Ionically cross-linked chitosan–halloysite composite microparticles for sustained drug release

Clay Minerals ◽  
2017 ◽  
Vol 52 (4) ◽  
pp. 413-426 ◽  
Author(s):  
Bojan Čalija ◽  
Jela Milić ◽  
Jelena Janićijević ◽  
Aleksandra Daković ◽  
Danina Krajišnik
Keyword(s):  
Drug Release ◽  
Ftir Spectroscopy ◽  
Encapsulation Efficiency ◽  
Spherical Shape ◽  
Halloysite Nanotubes ◽  
Water Soluble ◽  
Composite Particles ◽  
Sustained Drug Release ◽  
Model Drug ◽  
Dta And Tg

AbstractThis study investigated the potential of halloysite nanotubes (HNTs) to improve the sustained release properties of chitosan (CS) microparticles cross-linked ionically with tripolyphosphate (TPP). Composite CS-HNTs microparticles were obtained by a simple and eco-friendly procedure based on a coaxial extrusion technique. Prior to encapsulation, a water-soluble model drug, verapamil hydrochloride (VH), was adsorbed successfully on HNTs. The microparticles were characterized by optical microscopy, Fourier transform infrared (FTIR) spectroscopy, differential thermal analysis/ thermogravimetric analysis (DTA/TG) and evaluated for encapsulation efficiency and drug-release properties. The composite particles had a slightly deformed spherical shape and micrometric size with average perimeters ranging from 485.4 ± 13.3 to 492.4 ± 11.9 μm. The results of FTIR spectroscopy confirmed non-covalent interactions between CS and HNTs within composite particle structures. The DTA and TG studies revealed increased thermal stability of the composite particles in comparison to the CS-TPP particles. Drug adsorption on HNTs prior to encapsulation led to an increase in encapsulation efficiency from 19.6 ± 2.9 to 84.3 ± 1.9%. In contrast to the rapid release of encapsulated model drug from CS-TPP microparticles, the composite CS-HNTs microparticles released drug in a sustained manner, showing the best fit to the Bhaskar model. The results presented here imply that HNTs could be used to improve morphology, encapsulation efficiency and sustained drug-release properties of CS microparticles cross-linked ionically with TPP.

Reverse micelles-in-microspheres with sustained release of water-soluble combretastatin A4 phosphate for S180 tumor treatment

2016 ◽  
Vol 4 (4) ◽  
pp. 760-767 ◽  
Author(s):  
Liping wu ◽  
Liyan Qiu
Keyword(s):  
Cancer Therapy ◽  
Drug Release ◽  
Sustained Release ◽  
Reverse Micelles ◽  
Encapsulation Efficiency ◽  
Water Soluble ◽  
Tumor Treatment ◽  
Sustained Drug Release ◽  
Unique Type ◽  
Combretastatin A4

CA4P-loaded microspheres (CA4P-MS) composed of PELA reverse micelles (CA4P-RM) and PLGA with a sea-island structure were prepared. This unique type of construction can greatly improve the encapsulation efficiency of water-soluble CA4P and provide sustained drug release and action for cancer therapy.

scholarly journals Synthesis, Characterization, and In Vitro Drug Delivery of Chitosan-Silica Hybrid Microspheres for Bone Tissue Engineering

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Niu Niu ◽  
Shu-Hua Teng ◽  
Hua-Jian Zhou ◽  
Hai-Sheng Qian
Keyword(s):  
Drug Release ◽  
Sol Gel ◽  
Particle Diameter ◽  
Spherical Shape ◽  
Average Particle ◽  
High Dispersity ◽  
Model Drug ◽  
Regular Spherical Shape

Chitosan-silica (CS-SiO2) hybrid microspheres were prepared through the combined process of sol-gel and emulsification-crosslinking. Their composition, morphology, in vitro bioactivity, and drug release behavior were investigated. The results showed that, when 20 wt% SiO2 was incorporated, the as-prepared CS-SiO2 hybrid microspheres exhibited a regular spherical shape, a high dispersity, and a uniform microstructure. Their average particle diameter was determined to be about 24.0 μm. The in situ deposited inorganic phase of the hybrid microspheres was identified as amorphous SiO2, and its actual content was determined by the TG analysis. As compared with the pure chitosan microspheres, the CS-SiO2 hybrid microspheres displayed a greatly improved in vitro bioactivity. Vancomycin hydrochloride (VH) was selected as a model drug. It was demonstrated that the CS-SiO2 hybrid microspheres presented a good capacity for both loading and sustained release of VH. Moreover, the increase of the SiO2 content efficiently slowed down the drug release rate of the CS-SiO2 hybrid microspheres.

scholarly journals High-Amylose Sodium Carboxymethyl Starch Matrices: Development and Characterization of Tramadol Hydrochloride Sustained-Release Tablets for Oral Administration

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Teresa Nabais ◽  
Grégoire Leclair
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Corn Starch ◽  
Water Soluble ◽  
Hydroxyl Groups ◽  
Sustained Drug Release ◽  
Tramadol Hydrochloride ◽  
Carboxymethyl Starch ◽  
High Amylose ◽  
Sodium Carboxymethyl Starch

Substituted amylose (SA) polymers were produced from high-amylose corn starch by etherification of its hydroxyl groups with chloroacetate. Amorphous high-amylose sodium carboxymethyl starch (HASCA), the resulting SA polymer, was spray-dried to obtain an excipient (SD HASCA) with optimal binding and sustained-release (SR) properties. Tablets containing different percentages of SD HASCA and tramadol hydrochloride were produced by direct compression and evaluated for dissolution. Once-daily and twice-daily SD HASCA tablets containing two common dosages of tramadol hydrochloride (100 mg and 200 mg), a freely water-soluble drug, were successfully developed. These SR formulations presented high crushing forces, which facilitate further tablet processing and handling. When exposed to both a pH gradient simulating the pH variations through the gastrointestinal tract and a 40% ethanol medium, a very rigid gel formed progressively at the surface of the tablets providing controlled drug-release properties. These properties indicated that SD HASCA was a promising and robust excipient for oral, sustained drug-release, which may possibly minimize the likelihood of dose dumping and consequent adverse effects, even in the case of coadministration with alcohol.

scholarly journals Nanoencapsulation of Nimodipine in Novel Biocompatible Poly(propylene-co-butylene succinate) Aliphatic Copolyesters for Sustained Release

2009 ◽  
Vol 2009 ◽  
pp. 1-11 ◽  
Author(s):  
Sofia Papadimitriou ◽  
George Z. Papageorgiou ◽  
Feras I. Kanaze ◽  
Manolis Georgarakis ◽  
Dimitrios N. Bikiaris
Keyword(s):  
Chemical Interaction ◽  
Spherical Shape ◽  
Water Soluble ◽  
Degree Of Crystallinity ◽  
Butylene Succinate ◽  
Melt Polycondensation ◽  
Water Soluble Drug ◽  
The Matrix ◽  
Model Drug ◽  
Poly Propylene

Biocompatible poly(propylene-co-butylene succinate) (PPBSu) copolyesters, containing up to 50 mol% butylene succinate units, were synthesized by the two-stage melt polycondensation method (esterification and polycondensation). The copolymers were fully characterized and biocompatibility studies were also performed. They were proved to be biocompatible and they were used as polymer matrices for the preparation of drug loaded nanoparticles. Nimodipine was selected as a model hydrophobic poorly water soluble drug. From the results obtained by dynamic light scattering (DLS) and scanning electron microscopy (SEM), drug loaded copolymer nanoparticles were found to exhibit a spherical shape and their mean diameter appeared in the range of 180–200 nm. Fourier Transformation-Infrared Spectroscopy (FTIR) spectra indicated that no chemical interaction between the drug and the matrix could be justified, while Wide-Angle X-Ray Diffraction (WAXD) patterns proved a low degree of crystallinity of Nimodipine in the nanoparticles. The release behavior of the model drug from nanoparticles was also investigated in order to identify modifications and find out any possible correlation between the chemical composition of the polymer matrix and the drug release rates.

Fabrication of Shellac-Based Effervescent Floating Matrix Tablet as a Novel Carrier for Controlling of Drug Release

2013 ◽  
Vol 747 ◽  
pp. 135-138 ◽  
Author(s):  
Noppadol Chongcherdsak ◽  
Direk Aekthammarat ◽  
Chutima Limmatvapirat ◽  
Sontaya Limmatvapirat
Keyword(s):  
Drug Release ◽  
Equation Model ◽  
Matrix Tablets ◽  
Basic Knowledge ◽  
Matrix Tablet ◽  
Sustained Drug Release ◽  
Factors Affecting ◽  
Model Drug ◽  
High Level ◽  
Power Law Equation

The aim of this research was to elucidate the factors affecting drug release and buoyancy properties of effervescent shellac based matrix tablet. Theophylline was selected as a model drug and sodium bicarbonate was used as a gas forming agent. To fabricate floating matrix tablets, the model drug, gas forming agent and other excipients were blended, compressed and then annealed at 80C for 24 h. The factors affecting floating and drug release, including amount of SHL and gas forming agent were investigated. The result demonstrated that the hardness of all formulations before annealing was within the range of 60+10 N. After annealing process, the hardness was significantly increased especially for formulation containing high level of SHL. The hardness of tablets containing 55% w/w or more of SHL was more than 200 N. As increasing amount of SHL (> 35% w/w), the more sustained drug release was also observed. The results were agreed well with the increased hardness. In addition, the tablets containing 20% w/w or more of gas forming agent were floated in 0.1 N HCl for more than 10 h, suggesting the good buoyancy characteristic. The kinetics of drug release in 0.1N HCl for all formulations were both fitted with Higuchi model and power law equation model, suggesting that the main mechanism of drug release in 0.1N HCl was obeyed the diffusion process. The result from this research could provide the basic knowledge for fabricating of SHL-based floating matrix tablet through varying amount of SHL and gastric forming agent.

scholarly journals Preparation and in vitro characterization of gellan based floating beads of acetohydroxamic acid for eradication of H. pylori

2007 ◽  
Vol 57 (4) ◽  
pp. 413-427 ◽  
Author(s):  
Parauvathanahalli Rajinikanth ◽  
Brahmeshwar mishra
Keyword(s):  
Drug Release ◽  
Encapsulation Efficiency ◽  
Diffusion Mechanism ◽  
Oral Dosage ◽  
Acetohydroxamic Acid ◽  
Burst Release ◽  
Sustained Drug Release ◽  
H Pylori

Preparation andin vitrocharacterization of gellan based floating beads of acetohydroxamic acid for eradication ofH. pyloriGellan based floating beads of acetohydroxamic acid (AHA) were prepared by the ionotropic gellation method to achieve controlled and sustained drug release for treatment ofHelicobacter pyloriinfection. The prepared beads were evaluated for diameter, surface morphology and encapsulation efficiency. Formulation parameters like concentrations of gellan, chitosan, calcium carbonate and the drug influenced thein vitrodrug release characteristics of beads. Drug and polymer interaction studies were carried out using differential scanning calorimetry. Chitosan coating increased encapsulation efficiency of the beads and reduced the initial burst release of the drug from the beads. Kinetic treatment of the drug release data revealed a matrix diffusion mechanism. Prepared floating beads showed good antimicrobial activity (in vitro H. pyloriculture) as potent urease inhibitors. In conclusion, an oral dosage form of floating gellan beads containing AHA may form a useful stomach site specific drug delivery system for the treatment ofH. pyloriinfection.

Preparation and Evaluation of Ternary Polymeric Blends for Controlled Release Matrices Containing Weakly Basic Model Drug

2020 ◽  
Vol 17 ◽  
Author(s):  
Wasfy M. Obeidat ◽  
Shadi F. Gharaibeh ◽  
Abdolelah A. Jaradat ◽  
Osama Abualsuod
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Sodium Alginate ◽  
Matrix Tablets ◽  
Wet Granulation ◽  
Sustained Drug Release ◽  
Basic Drug ◽  
Basic Model ◽  
Polymeric Compositions ◽  
Model Drug

Objective: The objective of this study was to evaluate the suitability of ternary mixture of smart polymers comprised of Eudragit®E100, Eudragit®L100, and sodium alginate to serve as a carrier for sustained drug release for weakly basic drugs. The model drug chosen in this part of the study is Metronidazole. Methods: Matrix tablets formulations were prepared by either direct compression or by wet granulation. Dissolution studies were conducted using USP XXΠ rotating paddle apparatus in three different consecutive stages (pH 1.2, 4.8 and 6.8). Tablets made of low to intermediate proportions of sodium alginate and an approximately equal proportions of Eudragit®E100 and Eudragit®L100 were found to have significant modification of drug release rates. Result: Thus, indicating a potential for controlling the drug release for 12 hours depending on polymers ratios in the formulation. The ratio of sodium alginate to total Eudragit® polymers and the ratio of Eudragit®E100 to Eudragit®L100 within the ternary polymeric composition were found critical in determining the controlled release performance. Conclusion: Results of swelling studies were in agreement with the dissolution behaviors of the tablets. The findings suggest the significance of the ternary polymeric compositions in controlling the release of weakly basic drug.

scholarly journals Mechanical characterization of calcium pectinate hydrogel for controlled drug delivery

2003 ◽  
Vol 57 (12) ◽  
pp. 611-616 ◽  
Author(s):  
Jin Chung ◽  
Zhang Zhibing
Keyword(s):  
Mechanical Properties ◽  
Drug Release ◽  
Oral Delivery ◽  
Drug Carrier ◽  
Release Profile ◽  
Water Soluble ◽  
Drug Release Profile ◽  
Force Relaxation ◽  
Calcium Pectinate ◽  
Model Drug

Calcium pectinate beads, a paniculate hydrogel system, is an attractive drug carrier for oral delivery. In this study, a poorly water-soluble model drug indomethacin was incorporated into calcium pectinate beads made of different pectin concentrations, which were produced by an extrusion method. The effect of pectin concentration on bead size, circularity, swelling behavior, and mechanical properties, as well as in vitro drug release profile was investigated. The mechanical properties of calcium pectinate beads were determined by a micromanipulation technique. The drug release profile was measured using a standard British Pharmacopoeia method. It was found that the beads made of higher pectin concentration in general had a less permeable matrix structure and greater mechanical rigidity, although they swelled more after hydration. However, such an effect was not significant when the pectin concentration was increased to above 8%. Micromanipulation measurements showed that there was significant relaxation of the force being imposed on single hydrated beads when they were held, but this phenomenon did not occur on dry beads, which means that the force relaxation was dominated by liquid loss from the beads. The rate of the force relaxation was determined, and has been related to the release rate of the model drug entrapped in the calcium pectinate beads.

scholarly journals Fabrication of bionanocomposite based on LDH using biopolymer of gum arabic and chitosan-coating for sustained drug-release

2020 ◽  
Vol 85 (9) ◽  
pp. 1223-1235 ◽  
Author(s):  
Milad Abniki ◽  
Ali Moghimi ◽  
Fariborz Azizinejad
Keyword(s):  
Drug Release ◽  
Gum Arabic ◽  
X Ray Diffraction ◽  
Sustained Drug Release ◽  
Experimental Conditions ◽  
X Ray ◽  
Model Drug ◽  
Diffraction Patterns ◽  
New Formulation

The study proposed a new formulation to the sustained delivery of mefenamate anions intercalated into Mg?Al layered double hydroxide (LDH) for oral administration. Different experimental conditions were evaluated to incorporate the mefenamic acid (MEF) and gum arabic (GUM) into LDH structure. The LDH?MEF and LDH?MEF/GUM were covered with chitosan (CHIT). In another experiment, LDH?Cl was used to adsorb mefenamate anions and evaluate the mechanism. The products of LDH were characterized by using different techniques such as FESEM (field emission scanning electron microscopy), XRD (X-ray diffraction), FTIR (Fourier transform infrared) spectroscopy and TGA (thermogravimetric analysis). The X-ray diffraction patterns and FTIR analyses confirmed that the MEF and GUM were successfully intercalated into the interlayer space of LDH. TG analysis verified that the thermal stability of intercalated MEF in the form of bionanocomposite (LDH?MEF/ /GUM/CHIT) was enhanced. Finally, In vitro drug release experiments of bionanocomposite at a pH of 1.2 (acidic medium) and a pH of 7.4 (phosphate buffer medium) showed sustained release profiles with mefenamate anions as an anti-inflammatory model drug.

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