Preparation of pH ‐responsive cellulose nanofibril/sodium alginate based hydrogels for drug release

2021 ◽  
pp. 51647
Author(s):  
Yuhang Li ◽  
Cong Wang ◽  
Yunhao Luan ◽  
Wanyi Liu ◽  
Tiantian Chen ◽  
...  
Author(s):  
Bipul Nath ◽  
Santimoni Saikia

In the present investigation, sodium alginate based multiparticulate system overcoated with time and pH dependent polymer was studied in the form of oral pulsatile system to achieve pulsatile with sustained release of aceclofenac for chronotherapy of rheumatoid arthritis seven batches of micro beads with varying concentration of sodium alginate (2-5 %) were prepared by ionotropic-gelation method using CaCl2 as cross-linking agent. The prepared Ca-alginate beads were coated with 5% Eudragit L100 and filled into pulsatile capsule with varying proportion of plugging materials. Drug loaded microbeads were investigated for physicochemical properties and drug release characteristics. The mean particle sizes of drug-loaded microbeads were found to be in the range 596±1.1 to 860 ± 1.2 micron and %DEE in the range of 65-85%. FT-IR and DSC studies revealed the absence of drug polymer interactions. The release of aceclofenac from formulations F1 to F7 in buffer media (pH 6.8) at the end of 5h was 65.6, 60.7, 55.7, 41.2, 39.2, 27 and 25% respectively. Pulsatile system filled with eudragit coated Ca-alginate microbeads (F2) showed better drug content, particle size, surface topography, in-vitro drug release in a controlled manner. Different plugging materials like Sterculia gum, HPMC K4M and Carbopol were used in the design of pulsatile capsule. The pulsatile system remained intact in buffer pH 1.2 for 2 hours due to enteric coat of the system with HPMCP. The enteric coat dissolved when the pH of medium was changed to 7.4. The pulsatile system developed with Sterculia gum as plugging material showed satisfactory lag period when compared to HPMC and Carbopol.


2018 ◽  
Vol 25 (25) ◽  
pp. 3036-3057 ◽  
Author(s):  
Xiao Sun ◽  
Guilong Zhang ◽  
Zhengyan Wu

According to the differences of microenvironments between tumors and healthy tissues, if the anticancer drugs or magnetic resonance contrast agents (MRCAs) can be controlled to precisely match physiological needs at targeted tumor sites, it is expected to acquire better therapeutic efficacy and more accurate diagnosis. Over the decade, stimuli-responsive nanomaterials have been a research hotspot for cancer treatment and diagnosis because they show many excellent functions, such as in vivo imaging, combined targeting drug delivery and systemic controlled release, extended circulation time, etc. Among the various stimuli nanosystems, pH-stimuli mode is regarded as the most general strategy because of solid tumors acidosis. When exposed to weakly acidic tumor microenvironment, pH-responsive nanoplatforms can generate physicochemical changes for their structure and surface characteristics, causing drug release or contrast enhancement. In this review, we focused on the designs of various pH-responsive nanoplatforms and discussed the mechanisms of controlled drug release or switch on-off in MRCAs. This review also discussed the efficacy of cellular internalization for these nanoplatforms via endocytosis of acidic tumor cell. Meanwhile, nanoplatforms response to acidic intracellular pH (such as endosome, lysosome) are discussed, along with approaches for improving drug release performance and magnetic resonance contrast enhancement. A greater understanding of these pH-responsive nanoplatforms will help design more efficient nanomedicine to address the challenges encountered in conventional diagnosis and chemotherapy.


2021 ◽  
Vol 146 ◽  
pp. 110267
Author(s):  
Chunqing Niu ◽  
Xinyu Liu ◽  
Yiyu Wang ◽  
Xiang Li ◽  
Jian Shi

RSC Advances ◽  
2020 ◽  
Vol 10 (71) ◽  
pp. 43904-43914
Author(s):  
Deola Majhi ◽  
Braja N. Patra

Polyaniline and sodium alginate nanocomposite was synthesized and it was used for selective removal of both cationic and anionic dyes from water at different pH.


Carbon ◽  
2016 ◽  
Vol 97 ◽  
pp. 78-86 ◽  
Author(s):  
Zhifen Cui ◽  
Yu Zhang ◽  
Jichao Zhang ◽  
Huating Kong ◽  
Xiaoxing Tang ◽  
...  

2012 ◽  
Vol 62 (4) ◽  
pp. 529-545 ◽  
Author(s):  
Anuj Chawla ◽  
Pooja Sharma ◽  
Pravin Pawar

The aim of the study was to prepare site specific drug delivery of naproxen sodium using sodium alginate and Eudragit S-100 as a mucoadhesive and pH-sensitive polymer, respectively. Core microspheres of alginate were prepared by a modified emulsification method followed by cross-linking with CaCl2, which was further coated with the pH dependent polymer Eudragit S-100 (2.5 or 5 %) to prevent drug release in the upper gastrointestinal environment. Microspheres were characterized by FT-IR spectroscopy, X-ray diffraction, differential scanning calorimetry and evaluated by scanning electron microscopy, particle size analysis, drug loading efficiency, in vitro mucoadhesive time study and in vitro drug release study in different simulated gastric fluids. Stability studies of the optimized formulation were carried out for 6 months. SEM images revealed that the surface morphology was rough and smooth for core and coated microspheres, respectively. Core microspheres showed better mucoadhesion compared to coated microspheres when applied to the mucosal surface of freshly excised goat colon. The optimized batch of core microspheres and coated microspheres exhibited 98.42 ± 0.96 and 95.58 ± 0.74 % drug release, respectively. Drug release from all sodium alginate microsphere formulations followed Higuchi kinetics. Moreover, drug release from Eudragit S-100 coated microspheres followed the Korsmeyer-Peppas equation with a Fickian kinetics mechanism. Stability study suggested that the degradation rate constant of microspheres was minimal, indicating 2 years shelf life of the formulation.


Biomaterials ◽  
2018 ◽  
Vol 154 ◽  
pp. 169-181 ◽  
Author(s):  
Yanan Tan ◽  
Yun Zhu ◽  
Yue Zhao ◽  
Lijuan Wen ◽  
Tingting Meng ◽  
...  

2016 ◽  
Vol 7 (12) ◽  
pp. 2202-2208 ◽  
Author(s):  
Shuai Li ◽  
Zhouxiang Zhao ◽  
Wei Wu ◽  
Chunmei Ding ◽  
Jianshu Li

Two types of diblock copolymers are synthesized to construct dual pH-responsive micelles with a charge-conversional property for effective drug delivery.


INDIAN DRUGS ◽  
2016 ◽  
Vol 53 (01) ◽  
pp. 25-31
Author(s):  
M Priyanka ◽  
◽  
F. S. Dasankoppa ◽  
H. N Sholapur ◽  
NGN Swamy ◽  
...  

The poor bioavailability and the therapeutic effectiveness exhibited by the anti-depressant venlafaxine hydrochloride on oral administration is overcome by the use of ion-activated gel forming systems that are instilled as drops; these undergo gelation in the nasal cavity. The present study describes the design, characterization and evaluation of mucoadhesive nasal in situ gelling drug delivery of venlafaxine hydrochloride using different polymers like sodium alginate, HPMC and pectin in various concentrations. DSC studies revealed compatibility of the drug and excipients used. The in situ gels were characterized for physicochemical parameters, gelling ability, rheological studies, drug content, drug entrapment efficiency, in vitro mucoadhesive strength, water holding capacity, gel expansion coefficient and in vitro drug release studies. The amount of polymer blends was optimized using 23 full factorial design. The influence of experimental factors on percentage cumulative drug release at the end of 2 and 8 hours were investigated to get optimized formulation. The responses were analyzed using ANOVA and polynomial equation was generated for each response using multiple linear regression analysis. Optimized formulation, F9, containing 1.98% w/V sodium alginate, 0.64% w/V hydroxylpropyl methylcellulose, 0.99% w/V pectin showed percentage cumulative drug release of 19.33 and 80.44 at the end of 2 and 8 hours, respectively, which were close to the predicted values. The optimized formulation was subjected to stability study for three months at 300C /75% RH. The stability study revealed no significant change in pH, drug content and viscosity. Thus, venlafaxine hydrochloride nasal mucoadhesive in situ gel could be successfully formulated to improve bioavailability and to target the brain.


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