Application of a Binary Polymer System in Drug Release Rate Modulation. 1. Characterization of Release Mechanism

1997 ◽  
Vol 86 (3) ◽  
pp. 316-322 ◽  
Author(s):  
Hyunjo Kim ◽  
Reza Fassihi
Pharmaceutics ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 40 ◽  
Author(s):  
Ahmed Khames

Because Eplerenone (EPL) is a Biopharmaceutical Classification System (BCS) class-II drug and is prone to extensive liver degradation, it suffers from poor bioavailability after oral administration. This work aimed to prepare liquisolids loaded with EPL-nanoemulsions (EPL-NEs) that have a higher drug release rate and improved bioavailability by the oral route. Based on solubility studies, mixtures of Triacetin (oil) and Kolliphor EL/PEG 400 surfactant/co-surfactant (Smix) in different ratios were used to prepare EPL-NE systems, which were characterized and optimized for droplet size, zeta potential, polydispersity index (PDI), and drug content. Systems were then loaded onto liquisolid formulations and fully evaluated. A liquisolid formulation with better drug release and tableting properties was selected and compared to EPL-NEs and conventional EPL oral tablets in solid-state characterization studies and bioavailability studies in rabbits. Only five NEs prepared at 1:3, 1:2, and 3:1 Smix met the specified optimization criteria. The drug release rate from liquisolids was significantly increased (90% within 45 minutes). EPL-NE also showed significantly improved drug release but with a sustained pattern for four hours. Liquisolid bioavailability reached 2.1 and 1.2 relative to conventional tablets and EPL-NE. This suggests that the EPL-NE liquisolid is a promising oral delivery system with a higher drug release rate, enhanced absorption, decreased liver degradation, and improved bioavailability.


2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Desta Tesfay ◽  
Solomon Abrha ◽  
Zewdu Yilma ◽  
Gebremariam Woldu ◽  
Fantahun Molla

Ensete ventricosum (Welw.) cheeseman which belongs to the family of Musaceae is one of the main sources of starch in Ethiopia. This study aimed at evaluating epichlorohydrin cross-linked enset starch as a drug release sustaining excipient in microsphere formulations of theophylline. Extracted enset starch was cross-linked using epichlorohydrin as a cross-linking agent. The effect of cross-linker concentration, cross-linking duration, and cross-linking temperature on the degree of cross-linking and release rate of microspheres prepared by emulsion solvent evaporation method was investigated using the two-level full factorial design. Accordingly, the concentration of epichlorohydrin and duration of cross-linking were the most significant factors affecting both the degree of cross-linking and drug release rate. Thus, the effects of these two factors were further studied and optimized using the central composite design. As per the numerical method of central composite design, the optimal points were obtained at epichlorohydrin concentration of 13.70% and cross-linking time of 3.82 h. Under these optimal conditions, the model predicts the degree of cross-linking of 74.70% and drug release rate of 28.00 h1/2. The validity of these optimal points was confirmed experimentally. The microspheres of the optimum formulation also exhibited minimum burst release with sustained release for 12 h. Besides, the optimized formulation followed the Higuchi square root kinetic model with non-Fickian diffusion release mechanism. The finding of this study suggested that cross-linked enset starch can be used as an alternative drug-release-sustaining pharmaceutical excipient in microsphere formulation.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1880
Author(s):  
Lubos Zauska ◽  
Stefan Bova ◽  
Eva Benova ◽  
Jozef Bednarcik ◽  
Matej Balaz ◽  
...  

Mesoporous SBA-15 silica material was prepared by the sol–gel method and functionalized with thermosensitive polyethylenimine polymers with different molecular weight (g·mol−1): 800 (SBA-15(C)-800), 1300 (SBA-15(C)-1300) and 2000 (SBA-15(C)-2000). The nonsteroidal anti-inflammatory drug (NSAID) diclofenac sodium was selected as a model drug and encapsulated into the pores of prepared supports. Materials were characterized by the combination of infrared spectroscopy (IR), atomic force microscopy (AFM), transmission electron microscopy (TEM), photon cross-correlation spectroscopy (PCCS), nitrogen adsorption/desorption analysis, thermogravimetry (TG), differential scanning calorimetry (DSC) and small-angle X-ray diffraction (SA-XRD) experiments. The drug release from prepared matrixes was realized in two model media differing in pH, namely small intestine environment/simulated body fluid (pH = 7.4) and simulated gastric fluid (pH = 2), and at different temperatures, namely normal body temperature (T = 37 °C) and inflammatory temperature (T = 42 °C). The process of drug loading into the pores of prepared materials from the diclofenac sodium salt solutions with different concentrations and subsequent quantitative determination of released drugs was analyzed by UV-VIS spectroscopy. Analysis of prepared SBA-15 materials modified with polyethylenimines in solution showed a high ability to store large amounts of the drug, up to 230 wt.%. Experimental results showed their high drug release into the solution at pH = 7.4 for both temperatures, which is related to the high solubility of diclofenac sodium in a slightly alkaline environment. At pH = 2, a difference in drug release rate was observed between both temperatures. Indeed, at a higher temperature, the release rates and the amount of released drug were 2–3 times higher than those observed at a lower temperature. Different kinetic models were used to fit the obtained drug release data to determine the drug release rate and its release mechanism. Moreover, the drug release properties of prepared compounds were compared to a commercially available medicament under the same experimental conditions.


RSC Advances ◽  
2015 ◽  
Vol 5 (32) ◽  
pp. 25164-25170 ◽  
Author(s):  
Bo Zhang ◽  
Teng Zhang ◽  
Quanxi Wang ◽  
Tianrui Ren

A controlled release system was prepared, it based on UF modified PCC cells in which TEB are loaded into cells. It can control the drug release rate, depress the initial “burst effect”, and was efficacious in controlling wheat powdery mildew.


Biomaterials ◽  
2001 ◽  
Vol 22 (21) ◽  
pp. 2857-2865 ◽  
Author(s):  
Giacomo Fontana ◽  
Mariano Licciardi ◽  
Silvana Mansueto ◽  
Domenico Schillaci ◽  
Gaetano Giammona

INDIAN DRUGS ◽  
2018 ◽  
Vol 55 (11) ◽  
pp. 71-73
Author(s):  
Ch. Taraka Ramarao ◽  
◽  
J Vijaya Ratna ◽  
R. B. Srinivasa

The present investigation involves developing gastro retentive drug delivery systems (GFDDS) of alfuzosin HCl using HPMCK100M a is the matrixing agent and floating enhancer. Sodium bicarbonate in the acidic environment reacts with the acid and produces carbon dioxide. The gastro retentive tablets can be formulated to increase the gastric residence time and thereby increase the oral bioavailability. From the drug release study, it was concluded that the AFTB4 formula of HPMC K 100 M matrix tablets gives the controlled release up to 12 hours by showing increased release with floating lag time 24 seconds. Non – Fickian diffusion was the drug release mechanism from the matrix tablets formulated employing HPMC K 100 M. The matrix tablets (AFTB4) formulated employing 40 % HPMC K 100 M are best suited to be used for gastro retentive dosage form of alfuzosin HCl. Finally, it can be concluded that good candidates for the preparation of gastro retentive dosage forms due its gastric stability, gastric absorption and better bioavailability.


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