scholarly journals Short-Stability Study of Rifaximin-Based Samples

2020 ◽  
Vol 103 (3) ◽  
pp. 743-746
Author(s):  
Ana Carolina Kogawa ◽  
Leena Peltonen ◽  
Hérida Regina Nunes Salgado ◽  
Marlus Chorilli
Keyword(s):  
Reaction Order ◽  
Solubility Diagram ◽  
Stability Study ◽  
New Drugs ◽  
Phase Solubility ◽  
Microbiological Analysis ◽  
Wet Milling ◽  
Pharmaceutical Technology ◽  
Microbiological Methods ◽  
Temperature And Humidity

Abstract Background Rifaximin is an oral antimicrobial with a daily dose ranging from 600 to 800 mg. It is classified as Class IV in the Biopharmaceutic Classification System. Thus, rifaximin-based samples were developed by complexation to β-cyclodextrin using a phase solubility diagram, and malaxation and decreasing particle size using wet milling. Objective Concomitant to the pharmaceutical technology, a stability studywas undertaken with the objective of verifying the integrity of the drug. Methods The stability of the new samples were studied for 6 months, without interruption, under controlled conditions of temperature and humidity in a climatic chamber. They were analyzed simultaneously by HPLC and microbiological turbidimetry at zero, 3, and 6 months. Results Two of the samples follow second reaction order and one follows zero reaction order. Microbiological analysis proved to be important in assessing the potency of rifaximin in one of the samples, and its results were more consistent than the results by HPLC. Conclusions The rifaximin-based samples were stable under controlled temperature and humidity conditions and the physical-chemical and microbiological methods were able to evaluate their behavior during the 6-month study. Highlights It is worth considering the development of these products, since the design process of formulation and pharmaceutical technology is financially more attractive than the development of new drugs that require high levels of investment in research and development, innovation of public policies, and regulatory actions.

scholarly journals Thermodynamic Investigations on the Inclusion Complexation of Piroxicam with Cyclodextrin Derivatives

2005 ◽  
Vol 73 (3) ◽  
pp. 147-161 ◽  
Author(s):  
Charumanee S. ◽  
Weiss-Greiler P. ◽  
Wolschann P. ◽  
Viernstein H. ◽  
Titwan A. ◽  
...  
Keyword(s):  
Ph Value ◽  
Equilibrium Constants ◽  
Inclusion Complexation ◽  
Solubility Diagram ◽  
Phase Solubility ◽  
Cyclodextrin Derivatives ◽  
Ph Values ◽  
Solubility Behavior ◽  
Solubility Method ◽  
Different Temperatures

Thermodynamic studies of piroxicam in aqueous solution complexed with β-cyclodextrin (β-CD), γ-cyclodextrin (γ-CD) and two β-cyclodextrin derivatives, hydroxypropyl-β-cyclodextrin (HP-P-CD) and methyl-β-cyclodextrin (Me-β-CD) were performed at different temperatures and pH values using the phase solubility method. The phase solubility diagrams of β-CD, γ-CD and HP-β-CD is of AL-type behavior, indicating the formation of 1:l complexes. The related stability constants range from β-CD > γ-CD > Me-β-CD > HP-β-CD, respectively. An Ap-type solubility diagram is observed for Me-β-CD, indicating the formation of 1:2 complexes at higher CD concentrations. From the temperature dependence of the equilibrium constants the reaction enthalpies and entropies have been determined. The contributions of the reaction entropies are small and no enthalpy-entropy-compensation is observed, except for γ-CD, where a very small negative reaction entropy could be estimated. Moreover, the influence of the pH value is rather high because the differently charged forms of piroxicam show different solubility behavior in water.

scholarly journals Limitations and Challenges in the Stability of Cysteamine Eye Drop Compounded Formulations

2021 ◽  
Vol 15 (1) ◽  
pp. 2
Author(s):  
Cristina Martín-Sabroso ◽  
Mario Alonso-González ◽  
Ana Fernández-Carballido ◽  
Juan Aparicio-Blanco ◽  
Damián Córdoba-Díaz ◽  
...  
Keyword(s):  
Shelf Life ◽  
Stability Study ◽  
Eye Drops ◽  
Microbiological Analysis ◽  
Nitrogen Gas ◽  
Long Term Stability ◽  
Main Degradation Product ◽  
The Stability ◽  
Unstable Molecule

Accumulation of cystine crystals in the cornea of patients suffering from cystinosis is considered pathognomonic and can lead to severe ocular complications. Cysteamine eye drop compounded formulations, commonly prepared by hospital pharmacy services, are meant to diminish the build-up of corneal cystine crystals. The objective of this work was to analyze whether the shelf life proposed for six formulations prepared following different protocols used in hospital pharmacies is adequate to guarantee the quality and efficacy of cysteamine eye drops. The long-term and in-use stabilities of these preparations were studied using different parameters: content of cysteamine and its main degradation product cystamine; appearance, color and odor; pH and viscosity; and microbiological analysis. The results obtained show that degradation of cysteamine was between 20% and 50% after one month of storage in the long-term stability study and between 35% and 60% in the in-use study. These data confirm that cysteamine is a very unstable molecule in aqueous solution, the presence of oxygen being the main degradation factor. Saturation with nitrogen gas of the solutions offers a means of reducing cysteamine degradation. Overall, all the formulae studied presented high instability at the end of their shelf life, suggesting that their clinical efficacy might be dramatically compromised.

scholarly journals Effect of Antibacterial Agents on the Microbial Flora of Some Fruits and Vegetables.

2020 ◽  
pp. 299-304
Author(s):  
Omorodion Nnenna ◽  
Oriji Gift
Keyword(s):  
Fruits And Vegetables ◽  
Antimicrobial Agents ◽  
Reduction Rate ◽  
Total Coliform ◽  
Viable Count ◽  
Microbiological Analysis ◽  
Total Viable Count ◽  
Coliform Count ◽  
Microbiological Methods ◽  
Bacillus Spp

Six samples of fruits (apple, banana, mango, orange, pineapple and watermelon) and six samples of vegetables (cabbage, carrot, cucumber, lettuce, potato and tomato) were purchased from wokem market in Choba town PH, Rivers State and microbiological analysis were carried out these fruits and vegetables samples and the effects of the antimicrobial agents (Ethanol and Hydrogen peroxide) on the microbial load. The Total viable count, Total coliform count and Escherichia count were determined via standard microbiological methods. The Total viable count ranged from 4.1x10106 to 1.0x107 cfu/g Total coliform count from 4.5x107 to 1.5x106 cfu/g nd the E.coli count ranged from 5.1x102 to 1.0x102 cfu/g. The Total viable count for apple ranged between to 5.1 x107 to 2.07x109 , Cabbage 1.45x109 to 4.9x107 , banana 1.10x109 to 5.9x107 , cucumber 1.82x108 to 6.0x107. The microorganisms isolated were Escherichia coli 42%, Staphylococcus aureus 30%, Pseudomonas spp 18%, Bacillus spp,6% and Serratia spp, 2%. Hydrogen perioxide had a high pathogen reduction rate than ethanol.The isolation of E coli and other pathogenic microorganisms indicates the presences of faecal contamination and the poor hygienic production, storage and transport system. Fruits and vegetables should be properly handled from their seeds planted in the farm to the matured ones sold in the market

Microbiological quality and safety of Ready- to- eat foods from restaurants and food establishments in Yirgalem town Southern, Ethiopia

2019 ◽  
Author(s):  
Tsegaye Shamebo Arficho ◽  
Asefa Hamato Kebede
Keyword(s):  
Bacterial Load ◽  
Microbiological Quality ◽  
Food Samples ◽  
Coliform Bacteria ◽  
Plate Count ◽  
Southern Ethiopia ◽  
Microbiological Analysis ◽  
Quality And Safety ◽  
Mannitol Salt Agar ◽  
Microbiological Methods

Abstract Background: Foodborne illnesses are considered as one of the most important public health problems particularly in developing countries like Ethiopia. This study aimed to determine the microbiological quality and safety of ready-to-eat foods in Yirgalem town, southern Ethiopia from November 2016 to August 2017. Methods: The collection of ready-to-eat food samples and laboratory-based microbiological analysis was used as the study design. A total of 160 food samples comprising of 40 ‘Injera firfir’, 40‘Bayeaynet’, 40 Vegetables and 40 Spaghetti were collected and analyzed for microbial contamination following standard microbiological methods. Ten grams of each food sample was transferred into 90 ml of buffered peptone water and homogenized for 5 minutes using a vortex mixer. The homogenates were serial diluted up to 10-7 and a volume of 0.1ml aliquot was spread plated on pre-solidified media of Aerobic plate count agar, MacConkey agar, Mannitol salt agar, and Salmonella-Shigella agar and incubate at 35-37oc for 24 hrs. Also, Potato Dextrose Agar was used for the isolation of fungi. Data were entered into Microsoft Excel and analyzed using SPSS version 20.0. Results: All the collected food samples were subjected to total aerobic mesophilic bacteria, Coliform bacteria, Enterobacteriaceae, Staphylococcal, Yeasts, and Molds counts. Accordingly, the mean counts expressed as log10 CFU/g of food for each group of the organism were 7.90 ± 0.71, 4.31±1.30, 4.32 ± 1.30, 6.70 ± 0.34 and 4.5 ± 1.01, respectively. The highest bacterial load 162(28.9%) was detected in ‘Injera firfir’ whereas the lowest 108(19.2%) case was investigated in Spaghettis. Regarding the food safety issue, the frequency of S. aureus, E. coli and Salmonella spp in the food samples were 54.4%, 43.8%, and 0.6%, respectively. Conclusion: The high microbial load and existence of foodborne pathogens in ready-to-eat foods in Yirgalem town, Southern Ethiopia is calling for the creation of awareness among restaurant and food establishment owners and food handlers concerning the hygienic practice. Keyword: Microbial quality, Yirgalem town, Southern Ethiopia

Standardization of Microbiological Methods for Analysis of Water

1978 ◽  
Vol 41 (4) ◽  
pp. 314-319 ◽  
Author(s):  
ROBERT H. BORDNER
Keyword(s):  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Microbiological Analysis ◽  
Protection Agency ◽  
Monitoring Programs ◽  
Microbiological Methods ◽  
Standardization Process

This paper discusses characteristics and advantages of standardized methods for microbiological analysis of water and their use in enforcement and monitoring programs of the Environmental Protection Agency. The increasing numbers of other methods-standardizing organizations are documented. The present standardization process is reviewed and recommendations are made for improved approaches to standardizing methods.

scholarly journals Soluble 1:1 complexes and insoluble 3:2 complexes – Understanding the phase-solubility diagram of hydrocortisone and γ-cyclodextrin

2017 ◽  
Vol 531 (2) ◽  
pp. 504-511 ◽  
Author(s):  
Christian Schönbeck ◽  
Tobias L. Madsen ◽  
Günther H. Peters ◽  
René Holm ◽  
Thorsteinn Loftsson
Keyword(s):  
Solubility Diagram ◽  
Phase Solubility ◽  
Phase Solubility Diagram

scholarly journals Physical properties and biological activities of hesperetin and naringenin in complex with methylated β-cyclodextrin

2015 ◽  
Vol 11 ◽  
pp. 2763-2773 ◽  
Author(s):  
Waratchada Sangpheak ◽  
Jintawee Kicuntod ◽  
Roswitha Schuster ◽  
Thanyada Rungrotmongkol ◽  
Peter Wolschann ◽  
...  
Keyword(s):  
Physical Properties ◽  
Inclusion Complexes ◽  
Biological Activities ◽  
Solubility Diagram ◽  
Dynamics Simulation ◽  
Phase Solubility ◽  
Free Energies ◽  
Scanning Calorimetry ◽  
Host Interaction ◽  
Vdw Force

The aim of this work is to improve physical properties and biological activities of the two flavanones hesperetin and naringenin by complexation with β-cyclodextrin (β-CD) and its methylated derivatives (2,6-di-O-methyl-β-cyclodextrin, DM-β-CD and randomly methylated-β-CD, RAMEB). The free energies of inclusion complexes between hesperetin with cyclodextrins (β-CD and DM-β-CD) were theoretically investigated by molecular dynamics simulation. The free energy values obtained suggested a more stable inclusion complex with DM-β-CD. The vdW force is the main guest–host interaction when hesperetin binds with CDs. The phase solubility diagram showed the formation of a soluble complex of AL type, with higher increase in solubility and stability when hesperetin and naringenin were complexed with RAMEB. Solid complexes were prepared by freeze-drying, and the data from differential scanning calorimetry (DSC) confirmed the formation of inclusion complexes. The data obtained by the dissolution method showed that complexation with RAMEB resulted in a better release of both flavanones to aqueous solution. The flavanones-β-CD/DM-β-CD complexes demonstrated a similar or a slight increase in anti-inflammatory activity and cytotoxicity towards three different cancer cell lines. The overall results suggested that solubilities and bioactivities of both flavanones were increased by complexation with methylated β-CDs.

Elucidation of the complexation mechanism between (+)-usnic acid and cyclodextrins studied by isothermal titration calorimetry and phase-solubility diagram experiments

2009 ◽  
Vol 22 (3) ◽  
pp. 232-241 ◽  
Author(s):  
Freimar Segura-Sanchez ◽  
Kawthar Bouchemal ◽  
Geneviève Lebas ◽  
Christine Vauthier ◽  
Néréide S. Santos-Magalhaes ◽  
...  
Keyword(s):  
Isothermal Titration Calorimetry ◽  
Usnic Acid ◽  
Solubility Diagram ◽  
Titration Calorimetry ◽  
Phase Solubility ◽  
Complexation Mechanism ◽  
Phase Solubility Diagram
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