scholarly journals Synthesis and Characterization of Lyophilized Chitosan-Based Hydrogels Cross-Linked with Benzaldehyde for Controlled Drug Release

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Fouad Damiri ◽  
Yahya Bachra ◽  
Chaimaa Bounacir ◽  
Asmae Laaraibi ◽  
Mohammed Berrada
Keyword(s):  
Ascorbic Acid ◽  
Drug Release ◽  
Drug Loading ◽  
In Vitro Release ◽  
Controlled Drug Release ◽  
Tween 20 ◽  
Release Mechanism ◽  
Synthetic Process ◽  
Chitosan Salt

In this study, chitosan-based hydrogels were produced by incorporating three drugs with a different solubility into a polymer matrix. The lyophilized chitosan salt was prepared using an innovative and less-expensive synthetic process by the freeze-drying technique. Firstly, the three drugs (caffeine, ascorbic acid, and 5-fluorouracil (5-FU)) were selected as model drugs to test the in vitro release behavior of the hydrogel. The drugs were solubilized in chitosan salt, lyophilized, and cross-linked with benzaldehyde involving the formation of a Schiff base with (–C=N-) linkage to produce a physical hydrogel. Subsequently, the physicochemical properties of N-benzyl chitosan and lyophilized chitosan salt were evaluated by Fourier-transform infrared (FTIR) spectra, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The intrinsic viscosity of the conventional chitosan was determined by the Mark–Houwink–Sakurada equation. Moreover, the kinetics of hydrogel swelling and drug release were studied by the UV-visible method at physiological conditions (pH = 7.4 at 37°C). The results show that lyophilized N-benzyl chitosan had a maximum swelling ratio of 720 ± 2% by immersion in phosphate-buffered saline solutions (PBS) (pH = 7.4 at 37°C). In vitro drug releases were evaluated in PBS, and the obtained results show that the maximum drug release after 24 h was 42% for caffeine, 99% for 5-FU, and 94% for ascorbic acid. Then, to optimize the cumulative release of caffeine, Tween 20 was added and 98% as a release percentage was obtained. The drug-loading results were investigated with the Korsmeyer–Peppas kinetic model and applied to determine the drug release mechanism.

scholarly journals FABRICATION OF NANO CLAY INTERCALATED POLYMERIC MICROBEADS FOR CONTROLLED RELEASE OF CURCUMIN

2021 ◽  
pp. 206-215
Author(s):  
DHARMENDER PALLERLA ◽  
SUMAN BANOTH ◽  
SUNKARI JYOTHI
Keyword(s):  
Drug Release ◽  
In Vitro Release ◽  
Controlled Drug Release ◽  
Fickian Diffusion ◽  
Simulated Gastric Fluid ◽  
Release Mechanism ◽  
Release Studies ◽  
Swelling Studies ◽  
Vitro Release

Objective: The objective of this study was to formulate and evaluate the Curcumin (CUR) encapsulated sodium alginate (SA)/badam gum (BG)/kaolin (KA) microbeads for controlled drug release studies. Methods: The fabricated microbeads were characterized by fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (X-RD), and scanning electron microscopy (SEM). Dynamic swelling studies and in vitro release kinetics were performed in simulated intestinal fluid (pH 7.4) and simulated gastric fluid (pH 1.2) at 37 °C. Results: FTIR confirms the formation of microbeads. DSC studies confirm the polymorphism of CUR in drug loaded microbeads which indicate the molecular level dispersion of the drug in the microbeads. SEM studies confirmed the microbeads are spherical in shape with wrinkled and rough surfaces. XRD studies reveal the molecular dispersion of CUR and the presence of KA in the developed microbeads. In vitro release studies and swelling studies depend on the pH of test media, which might be suitable for intestinal drug delivery. The % of drug release values fit into the Korsmeyer-Peppas equation and n values are obtained in the range of 0.577-0.664, which indicates that the developed microbeads follow the non-Fickian diffusion drug release mechanism. Conclusion: The results concluded that the CUR encapsulated microbeads are potentially good carriers for controlled drug release studies.

A thermoresponsive amphiphilic dendron — Synthesis, characterization, and self-assembled micelles for controlled drug release

2012 ◽  
Vol 90 (7) ◽  
pp. 600-607 ◽  
Author(s):  
Li Xu ◽  
Lidong Shao ◽  
Minqi Hu ◽  
Lin Chen ◽  
Yunmei Bi
Keyword(s):  
Drug Release ◽  
Drug Loading ◽  
In Vitro Release ◽  
Controlled Drug Release ◽  
Solution Temperature ◽  
Stimuli Responsive ◽  
H Nmr ◽  
Dendron Micelles ◽  
Model Drug

A new third-generation thermoresponsive amphiphilic dendron consisting of a hydrophobic poly(benzyl ether) dendritic core and hydrophilic oligo(ethylene glycol) peripheries was synthesized by an efficient convergent approach. Its structure was confirmed by 1H NMR, 13C NMR, IR, GPC, MALDI-TOF MS, and elemental analysis. Turbidity and dynamic light scattering (DLS) measurements demonstrated that the dendron showed a reversible temperature-dependent phase-transition behavior in aqueous solution and its lower critical solution temperature (LCST) was lower than that of the corresponding second-generation dendron, indicating the dependence of LCSTs on the generation of dendrons. Fluorescent spectroscopy and TEM studies revealed that the dendron would self-assemble into nanospherical micelles with a very low critical micelle concentration (CMC) in water. The core-shell structure of the micelles was proved by 1H NMR analyses of the micelles in D2O. The drug-loading capacity of the dendron micelles is about 29 wt % for podophyllotoxin (POD) used as a model drug, and in vitro release tests showed a desired thermoresponsive drug-release behavior. These results indicate that the dendron is promising as stimuli-responsive material for biomedical applications.

scholarly journals THE ROLE OF NEEDLE IN FORMULATION OF pH SENSITIVE SWELLABLE MICROBEADS PREPARED WITH HYDROPHILIC POLYMERS FOR ATORVASTATIN AND THEIR CHARACTERIZATION STUDIES

2017 ◽  
Vol 9 (3) ◽  
pp. 20
Author(s):  
K.v. Ramana Reddy ◽  
M. V. Nagabhushanam
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Drug Loading ◽  
In Vitro Release ◽  
Process Variable ◽  
Ph Sensitive ◽  
Hydrophilic Polymers ◽  
Release Mechanism ◽  
Curing Agents

Objective: The aim of the study was to develop and characterize mucoadhesive microbeads for oral sustained release of atorvastatin by using hydrophilic polymers and application of different process variables in designing of pH sensitive swellable microbeads.Methods: Microbeads were prepared by ionic gelation method. The compatibility studies of atorvastatin with polymers were investigated by differential scanning calorimeter and fourier transform infrared spectroscopy studies. In this work process variable like optimization of curing agents and their quantity, effect of rpm, and their influence in drug entrapment were studied. Prepared beads were characterized for particle size, swelling index, erosion studies and drug release studies.Results: Mixture of alginate and carbopol 934 P at 3.3 % w/v shows sustained release and good mucoadhesive capacity. Furthermore, drug loading and swelling increased with the use of a combination of polymers. On basis of in vitro release studies and swelling studies, it was observed that sodium alginate coated with carbopol 934 P showed sustained release of 84.5 % at end of 10 h in 6.8 phosphate buffer. The optimised batch followed peppas and higuchi release mechanism and releasing the drug by non-fickian transport.Conclusion: The alginate beads with a combination of carbopol 934P showed a sustain release pattern. The release rate and swelling of atorvastatin beads could be adjusted by adding other hydrophilic polymers or by optimising curing agents, curing time and their volume. The zero order of drug release was confirmed for all the batches. The in vitro data was better fit to Higuchi’s diffusion model and diffusion rate limited.

Preparation, evaluation, and in vitro release of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules

2020 ◽  
pp. 1-9
Author(s):  
Yunhong Wang ◽  
Rong Hu ◽  
Yanlei Guo ◽  
Weihan Qin ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Release Rate ◽  
Orthogonal Design ◽  
Drug Loading ◽  
In Vitro Release ◽  
Core Material ◽  
Evaluation Indexes ◽  
Vitro Release

OBJECTIVE: In this study we explore the method to prepare tanshinone self-microemulsifying sustained-release microcapsules using tanshinone self-microemulsion as the core material, and chitosan and alginate as capsule materials. METHODS: The optimal preparation technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules was determined by using the orthogonal design experiment and single-factor analysis. The drug loading and entrapment rate were used as evaluation indexes to assess the quality of the drug, and the in vitro release rate was used to evaluate the drug release performance. RESULTS: The best technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules is as follows: the concentration of alginate is 1.5%, the ratio of tanshinone self-microemulsion volume to alginate volume to chitosan mass is 1:1:0.5 (ml: ml: g), and the best concentration of calcium chloride is 2.0%. To prepare the microcapsules using this technology, the drug loading will be 0.046%, the entrapment rate will be 80.23%, and the 24-hour in vitro cumulative release rate will be 97.4%. CONCLUSION: The release of the microcapsules conforms to the Higuchi equation and the first-order drug release model and has a good sustained-release performance.

scholarly journals DESIGN AND IN VITRO/IN VIVO EVALUATION OF EXTENDED RELEASE MATRIX TABLETS OF NATEGLINIDE

2018 ◽  
Vol 7 (6) ◽  
Author(s):  
Mohini Sihare ◽  
Rajendra Chouksey
Keyword(s):  
Drug Release ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Release Profile ◽  
Matrix Tablets ◽  
In Vivo Studies ◽  
Release Mechanism ◽  
In Vivo Evaluation

Aim: Nateglinide is a quick acting anti-diabetic medication whose potent activity lasts for a short duration. One of the dangerous side effects of nateglinide administration is rapid hypoglycemia, a condition that needs to be monitored carefully to prevent unnecessary fatalities. The aim of the study was to develop a longer lasting and slower releasing formulation of nateglinide that could be administered just once daily. Methods: Matrix tablets of nateglinide were prepared in combination with the polymers hydroxypropylmethylcellulose (HPMC), eudragits, ethyl cellulose and polyethylene oxide and the formulated drug release patterns were evaluated using in vitro and in vivo studies. Conclusion: Of the seventeen formulated matrix tablets tested, only one formulation labelled HA-2 that contained 15% HPMC K4M demonstrated release profile we had aimed for. Further, swelling studies and scanning electron microscopic analysis confirmed the drug release mechanism of HA-2. The optimized formulation HA-2 was found to be stable at accelerated storage conditions for 3 months with respect to drug content and physical appearance. Mathematical analysis of the release kinetics of HA-2 indicated a coupling of diffusion and erosion mechanisms. In-vitro release studies and pharmacokinetic in vivo studies of HA-2 in rabbits confirmed the sustained drug release profile we had aimed for. Keywords: Hydroxypropylmethylcellulose, Matrix tablets, Nateglinide, Sustained release

scholarly journals Novel Gliclazide Electrosprayed Nano-Solid Dispersions: Physicochemical Characterization and Dissolution Evaluation

2019 ◽  
Vol 9 (2) ◽  
pp. 231-240
Author(s):  
Khosro Adibkia ◽  
Solmaz Ghajar ◽  
Karim Osouli-Bostanabad ◽  
Niloufar Balaei ◽  
Shahram Emami ◽  
...  
Keyword(s):  
Drug Release ◽  
Solid Dispersions ◽  
In Vitro Release ◽  
Physicochemical Characterization ◽  
Amorphous State ◽  
Water Soluble ◽  
Fickian Diffusion ◽  
Release Mechanism ◽  
Peg 6000

Purpose: In the current study, electrospraying was directed as a novel alternative approach to improve the physicochemical attributes of gliclazide (GLC), as a poorly water-soluble drug, by creating nanocrystalline/amorphous solid dispersions (ESSs). Methods: ESSs were formulated using Eudragit® RS100 and polyethylene glycol (PEG) 6000 as polymeric carriers at various drug: polymer ratios (i.e. 1:5 and 1:10) with different total solution concentrations of 10, 15, and 20% w/v. Morphological, physicochemical, and in-vitro release characteristics of the developed formulations were assessed. Furthermore, GLC dissolution behaviors from ESSs were fitted to various models in order to realize the drug release mechanism. Results: Field emission scanning electron microscopy analyses revealed that the size and morphology of the ESSs were affected by the drug: polymer ratios and solution concentrations. The polymer ratio augmentation led to increase in the particle size while the solution concentration enhancement yielded in a fiber establishment. Differential scanning calorimetry and powder X-ray diffraction investigations demonstrated that the ESSs were present in an amorphous state. Furthermore, the in vitro drug release studies depicted that the samples prepared employing PEG 6000 as carrier enhanced the dissolution rate and the model that appropriately fitted the release behavior of ESSs was Weibull model, where demonstrating a Fickian diffusion as the leading release mechanism. Fourier-transform infrared spectroscopy results showed a probability of complexation or hydrogen bonding, development between GLC and the polymers in the solid state. Conclusion: Hence the electrospraying system avails the both nanosizing and amorphization advantages, therefore, it can be efficiently applied to formulating of ESSs of BCS Class II drugs.

scholarly journals DESIGN AND CHARACTERISATION OF TRANSDERMAL PATCHES OF PHENFORMIN HYDROCHLORIDE

2017 ◽  
Vol 9 (6) ◽  
pp. 90
Author(s):  
Pratik Swarup Das ◽  
Puja Saha
Keyword(s):  
Drug Release ◽  
Diffusion Mechanism ◽  
Skin Irritation ◽  
In Vitro Release ◽  
Chemical Properties ◽  
In Vitro Dissolution ◽  
Release Mechanism ◽  
Transdermal Patches ◽  
The Matrix

Objective: In present work was designed to develop suitable transdermal matrix patches of Phenformin hydrochloride using various hydrophilic (HPMC) and hydrophobic (EUDRAGID) polymers as matrix formers.Methods: Transdermal patches containing Phenformin hydrochloride were prepared by the solvent casting evaporation technique.Results: Revealed that prepared patches showed good physical characteristics, no drug-polymer interaction and no skin irritation was observed. The in vitro release study revealed that F3 formulation showed maximum release in 24 h. Formulation F3 was subjected for accelerated stability studies. The F3 formulation was found to be stable as there was no drastic change in the Physico-chemical properties of the patches, which was also confirmed by FTIR.Conclusion: Thus conclusion can be made that stable transdermal patches of Phenformin hydrochloride has been developed. F1, F2, F3, F4 formulations showed highest cumulative percentage drug release of 98.13%, 95.50%, 98.65%, 97.21% were obtained during in vitro drug release studies after 24 h. The release of Phenformin hydrochloride appears to be dependent on lipophilicity of the matrix. Moderately lipophillic matrices showed best release. The predominant release mechanism of drug through the fabricated matrices was believed to be by diffusion mechanism. Based upon the in vitro dissolution data the F3 formulation was concluded as optimized formulation.

Pseudolatex from STR 5L Block Rubber for Drug Delivery

2013 ◽  
Vol 844 ◽  
pp. 166-169 ◽  
Author(s):  
Prapaporn Boonme ◽  
Kamon Panrat ◽  
Wiwat Pichayakorn
Keyword(s):  
Drug Release ◽  
Contact Allergy ◽  
Drug Loading ◽  
Methyl Cellulose ◽  
Controlled Drug Release ◽  
Colloidal Dispersion ◽  
Mineral Oil ◽  
Lauryl Sulfate ◽  
Drug Encapsulation

Pseudolatex is colloidal dispersion containing spherical solid or semisolid particles and can be prepared from any existing thermoplastic water-insoluble polymers. It is useful for drug encapsulation and controlled drug release. In this study, pseudolatex base was prepared from STR 5L block rubber. The various parameters such as speed and time of homogenization, type and concentration of surfactants, amount of mineral oil, and type of drug loading were studied to prepare the stable pseudolatex. These preparations were evaluated in particle size, pH, viscosity, emulsion stability, drug encapsulation, and in vitro drug release. It was found that the most stable formulation contained 3.5% block rubber, 0.2% methyl cellulose, 6% mineral oil, 4% dibutyl phthalate, 2% sodium lauryl sulfate, and 2% Uniphen P-23 using the speed and time of homogenizer as 20000 rpm and 20 minutes, respectively. Furthermore, the pseudolatex bases reduced the protein impurity form 0.5516% to 0.2108% in formulation with mineral oil and to 0.1781% in formulation without mineral oil, that could decrease contact allergy caused by the protein allergens. Dichloromethane residues in pseudolatex bases were 22.05 mg/L and 7.85 mg/L in formulations with and without mineral oil, respectively, that were satisfied from USP recommendation value of lower than 600 mg/L. Propranolol HCl, lidocaine HCl, and indomethacin could be loaded into pseudolatex only in the concentration of 1%. However, lidocaine base in the concentration of 1-5% could be loaded into pseudolatex which had the similar physical properties and stability to pseudolatex base. The in vitro drug release from pseudolatexs provided the controlled drug release for more than 24 hr.

scholarly journals Influence of sterilization on the drug release behaviour of drug coated silicone

2021 ◽  
Vol 7 (2) ◽  
pp. 672-675
Author(s):  
Katharina Wulf ◽  
Stefan Raggl ◽  
Thomas Eickner ◽  
Gerrit Paasche ◽  
Niels Grabow
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Polymer Coating ◽  
Drug Loading ◽  
In Vitro Release ◽  
Physical Chemical ◽  
Release Studies ◽  
Vitro Release ◽  
Dual Drug

Abstract Sterilization processes ensure sterility of drug delivery systems, but may negatively affect the properties of biomaterials and incorporated drugs by changing their physical, chemical, mechanical properties and drug release behaviour. Therefore, it is important to investigate their influence. In this study, the influence of ethylene oxide (EtO) sterilization on the drug loading and release behaviour of incorporated Diclofenac (DCF) in a Poly-L-lactide (PLLA) coating and Dexamethasone (DMS) in the silicone carrier is presented. Silicone samples containing DMS were coated with PLLA containing DCF varying in layer thickness (5, 10, and 20 μm). Half of the samples underwent EtO sterilization, the other half was not sterilized. All un-/sterilized sample surfaces were in view of the morphology and hydrophilicity examined. Furthermore, in vitro release studies of DMS and DCF were conducted. The sterilized sample surfaces showed no morphological and hydrophilicity changes. The DCF and DMS loadings were similar for the sterile and untreated samples. This also applied to the in vitro DMS release profiles apart from the end of the studies where slight differences were evident. The results indicate that both drugs loaded in the polymer coating and the silicone were not impaired by the sterilization process. Thus, EtO sterilization appears suitable for DMS containing silicone and DCF incorporated PLLA coatings as a dual drug delivery system.

scholarly journals Nanocellulose-Based Patches Loaded with Hyaluronic Acid and Diclofenac towards Aphthous Stomatitis Treatment

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 628 ◽  
Author(s):  
João P. F. Carvalho ◽  
Ana C. Q. Silva ◽  
Verónica Bastos ◽  
Helena Oliveira ◽  
Ricardo J. B. Pinto ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
In Vitro Release ◽  
Three Dimensional ◽  
Human Keratinocytes ◽  
Controlled Drug Release ◽  
Dynamic Mechanical Properties ◽  
Aphthous Stomatitis ◽  
Release Mechanism ◽  
Porous Network

Nanostructured patches composed of bacterial nanocellulose (BNC), hyaluronic acid (HA) and diclofenac (DCF) were developed, envisioning the treatment of aphthous stomatitis. Freestanding patches were prepared via diffusion of aqueous solutions of HA and DCF, with different concentrations of DCF, into the wet BNC three-dimensional porous network. The resultant dual polysaccharides-based patches with a nanostructured morphology present thermal stability up to 200 °C, as well as good dynamic mechanical properties, with a storage modulus higher than 1.0 GPa. In addition, the patches are non-cytotoxic to human keratinocytes (HaCaT cells), with a cell viability of almost 100% after 24 h. The in vitro release profile of DCF from the patches was evaluated in simulated saliva, and the data refer to a diffusion- and swelling-controlled drug-release mechanism. The attained results hint at the possibility of using these dual polysaccharides-based oral mucosal patches to target aphthous stomatitis.

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