scholarly journals Evaluation of the Release Mechanism of Sustained-Release Tracers and its Application in Horizontal Well Inflow Profile Monitoring

ACS Omega ◽  
2021 ◽  
Author(s):  
Haitao Li ◽  
Zimin Liu ◽  
Ying Li ◽  
Hongwen Luo ◽  
Xiaojiang Cui ◽  
...  
Keyword(s):  
Sustained Release ◽  
Horizontal Well ◽  
Release Mechanism ◽  
Profile Monitoring ◽  
Inflow Profile

Effects of release modifier on Carvedilol release from Kollidon SR based matrix

2012 ◽  
Vol 1 (8) ◽  
pp. 186 ◽  
Author(s):  
Urmi Das ◽  
Mohammad Salim Hossain
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Microcrystalline Cellulose ◽  
Matrix Tablets ◽  
Dissolution Time ◽  
Release Mechanism ◽  
Matrix Tablet ◽  
Weight Variation ◽  
The Matrix ◽  
Tablet Formulations

<p>Sustained release Carvedilol matrix tablets constituting Kollidon SR were developed in this study in an attempt to investigate the effect of release modifiers on the release profile of Carvedilol from matrix. Three matrix tablet formulations were prepared by direct compression of Kollidon SR in combination with release modifier (HPMC and Microcrystalline Cellulose) and magnesium stearate. Tablets containing only Kollidon SR with the active ingredient demonstrated a rapid rate of drug release. Incorporation of HPMC in the matrix tablet prolonged the release of drug but incorporation of Microcrystalline Cellulose showed superimposable release pattern with an initial burst effect as confirmed by mean dissolution time and Higuchi release rate data. After 7 hours of dissolution, Carvedilol release from the matrix systems were 91.42%, 83.41%, from formulation F1 and F2 respectively. Formulation F3 exhibited 100 % release at 4 hours. All the tablet formulations showed acceptable pharmaco-technical properties and complied with the in-house specifications for tablet weight variation, friability, hardness, thickness, and diameter. Prepared tablets also showed sustained release property for carvedilol. The drug release mechanism from the matrix tablets of F1 and F2 was found to be followed by Fickian and F3 by Non-Fickian mechanism.</p><p>DOI: <a href="http://dx.doi.org/10.3329/icpj.v1i8.11095">http://dx.doi.org/10.3329/icpj.v1i8.11095</a></p> <p>International Current Pharmaceutical Journal 2012, 1(8): 186-192</p>

scholarly journals A Novel Design of Tri-Layer Membrane with Controlled Delivery of Paclitaxel and Anti-Biofilm Effect for Biliary Stent Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 486
Author(s):  
Abdelrahman I. Rezk ◽  
Jeesoo Park ◽  
Joon Yeon Moon ◽  
Sunny Lee ◽  
Chan Hee Park ◽  
...  
Keyword(s):  
Sustained Release ◽  
Antibacterial Effect ◽  
Release Profile ◽  
Biliary Stent ◽  
Fickian Diffusion ◽  
Release Mechanism ◽  
Dual Function ◽  
Electrospinning Technique ◽  
Layer Membrane

Here, we developed a novel biliary stent coating material that is composed of tri-layer membrane with dual function of sustained release of paclitaxel (PTX) anticancer drug and antibacterial effect. The advantages of using electrospinning technique were considered for the even distribution of PTX and controlled release profile from the nanofiber mat. Furthermore, film cast method was utilized to fabricate AgNPs-immobilized PU film to direct the release towards the tumor site and suppress the biofilm formation. The in vitro antibacterial test conducted against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria species showed excellent antibacterial effect. The in vitro drug release study confirmed the sustained release of PTX from the tri-layer membrane and the release profile fitted first order with correlation coefficient of R2 = 0.98. Furthermore, the release mechanism was studied using Korsmeyer–Peppas model, revealing that the release mechanism follows Fickian diffusion. Based on the results, this novel tri-layer membrane shows curative potential in clinical development.

scholarly journals Investigation of the sustained-release mechanism of hydroxypropyl methyl cellulose skeleton type Acipimox tablets

2018 ◽  
Vol 16 (1) ◽  
pp. 333-339
Author(s):  
Wanying Liu ◽  
Qing Huo ◽  
Yue Wang ◽  
Na Yu ◽  
Rongjian Shi
Keyword(s):  
Sustained Release ◽  
Diffusion Mechanism ◽  
Methyl Cellulose ◽  
Magnesium Stearate ◽  
Test Method ◽  
Release Mechanism ◽  
Hydroxypropyl Methyl Cellulose ◽  
Hypolipidemic Agents ◽  
Sustained Release Tablets ◽  
The Difference

AbstractIn this study, we investigate the production of hypolipidemic agents in the form of Acipimox sustained-release tablets, using a wet pelleting process. The purpose of this research is to reduce the total intake time for patients and to lower the initial dose in such that the adverse reactions could be reduced. This study adopts the single-factor method and orthogonal experiments by using hydroxypropyl methyl cellulose (HPMC K15M) as the main sustained-release prescription composition. The final prescription is Acipimox 20%, HPMC K15M 26.67%, sodium carboxymethyl cellulose 30%, polyethylene glycol (PEG 6000) 1%, ethyl cellulose 16.6%, lactose 4.67% and magnesium stearate 1%. The dissolution of tablets reached 85.88% in 8 h. The difference in the weight, hardness and friability of the tables met the requirements in the Chinese Pharmacopoeia; to test the stability, a temperature and illumination accelerated test method was used, the results indicate that the Acipimox sustained-release tablets should be sealed and stored in a dark, cool area. A preliminary study on the tablets’ releasing mechanism showed that their release curve fitted the Higuchi model (the formula is Mt/M∞ = 31.137 t1/2–3.605 (R2 = 0.9903)). The Acipimox tablets’ release principle is dominated by the diffusion mechanism.

scholarly journals Development and evaluation of sustained release losartan potassium matrix tablet using kollidon SR as release retardant

2012 ◽  
Vol 48 (4) ◽  
pp. 621-628 ◽  
Author(s):  
Shahid Sarwar ◽  
Mohammad Salim Hossain
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Release Kinetics ◽  
Polymer Concentration ◽  
In Vitro Release ◽  
Matrix Tablets ◽  
Losartan Potassium ◽  
Dissolution Time ◽  
Release Mechanism ◽  
Matrix Tablet

The present study was undertaken to develop sustained release (SR) matrix tablets of losartan potassium, an angiotensin-II antagonist for the treatment of hypertension. The tablets were prepared by direct compression method, along with Kollidon SR as release retardant polymer. The amount of losartan potassium remains fixed (100 mg) for all the three formulations whereas the amounts of Kollidon SR were 250 mg, 225 mg, and 200 mg for F-1, F-2, and F-3 respectively. The evaluation involves three stages: the micromeritic properties evaluation of granules, physical property studies of tablets, and in-vitro release kinetics studies. The USP apparatus type II was selected to perform the dissolution test, and the dissolution medium was 900 mL phosphate buffer pH 6.8. The test was carried out at 75 rpm, and the temperature was maintained at 37 ºC ± 0.5 ºC. The release kinetics was analyzed using several kinetics models. Higher polymeric content in the matrix decreased the release rate of drug. At lower polymeric level, the rate and extent of drug release were enhanced. All the formulations followed Higuchi release kinetics where the Regression co-efficient (R²) values are 0.958, 0.944, and 0.920 for F-1, F-2, and F-3 respectively, and they exhibited diffusion dominated drug release. Statistically significant (P<0.05) differences were found among the drug release profile from different level of polymeric matrices. The release mechanism changed from non-fickian (n=0.489 for F-1) to fickian (n=0.439 and 0.429 for F-2, and F-3 respectively) as a function of decreasing the polymer concentration. The Mean Dissolution Time (MDT) values were increased with the increase in polymer concentration.

scholarly journals Novel polystyrene sulfonate–silica microspheres as a carrier of a water soluble inorganic salt (KCl) for its sustained release, via a dual-release mechanism

RSC Advances ◽  
2017 ◽  
Vol 7 (1) ◽  
pp. 478-481 ◽  
Author(s):  
Cong Sui ◽  
Jon A. Preece ◽  
Zhibing Zhang
Keyword(s):  
Sustained Release ◽  
Potassium Chloride ◽  
Inorganic Salt ◽  
Water Soluble ◽  
Release Mechanism ◽  
Aqueous Environment ◽  
Polystyrene Sulfonate ◽  
Silica Microspheres ◽  
Dual Release

Polystyrene sulfonate and silica microspheres with potassium chloride encapsulated show a dual-release mechanism of K+ in an aqueous environment.

scholarly journals Electrospun Nanofibers of Polycaprolactone/Collagen as a Sustained-Release Drug Delivery System for Artemisinin

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1228
Author(s):  
Peipei Huo ◽  
Xinxu Han ◽  
Wenyu Zhang ◽  
Jing Zhang ◽  
Parveen Kumar ◽  
...  
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Electrospun Nanofibers ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Release Mechanism ◽  
Sustained Drug Release ◽  
Water Contact ◽  
Release Curve ◽  
Index Value

The application of artemisinin (ART) in the treatment of malaria has been restricted to a certain degree due to its inherent limitations, such as short half-life, poor solubility, limited bioavailability, and re-crystallization. Electrospun nanofibers loaded with ART provide an excellent solution to these limitations and yield sustained drug release as well as inhibition of drug re-crystallization. In this study, ART-loaded polycaprolactone (PCL)/collagen (Col) nanofibers with different proportions of polymers were prepared. ART-loaded PCL/Col nanofibers were characterized, and further ART anti-crystallization and release behaviors were studied. SEM was used to observe the morphology of PCL/Col nanofibers. X-ray diffraction (XRD) was used to characterize the physical state of ART in ART-loaded PCL/Col nanofibers. Fourier transform infrared spectroscopy (FTIR), water contact angle measurement, weight loss, degree of swelling, and drug release experiments can verify the differences in performance of ART-loaded PCL/Col nanofibers due to different polymer ratios. The release curve was analyzed by kinetics, showing sustained release for up to 48 h, and followed the Fickian release mechanism, which was shown by the diffusion index value obtained from the Korsmeyer-Peppas equation.

scholarly journals Formulation and Evaluation of Acyclovir Microspheres

2018 ◽  
Vol 27 (1) ◽  
pp. 1-7
Author(s):  
Pavani S ◽  
Mounika K ◽  
Naresh K
Keyword(s):  
Particle Size ◽  
Sustained Release ◽  
Sodium Alginate ◽  
Calcium Chloride ◽  
Polymer Concentration ◽  
Entrapment Efficiency ◽  
In Vitro Dissolution ◽  
Release Mechanism ◽  
Natural Polymers

The present study is to formulate and evaluate Acyclovir (ACV) microspheres using natural polymers like chitosan and sodium alginate. ACV is a DNA polymerase inhibitor used in treating herpes simplex virus infection and zoster varicella infections. Acyclovir is a suitable candidate for sustained-release (SR) administration as a result of its dosage regimen twice or thrice a day and relatively short plasma half-life (approximately 2 to 4 hours). Microspheres of ACV were prepared by an ionic dilution method using chitosan and sodium alginate as polymers. The prepared ACV microspheres were then subjected to FTIR, SEM, particle size, % yield, entrapment efficiency, in vitro dissolution studies and release kinetics mechanism. The FTIR spectra’s revealed that, there was no interaction between polymer and ACV. ACV microspheres were spherical in nature, which was confirmed by SEM. The particle size of microspheres was in the range of 23.8µm to 39.4µm. 72.9% drug entrapment efficiency was obtained in the formulation F3 (1:3 ratio) with a high concentration of calcium chloride (4% w/v). The in vitro performance of ACV microspheres showed sustained release depending on the polymer concentration and concentration of calcium chloride.   The release data was best fitted with zero order kinetics and Korsemeyer -Peppas release mechanism and diffusion exponent ‘n’ value of was found to be Non-Fickian.

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