scholarly journals Tunable delayed controlled release profile from layered polymeric microparticles

2017 ◽  
Vol 5 (23) ◽  
pp. 4487-4498 ◽  
Author(s):  
D. Dutta ◽  
C. Fauer ◽  
K. Hickey ◽  
M. Salifu ◽  
S. E. Stabenfeldt
Keyword(s):  
Controlled Release ◽  
Solvent Evaporation ◽  
Release Profile ◽  
Protein Release ◽  
Protein Distribution ◽  
Ethanol Content ◽  
Polymeric Microparticles ◽  
Release Profiles

Solvent evaporation parameters and ethanol content during PLGA/PLLA microparticle (MP) fabrication affect protein distribution and MP structure, thereby altering the protein release profiles.

scholarly journals Targeted protein delivery: carbodiimide crosslinking influences protein release from microparticles incorporated within collagen scaffolds

2019 ◽  
Vol 6 (5) ◽  
pp. 279-287 ◽  
Author(s):  
Constantin Edi Tanase ◽  
Omar Qutachi ◽  
Lisa J White ◽  
Kevin M Shakesheff ◽  
Andrew W McCaskie ◽  
...  
Keyword(s):  
Protein Delivery ◽  
Three Dimensional ◽  
Fluorescein Isothiocyanate ◽  
Release Profile ◽  
Protein Release ◽  
Crosslinking Reaction ◽  
Protein Distribution ◽  
Collagen Scaffolds ◽  
Covalent Crosslinking ◽  
Model Protein

Abstract Tissue engineering response may be tailored via controlled, sustained release of active agents from protein-loaded degradable microparticles incorporated directly within three-dimensional (3D) ice-templated collagen scaffolds. However, the effects of covalent crosslinking during scaffold preparation on the availability and release of protein from the incorporated microparticles have not been explored. Here, we load 3D ice-templated collagen scaffolds with controlled additions of poly-(DL-lactide-co-glycolide) microparticles. We probe the effects of subsequent N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride crosslinking on protein release, using microparticles with different internal protein distributions. Fluorescein isothiocyanate labelled bovine serum albumin is used as a model protein drug. The scaffolds display a homogeneous microparticle distribution, and a reduction in pore size and percolation diameter with increased microparticle addition, although these values did not fall below those reported as necessary for cell invasion. The protein distribution within the microparticles, near the surface or more deeply located within the microparticles, was important in determining the release profile and effect of crosslinking, as the surface was affected by the carbodiimide crosslinking reaction applied to the scaffold. Crosslinking of microparticles with a high proportion of protein at the surface caused both a reduction and delay in protein release. Protein located within the bulk of the microparticles, was protected from the crosslinking reaction and no delay in the overall release profile was seen.

Optimization Study to Develop Once-a-day Controlled Release Formulation of Metoclopramide with Predictable Design Space

1970 ◽  
Vol 1 (1) ◽  
pp. 71-76
Author(s):  
Rajesh Dubey ◽  
Udaya K. Chowdary ◽  
Venkateswarlu V.
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Design Space ◽  
Release Kinetics ◽  
Release Profile ◽  
Release Formulation ◽  
Linear Effect ◽  
Controlled Release Formulation ◽  
The Difference ◽  
Face Centered

A controlled release formulation of metoclopramide was developed using a combination of hypromellose (HPMC) and hydrogenated castor oil (HCO). Developed formulations released the drug over 20 hr with release kinetics following Higuchi model. Compared to HCO, HPMC showed significantly higher influence in controlling the drug release at initial as well as later phase. The difference in the influence can be explained by the different swelling and erosion behaviour of the polymers. Effect of the polymers on release was optimized using a face-centered central composite design to generate a predictable design space. Statistical analysis of the drug release at various levels indicated a linear effect of the polymers’ levels on the drug release. The release profile of formulations containing the polymer levels at extremes of their ranges in design space was found to be similar to the predicted release profile

scholarly journals Electrospun Janus Beads-On-A-String Structures for Different Types of Controlled Release Profiles of Double Drugs

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 635
Author(s):  
Ding Li ◽  
Menglong Wang ◽  
Wen-Liang Song ◽  
Deng-Guang Yu ◽  
Sim Wan Annie Bligh
Keyword(s):  
Controlled Release ◽  
Combined Therapy ◽  
Diffusion Mechanism ◽  
Amorphous State ◽  
Electrospinning Process ◽  
Fickian Diffusion ◽  
In Vitro Dissolution ◽  
Sem Images ◽  
Release Profiles

A side-by-side electrospinning process characterized by a home-made eccentric spinneret was established to produce the Janus beads-on-a-string products. In this study, ketoprofen (KET) and methylene blue (MB) were used as model drugs, which loaded in Janus beads-on-a-string products, in which polyvinylpyrrolidone K90 (PVP K90) and ethyl cellulose (EC) were exploited as the polymer matrices. From SEM images, distinct nanofibers and microparticles in the Janus beads-on-a-string structures could be observed clearly. X-ray diffraction demonstrated that all crystalline drugs loaded in Janus beads-on-a-string products were transferred into the amorphous state. ATR-FTIR revealed that the components of prepared Janus nanostructures were compatibility. In vitro dissolution tests showed that Janus beads-on-a-string products could provide typical double drugs controlled-release profiles, which provided a faster immediate release of MB and a slower sustained release of KET than the electrospun Janus nanofibers. Drug releases from the Janus beads-on-a-string products were controlled through a combination of erosion mechanism (linear MB-PVP sides) and a typical Fickian diffusion mechanism (bead KET-EC sides). This work developed a brand-new approach for the preparation of the Janus beads-on-a-string nanostructures using side-by-side electrospinning, and also provided a fresh idea for double drugs controlled release and the potential combined therapy.

scholarly journals How Poloxamer Addition in Hyaluronic-Acid-Decorated Biodegradable Microparticles Affects Polymer Degradation and Protein Release Kinetics

2021 ◽  
Vol 11 (16) ◽  
pp. 7567
Author(s):  
Teresa Silvestri ◽  
Barbara Immirzi ◽  
Giovanni Dal Poggetto ◽  
Paola Di Donato ◽  
Valentina Mollo ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Degradation Rate ◽  
Degradation Kinetics ◽  
Dynamic Balance ◽  
Release Kinetics ◽  
Slight Modification ◽  
Gel Permeation Chromatography ◽  
Protein Release ◽  
Polymeric Microparticles ◽  
Biodegradable Microparticles

Polymeric microparticles (MPs) designed for the intravitreal administration of therapeutic proteins result in a prolonged half-life in the vitreous and can delay or discourage the onset of adverse effects inevitably related to this route of administration. Hence, here we designed MPs composed of a polymeric blend based on poly(lactic-co-glycolic) acid and poloxamers, externally decorated with hyaluronic acid. The MPs are intended for intravitreal administration of bovine serum albumin. In detail, a systematic formulative study aiming to shed light on the complex relationship between protein release rate and MP degradation rate was carried out by means of calorimetric and gel permeation chromatography analyses. We found out that poloxamer addition caused a compact MP matrix, which led to a slight modification of the degradation kinetics and a reduction in the initial BSA initial release, which is of the utmost importance to ensure a relatively regular BSA release. It must also be underlined that for acid-labile molecules such as proteins, the poloxamer’s presence induced complex and hardly predictable effects on MP degradation/protein release, due to the dynamic balance between the time-evolving hydrophilicity of MPs and the influence of poloxamers themselves on the PLGA degradation rate.

scholarly journals Evaluating the Flow and Release Profiles of Ibuprofen Formulations by Increasing the Binder Concentration

2021 ◽  
Vol 16 (2) ◽  
pp. 111-117
Author(s):  
B.B. Mohammed ◽  
E.J. John ◽  
G.T. Abdulsalam ◽  
K.P. Bahago
Keyword(s):  
Release Rate ◽  
Active Drug ◽  
Release Profile ◽  
Wet Granulation ◽  
Flow Properties ◽  
Disintegration Time ◽  
Weight Variation ◽  
Tablet Dissolution ◽  
Tablet Formulations ◽  
Release Profiles

Background: Tablets must be able to release the active drug in the gastrointestinal tract for absorption. The release profile of solid pharmaceutical dosage formulations can be quantified by assessing the disintegration and dissolution times tests. Binders are adhesives either from sugar or polymeric material that are added to tablet formulations to provide the cohesiveness required for the bonding together of the granules under compaction to form tablets.Objective: The objective of the study was to formulate and assess ibuprofen tablets using different concentrations of binders (Acacia and Gelatin).Methods: The granules were prepared using wet granulation method and analysed for flow properties based on USP/NF protocols. After granule compression, the tablets release profiles were thereafter assessed via the tablet dissolution and disintegration tests.Results: Weight variation, thickness and diameter were within the acceptable values for all batches indicative of a uniform flow. Batches with binder concentrations of 10 % and 20 % failed disintegration test due to a disintegration time above 15 min while the release rate for batches 1 and 4 was about 88 % in 60 min as against the other batches whose release rate was less than 50 % in 60 min as a result of increasing their binder concentrations.Conclusion: The study concluded that increasing the concentration of acacia and gelatin above 5% led to a decrease in percentage of drug released and an increase in disintegration time above 30 mins because 5% batches gave the best release profiles.

scholarly journals Effect of Physicochemical Properties in Water on Release Profile of Metominostrobin from Time-Controlled Release Granule

2001 ◽  
Vol 26 (3) ◽  
pp. 244-247 ◽  
Author(s):  
Shigeru TASHIMA ◽  
Shinji SHIMADA ◽  
Kohei MATSUMOTO ◽  
Reiji TAKEDA ◽  
Tomonori SHIRAISHI
Keyword(s):  
Controlled Release ◽  
Physicochemical Properties ◽  
Release Profile

scholarly journals PREPARATION, CHARACTERISATION AND EVALUATION OF ROPINIROLE HYDROCHLORIDE LOADED CONTROLLED RELEASE MICROSPHERES USING SOLVENT EVAPORATION TECHNIQUE

2018 ◽  
Vol 10 (6) ◽  
pp. 57
Author(s):  
Koyel Kar ◽  
R. N. Pal ◽  
N. N. Bala
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Release Kinetics ◽  
Drug Loading ◽  
Solvent Evaporation ◽  
In Vitro Drug Release ◽  
Aqueous Solvent ◽  
Evaporation Technique ◽  
Ropinirole Hydrochloride

Objective: The major objective of the research work was to design, characterise and evaluate controlled release microspheres of ropinirole hydrochloride by using non-aqueous solvent evaporation technique to facilitate the delivery of the drug at a predetermined rate for a specific period of time.Methods: Ropinirole hydrochloride microspheres were prepared by using different low-density polymers such as eudragit RL 100, eudragit RS 100 and ethylcellulose either alone or in combination with the help of non-aqueous solvent evaporation technique. All the formulated microparticles were subjected to various evaluation parameters such as particle size analysis, micrometric properties, drug entrapment efficiency, percentage drug loading, percentage yield and in vitro drug release study. The compatibility of the drug and polymers was confirmed by physical compatibility study, fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and x-ray diffraction study (XRD). The formation of the most optimized batch of the microsphere (F12) was confirmed by scanning electron microscopy (SEM), DSC, FTIR, and XRD. In vitro drug release study and in vitro drug release kinetics study of the formulated microspheres were also carried out.Results: Drug-polymer compatibility studies performed with the help of FTIR and DSC indicated that there were no interactions. Results revealed that non-aqueous solvent evaporation technique was a suitable technique for the preparation of microspheres as most of the formulations were discrete, free-flowing and spherical in shape with a good yield of 55.67% to 80.09%, percentage drug loading of 35.52% to 94.50% and percentage drug entrapment efficiency of 36.24% to 95.07%. Different drug-polymer ratios, as well as the combination of polymers, played a significant role in the variation of over-all characteristics of formulations. Based on the data of various evaluation parameters such as particle size analysis, percentage drug loading, percentage drug entrapment, percentage yield, rheological studies and in vitro drug release characteristics, formulation F12 was found to fulfil the criteria of ideal controlled release drug delivery system. F12 showed controlled release till the 14th hour (97.99%) and its in vitro release kinetics was best explained by zero-order kinetics and followed Korsemeyer-Pappas model (Non-Fickian mechanism). SEM of F12 revealed the formation of spherical structures. The FTIR study of F12 confirmed the stable nature of ropinirole in the drug-loaded microspheres. DSC and XRD patterns showed that ropinirole hydrochloride was dispersed at the molecular level in the polymer matrix.Conclusion: The controlled release microparticles were successfully prepared and from this study, it was concluded that the developed microspheres of ropinirole hydrochloride can be used for controlled drug release to improve the bioavailability and patient compliance and to maintain a constant drug level in the blood target tissue by releasing the drug in zero order pattern.

scholarly journals Optimising Hydrogel Release Profiles for Viro-Immunotherapy Using Oncolytic Adenovirus Expressing IL-12 and GM-CSF with Immature Dendritic Cells

2020 ◽  
Vol 10 (8) ◽  
pp. 2872 ◽  
Author(s):  
Adrianne L. Jenner ◽  
Federico Frascoli ◽  
Chae-Ok Yun ◽  
Peter S. Kim
Keyword(s):  
Dendritic Cells ◽  
Sustained Release ◽  
Immune Cells ◽  
Fundamental Problem ◽  
Release Kinetics ◽  
Delivery Systems ◽  
Release Profile ◽  
Oncolytic Viruses ◽  
Immature Dendritic Cells ◽  
Release Profiles

Sustained-release delivery systems, such as hydrogels, significantly improve cancer therapies by extending the treatment efficacy and avoiding excess wash-out. Combined virotherapy and immunotherapy (viro-immunotherapy) is naturally improved by these sustained-release systems, as it relies on the continual stimulation of the antitumour immune response. In this article, we consider a previously developed viro-immunotherapy treatment where oncolytic viruses that are genetically engineered to infect and lyse cancer cells are loaded onto hydrogels with immature dendritic cells (DCs). The time-dependent release of virus and immune cells results in a prolonged cancer cell killing from both the virus and activated immune cells. Although effective, a major challenge is optimising the release profile of the virus and immature DCs from the gel so as to obtain a minimum tumour size. Using a system of ordinary differential equations calibrated to experimental results, we undertake a novel numerical investigation of different gel-release profiles to determine the optimal release profile for this viro-immunotherapy. Using a data-calibrated mathematical model, we show that if the virus is released rapidly within the first few days and the DCs are released for two weeks, the tumour burden can be significantly decreased. We then find the true optimal gel-release kinetics using a genetic algorithm and suggest that complex profiles present unnecessary risk and that a simple linear-release model is optimal. In this work, insight is provided into a fundamental problem in the growing field of sustained-delivery systems using mathematical modelling and analysis.

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