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 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 Hybrid Systems Based on Talc and Chitosan for Controlled Drug Release

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3634 ◽  
Author(s):  
Luciano C. B. Lima ◽  
Caio C. Coelho ◽  
Fabrícia C. Silva ◽  
Andréia B. Meneguin ◽  
Hernane S. Barud ◽  
...  
Keyword(s):  
Drug Release ◽  
Sol Gel ◽  
In Vitro Release ◽  
Controlled Drug Release ◽  
Therapeutic Window ◽  
X Ray Diffraction ◽  
Release Capacity ◽  
Model Drug ◽  
Drug Incorporation

Inorganic matrices and biopolymers have been widely used in pharmaceutical fields. They show properties such as biocompatibility, incorporation capacity, and controlled drug release, which can become more attractive if they are combined to form hybrid materials. This work proposes the synthesis of new drug delivery systems (DDS) based on magnesium phyllosilicate (Talc) obtained by the sol–gel route method, the biopolymer chitosan (Ch), and the inorganic-organic hybrid formed between this matrix (Talc + Ch), obtained using glutaraldehyde as a crosslink agent, and to study their incorporation/release capacity of amiloride as a model drug. The systems were characterized by X-ray diffraction (XRD), Therma analysis TG/DTG, and Fourier-transform infrared spectroscopy (FTIR) that supported the DDS’s formation. The hybrid showed a better drug incorporation capacity compared to the precursors, with a loading of 55.74, 49.53, and 4.71 mg g−1 for Talc + Ch, Talc, and Ch, respectively. The release assays were performed on a Hanson Research SR-8 Plus dissolver using apparatus I (basket), set to guarantee the sink conditions. The in vitro release tests showed a prolongation of the release rates of this drug for at least 4 h. This result proposes that the systems implies the slow and gradual release of the active substance, favoring the maintenance of the plasma concentration within a therapeutic window.

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 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.

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.

Cap-free dual stimuli-responsive biodegradable nanocarrier for controlled drug release and chemo-photothermal therapy

2018 ◽  
Vol 6 (48) ◽  
pp. 8188-8195 ◽  
Author(s):  
Fang Wang ◽  
Zemin Wang ◽  
Yansheng Li ◽  
Liang Zhao ◽  
Yongqiang Wen ◽  
...  
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Photothermal Therapy ◽  
Controlled Drug Release ◽  
Stimuli Responsive

The cap-free nanocarrier with fast biodegradability achieved controlled release and chemo-photothermal therapy in vitro.

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 Zirconium-Porphyrin PCN-222: pH-responsive Controlled Anticancer Drug Oridonin

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xin Leng ◽  
Hongliang Huang ◽  
Wenping Wang ◽  
Na Sai ◽  
Longtai You ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Hepg2 Cells ◽  
Drug Loading ◽  
Annexin V ◽  
Controlled Drug Release ◽  
Dapi Staining ◽  
High Drug ◽  
High Drug Loading

Drug delivery carriers with a high drug loading capacity and biocompatibility, especially for controlled drug release, are urgently needed due to the side effects and frequent dose in the traditional therapeutic method. Guided by nanomaterials, we have successfully synthesized zirconium-based metal−organic frameworks, Zr-TCPP (TCPP: tetrakis (4-carboxyphenyl) porphyrin), namely, PCN-222, which is synthesized by solvothermal method. And it has been designed as a drug delivery system (DDS) with a high drug loading of 38.77 wt%. In our work, PCN-222 has achieved pH-sensitive drug release and showed comprehensive SEM, TEM, PXRD, DSC, FTIR, and N2 adsorption-desorption. The low cytotoxicity and good biocompatibility of PCN-222 were certificated by the in vitro results from an MTT assay, DAPI staining, and Annexin V/PI double-staining even cultivated L02 cells and HepG2 cells for 48h. Furthermore, Oridonin, a commonly used cancer chemotherapy drug, is adsorbed into PCN-222 via the solvent diffusion technique. Based on an analysis of the Oridonin release profile, results suggest that it can last for more than 7 days in vitro. And cumulative release rate of Ori at the 7 d was about 86.29% and 63.23% in PBS (pH 5.5 and pH 7.2, respectively) at 37°C. HepG2 cells were chosen to research the cytotoxicity of PCN-222@Ori and free Oridonin. The results demonstrated that the PCN-222@Ori nanocarrier shows higher cytotoxicity in HepG2 cells compared to Oridonin.

Core–shell noble-metal@zeolitic-imidazolate-framework nanocarriers with high cancer treatment efficiency in vitro

2019 ◽  
Vol 7 (7) ◽  
pp. 1050-1055 ◽  
Author(s):  
Liangcan He ◽  
Kanglei Pang ◽  
Wenwen Liu ◽  
Yue Tian ◽  
Lin Chang ◽  
...  
Keyword(s):  
Drug Release ◽  
Cancer Treatment ◽  
Drug Loading ◽  
Controlled Drug Release ◽  
Core Shell ◽  
Treatment Efficiency ◽  
Zeolitic Imidazolate Framework ◽  
High Drug ◽  
High Drug Loading

Core–shell Au@zeolitic-imidazolate-framework nanocarriers with high drug-loading, controlled drug release properties, and high cancer treatment efficiency.

scholarly journals The properties of MOF-Zn2(EBNB)2(BPY)2·2H2O and its basic study of loading Methadone

2020 ◽  
Author(s):  
Deng Linxin ◽  
Li Song ◽  
Xuehua Sun
Keyword(s):  
Drug Loading ◽  
In Vitro Release ◽  
In Vitro Cytotoxicity ◽  
Cytotoxicity Test ◽  
Two Phase ◽  
Basic Study ◽  
Nitrobenzoic Acid ◽  
Model Drug ◽  
Loading Amount

Abstract The ligands of (E)-bis(p-3-nitrobenzoic acid) vinyl (C16H10N2O8) were synthesized in three steps, and then the MOF-Zn2(EBNB)2(BPY)2·2H2O was synthesized by solvothermal method. This structure was characterized by X-ray single crystal diffraction, SEM and TG. The drug loading and in vitro release of Zn2(EBNB)2(BPY)2·2H2O were also studied with Methadone as model drug. The result shows that the highest loading amount of Zn2(EBNB)2(BPY)2·2H2O to Methadone was 0.256g/g, and the drug delivery system was a two-phase mode. The results of in vitro cytotoxicity test shows that Zn2(EBNB)2(BPY)2·2H2O has good biocompatibility.

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