scholarly journals Systematic Studies on Surface Erosion of Photocrosslinked Polyanhydride Tablets and Data Correlation with Release Kinetic Models

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1105 ◽  
Author(s):  
Armin Geraili ◽  
Kibret Mequanint
Keyword(s):  
Drug Delivery ◽  
Mass Loss ◽  
Kinetic Models ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Release Kinetic ◽  
Surface Erosion ◽  
The Media ◽  
Polymer Erosion ◽  
Release Kinetic Models

Photocrosslinkable polyanhydrides that undergo surface erosion are suitable materials for controlled-release drug delivery systems. Investigating the impact of different parameters on their erosion behavior is essential before use in drug delivery systems. Although their synthesis is well-established, parameters that may substantially affect the erosion of thiol-ene polyanhydrides including temperature and pH of the media, the geometry of the polymers, and the media shaking rate (the convective force for the polymer erosion), have not yet been studied. This study explores the effects of different environmental and geometric parameters on mass loss (erosion) profiles of polyanhydrides synthesized by thiol-ene photopolymerization. A comparative study on several release kinetic models fitting is also described for a better understanding of the polymer erosion behavior. The results demonstrated that although the temperature was the only parameter that affected the induction period substantially, the mass-loss rate was influenced by the polymer composition, tablet geometry, temperature, pH, and mass transfer (shaking) rate. With regard to geometrical parameters, polymers with the same surface area to volume ratios showed similar mass loss trends despite their various volumes and surface areas. The mass loss of polyanhydride tablets with more complicated geometries than a simple slab was shown to be non-linear, and the kinetic model study indicated the dominant surface erosion mechanism. The results of this study allow for designing and manufacturing efficient delivery systems with a high-predictable drug release required in precision medicine using surface-erodible polyanhydrides.

scholarly journals Understanding nanoparticle flow with a new in vitro experimental and computational approach using hydrogel channels

2020 ◽  
Vol 11 ◽  
pp. 296-309
Author(s):  
Armel Boutchuen ◽  
Dell Zimmerman ◽  
Abdollah Arabshahi ◽  
John Melnyczuk ◽  
Soubantika Palchoudhury
Keyword(s):  
Drug Delivery ◽  
Mass Loss ◽  
Flow Velocity ◽  
Brownian Dynamics ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Preclinical Stage ◽  
Flow Channels ◽  
Mass Concentrations

Nanoparticles (NPs) are considered as one of the most promising drug delivery vehicles and a next-generation solution for current medical challenges. In this context, variables related to flow of NPs such as the quantity of NPs lost during transport and flow trajectory greatly affect the clinical efficiency of NP drug delivery systems. Currently, there is little knowledge of the physical mechanisms dominating NP flow inside the human body due to the limitations of available experimental tools for mimicking complex physiological environments at the preclinical stage. Here, we report a coupled experimental and computational fluid dynamics (CFD)-based novel in vitro approach to predict the flow velocity and binding of NP drug delivery systems during transport through vasculature. Poly(hydroxyethyl)methacrylate hydrogels were used to form soft cylindrical constructs mimicking vascular sections as flow channels for synthesized iron oxide NPs in these first-of-its-kind transport experiments. Brownian dynamics and material of the flow channels played key roles in NP flow, based on the measurements of NP flow velocity over seven different mass concentrations. A fully developed laminar flow of the NPs under these conditions was simultaneously predicted using CFD. Results from the mass loss of NPs during flow indicated a diffusion-dominated flow at higher particle concentrations but a flow controlled by the surrounding fluid and Brownian dynamics at the lowest NP concentrations. The CFD model predicted a mass loss of 1.341% and 6.253% for the 4.12 g·mL−1 and 2.008 g·mL−1 inlet mass concentrations of the NPs, in close confirmation with the experimental results. This further highlights the reliability of our new in vitro technique in providing mechanistic insights of NP flow for potential preclinical stage applications.

Role of polymer/polymer and polymer/drug specific interactions in drug delivery systems

2019 ◽  
Vol 39 (6) ◽  
pp. 534-544
Author(s):  
Farid Ouazib ◽  
Naima Bouslah Mokhnachi ◽  
Nabila Haddadine ◽  
Regis Barille
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Polymer System ◽  
Amorphous State ◽  
Delivery Systems ◽  
Release Mechanism ◽  
Release Kinetic ◽  
X Ray Diffraction ◽  
Scanning Calorimetry

Abstract Drug delivery systems based upon the blending of Arabic gum and poly(N-vinylpyrrolidone) (AG/PVP) were prepared for the controlled release of acebutolol (Acb) hydrochloride. The prepared blends containing Acb were characterized using different techniques. The presence of physical interactions between the drug and polymer matrices was observed with Fourier-transform infrared spectroscopy. These interactions resulted in the transition of the drug from a crystalline to an amorphous state into the polymeric matrices, as demonstrated by differential scanning calorimetry and X-ray diffraction analysis. The thermogravimetric analysis study confirmed the presence of these interactions, which had a stabilizing effect on the drug against both thermal degradation and crystallinity. The in vitro release of Acb from the AG/PVP polymer system was investigated. Each drug-loaded system was used in a tablet formulation. Moreover, an in vitro dissolution study was carried out in three different dissolution media, and comparison of the dissolution profiles of the different dosage forms revealed that the polymer blend matrix had a better release-retarding efficiency. To better understand the release mechanism, the dissolution data were fitted to various release kinetic models.

Aspects of Polymer Erosion

1995 ◽  
Vol 394 ◽  
Author(s):  
Achim Göpferich ◽  
Lisa Shieh ◽  
Robert Langer
Keyword(s):  
Drug Delivery ◽  
Monte Carlo ◽  
Drug Delivery Systems ◽  
Controlled Drug Delivery ◽  
Delivery Systems ◽  
Degradable Polymers ◽  
Polymer Swelling ◽  
Chemical Erosion ◽  
Controlled Systems ◽  
Polymer Erosion

The importance of non-enzymatic chemical erosion for the release of drugs from degradable polymers is discussed. In order to have purely erosion controlled systems, polymer erosion has to be faster than polymer swelling or drug diffusivity inside degradable polymers. Therefore, fast hydrolyzing polymers are especially suited for the manufacture of erosion controlled drug delivery systems. Poly(anhydrides) are one such polymer class and are presented in more detail. It is shown that it is possible to predict drug release from such systems using discrete Monte Carlo Models. Such models are useful for the design of new implant type drug delivery systems.

scholarly journals Nano-Based Biomaterials as Drug Delivery Systems Against Osteoporosis: A Systematic Review of Preclinical and Clinical Evidence

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 530 ◽  
Author(s):  
Francesca Salamanna ◽  
Alessandro Gambardella ◽  
Deyanira Contartese ◽  
Andrea Visani ◽  
Milena Fini
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Controlled Trial ◽  
Drug Loading ◽  
Delivery Systems ◽  
Clinical Translation ◽  
Release Kinetic ◽  
Degenerative Lumbar Diseases ◽  
Post Menopausal ◽  
Almost All

Osteoporosis (OP) is one of the most significant causes of morbidity, particularly in post-menopausal women and older men. Despite its remarkable occurrence, the search for an effective treatment is still an open challenge. Here, we systematically reviewed the preclinical and clinical progress in the development of nano-based materials as drug delivery systems against OP, considering the effects on bone healing and regeneration, the more promising composition and manufacturing methods, and the more hopeful drugs and delivery methods. The results showed that almost all the innovative nano-based delivery systems developed in the last ten years have been assessed by preclinical investigations and are still in the preliminary/early research stages. Our search strategy retrieved only one non-randomized controlled trial (RCT) on oligosaccharide nanomedicine of alginate sodium used for degenerative lumbar diseases in OP patients. Further investigations are mandatory for assessing the clinical translation and commercial purposes of these materials. To date, the main limits for the clinical translation of nano-based materials as drug delivery systems against OP are probably due to the low reproducibility of the manufacturing processes, whose specificity and complexity relies on an adequate chemical, structural, and biomechanical characterization, as the necessary prerequisite before assessing the efficacy of a given treatment or process. Finally, an unsatisfactory drug-loading capacity, an uncontrollable release kinetic, and a low delivery efficiency also limit the clinical application.

Techniques For The Preparation of Tissue Samples Containing Injectable Polymer Microcapsules

1985 ◽  
Vol 43 ◽  
pp. 710-711
Author(s):  
G.E. Visscher ◽  
R. L. Robison ◽  
G. J. Argentieri
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Gastrocnemius Muscle ◽  
Degradation Process ◽  
Delivery Systems ◽  
Tissue Reaction ◽  
Electron Microscopic ◽  
Tissue Samples ◽  
Injectable Polymer ◽  
Microscopic Techniques

The use of various bioerodable polymers as drug delivery systems has gained considerable interest in recent years. Among some of the shapes used as delivery systems are films, rods and microcapsules. The work presented here will deal with the techniques we have utilized for the analysis of the tissue reaction to and actual biodegradation of injectable microcapsules. This work has utilized light microscopic (LM), transmission (TEM) and scanning (SEM) electron microscopic techniques. The design of our studies has utilized methodology that would; 1. best characterize the actual degradation process without artifacts introduced by fixation procedures and 2. allow for reproducible results.In our studies, the gastrocnemius muscle of the rat was chosen as the injection site. Prior to the injection of microcapsules the skin above the sites was shaved and tattooed for later recognition and recovery. 1.0 cc syringes were loaded with the desired quantity of microcapsules and the vehicle (0.5% hydroxypropylmethycellulose) drawn up. The syringes were agitated to suspend the microcapsules in the injection vehicle.

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