scholarly journals Influence of Hydrophilic Polymers on theβFactor in Weibull Equation Applied to the Release Kinetics of a Biologically Active Complex ofAesculus hippocastanum

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Justyna Kobryń ◽  
Sandra Sowa ◽  
Monika Gasztych ◽  
Andrzej Dryś ◽  
Witold Musiał
Keyword(s):  
Release Kinetics ◽  
Weibull Model ◽  
Biologically Active ◽  
Fickian Diffusion ◽  
Horse Chestnut ◽  
Clinical Activity ◽  
Weibull Function ◽  
Biological Origin ◽  
Triterpenoid Saponins ◽  
Weibull Equation

Triterpenoid saponins complex of biological origin, escin, exhibits significant clinical activity in chronic venous insufficiency, skin inflammation, epidermal abrasions, allergic dermatitis, and acute impact injuries, especially in topical application. The aim of the study is the comparison of various hydrogel formulations, as carriers for a horse chestnut seed extract (EH). Methylcellulose (MC), two polyacrylic acid derivatives (PA1 and PA2), and polyacrylate crosspolymer 11 (PC-11) were employed. The release rates of EH were examined and a comparison with the Weibull model equation was performed. Application of MC as the carrier in the hydrogel preparation resulted in fast release rate of EH, whereas in the case of the hydrogel composed with PC-11 the release was rather prolonged. Applied Weibull function adhered best to the experimental data. Due to the evaluated shape parameterβ, in the Weibull equation, the systems under study released the active compound according to the Fickian diffusion.

Preliminary Evaluation of a Weibull Function for Fitting Slow-Component Eye Velocity over the Time Course of Caloric-Induced Nystagmus

1989 ◽  
Vol 32 (3) ◽  
pp. 681-687 ◽  
Author(s):  
C. Formby ◽  
B. Albritton ◽  
I. M. Rivera
Keyword(s):  
Time Course ◽  
Slow Component ◽  
Weibull Function ◽  
Preliminary Evaluation ◽  
Mathematical Function ◽  
Before And After ◽  
Best Fitting ◽  
Eye Velocity ◽  
Fitting Parameters ◽  
Weibull Equation

We describe preliminary attempts to fit a mathematical function to the slow-component eye velocity (SCV) over the time course of caloric-induced nystagmus. Initially, we consider a Weibull equation with three parameters. These parameters are estimated by a least-squares procedure to fit digitized SCV data. We present examples of SCV data and fitted curves to show how adjustments in the parameters of the model affect the fitted curve. The best fitting parameters are presented for curves fit to 120 warm caloric responses. The fitting parameters and the efficacy of the fitted curves are compared before and after the SCV data were smoothed to reduce response variability. We also consider a more flexible four-parameter Weibull equation that, for 98% of the smoothed caloric responses, yields fits that describe the data more precisely than a line through the mean. Finally, we consider advantages and problems in fitting the Weibull function to caloric data.

Exploring siRNA Umpired Nanogels: A Tale of Barrier Combating Carrier

2020 ◽  
Vol 26 (27) ◽  
pp. 3234-3250
Author(s):  
Sushil K. Kashaw ◽  
Prashant Sahu ◽  
Vaibhav Rajoriya ◽  
Pradeep Jana ◽  
Varsha Kashaw ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Biomedical Engineering ◽  
Viral Infections ◽  
Slow Release ◽  
Molecular Level ◽  
Release Kinetics ◽  
Biologically Active ◽  
Release Process ◽  
Rapid Release ◽  
Wide Range

Potential short interfering RNAs (siRNA) modulating gene expression have emerged as a novel therapeutic arsenal against a wide range of maladies and disorders containing cancer, viral infections, bacterial ailments and metabolic snags at the molecular level. Nanogel, in the current medicinal era, displayed a comprehensive range of significant drug delivery prospects. Biodegradation, swelling and de-swelling tendency, pHsensitive drug release and thermo-sensitivity are some of the renowned associated benefits of nanogel drug delivery system. Global researches have also showed that nanogel system significantly targets and delivers the biomolecules including DNAs, siRNA, protein, peptides and other biologically active molecules. Biomolecules delivery via nanogel system explored a wide range of pharmaceutical, biomedical engineering and agro-medicinal application. The siRNAs and DNAs delivery plays a vivacious role by addressing the hitches allied with chronic and contemporary therapeutic like generic possession and low constancy. They also incite release kinetics approach from slow-release while mingling to rapid release at the targets will be beneficial as interference RNAs delivery carriers. Therefore, in this research, we focused on the latest improvements in the delivery of siRNA loaded nanogels by enhancing the absorption, stability, sensitivity and combating the hindrances in cellular trafficking and release process.

Design and Synthesis of a Novel Gabapentin-Phosphotidylcholine Conjugate for Targeting to Phospholipase A2 Enzyme through Nanostructured Lipid Carrier

2020 ◽  
Vol 16 ◽  
Author(s):  
Anjali P.B ◽  
Jawahar N. ◽  
Jubie S. ◽  
Neetu Yadav ◽  
Selvaraj A. ◽  
...  
Keyword(s):  
Drug Release ◽  
Phospholipase A2 ◽  
Release Kinetics ◽  
Entrapment Efficiency ◽  
Structural Analog ◽  
Fickian Diffusion ◽  
Release Kinetic ◽  
Nanostructured Lipid Carrier ◽  
Discovery Studio

Background: : Epilepsy is a genuine neurological turmoil that effects around 50 million individuals around the world. Practically 30% of epileptic patients experience the ill effects of pharmaco-obstruction, which is related with social seclusion, subordinate conduct, low marriage rates, joblessness, mental issues and diminished personal satisfaction. At present accessible antiepileptic drugs have a restricted viability, and their negative properties limit their utilization and cause challenges in patient administration. Gabapentin 1-(aminomethyl)cyclohexane acetic acid, Gbp , (trade name Neurontin), a structural analog of γ-aminobutyric acid (GABA), BCS class 3 drug with having permeability issues. Objective: This work was an attempt to formulate and characterize a new approach to treat epilepsy by targeting to Phospholipase A2 Enzyme through Nanostructured Lipid Carrier. Methods: Docking studied carried out using Accelrys Discovery studio 4.1 Client and gabapentin and phosphotidylcholine were conjugated through chemical conjugation. Nanostructured lipid carrier (NLC) was prepared using hot homogenization technique. Results: The libdock score of Gabapentin- Phosphotidylcholine conjugate (192.535) were found to be more than Gabapentin (77.1084) and Phosphotidylcholine (150.212). For the optimized formulation the particle size (50.08), zeta potential (-1.48), PDI (0.472) and entrapment efficiency (77.8) was observed. The NLC was studies for in-vitro drug release studies and release kinetics. Finally found that the drug release from the NLC followed Higuchi release kinetic and the mode of drug release from the NLC was found to be Non- Fickian diffusion. Conclusion: The formulated Nanostructured lipid carrier of Gabapentin-Phosphotidylcholine conjugate may be able to use to prevent seizure.

scholarly journals An Improved Methodology for Determination of Fluorine in Biological Samples Using High-Resolution Molecular Absorption Spectrometry via Gallium Fluorine Formation in a Graphite Furnace

2021 ◽  
Vol 11 (12) ◽  
pp. 5493
Author(s):  
Andrzej Gawor ◽  
Andrii Tupys ◽  
Anna Ruszczyńska ◽  
Ewa Bulska
Keyword(s):  
High Resolution ◽  
Limit Of Detection ◽  
Graphite Furnace ◽  
Absorption Spectrometry ◽  
Biological Tissues ◽  
Biologically Active ◽  
Molecular Absorption ◽  
Biological Origin ◽  
Molecular Absorption Spectrometry

Nowadays growing attention is paid to the control of fluorine content in samples of biological origin as it is present in the form of various biologically active organic compounds. Due to the chemically-rich matrix of biological tissues, the determination of fluorine becomes a very difficult task. Furthermore, a required complex sample preparation procedure makes the determination of the low contents of F by ion chromatography UV-Vis or ion-selective electrodes not possible. High-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) seems to be the best option for this purpose due to its high robustness to matrix interferences, especially in the presence of carefully selected modifiers. In this work the possibility of quantitative F determination in water and animal tissues was examined by measuring the molecular absorption of gallium monofluoride (GaF) at 211.248 nm with the use of a commercially available HR-CS GF MAS system. Experimental conditions for the sensitive and precise determination of fluorine were optimized, including the time/temperature program as well as addition of gallium and modifier mixture in combined mode. Under these conditions the fluoride present in the sample was stabilized up to 600 °C, and the optimum vaporization temperature for GaF was 1540 °C. Palladium and zirconium deposited onto the graphite surface served as solid modifiers; sodium acetate and ruthenium modifiers were added directly to the sample. The limit of detection and the characteristic mass of the method were 0.43 μg/L and 8.7 pg, respectively. The proposed procedure was validated by the use of certified reference materials (CRMs) of lake water and animal tissue; the acceptable recovery was obtained, proving that it can be applied for samples with a similar matrix.

scholarly journals COMPOSITION OF BIOLOGICALLY ACTIVE SUBSTANCES OF THE HORSE CHESTNUT (AECULUS HIPPOCASTANUM L.)

ÈKOBIOTEH ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 33-39
Author(s):  
V.P. Kurchenko ◽  
◽  
N.V. Sushinskaya ◽  
K.I. Maiorava ◽  
E.I. Tarun ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Biologically Active Substances ◽  
Biologically Active ◽  
Horse Chestnut ◽  
Hazard Class ◽  
Active Substances

The study of the composition of biologically active substances, alcoholic extracts from flowers of Aeculus hippocastanum L. According to the results of HPLC-MS and GC-MS analyzes, the extract contains the main amounts of phenolic compounds: quercetin, epicatechin, kaempferol. In addition, the extract contains fatty acids and their esters, alcohols, 3-deoxy-d-manno lactone, 1,2,3,5-cyclohexantethrol, α-methyl-mannofuranoside, γ sitosterol. Antioxidant activity of an extract from flowers of A. hippocastanum is associated with the peculiarities of the compositionof biologically active substances. The toxological-hygienic assessment of flowers of this species in acute and subacute experiments showed that it belongs to the 4th hazard class (low hazard).

scholarly journals Design and Characterization of Combinational Domperidone-Famotidine Floating Drug Delivery System - In vitro and In vivo studies

2021 ◽  
Vol 62 (2) ◽  
pp. 144-162
Author(s):  
Mounika Chidurala ◽  
Raveendra Reddy J
Keyword(s):  
Drug Release ◽  
Oral Administration ◽  
Quality By Design ◽  
Release Kinetics ◽  
Cost Effective ◽  
Fickian Diffusion ◽  
In Vivo Studies ◽  
Pharmacokinetic Studies

Introduction: The drawbacks assosiated with oral administration of drugscan be controlled or minimized by gastro retentive formulations that remain buoyant within the stomach for an extended time by providing prolonged gastric retention and releasethe drug in an exceedingly extended manner thereby improving bioavailability. The current research was to develop and optimize Domperidone and Famotidine floating tablets with extended release by Quality by Design approach. Method: Based on QTPP (Quality Target Product Profile), CQAs (Critical Quality Attributes)wereidentified. Risk analysis by the evaluation of formulation and process parameters showed that optimizing the levels of polymers could reduce high risk to achieve the target profile. A 23factor experimental design with midpoints was selected for statistical analysis and optimization. Results: HPMC K100 and Carbopol 934P had a positive effect while ethyl cellulose demonstrated a negative effect on the selected responses. Drug release kinetics followed the first-order release with Higuchi diffusion and Fickian diffusion. Optimized formula satisfying all the required parameters was selected and evaluated. The predicted response values were in close agreement with experimental response values. Abdominal X-ray imaging after oral administration of the tablets on a healthy rabbit’s stomach confirmed the extended floating behavior with shorter lag time. In vivo, pharmacokinetic studies in rabbits revealed that the optimized formulation exhibited prolonged drug release with enhanced Cmax, tmax, AUCo-t, and t1/2 of an optimized product when compared to the marketed product. Conclusions: It has been concluded that the application of Quality by Design in the formulation and optimization reduced the number of trials to produce a cost-effective formula.

STUDIES ON UREA CO-INCLUSION COMPLEXES OF EBASTINE FOR STEEP IMPROVEMENT IN DISSOLUTION PROFILE

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (08) ◽  
pp. 35-45
Author(s):  
M. Dhall ◽  
◽  
A. K. Madan
Keyword(s):  
Dissolution Rate ◽  
Release Kinetics ◽  
Thermal Studies ◽  
Physical Stability ◽  
Molar Fraction ◽  
Aqueous Solubility ◽  
Weibull Model ◽  
Complexing Agent ◽  
Content Uniformity ◽  
Dissolution Profile

Urea co-inclusion technique has been successfully utilized for steep enhancement in dissolution rate of ebastine (EB), a BCS class II potent drug. EB is a novel second generation H1 receptor antagonist used for prevention of chronic idiopathic urticaria and allergic rhinitis. It exhibits low aqueous solubility and consequent poor bioavailability. In the present study, EB was engulfed in urea channel/tunnels along with rapidly complexing agent (RCA). Resulting complexes of EB (EBUCIC) were characterized by DSC, FTIR, XRD and 1H-NMR. Minimum proportion of RCA for incorporation of EB in hexagonal urea was determined calorimetrically. The thermal studies indicated increase in heat of decomposition with increasing molar fraction of RCA in EBUCICs, ensuring better physical stability of complexes. Content uniformity study depicted uniform composition formulation of EB. Weibull model described release kinetics of EB. Enhancement in dissolution rate ensures urea co-inclusion to be a useful approach for development of rapid/instantaneous release dosage forms.

Quality by Design enabled anti-hypertensive Floating drug delivery system by Risk assessment and Design of Experiment (DoE) – In vitro – In vivo correlation studies

2021 ◽  
Vol 16 ◽  
Author(s):  
Mounika Chidurala ◽  
Raveendra Reddy J
Keyword(s):  
Drug Release ◽  
Risk Analysis ◽  
Quality By Design ◽  
Release Kinetics ◽  
Cost Effective ◽  
Fickian Diffusion ◽  
In Vivo Studies ◽  
Pharmacokinetic Studies

Background: The present research aimed to develop and optimize extended-release floating tablets of Sacubitril and Valsartan through Quality by Design (QbD) approach. Risk analysis by formulation assessment and process parameters showed that optimizing the levels of the polymer will minimize high risk to meet the target profile. A two (2) level three (3) full factorial experimental design along with midpoints was carefully chosen for optimization and statistical analysis. Based on the literature, the independent and dependent variables were selected. Results: HPMC K100, Carbopol 934P had a positive effect, whereas Ethylcellulose had a negative effect on Floating time, drug release at 2 h, drug release at 12 h and, 50% responses. Drug release kinetics followed the first-order release with Higuchi and Fickian diffusion. Contour and overlay plots were utilized for an assortment of design space and optimized formula. ANOVA results of all the factors exhibited significance at p<0.05. Abdominal X-ray imaging of the optimized tablets on healthy rabbit’s stomach confirmed the floating behavior for more than 12 h. In vivo pharmacokinetic studies in rabbits showed that the optimized formulation exhibited prolonged and extended drug release with improved Cmax, tmax, AUCo-t, and t1/2 of test product when compared to marketed product. IVIVC model was developed by using dissolution data of in vitro and pharmacokinetics data of in-vivo by de-convolution method (Wagner-Nelson method). Conclusion: The Quality by Design implementation in the formulation and optimization abridged the number of trials to produce a cost-effective formula. In vivo studies confirmed that the formula was successfully developed with extended floating time (12 h) and drug release by risk analysis and experimental designs. Level A correlation was observed which confirmed a good correlation between in vitro and in vivo data.

scholarly journals Application of Supercritical Solvent Impregnation for Production of Zeolite Modified Starch-Chitosan Polymers with Antibacterial Properties

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4717 ◽  
Author(s):  
Jelena Pajnik ◽  
Ivana Lukić ◽  
Jelena Dikić ◽  
Jelena Asanin ◽  
Milan Gordic ◽  
...  
Keyword(s):  
Release Kinetics ◽  
Antibacterial Properties ◽  
Water Vapor Permeability ◽  
Weibull Model ◽  
Vapor Permeability ◽  
E Coli ◽  
Supercritical Solvent ◽  
Composite Polymers ◽  
Before And After ◽  
Impregnation Time

In the present study, supercritical solvent impregnation (SSI) has been applied to incorporate thymol into bio-composite polymers as a potential active packaging material. Thymol, a natural component with a proven antimicrobial activity, was successfully impregnated into starch-chitosan (SC) and starch-chitosan-zeolite (SCZ) films using supercritical carbon dioxide (scCO2) as a solvent. Experiments were performed at 35 °C, pressures of 15.5 and 30 MPa, and an impregnation time in the range of 4–24 h. The highest impregnation yields of SC films with starch to chitosan mass ratios of 1:1 and 1:2 were 10.80% and 6.48%, respectively. The addition of natural zeolite (15–60%) significantly increased the loading capacity of films enabling thymol incorporation in a quantity of 16.7–27.3%. FTIR and SEM analyses were applied for the characterization of the films. Mechanical properties and water vapor permeability of films before and after the impregnation were tested as well. Thymol release kinetics in deionized water was followed and modeled by the Korsmeyer-Peppas and Weibull model. SCZ films with thymol loading of approximately 24% exhibited strong antibacterial activity against E. coli and methicillin-resistant Staphylococcus (S.) aureus (MRSA).

scholarly journals Formulation of non-effervescent floating matrix tablets of metronidazole using Abelmoschus esculentus gum as binder and 2-camphanone as sublimating agent.

2020 ◽  
Vol 19 (1) ◽  
pp. 387-397
Author(s):  
Airemwen Collins Ovenseri ◽  
Uwumagbe Michael Uhumwangho ◽  
Aiwaguore Johnbull Obarisiagbon ◽  
Chioma Promise Umechukwu
Keyword(s):  
Patient Adherence ◽  
Release Kinetics ◽  
Lag Time ◽  
Matrix Tablets ◽  
Angle Of Repose ◽  
Abelmoschus Esculentus ◽  
Fickian Diffusion ◽  
Simulated Gastric Fluid ◽  
Compatibility Study

The aim of this study was to formulate non-effervescent floating drug delivery system of metronidazole tablets using Abelmoschus esculentus (Okra) (AE) gum as a binder and 2-camphanone (camphor®) as the sublimating agent. Granules were prepared by wet granulation technique using varying concentrations of AE gum (2, 4, 6 and 8% w/w) admixed with 1%w/w acrylate methacrylate copolymer. A 30 %w/w of 2-camphanone was used as the sublimating agent. The granules were characterized for micromeritic properties. And thereafter, compressed at a compression pressure of 25 N/m2 using a Manesty single punch tableting machine. The metronidazole tablet was then sintered at 70oC for 12 h. Drug-excipient compatibility study was done using Fourier Transform Infra-red Spectroscopy (FTIR). Tablets were evaluated for floating lag time, in-vitro buoyancy and release kinetics. FTIR studies showed that the excipients and the active pharmaceutical ingredient (API) i.e. metronidazole, were compatible. All the granules were free flowing, with Carr’s index ≤ 15 %, Hausner ratio ≤ 1.18 and angle of repose of ≤ 33.5o. The tablets had hardness and friability values of 5.0-9.5 N and 0.4-0.8% respectively. The floating lag time was 0 s showing that the tablets floated immediately after immersion in the simulated gastric fluid. The maximum % release (m∞) and time to achieve it (t∞) were ≥ 88 % and ≥ 10 h, respectively. Release exponent (n) for all the formulations had values >0.45, hence their release was by non-Fickian diffusion. Non-effervescent floating matrix tablets of metronidazole were formulated using AE gum as the binder and 2-camphanone as the sublimating agent. The formulated floating tablets had increased in-vitro retention time, which indicated potential for sustained release of the drug. If well developed, this may help reduce the oral dosing frequency and encourage patient adherence to the drug therapy. Keywords: Non-effervescent, Abelmoschus esculentus, 2-camphanone, floating

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