Polymeric Conjugates of 9-[2-(Phosphonomethoxy)ethyl]purine with Potential Antiviral and Cytostatic Activity

2006 ◽  
Vol 71 (8) ◽  
pp. 1211-1220 ◽  
Author(s):  
Michal Pechar ◽  
Alena Braunová ◽  
Vladimír Šubr ◽  
Karel Ulbrich ◽  
Antonín Holý
Keyword(s):  
Drug Release ◽  
Random Copolymer ◽  
Sustained Drug Release ◽  
Polymer Carrier ◽  
Heterocyclic Base ◽  
Drug Conjugates ◽  
New Family ◽  
Hydroxypropyl Methacrylamide ◽  
Rate Of Hydrolysis

Syntheses and characterization of polymer conjugates of 9-[2-(phosphonomethoxy)ethyl] (PME) derivatives of adenine (PMEA), 2,6-diaminopurine (PMEDAP) and guanine (PMEG) are described. The phosphonate group of these acyclic nucleotide analogues was activated by reaction with triphenylphosphine and di(2-pyridyl) disulfide (TPP-PDS). The activated phosphonate reacted with a random copolymer containing N-(2-hydroxypropyl)methacrylamide (HPMA) and N-(3-methacrylamidopropanoyl)ethane-1,2-diamine (Ma-AP-ED) units. The phosphonamide bond between the nucleotide and polymer carrier proved to be relatively stable at physiological pH 7.4 while at pH 5.0 (corresponding to endosomal or lysosomal compartments of cells) underwent slow hydrolysis. The rate of hydrolysis (drug release) was shown to depend on the detailed structure of the heterocyclic base. The polymer-drug conjugates described in the paper represent a new family of antiviral and cytostatic drugs with potentially improved pharmacokinetics, sustained drug release and diminished non-specific toxicity.

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 characterization of iminodiacetic acid: magnetite nano-particles as a novel famotidine carrier substrate for sustained drug release

2014 ◽  
Vol 146 (2) ◽  
pp. 411-416 ◽  
Author(s):  
Amir Heydarinasab ◽  
Homayon Ahmad Panahi ◽  
Hamid Nematzadeh ◽  
Elham Moniri ◽  
Sara Nasrollahi
Keyword(s):  
Drug Release ◽  
Iminodiacetic Acid ◽  
Nano Particles ◽  
Sustained Drug Release

scholarly journals Design and characterization of chitosan-containing mucoadhesive buccal patches of propranolol hydrochloride

2007 ◽  
Vol 57 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Vishnu Patel ◽  
Bhupendra Prajapati ◽  
Madhabhai Patel
Keyword(s):  
Drug Release ◽  
Ex Vivo ◽  
Stability Study ◽  
Fickian Diffusion ◽  
Content Uniformity ◽  
Propranolol Hydrochloride ◽  
Sustained Drug Release ◽  
Surface Ph

Design and characterization of chitosan-containing mucoadhesive buccal patches of propranolol hydrochloride Mucoadhesive buccal patches containing propranolol hydrochloride were prepared using the solvent casting method. Chitosan was used as bioadhesive polymer and different ratios of chitosan to PVP K-30 were used. The patches were evaluated for their physical characteristics like mass variation, drug content uniformity, folding endurance, ex vivo mucoadhesion strength, ex vivo mucoadhesion time, surface pH, in vitro drug release, and in vitro buccal permeation study. Patches exhibited controlled release for a period of 7 h. The mechanism of drug release was found to be non-Fickian diffusion and followed the first-order kinetics. Incorporation of PVP K-30 generally enhanced the release rate. Swelling index was proportional to the concentration of PVP K-30. Optimized patches (F4) showed satisfactory bioadhesive strength of 9.6 ± 2.0 g, and ex vivo mucoadhesion time of 272 minutes. The surface pH of all patches was between 5.7 and 6.3 and hence patches should not cause irritation in the buccal cavity. Patches containing 10 mg of drug had higher bioadhesive strength with sustained drug release as compared to patches containing 20 mg of drug. Good correlation was observed between the in vitro drug release and in vitro drug permeation with a correlation coefficient of 0.9364. Stability study of optimized patches was done in human saliva and it was found that both drug and buccal patches were stable.

Redox-sensitive hyaluronic acid–paclitaxel conjugate micelles with high physical drug loading for efficient tumor therapy

2015 ◽  
Vol 6 (46) ◽  
pp. 8047-8059 ◽  
Author(s):  
Tingjie Yin ◽  
Jing Wang ◽  
Lifang Yin ◽  
Linjia Shen ◽  
Jianping Zhou ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Drug Release ◽  
Cellular Uptake ◽  
Drug Loading ◽  
Tumor Therapy ◽  
Drug Conjugates ◽  
Self Assembled ◽  
Polymer Drug Conjugates

Characterization of targeted redox-sensitive micelles self-assembled from polymer–drug conjugates exhibiting conspicuous drug loading capabilities, selective cellular uptake, rapid intracellular disassembly and drug release is presented.

scholarly journals Fabrication and Characterization of Ceftizoxime-Loaded Pectin Nanocarriers

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1452
Author(s):  
Pawan Kumar ◽  
Vinod Kumar ◽  
Ravinder Kumar ◽  
Catalin Iulian Pruncu
Keyword(s):  
Drug Release ◽  
Bacterial Infections ◽  
Enterobacter Aerogenes ◽  
Sustained Drug Release ◽  
In Vitro Drug Release ◽  
Method Optimization ◽  
Dialysis Method ◽  
Nose And Throat

Ceftizoxime (C13H12N5NaO5S2) is a parenteral, third-generationcephalosporin antibiotic used to treat bacterial infections including ear, nose, and throat infections. In this work, pectin has been used as a nanocarrier for ceftizoxime due to its high biocompatibility and non-toxicity with tunable surface properties. Ceftizoxime-loaded pectin nanocarriers (CPN) were successfully synthesized by the solvent displacement method. Optimization of nanoformulation was done by response surface methodology using Design-Expert software. The optimized formulation examined various in-vitro characterizations such as particle size, morphology, and FTIR studies. TEM results revealed irregular shape nanoparticles within the range of 29–110 nm. The in-vitro drug release using the dialysis method was performed after 24 h where nanoformulation showed sustained drug release. Drug-loaded nanoparticles revealed good antimicrobial activity against Bacillus cereus, Bacillus polymyxa, Enterobacter aerogenes, and Pseudomonas aeruginosa.

scholarly journals Formulation and Invitro characterization of Flurbiprofen loaded Nanosponges

2021 ◽  
Vol 12 (3) ◽  
pp. 1798-1802
Author(s):  
Gangadhara R. ◽  
Satheesh K. P. ◽  
Devanna N. ◽  
Sasikala L. ◽  
Vandavasi Koteswara Rao
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Guar Gum ◽  
Entrapment Efficiency ◽  
Sustained Drug Release ◽  
In Vitro Drug Release ◽  
Topical Gel ◽  
High Entrapment Efficiency

The aim of this analysis is to see how effective a Nanosponge-loaded topical gel is at distributing flurbiprofen through the skin. Flurbiprofen was entrapped in Nanosponge and formulated into a gel for this purpose. Flurbiprofen Nanosponges were developed by solvent evaporation using pluronic F68 and ethyl cellulose. The particle size and entrapment quality were discovered to be in the range of 200-410 nm and 90.94% to 98.68%, respectively. For gel formulation, Nanopsonges with high entrapment efficiency and the smallest particle size (F3) were chosen based on the characterization. Using Guar gum, Carbopol, and HPMC K4M, a total of 6 formulations were produced to determine the sustained drug release and were tested for physiochemical tests, producing positive results. According to the findings of the above in vitro drug release trials, formulations containing carbopol release more drug at the end of 11 hours than other formulations and follow a zero-order with case II transport mechanism.

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