scholarly journals Ocular Drug Delivery: Role of Degradable Polymeric Nanocarriers for Ophthalmic Application

2018 ◽  
Vol 19 (9) ◽  
pp. 2830 ◽  
Author(s):  
Cheng-Han Tsai ◽  
Peng-Yuan Wang ◽  
I-Chan Lin ◽  
Hu Huang ◽  
Guei-Sheung Liu ◽  
...  

Ocular drug delivery has been a major challenge for clinical pharmacologists and biomaterial scientists due to intricate and unique anatomical and physiological barriers in the eye. The critical requirement varies from anterior and posterior ocular segments from a drug delivery perspective. Recently, many new drugs with special formulations have been introduced for targeted delivery with modified methods and routes of drug administration to improve drug delivery efficacy. Current developments in nanoformulations of drug carrier systems have become a promising attribute to enhance drug retention/permeation and prolong drug release in ocular tissue. Biodegradable polymers have been explored as the base polymers to prepare nanocarriers for encasing existing drugs to enhance the therapeutic effect with better tissue adherence, prolonged drug action, improved bioavailability, decreased toxicity, and targeted delivery in eye. In this review, we summarized recent studies on sustained ocular drug/gene delivery and emphasized on the nanocarriers made by biodegradable polymers such as liposome, poly lactic-co-glycolic acid (PLGA), chitosan, and gelatin. Moreover, we discussed the bio-distribution of these nanocarriers in the ocular tissue and their therapeutic applications in various ocular diseases.

2020 ◽  
Vol 17 ◽  
Author(s):  
Anisha D’Souza ◽  
Ranjita Shegokar

: In recent years, SLNs and NLCs are among the popular drug delivery systems studied for delivery of lipophilic drugs. Both systems have demonstrated several beneficial properties as an ideal drug-carrier, optimal drug-loading and good long-term stability. NLCs are getting popular due to their stability advantages and possibility to load various oil components either as an active or as a matrix. This review screens types of oils used till date in combination with solid lipid to form NLCs. These oils are broadly classified in two categories: Natural oils and Essential oils. NLCs offer range advantages in drug delivery due to the formation of imperfect matrix owing to the presence of oil. The type and percentage of oil used determines optimal drug loading and stability. Literature shows that variety of oils is used in NLCs mainly as matrix, which is from natural origin, triglycerides class. On the other hand, essential oils not only serve as a matrix but as an active. In short, oil is the key ingredient in formation of NLCs, hence needs to be selected wisely as per the performance criteria expected.


2020 ◽  
Vol 17 ◽  
Author(s):  
Neeraj Mittal ◽  
Varun Garg ◽  
Sanjay Kumar Bhadada ◽  
O. P. Katare

: The corona virus disease 2019 (COVID-19) has found its roots from Wuhan (China). COVID-19 is caused by a novel corona virus SARS-CoV2, previously named as 2019-nCoV. COVID-19 has spread across the globe and declared as pandemic by World health organization (WHO) on 11th March, 2020. Currently, there is no standard drug or vaccine available for the treatment, so repurposing of existing drugs is the only solution. Novel drug delivery systems (NDDS) will be boon for the repurposing of drugs. The role of various NDDS in repurposing of existing drugs for treatment of various viral diseases and their relevance in COVID-19 has discussed in this paper. It focuses on the currently ongoing research in the implementation of NDDS in COVID-19. Moreover it describes the role of NDDS in vaccine development for COVID-19. This paper also emphasizes how NDDS will help to develop the improved delivery systems (dosage forms) of existing therapeutic agents and also explore the new insights to find out the void spaces for a potential targeted delivery. So in these tough times, NDDS and nanotechnology can be a safeguard to humanity.


2020 ◽  
Vol 17 (10) ◽  
pp. 911-924
Author(s):  
Rohitas Deshmukh

Colon cancer is one of the most prevalent diseases, and traditional chemotherapy has not been proven beneficial in its treatment. It ranks second in terms of mortality due to all cancers for all ages. Lack of selectivity and poor biodistribution are the biggest challenges in developing potential therapeutic agents for the treatment of colon cancer. Nanoparticles hold enormous prospects as an effective drug delivery system. The delivery systems employing the use of polymers, such as chitosan and pectin as carrier molecules, ensure the maximum absorption of the drug, reduce unwanted side effects and also offer protection to the therapeutic agent from quick clearance or degradation, thus allowing an increased amount of the drug to reach the target tissue or cells. In this systematic review of published literature, the author aimed to assess the role of chitosan and pectin as polymer-carriers in colon targeted delivery of drugs in colon cancer therapy. This review summarizes the various studies employing the use of chitosan and pectin in colon targeted drug delivery systems.


2015 ◽  
Vol 18 (5) ◽  
pp. 683 ◽  
Author(s):  
Andreza Maria Ribeiro ◽  
Ana Figueiras ◽  
Francisco Veiga

Conventional ophthalmic systems present very low corneal systemic bioavailability due to the nasolacrimal drainage and the difficulty to deliver the drug in the posterior segment of ocular tissue. For these reasons, recent advances have focused on the development of new ophthalmic drug delivery systems. This review provides an insight into the various constraints associated with ocular drug delivery, summarizes recent findings in soft contact lenses (SCL) and the applications of novel pharmaceutical systems for ocular drug delivery. Among the new therapeutic approaches in ophthalmology, SCL are novel continuous-delivery systems, providing high and sustained levels of drugs to the cornea. The tendency of research in ophthalmic drug delivery systems development are directed towards a combination of several technologies (bio-inspired and molecular imprinting techniques) and materials (cyclodextrins, surfactants, specific monomers). There is a tendency to develop systems which not only prolong the contact time of the vehicle at the ocular surface, but also at the same time slow down the clearance of the drug. Different materials can be applied during the development of contact lenses and can be combined with natural inspired strategies of drug immobilization and release, providing successful tools for ocular drug delivery systems. This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.


Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5672
Author(s):  
Bethany Almeida ◽  
Okhil K. Nag ◽  
Katherine E. Rogers ◽  
James B. Delehanty

In nanoparticle (NP)-mediated drug delivery, liposomes are the most widely used drug carrier, and the only NP system currently approved by the FDA for clinical use, owing to their advantageous physicochemical properties and excellent biocompatibility. Recent advances in liposome technology have been focused on bioconjugation strategies to improve drug loading, targeting, and overall efficacy. In this review, we highlight recent literature reports (covering the last five years) focused on bioconjugation strategies for the enhancement of liposome-mediated drug delivery. These advances encompass the improvement of drug loading/incorporation and the specific targeting of liposomes to the site of interest/drug action. We conclude with a section highlighting the role of bioconjugation strategies in liposome systems currently being evaluated for clinical use and a forward-looking discussion of the field of liposomal drug delivery.


Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5952
Author(s):  
Bwalya A. Witika ◽  
Pedzisai A. Makoni ◽  
Larry L. Mweetwa ◽  
Pascal V. Ntemi ◽  
Melissa T. R. Chikukwa ◽  
...  

The current COVID-19 pandemic has tested the resolve of the global community with more than 35 million infections worldwide and numbers increasing with no cure or vaccine available to date. Nanomedicines have an advantage of providing enhanced permeability and retention and have been extensively studied as targeted drug delivery strategies for the treatment of different disease. The role of monocytes, erythrocytes, thrombocytes, and macrophages in diseases, including infectious and inflammatory diseases, cancer, and atherosclerosis, are better understood and have resulted in improved strategies for targeting and in some instances mimicking these cell types to improve therapeutic outcomes. Consequently, these primary cell types can be exploited for the purposes of serving as a “Trojan horse” for targeted delivery to identified organs and sites of inflammation. State of the art and potential utilization of nanocarriers such as nanospheres/nanocapsules, nanocrystals, liposomes, solid lipid nanoparticles/nano-structured lipid carriers, dendrimers, and nanosponges for biomimicry and/or targeted delivery of bioactives to cells are reported herein and their potential use in the treatment of COVID-19 infections discussed. Physicochemical properties, viz., hydrophilicity, particle shape, surface charge, composition, concentration, the use of different target-specific ligands on the surface of carriers, and the impact on carrier efficacy and specificity are also discussed.


2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Jason A. Ellis ◽  
Matei Banu ◽  
Shaolie S. Hossain ◽  
Rajinder Singh-Moon ◽  
Sean D. Lavine ◽  
...  

Effective treatment for glioblastoma (GBM) will likely require targeted delivery of several specific pharmacological agents simultaneously. Intra-arterial (IA) delivery is one technique for targeting the tumor site with multiple agents. Although IA chemotherapy for glioblastoma (GBM) has been attempted since the 1950s, the predicted benefits remain unproven in clinical practice. This review focuses on innovative approaches to IA drug delivery in treating GBM. Guided by novel in vitro and in vivo optical measurements, newer pharmacokinetic models promise to better define the complex relationship between background cerebral blood flow and drug injection parameters. Advanced optical technologies and tracers, unique nanoparticles designs, new cellular targets, and rational drug formulations are continuously modifying the therapeutic landscape for GBM. Personalized treatment approaches are emerging; however, such tailored approaches will largely depend on effective drug delivery techniques and on the ability to simultaneously deliver multidrug regimens. These new paradigms for tumor-selective drug delivery herald dramatic improvements in the effectiveness of IA chemotherapy for GBM. Therefore, within this context of so-called “precision medicine,” the role of IA delivery for GBM is thoroughly reassessed.


2021 ◽  
Vol 11 ◽  
Author(s):  
Elizabeth Cooper ◽  
Peter J. Choi ◽  
William A. Denny ◽  
Jiney Jose ◽  
Mike Dragunow ◽  
...  

Effective cancer therapeutics for brain tumors must be able to cross the blood-brain barrier (BBB) to reach the tumor in adequate quantities and overcome the resistance conferred by the local tumor microenvironment. Clinically approved chemotherapeutic agents have been investigated for brain neoplasms, but despite their effectiveness in peripheral cancers, failed to show therapeutic success in brain tumors. This is largely due to their poor bioavailability and specificity towards brain tumors. A targeted delivery system might improve the efficacy of the candidate compounds by increasing the retention time in the tumor tissue, and minimizing the numerous side effects associated with the non-specific distribution of the chemotherapy agent. Heptamethine cyanine dyes (HMCDs) are a class of near-infrared fluorescence (NIRF) compounds that have recently emerged as promising agents for drug delivery. Initially explored for their use in imaging and monitoring neoplasms, their tumor-targeting properties have recently been investigated for their use as drug carrier systems. This review will explore the recent developments in the tumour-targeting properties of a specific group of NIRF cyanine dyes and the preclinical evidence for their potential as drug-delivery systems in the treatment of primary and metastatic brain tumors.


2015 ◽  
Vol 15 (7) ◽  
pp. 680-693 ◽  
Author(s):  
Ramya Vadlapatla ◽  
Aswani Vadlapudi ◽  
Dhananjay Pal ◽  
Ashim Mitra

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