scholarly journals pH-Sensitive Starch-Based Hydrogels: Synthesis and Effect of Molecular Components on Drug Release Behavior

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1974
Author(s):  
Juan Carlos Quintanilla de Stéfano ◽  
Vanessa Abundis-Correa ◽  
Sergio Daniel Herrera-Flores ◽  
Alejandro J. Alvarez
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Release Rate ◽  
Crosslinking Agent ◽  
Ph Sensitive ◽  
Fickian Diffusion ◽  
Butyl Methacrylate ◽  
Release Behavior ◽  
Drug Release Behavior ◽  
Swelling Capacity

The drug release behavior of pH-sensitive starch-based hydrogels was systematically studied. Hydrogels were synthesized by copolymerization of acrylic acid (AA) and other acrylate comonomers onto the starch backbone. The hydrophilic agents 2-hydroxy ethyl methacrylate (HEMA), and acrylamide (AAm), as well as the hydrophobic butyl-methacrylate (BMA), were utilized as comonomers. Methylene-bisacrylamide (MBA) was employed as a crosslinking agent. The synthesized hydrogels were loaded with caffeine as a model drug. The effects of the hydrophobic/hydrophilic character of the comonomers and chemical crosslinking on the swelling capacity and the release rate of caffeine were investigated. The use of the crosslinking agent and hydrophobic monomers decreased the swelling capacity of the hydrogels. The release rate of caffeine increased with the presence of a hydrophobic monomer. The fastest release was obtained with the AA/BMA/AAm formulation, and the slowest release was observed with the AA/HEMA/AAm formulation. The transport mechanism was controlled by Fickian diffusion in formulations containing AAm, and controlled by the polymer-relaxation mechanism in formulations containing MBA. Overall, our results showed that the swelling and drug delivery behavior can be tuned by varying the chemical composition of the copolymer formulations. These starch-based hydrogels can be useful as drug delivery devices in many biomedical applications.

STUDY OF THE DIFFERENT RELEASE CHARACTERISTICS OF ANTIBIOTICS FROM PATIENTS: A DYNAMIC ELUTING SYSTEM TO INVESTIGATE DRUG RELEASE FROM ANTIBIOTIC-IMPREGNATED CALCIUM SULFATE DELIVERY

2015 ◽  
Vol 15 (01) ◽  
pp. 1550012
Author(s):  
YANG ZHANG ◽  
RENJIE WU ◽  
YING HU ◽  
YU DONG ◽  
LIFENG SHEN ◽  
...  
Keyword(s):  
Drug Release ◽  
Delivery System ◽  
Release Rate ◽  
Calcium Sulfate ◽  
Fickian Diffusion ◽  
Release Behavior ◽  
Cumulative Release ◽  
In Vivo Release

Background: Antibiotic-impregnated calcium sulfate delivery systems (ACDS) are commonly used to treat chronic osteomyelitis. Our research is to investigate drug release in vitro over a longer period, as a cautious predictor of in vivo release. Methods: The local release behavior of antibiotic in vitro was simulated. The consecutive dynamic eluting experiment was performed based on the pro-operative characteristic of osteomyelitis patients and the determined results of drug concentration in the human drainage tissue fluid (DTF). The concentration of each drug in the receiving solution was detected by ultra-performance liquid chromatography-tandem quadrupole detector mass spectrometry. The ACDS was reviewed by scanning electronic microscopy (SEM) after 48 h, and prepared to be eluted for another examination after 33 days. The mechanism of antibiotic release was analyzed by using the Ritger–Peppas and Weibull equations. Results: The cumulative release rate of vancomycin in a vancomycin-calcium sulfate delivery system (VCDS) was 77.50 % (3.0 mm diameter) and 72.43 % (4.8 mm diameter), while that of the tobramycin in a tobramycin-calcium sulfate delivery system (TCDS) was 88.0 % (3.0 mm diameter) and 84.55 % (4.8 mm diameter). At the 15th day, approximately 27.92% of vancomycin was and 29.35% of tobramycin was released from the local implant in vivo. Using SEM, numerous vancomycin and tobramycin particles were found to be attached to the columnar calcium sulfate crystals at the start of the experiment. The release behavior of the two antibiotics followed a combination of Fickian diffusion and Case II transport mechanisms within the first 48 h, and a Fickian diffusion mechanism during the subsequent time period. The correlation coefficient of tobramycin and vancomycin in vivo and in vitro was 0.9704–0.9949 and 0.9549–0.9782, respectively. Conclusion: A good correlation of the in vivo and in vitro cumulative release rates was observed by comparing the cumulative release rate of drugs in vitro by means of the dynamic eluting model, and in the DTF. Therefore, our study has proved that it is possible to use the dynamic eluting model as a cautious predictor of in vivo release.

scholarly journals ENZYMATICALLY SYNTHESIZED pH-RESPONSIVE IPN FOR IN-SITU RELEASE OF PANTOPRAZOLE SODIUM

2019 ◽  
pp. 98-103
Author(s):  
Saruchi Sharma ◽  
VANEET KUMAR
Keyword(s):  
Drug Release ◽  
Polymer Network ◽  
Lateral Diffusion ◽  
Ph Sensitive ◽  
Interpenetrating Polymer Network ◽  
Release Behavior ◽  
Ph Responsive ◽  
Gum Tragacanth ◽  
Swelling Capacity

Objective: This study involves the synthesis of Gum tragacanth (gt) based interpenetrating polymer network (ipn) and its utilization for sustained release of anti-ulcerative drug i.e. pantoprazole sodium. Methods: IPN was synthesized from Gum tragacanth, polyacrylic acid (gt-cl-paa) hydrogel. gt-cl-paa was kept in distilled water. Further, acryamide (aam) and methylmethacrylate (mma) was added and then kept for overnight. Later on, lipase and glutaraldehyde were added. Homopolymers and the unreacted monomers were removed using acetone. Synthesized IPN was dried at 50 °C for further study. Synthesized ipn was swelled in water and the drug was added to it. The drug was entrapped in the pores of the synthesized ipn and then drug release behavior was studied using uv-vis spectrophotometer. Results: Gt, paa and mma based crosslinked IPN were synthesized using lipase-glutaraldehyde as initiator-crosslinker system. The synthesized IPN was pH sensitive and possessed the desired swelling capacity required for the controlled and systematic liberation of pantoprazole sodium at 37 °C. The kinetic of drug release was studied and found that lateral diffusion (DL) of drug was higher as compared to the initial diffusion (DI). The prepared IPN can be used as prospective carrier for prolonged drug delivery. Conclusion: A novel pH sensitive and colon targeted IPN was synthesized. It acts as an effective device for the controlled release of drug pantoprazole sodium.

Supramolecular, prodrug-based micelles with enzyme-regulated release behavior for controlled drug delivery

MedChemComm ◽  
2015 ◽  
Vol 6 (10) ◽  
pp. 1874-1881 ◽  
Author(s):  
Yongyong Li ◽  
Yuqin Chen ◽  
Haiqing Dong ◽  
Chunyan Dong
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Controlled Drug Delivery ◽  
Release Behavior ◽  
Drug Release Behavior

Supramolecular, prodrug-based micelles (SMPMs) with enzyme-induced drug release behavior were engineeredviahost–guest interaction of camptothecin carrying PCL and α-cyclodextrin.

pH-Sensitive graphene oxide conjugate purpurin-18 methyl ester photosensitizer nanocomplex in photodynamic therapy

2018 ◽  
Vol 42 (16) ◽  
pp. 13272-13284 ◽  
Author(s):  
Ying Zhang ◽  
Hongyue Zhang ◽  
Zhiqiang Wang ◽  
Yingxue Jin
Keyword(s):  
Graphene Oxide ◽  
Photodynamic Therapy ◽  
Methyl Ester ◽  
Drug Release ◽  
Ph Sensitive ◽  
Release Behavior ◽  
Drug Release Behavior

A GO–Pu18 composite showed excellent photodynamic bioactivity and pH-sensitive drug release behavior.

Preparation of Eudragit® L Beads for Intragastric Floating Drug Delivery

2014 ◽  
Vol 1060 ◽  
pp. 79-82 ◽  
Author(s):  
Tassanee Nernplod ◽  
Prasert Akkaramongkolporn ◽  
Pornsak Sriamornsak
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Gastric Fluid ◽  
Cetyl Alcohol ◽  
Simulated Gastric Fluid ◽  
Release Behavior ◽  
Slight Effect ◽  
Drug Release Behavior ◽  
Floating Drug Delivery ◽  
Enteric Polymer

The aim of this study was to prepare matrix beads made of enteric polymer, Eudragit® L, metronidazole and various amounts of cetyl alcohol (0, 0.1 and 1%). Eudragit® L, metronidazole and cetyl alcohol were dissolved in acetone and then extruded into dichloromethane. The influence of amount of cetyl alcohol on floating and drug release behavior of matrix beads of Eudragit® L was investigated. The results showed that, after extruding, cetyl alcohol dissolved out from the beads already formed, resulting in a porous structure. Thus, the beads can float in simulated gastric fluid for more than 8 hours. Different amounts of cetyl alcohol had a slight effect on the drug release. However, the increased amount of cetyl alcohol in the formulations significantly sustained the drug release while the beads remained floating. The results suggest that Eudragit® L beads could be used as a carrier for intragastric floating drug delivery.

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