scholarly journals Stability of Ampicillin in Normal Saline Following Refrigerated Storage and 24-Hour Pump Recirculation

2020 ◽  
pp. 001857872092538
Author(s):  
Mariah Huskey ◽  
Paul Lewis ◽  
Stacy D. Brown

Objective: Use of ampicillin in outpatient parenteral antimicrobial therapy (OPAT) has historically been complicated by frequent dosing and limited stability. The purpose of this study was to evaluate stability of ampicillin using high-pressure liquid chromatography (HPLC) in an OPAT dosing model using continuous infusion at room temperature over 24 hours immediately following preparation compared with batches stored under refrigeration for 24 hours, 72 hours, and 7 days. Methods: An HPLC method was developed and validated as stability indicating using guidance in USP general Chapter <1225>. Four ampicillin batches were prepared for each experimental condition (immediate use and refrigerated storage for 24 hours, 72 hours, and 7 days). A pump was used to recirculate the solutions through medical-grade tubing for 24 hours. Triplicate 1-mL aliquots were removed from each batch at time 0, 4, 8, 12, and 24 hours and analyzed for ampicillin concentration. Results: Each batch was assayed for initial concentration (20.34-21.50 mg/mL), and percent recovery compared with that concentration thereafter. For the duration of infusion, the average recoveries were 96.4%, 95.8%, 94.6%, and 90.3% for immediate use, 24-hour storage, 72-hour storage, and 7-day storage, respectively. The recovery remained above 90% for all batches and time points, except for 7-day storage, which fell below 90% after 4 hours of circulation. Conclusion: Ampicillin can be prepared and stored in a refrigerator for up to 72 hours prior to continuously infusing at room temperature over 24 hours with less than a 10% loss of potency over the dosing period. This model supports twice weekly OPAT delivery of ampicillin.

2021 ◽  
pp. 112972982110458
Author(s):  
Julia Bodega-Azuara ◽  
Maria Dolores Bellés-Medall ◽  
Josep Edo-Peñarrocha ◽  
Raúl Ferrando-Piqueres ◽  
Alejandro Perez-Alba ◽  
...  

Background: We investigated physical and chemical stability of daptomycin and vancomycin in heparin or sodium citrate lock solutions. The aim of this study was to find the optimal combination of antimicrobials and additives for lock solutions, which maximized patient safety. Methods: Vancomycin and daptomycin were diluted with heparin or sodium citrate to achieve final concentrations of vancomycin-heparin 2.5 mg/mL–833.33 U/mL, vancomycin-citrate 2.5–33.3 mg/mL, daptomycin-heparin 5 mg/mL–800 U/mL, and daptomycin-citrate 5–32 mg/mL and they were stored at room temperature (+25°C), 4°C, −20°C, and 37°C. Physical and chemical stability were analyzed for each antibiotic-anticoagulant combination in all conditions immediately after preparation, at 24, 48, 72 h and at different time points until unstable concentrations were obtained. Daptomycin-sodium citrate microbiological activity was also studied by evaluating two Staphylococcus aureus cultures in a calcium enriched medium with a daptomycin E test, with and without sodium citrate. Results: After incubation at 37°C vancomycin and daptomycin combined with heparin retained at least 90% of the initial concentration over 48 h. Vancomycin-sodium citrate solution stored at 37°C reduced more than 10% of the initial concentration at 24 h. On the other hand, daptomycin-sodium citrate preparation was stable at 37°C for 72 h but the microbiological activity of daptomycin was lower in the presence of sodium citrate. Conclusions: The purpose is to prepare vancomycin and daptomycin lock solutions combined with heparin. They should be changed at 48 h and its stability is over 3 days at 25°C and 7 days at 4°C, which allow Hospital Pharmacy Services to manage their stocks. Daptomycin-sodium citrate combination is more stable for extended periods but its bioactivity has not been demonstrated.


Author(s):  
Robert W. Roberson

The use of cryo-techniques for the preparation of biological specimens in electron microscopy has led to superior preservation of ultrastructural detail. Although these techniques have obvious advantages, a critical limitation is that only 10-40 μm thick cells and tissue layers can be frozen without the formation of distorting ice crystals. However, thicker samples (600 μm) may be frozen well by rapid freezing under high-pressure (2,100 bar). To date, most work using cryo-techniques on fungi have been confined to examining small, thin-walled structures. High-pressure freezing and freeze substitution are used here to analysis pre-germination stages of specialized, sexual spores (teliospores) of the plant pathogenic fungus Gymnosporangium clavipes C & P.Dormant teliospores were incubated in drops of water at room temperature (25°C) to break dormancy and stimulate germination. Spores were collected at approximately 30 min intervals after hydration so that early cytological changes associated with spore germination could be monitored. Prior to high-pressure freezing, the samples were incubated for 5-10 min in a 20% dextran solution for added cryoprotection during freezing. Forty to 50 spores were placed in specimen cups and holders and immediately frozen at high pressure using the Balzers HPM 010 apparatus.


2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
Imad Tarek Hanoon ◽  
Abed Mohammed Daheir AL-Joubory 2 ◽  
Marwa Mohamed Saied 3

A simple , specific, accurate and precise RP-HPLC method was developed for determination of Irbesartan (IRB) in pharmaceutical dosage forms in tablets products and sachet using symmetry (L 1 ) column at 30°C . The signal was detected at 225 nm. A mobile phase dissolve 0.5 g of buffer potassium phosphate in 100 ml distilled water and adjust pH 2.7 , methanol and acetonitrile at ratio (40 :30 :30 ) . and flow rate 1.2ml/min -1 at pH=7.2 a mobile phase The percent recovery was detected 101 % and the linearity of concentration was 10-50 µg.ml -1 and supported this method by using (FT.I.R.) spectrum method for organic spectrophotometer to prove the chemical structure of this drug and some physical properties . we are obtained the result is identical of other literature . The proposed method was applied successfully for determination of the IRB in tablets products.


2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.


Alloy Digest ◽  
1988 ◽  
Vol 37 (12) ◽  

Abstract RMI 6A1-4V ELI is an alpha-beta type of titanium-base alloy that can be strengthened by age hardening. In the mill-annealed condition it has a guaranteed minimum room-temperature yield strength of 120,000 psi and can be increased to as much as 160,000 psi by solution treating and aging. This alloy may be used for high-pressure cryogenic vessels down to 320 F. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and bend strength as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-89. Producer or source: RMI Company.


Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 34
Author(s):  
Akun Liang ◽  
Robin Turnbull ◽  
Enrico Bandiello ◽  
Ibraheem Yousef ◽  
Catalin Popescu ◽  
...  

We report the first high-pressure spectroscopy study on Zn(IO3)2 using synchrotron far-infrared radiation. Spectroscopy was conducted up to pressures of 17 GPa at room temperature. Twenty-five phonons were identified below 600 cm−1 for the initial monoclinic low-pressure polymorph of Zn(IO3)2. The pressure response of the modes with wavenumbers above 150 cm−1 has been characterized, with modes exhibiting non-linear responses and frequency discontinuities that have been proposed to be related to the existence of phase transitions. Analysis of the high-pressure spectra acquired on compression indicates that Zn(IO3)2 undergoes subtle phase transitions around 3 and 8 GPa, followed by a more drastic transition around 13 GPa.


2021 ◽  
Vol 103 (21) ◽  
Author(s):  
William Lafargue-Dit-Hauret ◽  
Daniel Braithwaite ◽  
Andrew D. Huxley ◽  
Tsuyoshi Kimura ◽  
Andres Saúl ◽  
...  

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 295
Author(s):  
Arianna Cubeddu ◽  
Patrizia Fava ◽  
Andrea Pulvirenti ◽  
Hossein Haghighi ◽  
Fabio Licciardello

The aim of the present study is to assess the use of polylactic acid (PLA) bottles as an alternative to polyethylene terephthalate (PET) ones for high-pressure processing (HPP) of apple juice. The treatment of PLA bottles at 600 MPa for 3 min did not cause alterations in the packaging shape and content, confirming the suitability of PLA bottles to withstand HPP conditions as well as PET bottles. Quantification of total mesophilic bacterial and fungal load suggested HPP treatment can be effectively applied as an alternative to pasteurization for apple juice packed in PLA bottles since it guarantees microbial stability during at least 28 days of refrigerated storage. The headspace gas level did not change significantly during 28 days of refrigerated storage, irrespective of the bottle material. Color parameters (L*, a*, and b*) of the HPP-treated juice were similar to those of the fresh juice. Irrespective of the packaging type, the total color variation significantly changed during storage, showing an exponential increase in the first 14 days, followed by a steady state until the end of observations. Overall, PLA bottles proved to offer comparable performances to PET both in terms of mechanical resistance and quality maintenance.


2016 ◽  
Vol 78 (6-9) ◽  
Author(s):  
Intan Fadhlina Mohamed ◽  
Seungwon Lee ◽  
Kaveh Edalati ◽  
Zenji Horita ◽  
Shahrum Abdullah ◽  
...  

This work presents a study related to the grain refinement of an aluminum A2618 alloy achieved by High-Pressure Torsion (HPT) known as a process of Severe Plastic Deformation (SPD). The HPT is conducted on disks of the alloy under an applied pressure of 6 GPa for 1 and 5 turns with a rotation speed of 1 rpm at room temperature. The HPT processing leads to microstructural refinement with an average grain size of ~250 nm at a saturation level after 5 turns. Gradual increases in hardness are observed from the beginning of straining up to a saturation level. This study thus suggests that hardening due to grain refinement is attained by the HPT processing of the A2618 alloy at room temperature.


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