scholarly journals Evaluation of the Release Kinetics of a Pharmacologically Active Substance from Model Intra-Articular Implants Replacing the Cruciate Ligaments of the Knee

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1202 ◽  
Author(s):  
Dorota Wojcik-Pastuszka ◽  
Justyna Krzak ◽  
Bartosz Macikowski ◽  
Ryszard Berkowski ◽  
Bogdan Osiński ◽  
...  
Keyword(s):  
Drug Release ◽  
Active Substance ◽  
Rate Constants ◽  
Incubation Temperature ◽  
Release Kinetics ◽  
Dissolution Kinetics ◽  
Second Order ◽  
Prolonged Release ◽  
Pharmacologically Active ◽  
Kinetics Of

Implants are readily applied as a convenient method of therapy. There is great interest in the prolonged release of active substances from implants. The objective of this work was to evaluate the dissolution kinetics of steroidal anti-inflammatory preparation (SAP) released from novel implants, and to test the influence of the technology on SAP release kinetics. The proposed long-acting preparations may overcome difficulties resulting from repeated injections and often visits to ambulatory clinic, as the stabilizing function of the artificial ligament would be enriched with pharmacological activity. The potential advantages provided by the new coatings of knee implants include the continuous, sustained, and prolonged release of an active substance. The study was carried out using a modified United States Pharmacopoeia (USP) apparatus 4. The amount of SAP was measured spectroscopically. It was revealed that the transport of the drug was mainly a diffusion process. The drug release kinetics was analyzed using zero-, first-, and second-order kinetics as well as Korsmeyer-Peppas, Higuchi, and Hixon-Crowell models. The highest values of the release rate constants were k0 = (7.49 ± 0.05) × 10−5 mg × min−1, k1 = (6.93 ± 0.05) × 10−6 min−1, and k2 = (7.70 ± 0.05) × 10−7 mg−1 × min−1 as calculated according to zero-, first-, and second-order kinetics equations, respectively. The values of the rate constants obtained for the slowest process were k0 = (3.63 ± 0.06) × 10−5 mg × min−1, k1 = (2.50 ± 0.03) × 10−6 min−1, and k2 = (2.80 ± 0.03) × 10−7 mg−1 × min−1. They may suggest the possibility of sustained release of betamethasone from the system. Due to the statistical analysis, differences were observed between most of the studied implants. Incubation, temperature, time of stabilization of layers, and the method of SAP deposition on the matrix affected the drug release.

scholarly journals New in vitro model to evaluate kinetics of antimycobacterial drug release from bioresorbable polymeric carriers

2020 ◽  
pp. 10-15
Author(s):  
SN Andreevskaya ◽  
TG Smirnova ◽  
EN Antonov ◽  
LN Chernousova ◽  
SE Bogorodsky ◽  
...  
Keyword(s):  
Drug Release ◽  
Culture Medium ◽  
Culture Media ◽  
Release Kinetics ◽  
Prolonged Release ◽  
Wide Range ◽  
Polymeric Carriers ◽  
The Matrix ◽  
Kinetics Of

Sustained-release drugs against tuberculosis are a promising approach to therapy since they positively affect patient compliance with long regimens, especially when it comes to the multidrug-resistant form of the disease. Conventional UV-visible spectroscopy does not work well with multicomponential culture media used for growing M. tuberculosis. The aim of this study was to develop a method for evaluating the kinetics of anti-tuberculosis drug released from bioresorbable polymeric carriers suitable for screening a wide range of encapsulated prolonged-release drugs and identifying the best performing candidate. While studying the growth dynamics of the laboratory susceptible strain M. tuberculosis H37Rv in the presence of different levofloxacin concentrations (from 0.03 to 0.4 μg/ml), we developed a model, which is essentially a set of 2 parallel experiments evaluating the kinetics of drug release into the culture medium. The results of these 2 experiments conducted on 3 encapsulated forms of levofloxacin loaded onto bioresorbable polymeric PLGA carriers (particles sized 50 μm and 100 μm and the matrix) revealed that release kinetics of the drug largely depended on the type of polymeric carrier. The best encapsulation of the antibiotic and its gradual release into the culture medium was observed for the matrix. All experiments were run in 3 replicates. The obtained data were analyzed using descriptive statistics.

scholarly journals THE EFFECTS OF MODIFIED CLAY ON CONTROLLED DRUG RELEASE SYSTEMS

STED JOURNAL ◽  
2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Davut Lacin ◽  
Ayse Zehra Aroguz ◽  
Vesna Teoflović ◽  
Olga Govedarica ◽  
Jelena Pavličević ◽  
...  
Keyword(s):  
Drug Release ◽  
Active Substance ◽  
Release Kinetics ◽  
Controlled Drug Release ◽  
Drug Carriers ◽  
Ammonium Bromide ◽  
Buffer Solutions ◽  
Cetyltrimethyl Ammonium ◽  
Specific Tissue ◽  
Kinetics Of

Recently, controlled drug release systems have been garnering a lot of attention, due to more targeted and effective approach for delivering drugs to a specific tissue. Because of a specific structure and natural abundance, clays are being added to those systems in order to increase its efficiency and minimize costs. In this study, controlled release kinetics of the drug active substance 5-Fluorouracil was studied, using halloysite clay/polymer drug carriers. For this purpose, the halloysite clay was initially modified with cetyltrimethyl ammonium bromide (CTAB). Drug carriers were prepared by adding modified halloysite clays in the mixtures of polyvinyl alcohol (PVA) and sodium alginate. Firstly, the swelling behaviour of the prepared substances was studied in buffer solutions at different pH. The drug release kinetics from the drug carriers, loaded with 5- Fluorouracil, was observed under a UV-spectrophotometer at 266 nm. Release profiles of the active substance were obtained by studying its release in buffer solutions at different pH. The results showed that the prepared drug carriers with modified halloysite clay were suitable for carrying and releasing of the 5-Fluorouracil.

scholarly journals Kinetics and the Theoretical Aspects of Drug Release from PLA/HAp Thin Films

2017 ◽  
Vol 758 ◽  
pp. 113-119 ◽  
Author(s):  
Innocent Jacob Macha ◽  
Besim Ben-Nissan ◽  
Wolfgang Müller
Keyword(s):  
Thin Film ◽  
Drug Release ◽  
Polymer Matrix ◽  
Degradation Kinetics ◽  
Release Kinetics ◽  
Dissolution Kinetics ◽  
Rate Processes ◽  
Thin Film Composites ◽  
Kinetics Of ◽  
Film Composites

The theory of dissolution kinetics of gentamicin from polylactic acid-hydroxyapatite thin film composites is spotlighted with the combination of diffusion and polymer degradation modeling. The use of various mathematical models, characterizing diffusion, dissolution or/and erosion prevalence as well as a mix of dissolution-diffusion rate processes were employed in order to compare theory with experimental data. A number of factors influence the release kinetics of gentamicin from medical drug release systems and devices. It is difficult to have a single mathematical model that takes all these factors into account. It is shown that the degradation of the polymer matrix plays the biggest role in the release kinetics of polymer-ceramics thin film composites. It was also observed that multistage drug release form these devices depends also on the degradation kinetics of the polymer matrix. The effect of pH and device sizes were not studied but could also be of interest in future studies.

Kinetics of the reaction between hexamethylenediisocyanate and 1-pentanol

1983 ◽  
Vol 48 (11) ◽  
pp. 3279-3286
Author(s):  
Slavko Hudeček ◽  
Miloslav Bohdanecký ◽  
Ivana Hudečková ◽  
Pavel Špaček ◽  
Pavel Čefelín
Keyword(s):  
Liquid Chromatography ◽  
Rate Constants ◽  
Reversed Phase ◽  
Order Reaction ◽  
Second Order ◽  
Second Order Reaction ◽  
Reversed Phase Liquid Chromatography ◽  
Consecutive Reactions ◽  
Phase Liquid ◽  
Kinetics Of

The reaction between hexamethylenediisocyanate and 1-pentanol in toluene was studied by means of reversed-phase liquid chromatography. By employing this method, it was possible to determine all components of the reaction mixture including both products, i.e. N-(6-isocyanate hexyl)pentylcarbamate and N,N'-bis(pentyloxycarbonyl)hexamethylenediamine. Relations for the calculation of kinetic constants were derived assuming a competitive consecutive second-order reaction. It was demonstrated that the reaction involved in this case is indeed a second-order reaction, and the rate constants of the first and second consecutive reactions were determined.

Determination of the Nucleophilicity of Tricarbonyliron Coordinated Cyclohepta-1,3,5-triene

1999 ◽  
Vol 64 (11) ◽  
pp. 1770-1779 ◽  
Author(s):  
Herbert Mayr ◽  
Karl-Heinz Müller
Keyword(s):  
Gibbs Energy ◽  
Ambient Temperature ◽  
Rate Constants ◽  
Second Order ◽  
Order Rate ◽  
Electrophilic Additions ◽  
Kinetics Of

The kinetics of the electrophilic additions of four diarylcarbenium ions (4a-4d) to tricarbonyl(η4-cyclohepta-1,3,5-triene)iron (1) have been studied photometrically. The second-order rate constants match the linear Gibbs energy relationship log k20 °C = s(E + N) and yield the nucleophilicity parameter N(1) = 3.69. It is concluded that electrophiles with E ≥ -9 will react with complex 1 at ambient temperature.

Fabrication and Release Kinetics of Liposomes Containing Leuprolide Acetate

2021 ◽  
Vol 7 (1) ◽  
pp. 35-38
Author(s):  
Sudipta Das ◽  
Arnab Samanta ◽  
Koushik Bankura ◽  
Debatri Roy ◽  
Amit Nayak
Keyword(s):  
Drug Release ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Zero Order ◽  
Leuprolide Acetate ◽  
Lipid Film ◽  
In Vitro Drug Release ◽  
Liposomal Formulations ◽  
Kinetics Of

The present work is focused on the preparation and in vitro release kinetics of liposomal formulation of Leuprolide Acetate. In this work, “Thin Lipid Film Hydration Method” was used for preparation of Leuprolide Acetate loaded liposomes. Prepared liposomal formulations of Leuprolide acetate was evaluated by drug entrapment study, in-vitro drug release kinetics and stability studies. The percentage drug entrapment of Leuprolide acetate for F1 and F2 formulations were found to be 78.14 ± 0.67 and 66.70 ± 0.81% respectively. In-vitro drug release study of liposomal formulations had shown zero order release pattern. Regression co-efficient (R2) value of Zero order kinetics for F1 and F2 formulations were 0.9912 and 0.9676 respectively. After storing formulations for 1 month, stability testing was done at 40C.It was found that all batches were stable. These liposomal formulations of Leuprolide acetate can be formulated for parenteral application to treat prostate cancer and in women, to treat symptoms of endometriosis (overgrowth of uterine lining outside of the uterus) or uterine fibroids.

Effect of Hydroxyapatite Nanoparticles on Ibuprofen Release from Carboxymethyl-Hexanoyl Chitosan/O-Hexanoyl Chitosan Hydrogel

2006 ◽  
Vol 6 (9) ◽  
pp. 2929-2935 ◽  
Author(s):  
Tse-Ying Liu ◽  
Ting-Yu Liu ◽  
San-Yuan Chen ◽  
Shian-Chuan Chen ◽  
Dean-Mo Liu
Keyword(s):  
Drug Release ◽  
Release Kinetics ◽  
Burst Release ◽  
Release Behavior ◽  
Chitosan Hydrogel ◽  
Sequential Release ◽  
Water Accessibility ◽  
Hydrophilic Nature ◽  
Hexanoyl Chitosan ◽  
Kinetics Of

In order to explore the effect of nanofiller on the regulation of the drug release behavior from microsphere-embedded hydrogel prepared by carboxymethyl-hexanoyl chitosan (HNOCC) and O-hexanoyl chitosan (OHC), the release kinetics was investigated in terms of various amounts of calcium-deficient hydroxyapatite (CDHA) nanoparticles incorporated. HNOCC is a novel chitosan-based hydrophilic matrix with a burst release profile in a highly swollen state. The drug release kinetics of the HNOCC hydrogel can be regulated by incorporation of well-dispersed CDHA nanoparticles. It was found that the release duration of ibuprofen (IBU) from HNOCC was prolonged with increasing amounts of CDHA which acts as a crosslink agent and diffusion barrier. On the contrary, the release duration of the IBU from OHC (hydrophobic phase) was shortened through increasing the CDHA amount over 5%, which is due to the hydrophilic nature of the CDHA nanoparticles destroying the intermolecular hydrophobic interaction and accelerating OHC degradation. Thus, water accessibility and molecular relaxation were enhanced, resulting in a higher release rate. In addition, sustained and sequential release behavior was achieved by embedding the OHC microspheres (hydrophobic phase) into the HNOCC (hydrophilic phase) matrix, which could significantly prolong the release duration of the HNOCC drug-loaded implant.

scholarly journals Development of a reservoir type prolonged release system with felodipine via simplex methodology

2015 ◽  
Vol 89 (1) ◽  
pp. 128-136
Author(s):  
Rareș Iuliu Iovanov ◽  
Ioan Tomuță ◽  
Sorin Emilian Leucuța
Keyword(s):  
Simplex Method ◽  
Release Kinetics ◽  
Prolonged Release ◽  
Lauryl Sulfate ◽  
Pore Former ◽  
Release System ◽  
Reservoir Type ◽  
Model Drug ◽  
Kinetics Of

Background and aims. Felodipine is a dihydropyridine calcium antagonist that presents good characteristics to be formulated as prolonged release preparations. The aim of the study was the formulation and in vitro characterization of a reservoir type prolonged release system with felodipine, over a 12 hours period using the Simplex method.Methods. The first step of the Simplex method was to study the influence of the granules coating method on the felodipine release. Furthermore the influence of the coating polymer type, the percent of the coating polymer and the percent of pore forming agent in the coating on the felodipine release were studied. Afterwards these two steps of the experimental design the percent of Surelease applied on the felodipine loaded granules and the percent of pore former in the polymeric coating formulation variables were studied. The in vitro dissolution of model drug was performed in phosphate buffer solution (pH 6.5) with 1% sodium lauryl sulfate. The released drug quantification was done using an HPLC method. The release kinetics of felodipine from the final granules was assessed using different mathematical models.Results. A 12 hours release was achieved using granules with the size between 315 – 500 µm coated with 45% Surelease with different pore former ratios in the coating via the top-spray method.Conclusion. We have prepared prolonged release coated granules with felodipine using a fluid bed system based on the Simplex method. The API from the studied final formulations was released over a 12 hours period and the release kinetics of the model drug substance from the optimized preparations fitted best the Higuchi and Peppas kinetic models. 

scholarly journals KINETICS OF OZONE REACTIONS WITH ADENINE AND CYTOSINE IN AQUEOUS SOLUTIONS

2020 ◽  
Vol 63 (10) ◽  
pp. 17-22
Author(s):  
Aigul A. Maksyutova ◽  
Elvina R. Khaynasova ◽  
Yuriy S. Zimin
Keyword(s):  
Aqueous Solutions ◽  
Rate Constants ◽  
Correlation Coefficients ◽  
Activation Parameters ◽  
Second Order ◽  
Order Kinetic ◽  
Temperature Dependences ◽  
Ozone Reactivity ◽  
Kinetics Of ◽  
Ozone Reactions

The ultraviolet spectroscopy method has been applied to study the kinetics of the ozone reactions with nitrogenous bases (NB), namely adenine and cytosine in aqueous solutions. At the first research stage, the range of NB working concentrations has been determined. It was found that linear dependences between optical densities and concentrations of nitrogenous bases aqueous solutions are quite reliable, with correlation coefficients r ≥ 0.998, are satisfied up to [NB] = 2.3 ∙ 10–4 mol/l. According to the Bouguer-Lambert-Beer law, adenine and cytosine extinction coefficients in aqueous solutions were determined and subsequently used to calculate their residual concentrations. At the next stage, the kinetics of nitrogenous bases ozonized oxidation was studied with equal initial concentrations of the starting substances ([NB]0 = [О3]0). The results revealed that the kinetic consumption curves of the starting reagents are fairly well linearized (r ≥ 0.996) in the second-order reaction equation coordinates. As found with the bubbling installation, 1 mol of the absorbed ozone falls on 1 mol of the used NB. Thus, the reactions of ozone with adenine and cytosine explicitly proceed according to the second-order kinetic laws (the first – according to О3 and the first – according to NB). The rate constants were calculated by the integral reaction equations, the values of which indicate a higher ozone reactivity in relation to nitrogen bases. The temperature dependences of the second-order rate constants was studied ranging 285-309 K, and the activation parameters (pre-exponential factors and activation energies) of the ozone reactions with adenine and cytosine in aqueous solutions were determined.

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