A novel accelerated in vitro release method for biodegradable coating of drug eluting stents: Insight to the drug release mechanisms

2009 ◽  
Vol 37 (3-4) ◽  
pp. 217-222 ◽  
Author(s):  
Marika Kamberi ◽  
Sushma Nayak ◽  
Kathy Myo-Min ◽  
Troy P. Carter ◽  
Leonard Hancock ◽  
...  
2015 ◽  
Vol 486 (1-2) ◽  
pp. 339-349 ◽  
Author(s):  
E. Ahnfelt ◽  
E. Sjögren ◽  
N. Axén ◽  
H. Lennernäs

2014 ◽  
Vol 87 (3) ◽  
pp. 570-578 ◽  
Author(s):  
Beatrice Semmling ◽  
Stefan Nagel ◽  
Katrin Sternberg ◽  
Werner Weitschies ◽  
Anne Seidlitz

Author(s):  
Sakthikumar T ◽  
Rajendran N N ◽  
Natarajan R

The present study was aimed to develop an extended release tablet of metoprolol Succinate for the treatment of hypertension.  Four extended release formulations F1-F4 were developed using varying proportions of hydroxylpropyl-methylcellulose K100M, sodium carboxy methyl cellulose and Eudragit L30 D55 by wet granulation. Five extended release formulations F5-F9 containing HPMC K100M and HPMC 5 cps in varying concentration were developed by direct compression. The physicochemical and in vitro release characteristics of all the formulations were investigated and compared. Two formulations, F7 and F8 have shown not more 25% drug release  in 1st h, 20%-40% drug release at 4th hour, 40%-60% drug release at 8th hour and not less than 80% at 20th hour and the release pattern conform with USP specification for 24 hours extended release formulation. It can be conclusively stated that optimum concentration of HPMC K100M (58%-65%) by direct compression method can yield an extended release of metoprolol succinate for 24 hours.


2020 ◽  
pp. 1-9
Author(s):  
Yunhong Wang ◽  
Rong Hu ◽  
Yanlei Guo ◽  
Weihan Qin ◽  
Xiaomei Zhang ◽  
...  

OBJECTIVE: In this study we explore the method to prepare tanshinone self-microemulsifying sustained-release microcapsules using tanshinone self-microemulsion as the core material, and chitosan and alginate as capsule materials. METHODS: The optimal preparation technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules was determined by using the orthogonal design experiment and single-factor analysis. The drug loading and entrapment rate were used as evaluation indexes to assess the quality of the drug, and the in vitro release rate was used to evaluate the drug release performance. RESULTS: The best technology of chitosan-alginate tanshinone self-microemulsifying sustained-release microcapsules is as follows: the concentration of alginate is 1.5%, the ratio of tanshinone self-microemulsion volume to alginate volume to chitosan mass is 1:1:0.5 (ml: ml: g), and the best concentration of calcium chloride is 2.0%. To prepare the microcapsules using this technology, the drug loading will be 0.046%, the entrapment rate will be 80.23%, and the 24-hour in vitro cumulative release rate will be 97.4%. CONCLUSION: The release of the microcapsules conforms to the Higuchi equation and the first-order drug release model and has a good sustained-release performance.


1970 ◽  
Vol 8 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Mohammad Nezab Uddin ◽  
Ishtiaq Ahmed ◽  
Monzurul Amin Roni ◽  
Muhammad Rashedul Islam ◽  
Mohammad Habibur Rahman ◽  
...  

The objective of this study was to design oral sustained release matrix tablets of Ranolazine usinghydroxypropyl methylcellulose (HPMC) as the retardant polymer and to study the effect of formulation factors suchas polymer proportion and polymer viscosity on the release of drug. In vitro release studies were performed usingUSP type II apparatus (paddle method) in 900 mL of 0.1N HCl at 100 rpm for 12 hours. The release kinetics wasanalyzed using the zero-order, first order, Higuchi and Korsmeyer-Peppas equations to explore and explain themechanism of drug release from the matrix tablets. In vitro release studies revealed that the release rate decreasedwith increase in polymer proportion and viscosity grade. Mathematical analysis of the release kinetics indicated thatthe nature of drug release from the matrix tablets was dependent on drug diffusion and polymer relaxation andtherefore followed non-Fickian or anomalous release. The developed controlled release matrix tablets of Ranolazineprepared with high viscosity HPMC extended release up to 12 hours.Key words: Ranolazine; Sustained release; Methocel E50 Premium LV; Methocel K100LV CR; Methocel K4M CR;Methocel K15M CR.DOI: 10.3329/dujps.v8i1.5333Dhaka Univ. J. Pharm. Sci. 8(1): 31-38, 2009 (June)


2015 ◽  
Vol 485 (1-2) ◽  
pp. 202-214 ◽  
Author(s):  
Maja Lusina Kregar ◽  
Marjana Dürrigl ◽  
Andrea Rožman ◽  
Želimir Jelčić ◽  
Biserka Cetina-Čižmek ◽  
...  

Author(s):  
DHARMENDER PALLERLA ◽  
SUMAN BANOTH ◽  
SUNKARI JYOTHI

Objective: The objective of this study was to formulate and evaluate the Curcumin (CUR) encapsulated sodium alginate (SA)/badam gum (BG)/kaolin (KA) microbeads for controlled drug release studies. Methods: The fabricated microbeads were characterized by fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (X-RD), and scanning electron microscopy (SEM). Dynamic swelling studies and in vitro release kinetics were performed in simulated intestinal fluid (pH 7.4) and simulated gastric fluid (pH 1.2) at 37 °C. Results: FTIR confirms the formation of microbeads. DSC studies confirm the polymorphism of CUR in drug loaded microbeads which indicate the molecular level dispersion of the drug in the microbeads. SEM studies confirmed the microbeads are spherical in shape with wrinkled and rough surfaces. XRD studies reveal the molecular dispersion of CUR and the presence of KA in the developed microbeads. In vitro release studies and swelling studies depend on the pH of test media, which might be suitable for intestinal drug delivery. The % of drug release values fit into the Korsmeyer-Peppas equation and n values are obtained in the range of 0.577-0.664, which indicates that the developed microbeads follow the non-Fickian diffusion drug release mechanism. Conclusion: The results concluded that the CUR encapsulated microbeads are potentially good carriers for controlled drug release studies.


2018 ◽  
Vol 8 (5-s) ◽  
pp. 235-239
Author(s):  
NILESH M MAHAJAN ◽  
Kalyanee Wanaskar ◽  
Yogesh Bhutada ◽  
Raju Thenge ◽  
Vaibhav Adhao

The aim of present study is to formulate and evaluate extended release matrix tablet of Nateglinide by direct compression method using different polymer like HPMC K4 and HPMC K15. Matrix tablet of nateglidine were prepared in combination with the polymer HPMC K4, HPMC K15, along with the excipients and the formulations were evaluated for tablet properties and in vitro drug release studies. Nateglinide matrix tablet prepared by using polymer such as HPMC K4 and HPMC K15,  it was found that HPMC K15 having higher viscosity as compare to HPMC K4 therefore different concentration of polymer were studied to extend the drug release up to 12 h. The tablets of Nateglinide prepared by direct compression had acceptable physical characteristics and satisfactory drug release. The study demonstrated that as far as the formulations were concerned, the selected polymers proved to have an acceptable flexibility in terms of in-vitro release profile. In present the study the percent drug release for optimize batch was found to 94.62%.  Hence it can be conclude that Nateglinide extended release matrix tablet can prepared by using HPMC. The swollen tablet also maintains its physical integrity during the drug release study Keywords: Tablet, in-vitro drug release, Nateglinide, HPMC


2021 ◽  
Vol 321 ◽  
pp. 04011
Author(s):  
Navideh Abbasnezhad ◽  
Farid Bakir ◽  
Stéphane Champmartin ◽  
Mohammadali Shirinbayan

Drug-eluting stents implanted in blood vessels are subject to various dynamics of blood flow. In this study, we present the evaluation of a mathematical model considering the effect of flow rate, to simulate the kinetic profiles of drug release (Diclofenac Sodium (DS)) from in-vitro from PLGA films. This model solves a set of non-linear equation for modeling simultaneously the burst, diffusion, swelling and erosion involved in the mechanisms of liberation. The release parameters depending on the flow rate are determined using the corresponding mathematical equations. For the evaluation of the proposed model, test data obtained in our laboratory are used. To quantify DS release from drug-carrier PLGA films, we used the flow-through cell apparatus in a closed-loop. Four flow rate values are applied. For each value, the model-substance liberation kinetics showed an increase in drug released with the flow rate. The simulated release profiles show good agreement with the experimental results. Therefore, the use of this model could provide a practical tool to assess in-vitro drug release profiles from polymer matrices under continuous flow rate constraint, and could help improve the design of drug eluting stents.


Author(s):  
Pearl Pires Dighe ◽  
Tank Hm

 Objective: The current study involves the fabrication of oral bilayer matrix designs of a combination of two drugs, metoprolol succinate and atorvastatin calcium, the optimization of their in vitro release and characterization using the design expert software. Metoprolol succinate, a β1- selective adrenergic receptor blocking agent, is used in the management of hypertension has a half-life of approximately 4–5 h; thus, there is the need to use extended-release formulation for prolonged action. Atorvastatin is a hydroxymethylglutaryl-coenzyme A reductase inhibitor, an antilipidemic, used to lower blood cholesterol. The rationale for this fixed-dose combination is to coadminister two drugs acting by different mechanisms of action together, reduce dosing frequency, and increase patient compliance.Methods: A 32 factorial design was selected to analyze the effect of critical factors, polymer concentration of Kollidon sustained release (SR), and Eudragit RS and their interaction on the in vitro release of the SR part containing metoprolol succinate. The drug release at 2 h (Q2), 8 h (Q8), and 20 h (Q20) was taken as responses. The blends of both layers were prepared, evaluated for precompression characteristics, and compressed by direct compression. The compressed bilayer tablets were evaluated for their hardness, weight variation, friability, content uniformity, diameter, and in vitro release.Result and Conclusion: The release profile indicates Higuchi’s kinetics. Contour and surface response plots show significant interaction among the formulation variables. Formulation MS06 containing 70 mg Kollidon SR and 10 mg Eurdragit RS was found to be the optimized formulation, controlling the drug release for a 24 h period.


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