scholarly journals A Rapid Dual-Responsive Releasing Nano-Carrier by Decomposing the Copolymer and Reversing the Core Dissolution

Author(s):  
Sen Liu ◽  
Can Shen ◽  
Cheng Qian ◽  
Jianquan Wang ◽  
Zhihao Wang ◽  
...  

The accumulation of nanotechnology-based drugs has been realized in various ways. However, the concentration of drugs encapsulated by nanomaterials is not equal to the concentration of effective drugs; often, the drugs become effective only when they are released from the nanomaterials as free drugs. This means only when the drugs are rapidly released after the accumulated drug-encapsulating nanomaterials can they truly achieve the purpose of increasing the concentration of drugs in the tumor. Therefore, we herein report a dual-response nano-carrier of glutathione and acid to achieve the rapid release of encapsulated drug and increase the effective drug concentration in the tumor. The nano-carrier was constructed using a dual-responsive amphiphilic copolymer, composed of polyethylene glycol and hydrophobic acetylated dextran and connected by a disulfide bond. In the tumor microenvironment, disulfide bonds could be biodegraded by glutathione that is overexpressed in the tumor, exposing the core of nano-carrier composed of acetylated dextran. Then the acidic environment would induce the deacetylation of acetylated dextran into water-soluble dextran. In this way, the nano-carrier will degrade quickly, realizing the purpose of rapid drug release. The results showed that the drug release rate of dual-responsive nano-carrier was much higher than that of glutathione or acid-responsive nano-carrier alone. Furthermore, both in vitro and in vivo experiments confirmed that dual-responsive nano-carrier possessed more efficient anti-tumor effects. Therefore, we believe that dual-responsive nano-carriers have better clinical application prospects.

Author(s):  
KUMAR BABU PASUPULETI ◽  
VENKATACHALAM A. ◽  
BHASKAR REDDY KESAVAN

Objective: This study is to formulate Nebivolol into a Pulsatile liquid, solid composite compression coated tablet, which will delay the release of the drug in early morning hypertension conditions. Methods: The liquid, solid composite tablet was formulated and compressed with the ethylcellulose coating polymer. The percent in vitro drug release of the liquid solid composite compressed tablet was tested. Based on disintegration time and wetting time, the LCS2, LCS3, LSC6, LCS7 and LCS12 formulations were found to be the optimized solid-liquid compacts fast-dissolving core tablet formulations, which may be excellent candidates for further coating with polymer to transfer into press coated pulsatile tablet formulations. Coating the core tablet with varying ethyl cellulose concentrations resulted in five different formulations of the pulsatile press-coated tablet (CT1, CT2, CT3, CT4, CT5). In vitro drug release, in vitro release, kinetic studies, in vivo pharmacokinetic and stability tests were all performed for the prepared pulsatile press coated tablet. Results: CT3 tablets are coated with ethyl cellulose polymer, which shows maximum controlled drug release from the core tablet i.e. 96.34±1.2% at 8th h. It shows there was an efficient delay in drug release form core tablet i.e. up to 3 h, followed by the maximum amount of drug release of 96.34±2.4 at 8h. Which shows the core drug will be more efficiently protected from the gastric acid environment 1.2 pH, duodenal environment 4.0 pH and release drug only in the small intestine. Conclusion: According to the findings, CT3 Pulsatile press-coated tablet increased the bioavailability of Nebivolol by 3.11 percent.


Author(s):  
Pradeep HK ◽  
Girish B ◽  
Nooruddeen K ◽  
Thimmasetty J ◽  
Venkateswarlu BS

The buccal cavity is an alternate route for the administration of the drug. This route gained acceptance as increase in bioavailability is observed due to bypass of first pass metabolism. Solvent casting method was employed for the preparation of the risperidone mucoadhesive patches using different combinations of water soluble and water insoluble polymers using polyvinyl alcohol as a backing layer. Our main objective of this study was to understand the behaviour of water soluble and water insoluble polymers in combination on release pattern. Six different formulations of mucoadhesive patches were evaluated for physicochemical parameters like weight uniformity, content uniformity, thickness uniformity, surface pH, swelling studies, tensile strength, folding endurance, in-vitro drug release, and in-vivo drug absorption. Drug loaded mucoadhesive patches of various polymer bases had shown 35.64 to 72.33% drug release in 30 min in phosphate buffer solution of pH 6.6. In-vitro release data from patches were fit to different equations and kinetic models to explain release profiles. Kinetic models like Hixon-Crowell and Higuchi models were used. The formulation containing HPMC (15Cps) and polyvinyl pyrrolidone was considered as optimized based on the physicochemical and pharmaceutical properties. In-vivo studies in rabbits, carried out with prior permission from IAEC, showed 80.40% of drug release from the optimized patches. In-vivo and in-vitro correlations were found to be good. The drug absorption was found significant from the optimized formulation in healthy rabbits. The structure of the buccal membrane and permeability factors are similar in both human beings and rabbits. Therefore mucoadhesive patches of risperidone may be accepted with the important advantage of reduced risperidone dose.


2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Xinyi Zhang ◽  
Tiantian Zhu ◽  
Yaxin Miao ◽  
Lu Zhou ◽  
Weifang Zhang

Abstract Background The enhancement of tumor retention and cellular uptake of drugs are important factors in maximizing anticancer therapy and minimizing side effects of encapsulated drugs. Herein, a delivery nanoplatform, armed with a pH-triggered charge-reversal capability and self-amplifiable reactive oxygen species (ROS)-induced drug release, is constructed by encapsulating doxorubicin (DOX) in pH/ROS-responsive polymeric micelle. Results The surface charge of this system was converted from negative to positive from pH 7.4 to pH 6.8, which facilitated the cellular uptake. In addition, methionine-based system was dissociated in a ROS-rich and acidic intracellular environment, resulting in the release of DOX and α-tocopheryl succinate (TOS). Then, the exposed TOS segments further induced the generation of ROS, leading to self-amplifiable disassembly of the micelles and drug release. Conclusions We confirms efficient DOX delivery into cancer cells, upregulation of tumoral ROS level and induction of the apoptotic capability in vitro. The system exhibits outstanding tumor inhibition capability in vivo, indicating that dual stimuli nano-system has great potential to function as an anticancer drug delivery platform.


2021 ◽  
Vol 14 (12) ◽  
pp. 1255
Author(s):  
Ju-Hyun Lee ◽  
Chulhun Park ◽  
Kwon-Yeon Weon ◽  
Chin-Yang Kang ◽  
Beom-Jin Lee ◽  
...  

Itraconazole (ITZ) is a class II drug according to the biopharmaceutical classification system. Its solubility is pH 3-dependent, and it is poorly water-soluble. Its pKa is 3.7, which makes it a weak base drug. The aim of this study was to prepare solid dispersion (SD) pellets to enhance the release of ITZ into the gastrointestinal environment using hot-melt extrusion (HME) technology and a pelletizer. The pellets were then filled into capsules and evaluated in vitro and in vivo. The ITZ changed from a crystalline state to an amorphous state during the HME process, as determined using DSC and PXRD. In addition, its release into the gastrointestinal tract was enhanced, as was the level of ITZ recrystallization, which was lower than the marketed drug (Sporanox®), as assessed using an in vitro method. In the in vivo study that was carried out in rats, the AUC0–48h of the commercial formulation, Sporanox®, was 1073.9 ± 314.7 ng·h·mL−1, and the bioavailability of the SD pellet (2969.7 ± 720.6 ng·h·mL−1) was three-fold higher than that of Sporanox® (*** p < 0.001). The results of the in vivo test in beagle dogs revealed that the AUC0–24h of the SD-1 pellet (which was designed to enhance drug release into gastric fluids) was 3.37 ± 3.28 μg·h·mL−1 and that of the SD-2 pellet (which was designed to enhance drug release in intestinal fluids) was 7.50 ± 4.50 μg·h·mL−1. The AUC of the SD-2 pellet was 2.2 times higher than that of the SD-1 pellet. Based on pharmacokinetic data, ITZ would exist in a supersaturated state in the area of drug absorption. These results indicated that the absorption area is critical for improving the bioavailability of ITZ. Consequently, the bioavailability of ITZ could be improved by inhibiting precipitation in the absorption area.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Madhuri S. Rodde ◽  
Ganesh T. Divase ◽  
Tejas B. Devkar ◽  
Avinash R. Tekade

The objective of this investigation was to improve the solubility of the poorly water soluble drug atorvastatin (ATR), using solid dispersion (SD) techniques, with Neem Gum (NG) as a hydrophilic carrier. The effects of the polymer concentration and method of preparation on the solubility and dissolution rate were studied. The results showed that the solubility of ATR increases with increasing NG concentration. However, dissolution rate of ATR from its SD was dependent on the method used to prepare SD. Anin vitrodrug release study revealed that the solvent evaporation technique is a more convenient and effective method of preparing SD than kneading method. The SD was characterized using DSC, SEM, and XRD study. Anin vivostudy was performed in which the 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG CoA) reductase inhibition activity was measured. A significant reduction in HMG CoA reductase activity was observed with SD of ATR compared with the plain drug. Anex vivoabsorption study was carried out using modified apparatus developed in our laboratory. Thein vitrodrug release andin vivoandex vivostudies clearly demonstrated the potential of hydrophilic NG in enhancing the solubility, dissolution rate, and bioavailability of ATR.


2002 ◽  
Vol 81 (1-2) ◽  
pp. 165-172 ◽  
Author(s):  
Kazuhiro Sako ◽  
Toyohiro Sawada ◽  
Hiroshi Nakashima ◽  
Shigeharu Yokohama ◽  
Takashi Sonobe

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1464
Author(s):  
Yang Yang ◽  
Fuwei Yang ◽  
Xiaotian Shan ◽  
Jiamin Xu ◽  
Wenjie Fang ◽  
...  

At present, the drug is still difficult to release completely and quickly only with single stimulation. In order to promote the rapid release of polymeric micelles at tumor site, pH/reduction sensitive polymers (PCT) containing disulfide bonds and orthoester groups were synthesized. The PCT polymers can self-assemble in water and entrap doxorubicin to form drug-loaded micelles (DOX/PCT). In an in vitro drug release experiment, the cumulative release of DOX/PCT micelles in the simulated tumor microenvironment (pH 5.0 with GSH) reached (89.7 ± 11.7)% at 72 h, while it was only (16.7 ± 6.1)% in the normal physiological environment (pH 7.4 without GSH). In addition, pH sensitive DOX loaded micellar system (DOX/PAT) was prepared as a control. Furthermore, compared with DOX/PAT micelles, DOX/PCT micelles showed the stronger cytotoxicity against tumor cells to achieve an effective antitumor effect. After being internalized by clathrin/caveolin-mediated endocytosis and macropinocytosis, DOX/PCT micelles were depolymerized in intercellular acidic and a reductive environment to release DOX rapidly to kill tumor cells. Additionally, DOX/PCT micelles had a better inhibitory effect on tumor growth than DOX/PAT micelles in in vivo antitumor activity studies. Therefore, pH/reduction dual sensitive PCT polymers have great potential to be used as repaid release nanocarriers for intercellular delivery of antitumor drugs.


2020 ◽  
Author(s):  
Xinyi Zhang ◽  
Tiantian Zhu ◽  
Yaxin Miao ◽  
Lu Zhou ◽  
Weifang Zhang

Abstract Background: The enhancement of tumor retention and cellular uptake of drugs are important factors in maximizing anticancer therapy and minimizing side effects of encapsulated drugs. Herein, a delivery nanoplatform, armed with a pH-triggered charge-reversal capability and self-amplifiable reactive oxygen species (ROS)-induced drug release, was constructed by encapsulating doxorubicin (DOX) in pH/ROS-responsive polymeric micelle.Results: The surface charge of this system can be converted from negative to positive from pH 7.4 to pH 6.8, which facilitates the cellular uptake. In addition, methionine-based system was dissociated in a ROS-rich and acidic intracellular environment, resulting in the release of DOX and α-tocopheryl succinate (TOS). Then, the exposed TOS segments can further induced the generation of ROS, leading to self-amplifiable disassembly of the micelles and drug release. Conclusions: We confirmed efficient DOX delivery into cancer cells, upregulation of tumoral ROS level and induction of the apoptotic capability in vitro. The system exhibited outstanding tumor inhibition capability in vivo, indicating that dual stimuli nanosytem has great potential as an anticancer drug delivery platform.


2020 ◽  
Author(s):  
Xinyi Zhang ◽  
Tiantian Zhu ◽  
Yaxin Miao ◽  
Lu Zhou ◽  
Weifang Zhang

Abstract Background: The enhancement of tumor retention and cellular uptake of drugs are important factors in maximizing anticancer therapy and minimizing side effects of encapsulated drugs. Herein, a delivery nanoplatform, armed with a pH-triggered charge-reversal capability and self-amplifiable reactive oxygen species (ROS)-induced drug release, is constructed by encapsulating doxorubicin (DOX) in pH/ROS-responsive polymeric micelle. Results: The surface charge of this system was converted from negative to positive from pH 7.4 to pH 6.8, which facilitated the cellular uptake. In addition, methionine-based system was dissociated in a ROS-rich and acidic intracellular environment, resulting in the release of DOX and α-tocopheryl succinate (TOS). Then, the exposed TOS segments further induced the generation of ROS, leading to self-amplifiable disassembly of the micelles and drug release. Conclusions: We confirms efficient DOX delivery into cancer cells, upregulation of tumoral ROS level and induction of the apoptotic capability in vitro . The system exhibits outstanding tumor inhibition capability in vivo , indicating that dual stimuli nano-system has great potential to function as an anticancer drug delivery platform.


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