scholarly journals Evaluation of the Influence of a Hydrogel Containing AMPD on the Stability of Tetracycline Hydrochloride

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1381
Author(s):  
Agnieszka Kostrzębska ◽  
Adrianna Złocińska ◽  
Witold Musiał
Keyword(s):  
Aqueous Solution ◽  
Fatty Acids ◽  
Antimicrobial Activity ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Tetracycline Hydrochloride ◽  
Dual Action ◽  
Hydrogel Formulation ◽  
The Stability ◽  
High Instability

Tetracyclines, as beneficial antimicrobial factors in both local and systemic therapy, are characterized by high instability. The aim of the study was the development of the influence of hydrogel formulation on the tetracycline hydrochloride (TC) level under varying storage conditions. The HPLC, XPRD as well as SEM and macroscopic observations were involved in the study. The TC concentration decreased within ca. two months from 9.37 µg/mL to 4.41 µg/mL in the case of the photoprotected TC solution stored at 23 °C, whereas the decrease in storage temperature did not improve the final level of TC. In the presence of AMPD, the TC level in aqueous solution decreased drastically to ca. 1 µg/mL. Application of a polyacrylic acid derivative enabled conservation of the TC level through the ca. two months. Thus, the use of alcoholamine in the preparation of the TC hydrogel may result in the development of a therapeutic product with a dual action against acne, including antimicrobial activity and saponification of free fatty acids deposited in the follicles.

Thermal and temporal stability on the enteric viruses infectivity in surface freshwater

2015 ◽  
Vol 16 (3) ◽  
pp. 620-627 ◽  
Author(s):  
V. Moresco ◽  
N. A. Damazo ◽  
C. R. M. Barardi
Keyword(s):  
Storage Temperature ◽  
Quantitative Polymerase Chain Reaction ◽  
Temporal Stability ◽  
Enteric Viruses ◽  
Human Adenovirus ◽  
Adenovirus Type ◽  
Storage Conditions ◽  
Murine Norovirus ◽  
Log Reduction ◽  
The Stability

The present study aimed to evaluate the stability of Human Adenovirus type 2 (HAdV2) and Murine Norovirus 1 (MNV-1) in surface freshwater samples stored at different temperatures. For HAdV2 the stability decreased with increasing temperatures (−80 > −20 > 4 > 22 °C). The time required to reach one log reduction in viral titers (T90) was similar among all the times and temperatures by different cell-culture based methods and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The HAdV2 stability decreased with the time of storage temperature and methods employed, aside from samples stored at 22 and 4 °C which showed the lowest T90 values (50 days). For MNV-1, the samples stored at 22 and −20 °C showed higher log10 decay values, followed by 4 and −80 °C; while genome persistence was ranked as −80 > −20 > 4 > 22 °C. The T90 values were lower for samples stored at 22 °C (33 days), followed by 4, −20 and −80 °C with 111, 100 and 333 days, respectively. The results indicate that, under laboratory storage conditions, freshwater samples should be kept at 4 °C and at −80 °C for short- and long-term periods, respectively. This study provided useful information about thermal and temporal stability of the enteric viruses regarding sample storage conditions.

Effect of storage of plasma and serum on enzymatic determination of non-esterified fatty acids

2001 ◽  
Vol 38 (3) ◽  
pp. 252-255 ◽  
Author(s):  
Luis García Menéndez ◽  
Ana L Fernández ◽  
Alfredo Enguix ◽  
Constanza Ciriza ◽  
Juan Amador
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Storage Conditions ◽  
The Other ◽  
Specific Reference ◽  
Enzymatic Method ◽  
Esterified Fatty Acids ◽  
Enzymatic Determination ◽  
The Stability

Many contradictory results have been published on the stability of total non-esterified fatty acids in blood, plasma and serum under different storage conditions. The present study was undertaken to investigate the stability of non-esterified fatty acids, measured with an enzymatic method, in samples of EDTA-treated plasma and serum under different temperature conditions. We conclude that EDTA-treated plasma and serum can both be used for analysis. Specific reference values should be established depending on the type of sample chosen. Samples that cannot be analysed immediately can be stored at -20°C for at least 14 days without significant changes in the concentration of total non-esterified fatty acids. None of the other storage conditions and periods studied are suitable for the measurement of non-esterified fatty acid concentration.

scholarly journals Effects of Formulation on Microbicide Potency and Mitigation of the Development of Bacterial Insusceptibility

2015 ◽  
Vol 81 (20) ◽  
pp. 7330-7338 ◽  
Author(s):  
Nicola L. Cowley ◽  
Sarah Forbes ◽  
Alejandro Amézquita ◽  
Peter McClure ◽  
Gavin J. Humphreys ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Antimicrobial Activity ◽  
Benzalkonium Chloride ◽  
Consumer Products ◽  
Repeated Exposure ◽  
Risk Assessments ◽  
Antimicrobial Compounds ◽  
Polyhexamethylene Biguanide ◽  
Before And After ◽  
The Stability

ABSTRACTRisk assessments of the potential for microbicides to select for reduced bacterial susceptibility have been based largely on data generated through the exposure of bacteria to microbicides in aqueous solution. Since microbicides are normally formulated with multiple excipients, we have investigated the effect of formulation on antimicrobial activity and the induction of bacterial insusceptibility. We tested 8 species of bacteria (7 genera) before and after repeated exposure (14 passages), using a previously validated gradient plating system, for their susceptibilities to the microbicides benzalkonium chloride, benzisothiozolinone, chlorhexidine, didecyldimethyl ammonium chloride, DMDM-hydantoin, polyhexamethylene biguanide, thymol, and triclosan in aqueous solution (nonformulated) and in formulation with excipients often deployed in consumer products. Susceptibilities were also assessed following an additional 14 passages without microbicide to determine the stability of any susceptibility changes. MICs and minimum bactericidal concentrations (MBC) were on average 11-fold lower for formulated microbicides than for nonformulated microbicides. After exposure to the antimicrobial compounds, of 72 combinations of microbicide and bacterium there were 19 ≥4-fold (mean, 8-fold) increases in MIC for nonformulated and 8 ≥4-fold (mean, 2-fold) increases in MIC for formulated microbicides. Furthermore, there were 20 ≥4-fold increases in MBC (mean, 8-fold) for nonformulated and 10 ≥4-fold (mean, 2-fold) increases in MBC for formulated microbicides. Susceptibility decreases fully or partially reverted back to preexposure values for 49% of MICs and 72% of MBCs after further passage. In summary, formulated microbicides exhibited greater antibacterial potency than unformulated actives and susceptibility decreases after repeated exposure were lower in frequency and extent.

scholarly journals Influence of Storage Conditions and Preservatives on Metabolite Fingerprints in Urine

Metabolites ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 203 ◽  
Author(s):  
Xinchen Wang ◽  
Haiwei Gu ◽  
Susana A. Palma-Duran ◽  
Andres Fierro ◽  
Paniz Jasbi ◽  
...  
Keyword(s):  
Large Scale ◽  
Storage Time ◽  
Storage Temperature ◽  
Urinary Metabolites ◽  
Storage Conditions ◽  
Inhibitory Effect ◽  
Urine Samples ◽  
C Storage ◽  
Liquid Chromatography Tandem Mass ◽  
The Stability

Human urine, which is rich in metabolites, provides valuable approaches for biomarker measurement. Maintaining the stability of metabolites in urine is critical for accurate and reliable research results and subsequent interpretation. In this study, the effect of storage temperature (4, 22, and 40 °C), storage time (24 and 48 h), and use of preservatives (boric acid (BA), thymol) and para-aminobenzoic acid (PABA) on urinary metabolites in the pooled urine samples from 20 participants was systematically investigated using large-scale targeted liquid chromatography tandem mass spectrometry (LC-MS/MS)-based metabolomics. Statistical analysis of 158 reliably detected metabolites showed that metabolites in urine with no preservative remained stable at 4 °C for 24 and 48 h as well as at 22 °C for 24 h, but significant metabolite differences were observed in urine stored at 22 °C for 48 h and at 40 °C. The mere addition of BA caused metabolite changes. Thymol was observed to be effective in maintaining metabolite stability in urine in all the conditions designed, most likely due to the inhibitory effect of thymol on urine microbiota. Our results provide valuable urine preservation guidance during sample storage, which is essential for obtaining reliable, accurate, and reproducible analytical results from urine samples.

scholarly journals Exhaled nitric oxide in mylar balloons: influence of storage time, humidity and temperature

2003 ◽  
Vol 12 (1) ◽  
pp. 47-49 ◽  
Author(s):  
Alessandro Bodini ◽  
Mariëlle W. H. Pijnenburg ◽  
Atillio L. Boner ◽  
Johan C. de Jongste
Keyword(s):  
Nitric Oxide ◽  
Silica Gel ◽  
Storage Time ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Air Samples ◽  
Exhaled Air ◽  
Oxide Concentration ◽  
Nitric Oxide Concentration ◽  
The Stability

Background:Mylar balloons are used to collect exhaled air for analysis of fractional nitric oxide concentration (FENO).Aim:We studied the effect of storage conditions on the stability of nitric oxide (NO) in mylar balloons.Methods:Exhaled air samples and calibration gases were stored in mylar balloons at 4, 21 and 37°C, with or without silica gel. NO was measured after 0, 6, 9, 24 and 48 h. Scheffe F-tests were used to compare NO values. Results NO remained stable in balloons for 9 h at all temperatures, without silica gel. NO increased between 9 and 48 h, but only with low initial FENO. Silica gel increased variability.Conclusions:FENO in mylar balloons is stable for at least 9 h. The storage temperature is not critical, but silica gel increases variability.

scholarly journals Influence of Storage Conditions on the Stability of Vitamin D3 and Kinetic Study of the Vitamin Degradation in Fortified Canola Oil during the Storage

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Mina Zareie ◽  
Azam Abbasi ◽  
Shiva Faghih
Keyword(s):  
Kinetic Study ◽  
Vitamin D3 ◽  
Canola Oil ◽  
Room Temperature ◽  
Storage Temperature ◽  
Storage Condition ◽  
Storage Conditions ◽  
Initial Concentration ◽  
The Stability ◽  
Polyethylene Terephthalate Bottles

Nowadays, fortified vegetable oils with vitamin D3 are widely available in different countries. In this study, the influence of storage conditions including light, air, storage temperature, and time on vitamin D3 retention in fortified canola oil was evaluated. Moreover, a kinetic study on vitamin D3 degradation in the oil was done. To this aim, fortified canola oil was prepared at two initial concentrations of 6.87 mg·kg−1 and 13.8 mg·kg−1 and then filled in transparent and dark-brown polyethylene terephthalate bottles at two filling levels of 50% and 100%. Samples were kept in two temperatures of 4°C and room temperature (27°C). The retention of vitamin D3 in different samples showed that the vitamin content was affected by the packaging type, storage temperature, and initial concentration. Vitamin D3 in the samples with a lower concentration of the vitamin which was stored in the refrigerator showed the highest retention (91%) after 70 days of storage, and the samples with higher initial concentration packed in transparent containers which were stored at room temperature (RT) showed the greatest loss (55.6%). Results of the kinetic study also showed that vitamin D3 was affected by storage condition. The half-life of the vitamin D3 differed from 96 to 577 days depending on the storage condition.

scholarly journals Development and stability of candy in soursop mass

2020 ◽  
Vol 42 ◽  
pp. e12
Author(s):  
Armando Carlos Diógenes Júnior ◽  
Stefanie De Freitas Almeida ◽  
Emanuel Neto Alves de Oliveira ◽  
Pedro Victor Crescêncio de Freitas ◽  
Bruno Fonsêca Feitosa ◽  
...  
Keyword(s):  
Water Content ◽  
Storage Temperature ◽  
Oxygen Demand ◽  
Titratable Acidity ◽  
Storage Conditions ◽  
Soluble Solids ◽  
Total Soluble Solids ◽  
Total Solids ◽  
Glucose Syrup ◽  
The Stability

The objective was to develop and characterize candies in soursop mass, replacing sucrose partially with glucose syrup, and to evaluate the stability during 90 days of storage under different temperatures. Two formulations of candies were prepared with sucrose substitution by glucose syrup, as well as a standard sample with sucrose alone. They were heated and concentrated to 71 °Brix for packaging in polyethylene packages. Afterwards, the candies were stored at 10 and 20 °C in a Biochemical Oxygen Demand (BOD) incubator and 28.1 °C (ambient temperature) for 90 days. During storage, the physical-chemical analyzes were performed: water content, total solids, pH, total titratable acidity, total soluble solids, water content and activity. It wasverified that the storage conditions caused reduction of the values of water content and water activity, besides increasing the values of total solids, total soluble solids and Ratio for all samples and storage conditions. The determining factor for the stability and preservation of product characteristics was the storage temperature; Being 10 ° C the ideal temperature for a better preservation of the candies in the standard formulation and 20 ° C for the added formulations of glucose syrup.

scholarly journals Effect of Unsaturation on the Stability of C18Polyunsaturated Fatty Acids Vesicles Suspension in Aqueous Solution

2011 ◽  
Vol 32 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Yin Yin Teo ◽  
Misni Misran ◽  
Kah Hin Low ◽  
Sharifuddin Md. Zain
Keyword(s):  
Aqueous Solution ◽  
Fatty Acids ◽  
The Stability

scholarly journals Effects of Storage Temperature and Time on Stability of Serum Tacrolimus and Cyclosporine A Levels in Whole Blood by LC-MS/MS

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
İbrahim Kaplan ◽  
Hatice Yüksel ◽  
Osman Evliyaoğlu ◽  
M. Kemal Basarali ◽  
Gülten Toprak ◽  
...  
Keyword(s):  
Cyclosporine A ◽  
Whole Blood ◽  
Room Temperature ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Blood Samples ◽  
Percent Change ◽  
Significant Difference ◽  
Whole Blood Samples ◽  
The Stability

Tacrolimus and cyclosporine A are immunosuppressant drugs with narrow therapeutic windows. The aim of this study was to investigate the stability of tacrolimus and cyclosporin A levels in whole blood samples under different storage conditions. Whole blood samples were obtained from 15 patients receiving tacrolimus and 15 patients receiving cyclosporine A. Samples were immediately analyzed and then stored at different conditions (room temperature (24°C−26°C) for 24 hours, +4°C for 24 and 48 hours, and −20°C for one month) and then analyzed again. For tacrolimus, there was a significant difference between samples analyzed immediately and those kept 24 hours at room temperature (P=0.005) (percent change 32.89%). However, there were no significant differences between the other groups. For cyclosporine A, there was a significant difference between samples analyzed immediately and those kept 24 hours (P=0.003) (percent change 19.47%) and 48 hours (P=0.002) (percent change 15.38%) at +4°C and those kept 24 hours at room temperature (P=0.011) (percent change 9.71%). Samples of tacrolimus should be analyzed immediately or stored at either +4°C or −20°C, while samples of cyclosporine A should be analyzed immediately or stored at −20°C.

scholarly journals Effect of Storage Temperature and Time on Stability of Liver Enzymes in Blood Serum

2020 ◽  
Vol 23 (5) ◽  
pp. 296-301
Author(s):  
Shadi Kolahdoozan ◽  
Sadaf G. Sepanlou ◽  
Maryam Sharafkhah ◽  
Elaheh Shaker ◽  
Ameneh Shayanrad ◽  
...  
Keyword(s):  
Linear Models ◽  
Liver Enzymes ◽  
Storage Temperature ◽  
Linear Regression Analysis ◽  
Storage Conditions ◽  
Prolonged Storage ◽  
Serum Samples ◽  
Long Term Storage ◽  
The Stability ◽  
Almost All

Background: It is increasingly common to collect and store specimens for future unspecified research. However, the effects of prolonged storage on the stability and quality of analytes in serum have not been well investigated. We aimed to determine whether the stability of liver enzymes extracted from frozen bio-samples stored at the baseline is affected by storage conditions. Methods: A total of four liver enzymes in the sera of 400 patients were examined following storage. After deter-mining the baseline measurements, the serum of each patient was aliquoted and stored at −70°C for three and six months, as well as one, two, and five years after collecting the original sample. The percent change from baseline measurements was calculated both statistically and clinically. Linear models were also used to correct the results of the samples based on the time they were frozen. Results: In almost all samples, liver enzymes were detectable until two years after the baseline, while in a signifi-cant proportion of samples, enzymes were not ultimately detectable five years after the baseline. Linear regression analysis on log-transformed levels of enzymes shows that the performance is acceptable until one year after the baseline. The performance of the prediction model declines substantially two and five years after the baseline, except for GGT. Conclusion: Long-term storage of serum samples significantly decreases the concentration of the liver enzymes from the baseline, except for GGT. It is not recommended to store samples for more than two years, as liver en-zymes are not detectable afterwards.

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