scholarly journals Pharmacokinetics of Pullulan–Dexamethasone Conjugates in Retinal Drug Delivery

Pharmaceutics ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 12
Author(s):  
Eva Kicková ◽  
Amir Sadeghi ◽  
Jooseppi Puranen ◽  
Shirin Tavakoli ◽  
Merve Sen ◽  
...  

The treatment of retinal diseases by intravitreal injections requires frequent administration unless drug delivery systems with long retention and controlled release are used. In this work, we focused on pullulan (≈67 kDa) conjugates of dexamethasone as therapeutic systems for intravitreal administration. The pullulan–dexamethasone conjugates self-assemble into negatively charged nanoparticles (average size 326 ± 29 nm). Intravitreal injections of pullulan and pullulan–dexamethasone were safe in mouse, rat and rabbit eyes. Fluorescently labeled pullulan particles showed prolonged retention in the vitreous and they were almost completely eliminated via aqueous humor outflow. Pullulan conjugates also distributed to the retina via Müller glial cells when tested in ex vivo retina explants and in vivo. Pharmacokinetic simulations showed that pullulan–dexamethasone conjugates may release free and active dexamethasone in the vitreous humor for over 16 days, even though a large fraction of dexamethasone may be eliminated from the eye as bound pullulan–dexamethasone. We conclude that pullulan based drug conjugates are promising intravitreal drug delivery systems as they may reduce injection frequency and deliver drugs into the retinal cells.

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1285
Author(s):  
Louise Van Gheluwe ◽  
Igor Chourpa ◽  
Coline Gaigne ◽  
Emilie Munnier

Progress in recent years in the field of stimuli-responsive polymers, whose properties change depending on the intensity of a signal, permitted an increase in smart drug delivery systems (SDDS). SDDS have attracted the attention of the scientific community because they can help meet two current challenges of the pharmaceutical industry: targeted drug delivery and personalized medicine. Controlled release of the active ingredient can be achieved through various stimuli, among which are temperature, pH, redox potential or even enzymes. SDDS, hitherto explored mainly in oncology, are now developed in the fields of dermatology and cosmetics. They are mostly hydrogels or nanosystems, and the most-used stimuli are pH and temperature. This review offers an overview of polymer-based SDDS developed to trigger the release of active ingredients intended to treat skin conditions or pathologies. The methods used to attest to stimuli-responsiveness in vitro, ex vivo and in vivo are discussed.


2008 ◽  
Vol 1139 ◽  
Author(s):  
Jeffrey T. Borenstein

AbstractThe emergence of BioMEMS fabrication technologies such as soft lithography, micromolding and assembly of 3D structures, and biodegradable microfluidics, are already making significant contributions to the field of regenerative medicine. Over the past decade, BioMEMS have evolved from early silicon laboratory devices to polymer-based structures and even biodegradable constructs suitable for a range of ex vivo and in vivo applications. These systems are still in the early stages of development, but the long-term potential of the technology promises to enable breakthroughs in health care challenges ranging from the systemic toxicity of drugs to the organ shortage. Ex vivo systems for organ assist applications are emerging for the liver, kidney and lung, and the precision and scalability of BioMEMS fabrication techniques offer the promise of dramatic improvements in device performance and patient outcomes.Ultimately, the greatest benefit from BioMEMS technologies will be realized in applications for implantable devices and systems. Principal advantages include the extreme levels of achievable miniaturization, integration of multiple functions such as delivery, sensing and closed loop control, and the ability of precision microscale and nanoscale features to reproduce the cellular microenvironment to sustain long-term functionality of engineered tissues. Drug delivery systems based on BioMEMS technologies are enabling local, programmable control over drug concentrations and pharmacokinetics for a broad spectrum of conditions and target organs. BioMEMS fabrication methods are also being applied to the development of engineered tissues for applications such as wound healing, microvascular networks and bioartificial organs. Here we review recent progress in BioMEMS-based drug delivery systems, engineered tissue constructs and organ assist devices for a range of ex vivo and in vivo applications in regenerative medicine.


2020 ◽  
Vol 21 (6) ◽  
Author(s):  
Christina Karavasili ◽  
Ioannis I. Andreadis ◽  
Maria P. Tsantarliotou ◽  
Ioannis A. Taitzoglou ◽  
Paschalina Chatzopoulou ◽  
...  

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 440 ◽  
Author(s):  
Patrick M. Glassman ◽  
Carlos H. Villa ◽  
Anvay Ukidve ◽  
Zongmin Zhao ◽  
Paige Smith ◽  
...  

Red blood cells (RBC) have great potential as drug delivery systems, capable of producing unprecedented changes in pharmacokinetics, pharmacodynamics, and immunogenicity. Despite this great potential and nearly 50 years of research, it is only recently that RBC-mediated drug delivery has begun to move out of the academic lab and into industrial drug development. RBC loading with drugs can be performed in several ways—either via encapsulation within the RBC or surface coupling, and either ex vivo or in vivo—depending on the intended application. In this review, we briefly summarize currently used technologies for RBC loading/coupling with an eye on how pharmacokinetics is impacted. Additionally, we provide a detailed description of key ADME (absorption, distribution, metabolism, elimination) changes that would be expected for RBC-associated drugs and address unique features of RBC pharmacokinetics. As thorough understanding of pharmacokinetics is critical in successful translation to the clinic, we expect that this review will provide a jumping off point for further investigations into this area.


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Ndidi C. Ngwuluka ◽  
Yahya E. Choonara ◽  
Girish Modi ◽  
Lisa C. du Toit ◽  
Pradeep Kumar ◽  
...  

One approach for delivery of narrow absorption window drugs is to formulate gastroretentive drug delivery systems. This study was undertaken to provide insight into in vivo performances of two gastroretentive systems (PXLNETand IPB matrices) in comparison to Madopar® HBS capsules. The pig model was used to assess gastric residence time and pharmacokinetic parameters using blood, cerebrospinal fluid (CSF), and urine samples. Histopathology and cytotoxicity testing were also undertaken. The pharmacokinetic parameters indicated that levodopa was liberated from the drug delivery systems, absorbed, widely distributed, metabolized, and excreted.Cmaxwere 372.37, 257.02, and 461.28 ng/mL and MRT were 15.36, 14.98, and 13.30 for Madopar HBS capsules,PXLNET, and IPB, respectively. In addition, X-ray imaging indicated that the gastroretentive systems have the potential to reside in the stomach for 7 hours. There was strong in vitro-in vivo correlation for all formulations withr2values of 0.906, 0.935, and 0.945 for Madopar HBS capsules,PXLNET, and IPB, respectively. Consequently,PXLNETand IPB matrices have pertinent potential as gastroretentive systems for narrow absorption window drugs (e.g., L-dopa) and, in this application specifically, enhanced the central nervous system and/or systemic bioavailability of such drugs.


Author(s):  
Anamika Saxena Saxena ◽  
Santosh Kitawat ◽  
Kalpesh Gaur ◽  
Virendra Singh

The main goal of any drug delivery system is to achieve desired concentration of the drug in blood or tissue, which is therapeutically effective and nontoxic for a prolonged period. Various attempts have been made to develop gastroretentive delivery systems such as high density system, swelling, floating system. The recent developments of FDDS including the physiological and formulation variables affecting gastric retention, approaches to design single-unit and multiple-unit floating systems, and their classification and formulation aspects are covered in detail. Gastric emptying is a complex process and makes in vivo performance of the drug delivery systems uncertain. In order to avoid this variability, efforts have been made to increase the retention time of the drug-delivery systems for more than 12 hours. The floating or hydrodynamically controlled drug delivery systems are useful in such application. Background of the research: Diltiazem HCL (DTZ), has short biological half life of 3-4 h, requires rather high frequency of administration. Due to repeated administration there may be chances of patient incompliance and toxicity problems. Objective: The objective of study was to develop sustained release alginate beads of DTZ for reduction in dosing frequency, high bioavailability and better patient compliance. Methodology: Five formulations prepared by using different drug to polymer ratios, were evaluated for relevant parameters and compared. Alginate beads were prepared by ionotropic external gelation technique using CaCl2 as cross linking agent. Prepared beads were evaluated for % yield, entrapment efficiency, swelling index in 0.1N HCL, drug release study and SEM analysis. In order to improve %EE and drug release, LMP and sunflower oil were used as copolymers along with sodium alginate.


2018 ◽  
Vol 14 (5) ◽  
pp. 432-439 ◽  
Author(s):  
Juliana M. Juarez ◽  
Jorgelina Cussa ◽  
Marcos B. Gomez Costa ◽  
Oscar A. Anunziata

Background: Controlled drug delivery systems can maintain the concentration of drugs in the exact sites of the body within the optimum range and below the toxicity threshold, improving therapeutic efficacy and reducing toxicity. Mesostructured Cellular Foam (MCF) material is a new promising host for drug delivery systems due to high biocompatibility, in vivo biodegradability and low toxicity. Methods: Ketorolac-Tromethamine/MCF composite was synthesized. The material synthesis and loading of ketorolac-tromethamine into MCF pores were successful as shown by XRD, FTIR, TGA, TEM and textural analyses. Results: We obtained promising results for controlled drug release using the novel MCF material. The application of these materials in KETO release is innovative, achieving an initial high release rate and then maintaining a constant rate at high times. This allows keeping drug concentration within the range of therapeutic efficacy, being highly applicable for the treatment of diseases that need a rapid response. The release of KETO/MCF was compared with other containers of KETO (KETO/SBA-15) and commercial tablets. Conclusion: The best model to fit experimental data was Ritger-Peppas equation. Other models used in this work could not properly explain the controlled drug release of this material. The predominant release of KETO from MCF was non-Fickian diffusion.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1108
Author(s):  
Oana Craciunescu ◽  
Madalina Icriverzi ◽  
Paula Ecaterina Florian ◽  
Anca Roseanu ◽  
Mihaela Trif

Osteoarthritis (OA) is a degenerative joint disease. An objective of the nanomedicine and drug delivery systems field is to design suitable pharmaceutical nanocarriers with controllable properties for drug delivery and site-specific targeting, in order to achieve greater efficacy and minimal toxicity, compared to the conventional drugs. The aim of this review is to present recent data on natural bioactive compounds with anti-inflammatory properties and efficacy in the treatment of OA, their formulation in lipid nanostructured carriers, mainly liposomes, as controlled release systems and the possibility to be intra-articularly (IA) administered. The literature regarding glycosaminoglycans, proteins, polyphenols and their ability to modify the cell response and mechanisms of action in different models of inflammation are reviewed. The advantages and limits of using lipid nanoformulations as drug delivery systems in OA treatment and the suitable route of administration are also discussed. Liposomes containing glycosaminoglycans presented good biocompatibility, lack of immune system activation, targeted delivery of bioactive compounds to the site of action, protection and efficiency of the encapsulated material, and prolonged duration of action, being highly recommended as controlled delivery systems in OA therapy through IA administration. Lipid nanoformulations of polyphenols were tested both in vivo and in vitro models that mimic OA conditions after IA or other routes of administration, recommending their clinical application.


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