Streptokinase Stability Pattern during Storage in Various Solvents and at Different Temperatures

1975 ◽  
Vol 33 (03) ◽  
pp. 586-596 ◽  
Author(s):  
M Martin ◽  
Fräulein H Auel ◽  
Keyword(s):  
Room Temperature ◽  
Group Iii ◽  
Charged Colloids ◽  
Group I ◽  
Different Temperatures ◽  
Order Of Magnitude ◽  
Stability Pattern ◽  
The Stability ◽  
Incubation Temperatures ◽  
Dextran Solution

SummaryThe activity drop of 5 u streptokinase was measured in 1 ml each of various solutions (0.9% NaCl solution, 5% glucose solution, 5% levulose solution, 10% dextran solution, gelatin solution, 3% albumin solution, Michaelis buffer, glucose (5%)-heparin (750 u/ml) solution) at different incubation temperatures (–20° c, 4° c, 20 c, 37 C), and over different observation periods (15 min, 30 min, 45 min, 60 min, 6 h, 12 h, 24 h, and 48 h). Solution media tested for streptokinase-protecting quality were broken down into three groups.Group I: Solvents displaying excellent stabilizing properties (gelatin and albumin solutions).Group II: Solvents displaying medium stabilizing properties (dextran and levulose solutions).Group III: Solvents displaying poor stabilizing properties (NaCl and glucose solutions, Michaelis buffer).In testing streptokinase concentrations as used for therapeutic purposes (1500 u/ml, 50,000 u/ml), no decay was found to take place over observation periods of up to 48 h, and no influence by different solvents (Group I, II or III) was traceable. Heparin stored with streptokinase at room temperature over a period of 48 h did not alter the streptokinase stability.Some mechanisms concerning the stability pattern of streptokinase are discussed. It appears that low streptokinase concentrations need negatively charged colloids to keep the protein structure intact. The streptokinase-protecting macro-molecules tested so far were albumin, gelatin, and streptokinase. Obviously, streptokinase by itself was able to preserve its own stability provided its concentration was of a certain order of magnitude (1500 u/ml, 50,000 u/ml).

Conductivities of Room Temperature Molten Salts Containing ZnCl2, Measured by a Computerized Direct Current Method

2002 ◽  
Vol 57 (3-4) ◽  
pp. 129-135
Author(s):  
Hsin-Yi Hsu ◽  
Chao-Chen Yang
Keyword(s):  
Activation Energy ◽  
Direct Current ◽  
Molten Salts ◽  
Room Temperature ◽  
Current Method ◽  
Cross Linking ◽  
Infra Red ◽  
Different Temperatures ◽  
The Stability ◽  
Benzyltriethylammonium Chloride

The conductivities of the binary room-temperature molten salt (RTMS) systems ZnCl2-N-nbutylpyridinium chloride (BPC), ZnCl2 -1-ethyl-3-methylimidazolium chloride (EMIC) and ZnCl2 - benzyltriethylammonium chloride (BTEAC) have been measured at different temperatures and compositions by a d.c. four-probes method. The conductivities of the three RTMS are in the order ZnCl2-EMIC > ZnCl2-BPC > ZnCl2-BTEAC. In ZnCl2-BPC the conductivity at 70 to 150 °C, is maximal for 40 mol% ZnCl2. In ZnCl2 - EMIC, the conductivity below 130 °C is almost constant for 30 to 50 mol% ZnCl2 and has the lowest activation energy 25.21 kJ/mol. For these two systems, the conductivities decrease rapidly beyond 50 mol% ZnCl2 owing to the rapid increase in cross-linking and resultant tightening of the polyelectrolyte structure. As to the ZnCl2-BTEAC system, the conductivities at 110 - 150 °C decrease slowly for 30 - 60 mol% ZnCl2. The conductivities of the ZnCl2-EMICmelt are compared with those of the AlCl3-EMIC melt previously studied. The stability of the ZnCl2-EMIC melt system is explored by the effect of the environment on the conductivity and the Far Transmission Infra Red (FTIR) spectrum. It reveals that the effect is slight, and that the ZnCl2-EMIC melt may be classified as stable.

scholarly journals Isolation and characterization of β- and γ-caseins from horse milk

1982 ◽  
Vol 203 (1) ◽  
pp. 131-139 ◽  
Author(s):  
S Visser ◽  
R Jenness ◽  
R J Mullin
Keyword(s):  
Room Temperature ◽  
Sodium Dodecyl ◽  
Sulphate Group ◽  
Group Iii ◽  
Isolation And Characterization ◽  
Group I ◽  
Beta Casein ◽  
Group Ii ◽  
Phosphate Groups

Three groups of casein components were isolated from horse milk. Group I is almost insoluble at acid and neutral pH, and is rather heterogeneous on alkaline gels with or without sodium dodecyl sulphate. Group II shows strong similarity to beta-casein from other species, as concluded from its amino acid composition and its N- and C-terminal sequences. This group consists of five electrophoretically distinguishable forms, all containing ester phosphate groups but no carbohydrate. Group III is composed of C-terminal fragments of the beta-like (group II) fraction and probably arises from the action of a plasmin-like enzyme present in horse milk. It does not contain phosphate or carbohydrate. Homology of this group with bovine gamma-caseins is demonstrated. Both beta- and gamma-like caseins are more soluble at 4 degrees C than at room temperature.

scholarly journals Stability of the Combination of Ceftazidime and Cephazolin in Icodextrin or PH Neutral Peritoneal Dialysis Solution

2014 ◽  
Vol 34 (2) ◽  
pp. 212-218 ◽  
Author(s):  
Rahul P. Patel ◽  
Madhur D. Shastri ◽  
Mohammad Bakkari ◽  
Troy Wanandy ◽  
Matthew D. Jose
Keyword(s):  
Peritoneal Dialysis ◽  
Body Temperature ◽  
High Performance ◽  
Room Temperature ◽  
Storage Conditions ◽  
Initial Concentration ◽  
Dialysis Solution ◽  
Different Temperatures ◽  
Colour Changes ◽  
The Stability

IntroductionThe objective of this study was to investigate the stability of ceftazidime and cephazolin in a 7.5% icodextrin or pH neutral peritoneal dialysis (PD) solution.MethodsCeftazidime and cephazolin were injected into either a 7.5% icodextrin or pH neutral PD bag to obtain the concentration of 125 mg/L of each antibiotic. A total of nine 7.5% icodextrin or pH neutral PD bags containing ceftazidime and cephazolin were prepared and stored at 1 of 3 different temperatures: 4°C in a domestic refrigerator; 25°C at room temperature; or 37°C (body temperature) in an incubator. An aliquot was withdrawn immediately before (0 hour) or after 12, 24, 48, 96, 120, 144, 168 and 336 hours of storage. Each sample was analyzed in duplicate for the concentration of ceftazidime and cephazolin using a stability-indicating high-performance liquid chromatography technique. Ceftazidime and cephazolin were considered stable if they retained more than 90% of their initial concentration. Samples were also assessed for pH, colour changes and evidence of precipitation immediately after preparation and on each day of analysis.ResultsCeftazidime and cephazolin in both types of PD solution retained more than 90% of their initial concentration for 168 and 336 hours respectively when stored at 4°C. Both of the antibiotics lost more than 10% of the initial concentration after 24 hours of storage at 25 or 37°C. There was no evidence of precipitation at any time under the tested storage conditions. Change in the pH and color was observed at 25 and 37°C, but not at 4°C.ConclusionPremixed ceftazidime and cephazolin in a 7.5% icodextrin or pH neutral PD solution is stable for at least 168 hours when refrigerated. This allows the preparation of PD bags in advance, avoiding the necessity for daily preparation. Both the antibiotics are stable for at least 24 hours at 25 and 37°C, permitting storage at room temperature and pre-warming of PD bags to body temperature prior to its administration.

scholarly journals Effect of Drying Processes on Stability of Anthocyanin Extracts from Saffron Petal

2014 ◽  
Vol 2 ◽  
pp. 13-18 ◽  
Author(s):  
Somayeh Heydari ◽  
Roya Rezaei ◽  
Gholam Hossein Haghayegh
Keyword(s):  
Room Temperature ◽  
Heating Temperature ◽  
Heating Time ◽  
Crocus Sativus ◽  
The Sun ◽  
Processing Treatment ◽  
Different Temperatures ◽  
The Stability ◽  
Synthetic Pigments ◽  
Good Substitute

Saffron (Crocus sativus) has cyanic color flowers with major colorant of anthocyanin. Attractive color and functional properties of anthocyanins make them a good substitute for synthetic pigments in the food industry. These natural soluble water colorants are rather unstable and influenced by final processing treatment. The drying process is critical to the stability of saffron petals anthocyanins. Four different dehydration methods were evaluated: traditional method (at room temperature and under the sun); dehydration with electrical oven at different temperatures; and dehydration with microwave at different powers. The results showed that the highest amount of anthocyanin was obtained when saffron petals treated by traditional methods (at room temperature and under the sun). According to the results, the stability of saffron petals anthocyanins gradually accessed with increase of the heating temperature and decrement of heating time until 100 °C. However, heated at 120 and 140 °C, the anthocyanins could break down, and their residual amounts declined within 20 min and 10 min, respectively. The results suggested that saffron petals anthocyanins tended to degrade at high temperatures (>100 °C). Between these methods, drying at room temperature and drying with microwave at 900 W obtained the highest and the lowest results respectively.

scholarly journals PHYSICAL STABILITY AND ANTIOXIDANT ACTIVITY ASSAY OF A NANOEMULSION GEL FORMULATION CONTAINING TOCOTRIENOL

2017 ◽  
Vol 9 ◽  
pp. 140
Author(s):  
Mentari Mayang Suminar ◽  
Mahdi Jufri
Keyword(s):  
Antioxidant Activity ◽  
Room Temperature ◽  
Inhibitory Concentration ◽  
Physical Stability ◽  
Tween 80 ◽  
Skin Damage ◽  
Activity Assay ◽  
Nanoemulsion Gel ◽  
Different Temperatures ◽  
The Stability

Objective: Tocotrienols have an antioxidant potential higher than that of tocopherols. Nanoemulsion gel can deliver tocotrienols into the skin toprevent skin damage caused by free radicals and improve the stability of the dosage form. The present study aimed to determine the physical stabilityand antioxidant activity of a nanoemulsion gel formulation containing tocotrienol.Methods: The tocotrienol nanoemulsion was made using tocotrienols, oleic acid, Tween 80, 96% ethanol, and propylene glycol. The gel base was madeusing a carbomer and triethanolamine. A physical stability test was conducted at three different temperatures, namely, low temperature (4±2°C),room temperature (27±2°C), and high temperature (40±2°C). The antioxidant activity was measured using the 2,2-diphenyl-1-picrylhydrazyl methodfor determining inhibitory concentration (IC50) values.Results: Formula 1 demonstrated the best physical stability, with a pH of 6.2. The droplet size of the tocotrienol nanoemulsion gel was 596 nm, witha zeta potential value of −27.1 nm. The IC50 of the tocotrienol nanoemulsion gel was 6252.14 ppm.Conclusion: The nanoemulsion gel formulation retained antioxidant activity and was physically stable for 8 weeks.

High Field Electrical Conductivity and Breakdown in Heteroepitaxial Diamond Films

1995 ◽  
Vol 416 ◽  
Author(s):  
S. Schröppel ◽  
R. Hessmer ◽  
M. Schreck ◽  
B. Stritzker
Keyword(s):  
High Field ◽  
Room Temperature ◽  
Diamond Films ◽  
Dielectric Strength ◽  
Breakdown Field ◽  
Thermal Breakdown ◽  
Breakdown Region ◽  
Different Temperatures ◽  
Order Of Magnitude ◽  
Observed Behaviour

ABSTRACTNominally undoped, heteroepitaxially nucleated diamond films have been grown on Si(001). For different temperatures ranging between room temperature and 490°C the DCconductivity through the films has been measured for field strengths up to 600kV/cm. In the framework of the Poole-Frenkel theory a fit of the curves is possible for the model of isolated as well as for the model of overlapping coulombic potentials yielding an activation energy of 1.03eV.In addition the breakdown voltage of the films has been measured as a function of the temperature. A drastic linear decrease with temperature is observed. Starting at a dielectric strength of about 1 MV/cm at room temperature the breakdown field decreases by an order of magnitude for 400°C. This observed behaviour is consistent with thermal breakdown based on Poole-Frenkel conduction in the pre-breakdown region.

Stability Study of Epirubicin in Nacl 0.9% Injection

1997 ◽  
Vol 31 (9) ◽  
pp. 992-995 ◽  
Author(s):  
Montserrat Pujol ◽  
Montserrat Muñoz ◽  
Josefina Prat ◽  
Victoria Girona ◽  
Jordi De Bolós
Keyword(s):  
Shelf Life ◽  
Room Temperature ◽  
Degradation Kinetics ◽  
Storage Conditions ◽  
Hplc Method ◽  
Stability Study ◽  
Chemistry Laboratory ◽  
Maximum Decrease ◽  
Different Temperatures ◽  
The Stability

Objective To determine the stability of epirubicin in NaCl 0.9% injection under hospital storage conditions. Methods NaCl 0.9% solution was added to epirubicin iyophilized powder to make a final concentration of 1 mg/mL to study the degradation kinetics and 2 mg/mL to study the stability in polypropylene syringes under hospital conditions. Setting Physical chemistry laboratory, Unitat de Fisicoquímica, Universitat de Barcelona. Main outcome Measures Solutions of epirubicin at 2 mg/mL in NaCl 0.9% solutions stored in plastic syringes were studied under hospital conditions at room temperature (25 ± 1 °C) and under refrigeration (4 ± 1 °C) both protected from light and exposed to room light (~50 lumens/m2). All samples were studied in triplicate and epirubicin concentrations were obtained periodically throughout each storage/time condition via a specific stability-indicating HPLC method. To determine the degradation kinetics, solutions of epirubicin in NaCl 0.9% at 1 mg/mL were stored at different temperatures (40, 50, and 60 °C) to obtain the rate degradation constant and the shelf life at room temperature and under refrigeration. Results The degradation of epirubicin in NaCl 0.9% solutions follows first-order kinetics. The shelf life was defined as the time by which the epirubicin concentration had decreased by 10% from the initial concentration. In this study, epirubicin was stable in NaCl 0.9% injection stored in polypropylene containers for all time periods and all conditions. That results in a shelf life of at least 14 and 180 days at 25 and 4 °C, respectively. The maximum decrease in epirubicin concentration observed at 25 °C and 14 days was 4%, and at 4 °C and 180 days was 8%. The predicted shelf life obtained from the Arrhenius equation was 72.9 ± 0.2 and 3070 ± 15 days at 25 and 4 °C, respectively, in both dark and illuminated conditions. Conclusions Solutions of epirubicin in NaCl 0.9% at 2 mg/mL are chemically stable when they are stored in polypropylene syringes under hospital storage conditions. No special precaution is neccessary to protect epirubicin solutions (2 mg/mL) from light.

scholarly journals The Effects on Sensorial Block, Motor Block, and Haemodynamics of Levobupivacaine at Different Temperatures Applied in the Subarachnoid Space

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Bahittin Nazli ◽  
Huseyin Oguzalp ◽  
Eyup Horasanli ◽  
Mehmet Gamli ◽  
Beyazit Dikmen ◽  
...  
Keyword(s):  
Side Effects ◽  
Motor Block ◽  
Room Temperature ◽  
Demographic Data ◽  
Sensory Block ◽  
Group I ◽  
Significant Difference ◽  
Different Temperatures ◽  
Group Ii ◽  
Transurethral Prostate Resection

Aim. To evaluate the effects of 0.5% levobupivacaine at 37°C preheated from room temperature, on sensorial block, motor block, and haemodynamics in patients undergoing transurethral prostate resection (TUR-P).Material and Method. The patients were randomly allocated to two groups: Group I patients were injected with 3 mL 0.5% levobupivacaine solution which had been kept at room temperature for at least 24 hours and Group II patients were injected with 3 mL 0.5% levobupivacaine solution which had been kept at 37°C for at least 24 hours. The patients were examined in terms of sensorial block, motor block, haemodynamic profile, and incidence of side effects.Results. No significant difference was found between the groups in terms of demographic data. The time to reachT10sensory block and the time of starting motor block were found to be significantly shorter in Group II . The duration of sensory block overT10andT6, the duration ofL1regression, the duration of the sensory block, and the regression time of the motor blocks from 3 to 2 were found to be longer in Group II.Conclusion. The use of 0.5% levobupivacaine spinal anaesthesia heated to 37°C accelerated the start of sensory and motor block.

scholarly journals Effect of Intracanal Cryotherapy and Negative Irrigation Technique on Postendodontic Pain

2016 ◽  
Vol 17 (12) ◽  
pp. 990-996 ◽  
Author(s):  
Talal Al-Nahlawi ◽  
Talaat Abo Hatab ◽  
Mahmoud Abd Alrazak ◽  
Ahmad Al-Abdullah
Keyword(s):  
Negative Pressure ◽  
Root Canal ◽  
Room Temperature ◽  
Control Group ◽  
P Value ◽  
Group Iii ◽  
Single Visit ◽  
Single Root ◽  
Group I ◽  
The Social

ABSTRACT Aim To evaluate the effect of intracanal cryotherapy with negative pressure irrigation (EndoVac) on postendodontic pain after vital single-visit root canal treatment (RCT). Materials and methods A total of 75 single-rooted teeth with single root canal were treated endodontically. After root canal preparation with Protaper Universal rotary system and irrigation, teeth were divided randomly into three groups (n = 25) according to additional irrigation protocol as follows: Group I: No additional irrigation was applied (control); group II: A 20 mL of room temperature saline was irrigated during 5 minutes using EndoVac, and group III: A 20 mL of 2 to 4°C cold saline was irrigated during 5 minutes using EndoVac. Pain levels were assessed by visual analog scale (VAS) and verbal evaluation of pain questionnaire after 6, 12, 24, 48 hours, and 7 days of canal obturation. The data were then analyzed using Statistical Package for the Social Sciences (SPSS) 13.0 using Kruskal–Wallis and Mann–Whitney U tests at p-value of 0.05. Results The results showed that pain levels were high in groups I and II after 6 hours that decreased with time to almost diminish after 1 week, and on the other hand, group III showed no pain among different monitoring periods. Also pain levels in groups II were lower compared with group I after only 6 hours, with significance p < 0.05. Conclusion Postendodontic pain presented with highest values after 6 hours of treatment and reduced to almost nil after 1 week. Intracanal cryotherapy eliminated postendodontic pain clinically. Negative pressure reduced postendodontic pain after 6 hours of treatment. Clinical significance The outcome of this study indicates that the use of intracanal cryotherapy technique with negative pressure irrigation eliminates postendodontic pain after single-visit RCTs. How to cite this article Al-Nahlawi T, Abo Hatab T, Abd Alrazak M, Al-Abdullah A. Effect of Intracanal Cryotherapy and Negative Irrigation Technique on Postendodontic Pain. J Contemp Dent Pract 2016;17(12):990-996.

scholarly journals Stability of Antibiotics for Intraperitoneal Administration in Extraneal 7.5% Icodextrin Peritoneal Dialysis Bags (Stab Study)

2016 ◽  
Vol 36 (4) ◽  
pp. 421-426 ◽  
Author(s):  
Dwarakanathan Ranganathan ◽  
Saiyuri Naicker ◽  
Steven C. Wallis ◽  
Jeffrey Lipman ◽  
Sharad K. Ratanjee ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Room Temperature ◽  
Intraperitoneal Administration ◽  
Stability Studies ◽  
Initial Value ◽  
Time Intervals ◽  
Storage Duration ◽  
Different Temperatures ◽  
The Stability ◽  
Drug Free

Background and objectivesPatients with peritoneal dialysis (PD)-associated peritonitis may be advised to store PD-bags with pre-mixed antibiotics at home, although there is a paucity of antibiotic stability studies in the commonly used icodextrin solutions. The purpose of this study was to assess the stability of various antibiotics in PD-bags when stored at different temperatures over a 14-day period.Methods7.5% icodextrin PD-bags were dosed with gentamicin 20 mg/L ( n = 9), vancomycin 1,000 mg/L ( n = 9), cefazolin 500 mg/L ( n = 9) and ceftazidime 500 mg/L ( n = 9) as for intermittent dosing. Combinations of gentamicin/vancomycin ( n = 9), cefazolin/ceftazidime ( n = 9), and cefazolin/gentamicin ( n = 9) were also tested. Nine drug-free bags were used as controls. Bags were stored in triplicate at 37°C, room-temperature (25°C), and refrigeration (4°C). Antibiotic concentrations were quantified at various time intervals using validated chromatography. Storage duration was considered unstable if the concentration of the antibiotic dropped ≤ 90% of the initial value.ResultsGentamicin was stable for 14 days at all temperatures. Vancomycin was stable for 4 days at 37°C and for 14 days at both 25°C and 4°C. The gentamicin and vancomycin combination was stable for 4 days at 37°C and for 14 days at 25°C and 4°C. Cefazolin alone was stable for 24 hours at 37°C, 7 days at 25°C, and 14 days at 4°C. Ceftazidime alone was stable for only 6 hours at 37°C, 2 days at 25°C, and 14 days at 4°C. The cefazolin and ceftazidime combination was stable for 24 hours at 37°C, 2 days at 25°C, and 14 days at 4°C. The cefazolin and gentamicin combination was stable for 1 day at 37°C, 4 days at 25°C, and 14 days at 4°C.ConclusionsAntibiotics premixed in icodextrin PD-bags have varying stabilities with stability generally least at 37°C and best at 4oC, permitting storage for 14 days when refrigerated and pre-warming to body temperature prior to administration. Further research confirming the sterility of these antibiotic-containing bags is recommended.

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