Chitosan-Pectin-Stearic Acid Film for Controlled-Release of Curcumin

2019 ◽  
Vol 948 ◽  
pp. 69-77
Author(s):  
Dwi Siswanta ◽  
Fithriya Hasanah ◽  
Heni Octaviani ◽  
Mudasir Mudasir
Keyword(s):  
Stearic Acid ◽  
Diffusion Mechanism ◽  
Acetic Acid Solution ◽  
Ethanol Solution ◽  
Release Mechanism ◽  
Buffer Solution ◽  
Buffer Solutions ◽  
Ft Ir ◽  
Isopropanol Solution ◽  
Kinetics Of

The release of curcumin from chitosan-pectin-stearic acid films was studied in the variation of the pH of the buffer solutions, the addition of ethanol in the buffer solution, the amount of loaded curcumin, the amount of stearic acids in the films. The chitosan-pectin films were prepared by addition of 1% acetic acid solution of chitosan into 1% aqueous pectin solution, followed by addition of isopropanol solution of stearic acid. The films were characterized using FT-IR spectrophotometer. The study of curcumin release was performed by soaking the film in buffer-ethanol solutions for 6hand measuring the released curcumin by UV-Vis spectrophotometer. The kinetics of releasing curcumin was analyzed using Korsmeyer-Peppas equations. The result showed that the releasing of curcumin was influenced by the amount of loaded curcumin, the amount of stearic acid in the film and buffer pH of the solution. The optimum releasing rate at buffer pH 7 in 40% ethanol solution was obtained when the amount of curcumin loaded and stearic acid were c.a. 55.5 and 136.4 mg/g film, respectively, which the curcumin release achieved 66.04%. Releasing kinetics of the curcumin followed a Korsmeyer-Peppas model with a rate constant (k) of 7.5270 and n of 0.378. The curcumin release mechanism was mainly based on the diffusion mechanism.

scholarly journals Iodometric determination of cystamine dihydrochloride in tablets using diperoxyadipic acid

2020 ◽  
Vol 8 (1) ◽  
pp. 19-27
Author(s):  
Mykola Blazheyevskiy ◽  
Valeriy Moroz
Keyword(s):  
Analytical Techniques ◽  
Second Order ◽  
Order Conditions ◽  
Buffer Solution ◽  
Buffer Solutions ◽  
Water Ph ◽  
Bulk Drug ◽  
Kinetics Of ◽  
Official Procedure

The kinetics of cystamine dihydrochloride oxidation by diperoxyadipic acid (DPAA) was studied in aqueous buffer solutions of pH 2.9, 6.9, 8.0, 8.5 and 9.2 under second-order conditions at the temperature 293 K. The second order rate constants, k (L mol−1 min−1) were calculated from kinetic values. A suitable mechanism scheme based on these observations was proposed. The possibility of application of DPAA as reagent for oxidimetric determination of cystamine dihydrochloride in tabtets was investigated. Cystamine dihydrochloride was determined by indirect titration with DPAA. The required amount of Cystamine dihydrochloride was dissolved in water, pH 8.0 buffer solution and DPAA solution was added. After 7 min, the solution was acidified. The excess DPAA was determined via iodometric titration. The advantages of the applied analytical techniques in the determination of cystamine dihydrochloride in tablets «Cystamine 0.2 g» was presented. The recovery of сystamine dihydrochloride was 99.32±1.45%. A paired t-test showed that all results obtained for bulk drug and in tablets «Cystamine 0.2 g», using the proposed procedure and the official procedure respectively, agreed at the 95% confidence level.

Direct observations of radiation-enhanced transformations in glass

1983 ◽  
Vol 41 ◽  
pp. 354-355
Author(s):  
J. F. DeNatale ◽  
D. G. Howitt
Keyword(s):  
Glass Matrix ◽  
Diffusion Mechanism ◽  
Bubble Formation ◽  
Silicate Glasses ◽  
Phase Decomposition ◽  
Direct Observations ◽  
Thin Foils ◽  
Oxygen Bubble ◽  
Electron Energy Loss ◽  
Kinetics Of

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

The Development of Pemetrexed Diacid-Loaded Gelatin-Cloisite 30B (MMT) Nanocomposite for Improved Oral Efficacy Against Cancer: Characterization, In-Vitro and Ex-Vivo Assessment

2020 ◽  
Vol 17 (3) ◽  
pp. 246-256
Author(s):  
Kriti Soni ◽  
Ali Mujtaba ◽  
Md. Habban Akhter ◽  
Kanchan Kohli
Keyword(s):  
Drug Release ◽  
Oral Delivery ◽  
Ex Vivo ◽  
Confocal Laser ◽  
Release Mechanism ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Cloisite 30B ◽  
Ft Ir

Aim: The intention of this investigation was to develop Pemetrexed Diacid (PTX)-loaded gelatine-cloisite 30B (MMT) nanocomposite for the potential oral delivery of PTX and the in vitro, and ex vivo assessment. Background: Gelatin/Cloisite 30 B (MMT) nanocomposites were prepared by blending gelatin with MMT in aqueous solution. Methods: PTX was incorporated into the nanocomposite preparation. The nanocomposites were investigated by Fourier Transmission Infra Red Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), Scanning Electron Microscope (SEM) X-Ray Diffraction (XRD) and Confocal Laser Microscopy (CLSM). FT-IR of nanocomposite showed the disappearance of all major peaks which corroborated the formation of nanocomposites. The nanocomposites were found to have a particle size of 121.9 ± 1.85 nm and zeta potential -12.1 ± 0.63 mV. DSC thermogram of drug loaded nanocomposites indicated peak at 117.165 oC and 205.816 oC, which clearly revealed that the drug has been incorporated into the nanocomposite because of cross-linking of cloisite 30 B and gelatin in the presence of glutaraldehyde. Results: SEM images of gelatin show a network like structure which disappears in the nanocomposite. The kinetics of the drug release was studied in order to ascertain the type of release mechanism. The drug release from nanocomposites was in a controlled manner, followed by first-order kinetics and the drug release mechanism was found to be of Fickian type. Conclusion: Ex vivo gut permeation studies revealed 4 times enhancement in the permeation of drug present in the nanocomposite as compared to plain drug solution and were further affirmed by CLSM. Thus, gelatin/(MMT) nanocomposite could be promising for the oral delivery of PTX in cancer therapy and future prospects for the industrial pharmacy.

Efficient adsorption of chlorpyrifos onto modified activated carbon by gamma irradiation; a plausible adsorption mechanism

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohamed S. Yahia ◽  
Ahmed S. Elzaref ◽  
Magdy B. Awad ◽  
Ahmed M. Tony ◽  
Ahmed S. Elfeky
Keyword(s):  
Gamma Irradiation ◽  
Area Measurement ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Pseudo First Order ◽  
Kinetics Of

Abstract Commercial Granulated Active Carbon (GAC) has been modified using 10 Gy dose Gamma irradiation (GAC10 Gy) for increasing its ability of air purification. Both, the raw and treated samples were applied for removing Chlorpyrifos pesticide (CPF) from ambient midair. Physicochemical properties of the two materials were characterized by Fourier Transform Infrared (FT-IR) and Raman spectroscopy. The phase formation and microstructure were monitored using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), supported with Energy-Dispersive X-ray (EDX). The Surface area measurement was detected using BET particle size prosometry. Obtained outcomes showed that, the maximum adsorption capacity, given by Langmuir equations, was greatly increased from 172.712 to 272.480 mg/g for GAC and GAC10 Gy, respectively, with high selectivity. The overall removal efficiency of GAC10 Gy was notably comparable to that of the original GAC-sorbent. The present study indicated that, gamma irradiation could be a promising technique for treating GAC and turned it more active in eliminating the pesticides pollutants from surrounding air. The data of equilibrium has been analyzed by Langmuir and Freundlich models, that were considerably better suited for the investigated materials than other models. The process kinetics of CPF adsorbed onto both tested carbon versions were found to obey the pseudo first order at all concentrations with an exception at 70 mg/l using GAC, where, the spontaneous exothermic adsorption of Chlorpyrifos is a strong function for the pseudo-first order (PFO) and pseudo second order (PSO) kinetics.

Rumination in sheep. III. Experimentally induced variations on the circadian pattern of rumination

1965 ◽  
Vol 16 (4) ◽  
pp. 649 ◽  
Author(s):  
GR Pearce
Keyword(s):  
Extended Period ◽  
High Protein ◽  
Circadian Pattern ◽  
Buffer Solution ◽  
Buffer Solutions ◽  
Experimentally Induced

The circadian (24-hr) pattern of rumination of caged sheep was found to be affected: (a) by the administration of a roughage ration per fistulam; (b) by the emptying of the rumen and the subsequent return of the rumen contents; (c) by the emptying of the rumen and the replacement of the contents by a buffer solution plus roughage. The period during which no rumination occurred following feeding was progressively shortened when increasing proportions of a ration of oaten chaff and lucerne chaff were administered per fistulam. The effect was much reduced when high protein sheep cubes were added to the chaff ration. The removal of the rumen contents after voluntary feeding and then their immediate return to the rumen tended to cause an early commencement of rumination. When the rumen contents were "pasteurized" before return, however, rumination did not occur for an extended period afterwards. When the rumen contents were replaced with buffer solutions plus roughage, variable rumination responses occurred. In one instance apparently uninhibited rumination resulted.

Surface Modification of Nanosized Biphasic α-TCP/HA Powders

2007 ◽  
Vol 330-332 ◽  
pp. 223-226 ◽  
Author(s):  
Li Li Pan ◽  
Yan Bao Li ◽  
Chao Zou ◽  
Wen Jian Weng ◽  
Kui Cheng ◽  
...  
Keyword(s):  
Surface Modification ◽  
Stearic Acid ◽  
Tricalcium Phosphate ◽  
Calcium Phosphates ◽  
Biological Characteristics ◽  
Buffer Solution ◽  
Solution Ph

Stearic acid was utilized to modify biphasic alpha-tricalcium phosphate (α-TCP)/hydroxyapatite (HA) powders in the ethanol. The results showed that the dispersion of biphasic α-TCP/HA powders (BCPs) in non-polar matrix improved. And the released content of Ca2+ and PO4 3- of the BCPs soaked in the NaAc-HAc buffer solution (pH 5.0) was almost same as that before modification. Stearic acid could modify the suface properties of BCPs and would not obviously affect their biological characteristics, which affords a good groundwork of application of calcium phosphates powders.

scholarly journals Isothermal and non-isothermal kinetics of hydrolysis of 1-[2-(2- pentyloxyphenylcarbamoyloxy)-(2-methoxymethyl)-ethyl]- perhydroazepinium chloride (BK 129)

2013 ◽  
Vol 60 (2) ◽  
pp. 43-48
Author(s):  
Stankovičová M. ◽  
Bezáková Ž. ◽  
Beňo P. ◽  
Húšťavová P.
Keyword(s):  
Biological Activity ◽  
Alkaline Hydrolysis ◽  
Functional Group ◽  
Isothermal Kinetics ◽  
Basic Part ◽  
Buffer Solutions ◽  
Kinetics Of Hydrolysis ◽  
Short Time ◽  
Kinetics Of ◽  
Hydrolysis Of

Abstract The substance BK 129 - 1-[2-(2-pentyloxyphenylcarbamoyloxy)-(2-methoxymethyl)-ethyl]-perhydroazepinium chloride was prepared in terms of influence of the connecting chain between the carbamate functional group and the basic part of molecule on biological activity. Such a structural feature is important with regard to its stability. In this work we determined the rate constants of alkaline hydrolysis of this compound at increased temperature under isothermal and non-isothermal conditions. The hydrolysis was also performed in buffer solutions with the purpose of evaluating its stability. Non-isothermal tests of stability enable to reduce the number of analyses. The necessary data for stability of compound are in this way achieved in a short time.

Synthesis of Silica Modified Large-Sized Hydroxyapatite Whiskers by a Hydrothermal Co-Precipitation Method

2015 ◽  
Vol 645-646 ◽  
pp. 1339-1344 ◽  
Author(s):  
Yan Ting Yin ◽  
Qing Hua Chen ◽  
Ting Ting Yan ◽  
Qing Hua Chen
Keyword(s):  
Bone Repair ◽  
Ethanol Solution ◽  
Morphological Properties ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Type ◽  
Ft Ir ◽  
Co Precipitation ◽  
Surface Modified

The objective of this study was to develop a novel silica modified large-sized hydroxyapatite whiskers with improved properties for use in bone repair applications. Large-sized whiskers with a mean length of 250μm were obtained by a hydrothermal co-precipitation method at 150°C, 7.5Mpa in high-pressure reactor. Silica modified hydroxyapatite whiskers were prepared by dissolving TEOS in ethanol solution, then sintering with hydroxyapatite. The compositional and morphological properties of prepared whiskers were studied by means of x-ray diffraction (XRD), Fouier transform infrared (FT-IR), scanning electron microscopy (SEM). The results indicated the evidence of nanosilicon dioxide particles on the surface of HAP whiskers. The size of nanosilicon dioxide particles depends on dropping and stirring rate. Hence, this new type of silica modified large-sized hydroxyapatite whiskers is a valuable candidate for biomedical applications.Key words: hydroxyapatite, hydrothermal co-precipitation, surface modified, whiskers

scholarly journals ULTRACENTRIFUGATION STUDIES ON THE ELEMENTARY BODIES OF VACCINE VIRUS

1938 ◽  
Vol 68 (4) ◽  
pp. 607-627 ◽  
Author(s):  
Joseph E. Smadel ◽  
Edward G. Pickels ◽  
Theodore Shedlovsky
Keyword(s):  
Sedimentation Rate ◽  
Vaccine Virus ◽  
Normal Rate ◽  
Buffer Solution ◽  
Buffer Solutions ◽  
Original Volume ◽  
Sucrose Solutions ◽  
Rate Of Sedimentation

Ultracentrifugal studies of the CL dermal strain of vaccine virus warrant the following conclusions: 1. When suspended in increasing concentrations of sucrose, glycerol, or urea solutions, elementary bodies of vaccinia show variations in sedimentation rate which indicate changes in the density or size of the particles. For a given change in the density of the medium these changes are smallest with sucrose and most marked with urea. The normal rate of sedimentation of Paschen bodies may be restored by resuspending them in dilute buffer solution. 2. The density of elementary bodies of vaccinia suspended in dilute buffer solutions is estimated to be 1.16 gm. per cc. Higher values for the density are found if the particles are suspended in solutions containing sucrose, glycerol, or urea. In 53 per cent sucrose, for example, the density is 1.25 gm. per cc. 3. Paschen bodies appear to be quite permeable to water and urea, less so to glycerol, and only slightly, if at all, to sucrose. 4. The increased density of the elementary bodies of vaccinia in sucrose solutions may be accounted for by an osmotic extraction of water from the particles. On this basis the water which can be thus extracted corresponds to at least a third of the original volume of the particles.

scholarly journals Investigation of the sustained-release mechanism of hydroxypropyl methyl cellulose skeleton type Acipimox tablets

2018 ◽  
Vol 16 (1) ◽  
pp. 333-339
Author(s):  
Wanying Liu ◽  
Qing Huo ◽  
Yue Wang ◽  
Na Yu ◽  
Rongjian Shi
Keyword(s):  
Sustained Release ◽  
Diffusion Mechanism ◽  
Methyl Cellulose ◽  
Magnesium Stearate ◽  
Test Method ◽  
Release Mechanism ◽  
Hydroxypropyl Methyl Cellulose ◽  
Hypolipidemic Agents ◽  
Sustained Release Tablets ◽  
The Difference

AbstractIn this study, we investigate the production of hypolipidemic agents in the form of Acipimox sustained-release tablets, using a wet pelleting process. The purpose of this research is to reduce the total intake time for patients and to lower the initial dose in such that the adverse reactions could be reduced. This study adopts the single-factor method and orthogonal experiments by using hydroxypropyl methyl cellulose (HPMC K15M) as the main sustained-release prescription composition. The final prescription is Acipimox 20%, HPMC K15M 26.67%, sodium carboxymethyl cellulose 30%, polyethylene glycol (PEG 6000) 1%, ethyl cellulose 16.6%, lactose 4.67% and magnesium stearate 1%. The dissolution of tablets reached 85.88% in 8 h. The difference in the weight, hardness and friability of the tables met the requirements in the Chinese Pharmacopoeia; to test the stability, a temperature and illumination accelerated test method was used, the results indicate that the Acipimox sustained-release tablets should be sealed and stored in a dark, cool area. A preliminary study on the tablets’ releasing mechanism showed that their release curve fitted the Higuchi model (the formula is Mt/M∞ = 31.137 t1/2–3.605 (R2 = 0.9903)). The Acipimox tablets’ release principle is dominated by the diffusion mechanism.

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