA-co-MA) to solve the compatibility between PBAT and the P(MMA-co-MA) matrix. The PBAT/P(MMA-co-MA)–SiO2 composites were characterized by studied FTIR spectroscopy, XRD, SEM, and TEM. A comparison of the composite film PBAT/P(MMA-co-MA)–SiO2 (PBMS-3) with the virgin PBAT and P(MMA-co-MA) film revealed its good tensile strength (19.81 MPa). The WVTR and OTR for the PBAT/P(MMA-co-MA)–SiO2 composites were much smaller than for PBAT/P(MMA-co-MA). The PBAT/P(MMA-co-MA)–SiO2 WVTR and OTR values of the composites were 318.9 ± 2.0 (cc m−2 per 24 h) and 26.3 ± 2.5 (g m−2 per 24 h). The hydrophobicity of the PBAT/P(MMA-co-MA) blend and PBAT/P(MMA-co-MA)–SiO2 composites was strengthened by the introduction of SiO2, as measured by the water contact angle. The PBAT/P(MMA-co-MA)–SiO2 composite films showed excellent antimicrobial activity against the food-pathogenic bacteria E. coli and S. aureus from the area of inhibition. Overall, the improved packaging characteristics, such as flexibility, tensile strength, low O2 and H2O transmission rate, and good antimicrobial activities, give the PBAT/P(MMA-co-MA)–SiO2 composite film potential for use in food packaging applications

Effects of particle size on the triboelectrification phenomenon in pharmaceutical excipients: Experiments and multi-scale modeling

Particle sizes play a major role to mediate charge transfer, both between identical and different material surfaces. The study probes into the probable mechanism that actuates opposite polarities between two different size fractions of the same material by analyzing the charge transfer patterns of two different sizes of microcrystalline cellulose (MCC). Quantum scale calculations confirmed alteration of charge transfer capacities due to variation of moisture content predicted by multiple surface and bulk analytical techniques. Discrete Element Method (DEM) based multi-scale computational models pertinent to predict charge transfer capacities were further implemented, and the results were in accordance to the experimental charge profiles