scholarly journals Critical Assessment of Implantable Drug Delivery Devices in Glaucoma Management

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Dharani Manickavasagam ◽  
Moses O. Oyewumi
Keyword(s):  
Drug Delivery ◽  
Ganglion Cells ◽  
Drug Stability ◽  
Unmet Need ◽  
Delivery Systems ◽  
Therapeutic Interventions ◽  
Future Research ◽  
Drug Bioavailability ◽  
Intraocular Drug Delivery ◽  
Drug Delivery Devices

Glaucoma is a group of heterogeneous disorders involving progressive optic neuropathy that can culminate into visual impairment and irreversible blindness. Effective therapeutic interventions must address underlying vulnerability of retinal ganglion cells (RGCs) to degeneration in conjunction with correcting other associated risk factors (such as elevated intraocular pressure). However, realization of therapeutic outcomes is heavily dependent on suitable delivery system that can overcome myriads of anatomical and physiological barriers to intraocular drug delivery. Development of clinically viable sustained release systems in glaucoma is a widely recognized unmet need. In this regard, implantable delivery systems may relieve the burden of chronic drug administration while potentially ensuring high intraocular drug bioavailability. Presently there are no FDA-approved implantable drug delivery devices for glaucoma even though there are several ongoing clinical studies. The paper critically assessed the prospects of polymeric implantable delivery systems in glaucoma while identifying factors that can dictate (a) patient tolerability and acceptance, (b) drug stability and drug release profiles, (c) therapeutic efficacy, and (d) toxicity and biocompatibility. The information gathered could be useful in future research and development efforts on implantable delivery systems in glaucoma.

scholarly journals Towards feedback-controlled nanomedicines for smart, adaptive delivery

2018 ◽  
Vol 244 (4) ◽  
pp. 283-293 ◽  
Author(s):  
Stephen J. Jones ◽  
Annette F. Taylor ◽  
Paul A Beales
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
The Body ◽  
Living Systems ◽  
Prolonged Release ◽  
Drug Bioavailability ◽  
Drug Release Profile ◽  
Chemical Systems

Nanomedicines for controlled drug release provide temporal and spatial regulation of drug bioavailability in the body. The timing of drug release is usually engineered either for slow gradual release over an extended period of time or for rapid release triggered by a specific change in its physicochemical environment. However, between these two extremes, there is the desirable possibility of adaptive nanomedicines that dynamically modulate drug release in tune with its changing environment. Adaptation and response through communication with its environment is a fundamental trait of living systems; therefore, the design of biomimetic nanomedicines through the approaches of bottom-up synthetic biology provides a viable route to this goal. This could enable drug delivery systems to optimize release in synchronicity with the body’s natural biological rhythms and the personalized physiological characteristics of the patient, e.g. their metabolic rate. Living systems achieve this responsiveness through feedback-controlled biochemical processes that regulate their functional outputs. Towards this goal of adaptive drug delivery systems, we review the general benefits of nanomedicine formulations, provide existing examples of experimental nanomedicines that encapsulate the metabolic function of enzymes, and give relevant examples of feedback-controlled chemical systems. These are the underpinning concepts that hold promise to be combined to form novel adaptive release systems. Furthermore, we motivate the advantages of adaptive release through chronobiological examples. By providing a brief review of these topics and an assessment of the state of the art, we aim to provide a useful resource to accelerate developments in this field. Impact statement The timing and rate of release of pharmaceuticals from advanced drug delivery systems is an important property that has received considerable attention in the scientific literature. Broadly, these mostly fall into two classes: controlled release with a prolonged release rate or triggered release where the drug is rapidly released in response to an environmental stimulus. This review aims to highlight the potential for developing adaptive release systems that more subtlety modulate the drug release profile through continuous communication with its environment facilitated through feedback control. By reviewing the key elements of this approach in one place (fundamental principles of nanomedicine, enzymatic nanoreactors for medical therapies and feedback-controlled chemical systems) and providing additional motivating case studies in the context of chronobiology, we hope to inspire innovative development of novel “chrononanomedicines.”

scholarly journals G-Quadruplex-Based Drug Delivery Systems for Cancer Therapy

2021 ◽  
Vol 14 (7) ◽  
pp. 671
Author(s):  
Jéssica Lopes-Nunes ◽  
Paula Oliveira ◽  
Carla Cruz
Keyword(s):  
Drug Delivery ◽  
Small Molecules ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
Nano Particles ◽  
Future Research ◽  
High Affinity ◽  
Dna And Rna ◽  
G Quadruplex ◽  
Gold Nano Particles

G-quadruplexes (G4s) are a class of nucleic acids (DNA and RNA) with single-stranded G-rich sequences. Owing to the selectivity of some G4s, they are emerging as targeting agents to overtake side effects of several potential anticancer drugs, and delivery systems of small molecules to malignant cells, through their high affinity or complementarity to specific targets. Moreover, different systems are being used to improve their potential, such as gold nano-particles or liposomes. Thus, the present review provides relevant data about the different studies with G4s as drug delivery systems and the challenges that must be overcome in the future research.

Drug Delivery Devices and Targeting Agents for Platinum(II) Anticancer Complexes

2008 ◽  
Vol 61 (9) ◽  
pp. 675 ◽  
Author(s):  
Anwen M. Krause-Heuer ◽  
Maxine P. Grant ◽  
Nikita Orkey ◽  
Janice R. Aldrich-Wright
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Anticancer Agents ◽  
Drug Transport ◽  
Water Solubility ◽  
Controlled Drug Release ◽  
Drug Bioavailability ◽  
Platinum Drug ◽  
Drug Delivery Devices

An ideal platinum-based delivery device would be one that selectively targets cancerous cells, can be systemically delivered, and is non-toxic to normal cells. It would be beneficial to provide drug delivery devices for platinum-based anticancer agents that exhibit high drug transport capacity, good water solubility, stability during storage, reduced toxicity, and enhanced anticancer activity in vivo. However, the challenges for developing drug delivery devices include carrier stability in vivo, the method by which extracellular or intracellular drug release is achieved, overcoming the various mechanisms of cell resistance to drugs, controlled drug release to cancer cells, and platinum drug bioavailability. There are many potential candidates under investigation including cucurbit[n]urils, cyclodextrins, calix[n]arenes, and dendrimers, with the most promising being those that are synthetically adaptable enough to attach to targeting agents.

scholarly journals Biodegradable Nanoparticle for Cornea Drug Delivery: Focus Review

Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1232
Author(s):  
Mohammadmahdi Mobaraki ◽  
Madjid Soltani ◽  
Samaneh Zare Harofte ◽  
Elham L. Zoudani ◽  
Roshanak Daliri ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Polymeric Nanoparticles ◽  
Delivery Systems ◽  
Sense Organs ◽  
Drug Bioavailability ◽  
Controllable Release ◽  
The World ◽  
Pros And Cons ◽  
Different Parts

During recent decades, researchers all around the world have focused on the characteristic pros and cons of the different drug delivery systems for cornea tissue change for sense organs. The delivery of various drugs for cornea tissue is one of the most attractive and challenging activities for researchers in biomaterials, pharmacology, and ophthalmology. This method is so important for cornea wound healing because of the controllable release rate and enhancement in drug bioavailability. It should be noted that the delivery of various kinds of drugs into the different parts of the eye, especially the cornea, is so difficult because of the unique anatomy and various barriers in the eye. Nanoparticles are investigated to improve drug delivery systems for corneal disease. Biodegradable nanocarriers for repeated corneal drug delivery is one of the most attractive and challenging methods for corneal drug delivery because they have shown acceptable ability for this purpose. On the other hand, by using these kinds of nanoparticles, a drug could reside in various part of the cornea for longer. In this review, we summarized all approaches for corneal drug delivery with emphasis on the biodegradable nanoparticles, such as liposomes, dendrimers, polymeric nanoparticles, niosomes, microemulsions, nanosuspensions, and hydrogels. Moreover, we discuss the anatomy of the cornea at first and gene therapy at the end.

scholarly journals Targeted Drug Delivery Systems for the Treatment of Glaucoma: Most Advanced Systems Review

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1742 ◽  
Author(s):  
Olga Cegielska ◽  
Paweł Sajkiewicz
Keyword(s):  
Drug Delivery ◽  
Side Effects ◽  
Targeted Delivery ◽  
Drug Targets ◽  
Drug Delivery Systems ◽  
Release Kinetics ◽  
Controlled Drug Release ◽  
Drug Carriers ◽  
Delivery Systems ◽  
Drug Bioavailability

Each year, new glaucoma drug delivery systems are developed. Due to the chronic nature of the disease, it requires the inconvenient daily administration of medications. As a result of their elution from the eye surface and penetration to the bloodstream through undesired permeation routes, the bioavailability of active compounds is low, and systemic side effects occur. Despite numerous publications on glaucoma drug carriers of controlled drug release kinetics, only part of them consider drug permeation routes and, thus, carriers’ location, as an important factor affecting drug delivery. In this paper, we try to demonstrate the importance of the delivery proximal to glaucoma drug targets. The targeted delivery can significantly improve drug bioavailability, reduce side effects, and increase patients’ compliance compared to both commercial and scientifically developed formulations that can spread over the eye surface or stay in contact with conjunctival sac. We present a selection of glaucoma drug carriers intended to be placed on cornea or injected into the aqueous humor and that have been made by advanced materials using hi-tech forming methods, allowing for effective and convenient sustained antiglaucoma drug delivery.

scholarly journals Cellulosic Polymers for Enhancing Drug Bioavailability in Ocular Drug Delivery Systems

2021 ◽  
Vol 14 (11) ◽  
pp. 1201
Author(s):  
Bharti Gupta ◽  
Varsha Mishra ◽  
Sankalp Gharat ◽  
Munira Momin ◽  
Abdelwahab Omri
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Aqueous Solubility ◽  
Class Ii ◽  
Delivery Systems ◽  
Solubility Enhancement ◽  
Ocular Drug Delivery ◽  
Drug Bioavailability ◽  
Bcs Class Ii ◽  
Cellulosic Polymers

One of the major impediments to drug development is low aqueous solubility and thus poor bioavailability, which leads to insufficient clinical utility. Around 70–80% of drugs in the discovery pipeline are suffering from poor aqueous solubility and poor bioavailability, which is a major challenge when one has to develop an ocular drug delivery system. The outer lipid layer, pre-corneal, dynamic, and static ocular barriers limit drug availability to the targeted ocular tissues. Biopharmaceutical Classification System (BCS) class II drugs with adequate permeability and limited or no aqueous solubility have been extensively studied for various polymer-based solubility enhancement approaches. The hydrophilic nature of cellulosic polymers and their tunable properties make them the polymers of choice in various solubility-enhancement techniques. This review focuses on various cellulose derivatives, specifically, their role, current status and novel modified cellulosic polymers for enhancing the bioavailability of BCS class II drugs in ocular drug delivery systems.

Recent Strategic Developments in the Use of Superdisintegrants for Drug Delivery

2020 ◽  
Vol 26 (6) ◽  
pp. 701-709
Author(s):  
Phuong H.L. Tran ◽  
Thao T.D. Tran
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Controlled Drug Release ◽  
Dosage Forms ◽  
Delivery Systems ◽  
Therapeutic Effects ◽  
Drug Bioavailability ◽  
Solid Dosage Forms ◽  
Solid Dosage ◽  
Innovative Materials

Improving drug bioavailability in the pharmaceutical field is a challenge that has attracted substantial interest worldwide. The controlled release of a drug can be achieved with a variety of strategies and novel materials in the field. In addition to the vast development of innovative materials for improving therapeutic effects and reducing side effects, the exploration of remarkable existing materials could encourage the discovery of diverse approaches for adapted drug delivery systems. Recently, superdisintegrants have been proposed for drug delivery systems as alternative approaches to maximize the efficiency of therapy. Although superdisintegrants are well known and used in solid dosage forms, studies on strategies for the development of drug delivery systems using superdisintegrants are lacking. Therefore, this study reviews the use of superdisintegrants in controlled drug release dosage formulations. This overview of superdisintegrants covers developed strategies, types (including synthetic and natural materials), dosage forms and techniques and will help to improve drug delivery systems.

Pharmacosomes: An approach to improve biopharmaceutical properties of drugs basic considerations in development

2021 ◽  
pp. 4485-4490
Author(s):  
Popat Kumbhar ◽  
Tejaswini Shinde ◽  
Tejaswini Jadhav ◽  
Tejas Gavade ◽  
Rushikesh Sorate ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Drug Stability ◽  
Entrapment Efficiency ◽  
Delivery Systems ◽  
Controlled Delivery ◽  
State Measurement ◽  
High Entrapment Efficiency ◽  
Biopharmaceutical Properties

Vesicular drug delivery systems including niososmes, liposomes, pharmacosomes, transferosomes, electrosomes, ethosomes, etc have been widely accepted for controlled delivery of the drug. Amongst, all these drug delivery systems pharmacosomes are gaining more attention of the researchers due to several benefits such as high entrapment efficiency, improved biopharmaceutical properties, and pharmacokinetic performance, no leakage or loss of drug, stability, etc. Pharmacosomes are amphiphilic phospholipid complexes of drugs having active hydrogen that bind to phospholipids and self-assembled into vesicles in an aqueous medium. Both hydrophilic and lipophilic drugs have been formulated into pharmacosomes that caused improved solubility and permeability of drugs. Pharmacosomes are prepared by using various techniques such as hand shaking method, ether injection, solvent evaporation method, supercritical fluid approach, etc and are characterized for prodrug confirmation, surface morphology, crystal state measurement, in vitro drug release, and stability, etc. Despite wide research and highly encouraging results in the preclinical studies, translation of these nanomedicines from laboratory to market has been very limited. The main aim of this review is to describe comprehensively the potential of pharmacosomes as a vesicular drug delivery system focusing mainly on their conventional and advanced methods of preparation, different characterization techniques, and their applications in the delivery of different types of drugs with improved biopharmaceutical properties and pharmacokinetic performance.

scholarly journals Neurotrophic Factors in Glaucoma and Innovative Delivery Systems

2020 ◽  
Vol 10 (24) ◽  
pp. 9015
Author(s):  
Fabiana Mallone ◽  
Marta Sacchetti ◽  
Alice Bruscolini ◽  
Luca Scuderi ◽  
Marco Marenco ◽  
...  
Keyword(s):  
Neurotrophic Factors ◽  
Targeted Delivery ◽  
Vision Loss ◽  
Ganglion Cells ◽  
Unmet Need ◽  
Delivery Systems ◽  
Neural Function ◽  
Novel Treatments ◽  
Recent Advances ◽  
Ganglion Cell Death

Glaucoma is a neurodegenerative disease and a worldwide leading cause of irreversible vision loss. In the last decades, high efforts have been made to develop novel treatments effective in inducing protection and/or recovery of neural function in glaucoma, including neurotrophic factors (NTFs). These approaches have shown encouraging data in preclinical setting; however, the challenge of sustained, targeted delivery to the retina and optic nerve still prevents the clinical translation. In this paper, the authors review and discuss the most recent advances for the use of NTFs treatment in glaucoma, including intraocular delivery. Novel strategies in drug and gene delivery technology for NTFs are proving effective in promoting long-term retinal ganglion cells (RGCs) survival and related functional improvements. Results of experimental and clinical studies evaluating the efficacy and safety of biodegradable slow-release NTF-loaded microparticle devices, encapsulated NTF-secreting cells implants, mimetic ligands for NTF receptors, and viral and non-viral NTF gene vehicles are discussed. NTFs are able to prevent and even reverse apoptotic ganglion cell death. Nevertheless, neuroprotection in glaucoma remains an open issue due to the unmet need of sustained delivery to the posterior segment of the eye. The recent advances in intraocular delivery systems pave the way for possible future use of NTFs in clinical practice for the treatment of glaucoma.

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