Microneedles is the technique of drug delivery enhancement, which was primarily designed for facilitating percutaneous drug delivery. Started from the development of simple solid microneedles, ...providing microporation of stratum corneum and therefore enhancement of topical drug delivery, for two decades the technique has progressed in various modifications such as hollow, coated, dissolving and hydrogel forming microneedles. In their turn, the modifications have resulted in new mechanisms of drug delivery enhancement and followed by the expansion of applicability range in terms of targeted tissues and organs. Thus, in addition to percutaneous drug delivery, microneedles have been considered as an efficient technique facilitating ocular, oral mucosal, gastrointestinal, ungual and vaginal drug administration. It is anticipated that the technique of microneedle-assisted drug delivery will soon become relevant for majority of organs and tissues.
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Photothermal therapy (PTT) combined with chemotherapy, a promising strategy for breast cancer treatment, has a high potential to control drug release, reduce multidrug resistance, and improve ...therapeutic efficacy. The challenge is how to realize tumor ablation in deeper tissue and NIR‐controlled drug delivery. Herein, tumor acidity and near‐infrared light (NIR) responsive folic acid (FA) functionalized polydopamine (DPA) nanoparticles (NPs) are developed for doxorubicin (DOX) and epigallocatechin‐3‐gallate (EGCG) dual delivery. With the assistance of NIR, the cellular uptake of DOX‐EGCG/DPA‐FA NPs is about three‐ to sixfold higher when compared with the free DOX group and the control group without NIR irradiation. Moreover, biodistribution study in vivo indicates that DPA‐FA NPs can enhance tumoral accumulation, penetration, retention of drugs, and display a ≈4‐ and 19‐fold higher intra‐tumoral distribution than that of the DPA NPs and free drug groups at 24 h postinjection. Furthermore, 60% of breast cancer‐bearing mice survive over 70 days in the DOX‐EGCG/DPA‐FA NPs group. Additionally, DOX‐EGCG/DPA‐FA NPs can effectively boost therapeutic efficacy by inducing significant suppression of tumor growth and angiogenesis, and enhancement of apoptosis and necrosis of breast cancer cells. Taken together, DOX‐EGCG/DPA‐FA NPs may have potential applications as a useful nanoscale vector for enhanced cancer therapy.
A novel nanosystem with doxorubicin (DOX) and epigallocatechin‐3‐gallate (EGCG) co‐delivery based on polydopamine (DOX‐EGCG/DPA‐FA NPs) is designed. DOX‐EGCG/DPA‐FA NPs possessing pH and NIR‐controlled chemo‐photothermal therapy effect can effectively enhance the therapeutic efficacy via suppression of tumor growth and angiogenesis, improved apoptosis, and necrosis of cancer cells. The findings demonstrate a useful chemo‐photothermal nanoscale vector for enhanced cancer therapy.
Posterior segment eye diseases (PSEDs) including age macular degeneration (AMD) and diabetic retinopathy (DR) are amongst the major causes of irreversible blindness worldwide. Due to the numerous ...barriers encountered, highly invasive intravitreal (IVT) injections represent the primary route to deliver drugs to the posterior eye tissues. Thus, the potential of a more patient friendly topical route has been widely investigated. Mucoadhesive formulations can decrease precorneal clearance while prolonging precorneal residence. Thus, they are expected to enhance the chances of adherence to corneal and conjunctival surfaces and as such, enable increased delivery to the posterior eye segment. Among the mucoadhesive polymers available, chitosan is the most widely explored due to its outstanding mucoadhesive characteristics. In this review, the major PSEDs, their treatments, barriers to topical delivery, and routes of topical drug absorption to the posterior eye are presented. To enable the successful design of mucoadhesive ophthalmic drug delivery systems (DDSs), an overview of mucoadhesion, its theory, characterization, and considerations for ocular mucoadhesion is given. Furthermore, chitosan-based DDs that have been explored to promote topical drug delivery to the posterior eye segment are reviewed. Finally, challenges of successful preclinical to clinical translation of these DDSs for posterior eye drug delivery are discussed.
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•Fabrication of polymeric microneedles (MNs) for controlled drug release.•Sustained transdermal drug delivery by MNs.•Instant transdermal drug delivery by MNs.•Protein and vaccines ...delivery by MNs.•Photothermal release for drug delivery by MNs.
Polymeric microneedle (MN) systems are interesting transdermal drug delivery systems because of their controlled drug delivery, tunable properties, and ease of patient self-administration. They are biocompatible and can easily and painlessly penetrate the stratum corneum, delivering their contents into the dermis where they can be adsorbed into systemic circulation. Polymeric MNs can facilitate appropriate therapeutic dosing by controlling the release kinetics of pre-loaded drugs, targeting specific tissues, or responding to changing physiological conditions. This can be accomplished by modifying the degradation and swelling profiles of the host polymer and the diffusion profiles of the encapsulated drugs. In this review various mechanisms of controlled drug delivery using polymeric MNs, including new strategies, applications, and their future outlook are summarized and evaluated.
Conventional drug delivery approaches are plagued by issues pertaining to systemic toxicity and repeated dosing. Hydrogels offer convenient drug delivery vehicles to ensure these disadvantages are ...minimized and the therapeutic benefits from the drug are optimized. With exquisitely tunable physical properties that confer them great controlled drug release features and the merits they offer for labile drug protection from degradation, hydrogels emerge as very efficient drug delivery systems. The versatility and diversity of the hydrogels extend their applications beyond targeted drug delivery also to wound dressings, contact lenses and tissue engineering to name but a few. They are 90% water, and highly porous to accommodate drugs for delivery and facilitate controlled release. Herein we discuss hydrogels and how they could be manipulated for targeted drug delivery applications. Suitable examples from the literature are provided that support the recent advancements of hydrogels in targeted drug delivery in diverse disease areas and how they could be suitably modified in very different ways for achieving significant impact in targeted drug delivery. With their enormous amenability to modification, hydrogels serve as promising delivery vehicles of therapeutic molecules in several disease conditions, including cancer and diabetes.
Poor aqueous solubility and poor bioavailability are major issues with many pharmaceutical industries. By some estimation, 70–90% drug candidates in development stage while up-to 40% of the marketed ...products are poorly soluble which leads to low bioavailability, reduced therapeutic effects and dosage escalation. That's why solubility is an important factor to consider during design and manufacturing of the pharmaceutical products. To-date, various strategies have been explored to tackle the issue of poor solubility. This review article focuses the updated overview of commonly used macro and nano drug delivery systems and techniques such as micronization, solid dispersion (SD), supercritical fluid (SCF), hydrotropy, co-solvency, micellar solubilization, cryogenic technique, inclusion complex formation-based techniques, nanosuspension, solid lipid nanoparticles, and nanogels/nanomatrices explored for solubility enhancement of poorly soluble drugs. Among various techniques, nanomatrices were found a promising and impeccable strategy for solubility enhancement of poorly soluble drugs. This article also describes the mechanism of action of each technique used in solubilization enhancement.
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A biodegradable drug delivery system (DDS) is one the most promising therapeutic strategies for cancer therapy. Here, we propose a unique concept of light activation of black phosphorus (BP) at ...hydrogel nanostructures for cancer therapy. A photosensitizer converts light into heat that softens and melts drug-loaded hydrogelbased nanostructures. Drug release rates can be accurately controlled by light intensity, exposure duration, BP concentration, and hydrogel composition. Owing to sufficiently deep penetration of near-infrared (NIR) light through tissues, our BP-based system shows high therapeutic efficacy for treatment of s.c. cancers. Importantly, our drug delivery system is completely harmless and degradable in vivo. Together, our work proposes a unique concept for precision cancer therapy by external light excitation to release cancer drugs. If these findings are successfully translated into the clinic, millions of patients with cancer will benefit from our work.
•Mucosal delivery systems differ in physicochemical and release characteristics.•Versatile in vitro release methods are currently used for their characterisation.•Compendial methods are used as a ...first approach whenever applicable.•Novel biorelevant methods are needed for the prediction of performance in vivo.
In vitro dissolution/release tests are an important tool in the drug product development phase as well as in its quality control and the regulatory approval process. Mucosal drug delivery systems are aimed to provide both local and systemic drug action via mucosal surfaces of the body and exhibit significant differences in formulation design, as well as in their physicochemical and release characteristics. Therefore it is not possible to devise a single test system which would be suitable for release testing of such complex dosage forms. This article is aimed to provide a comprehensive review of both compendial and noncompendial methods used for in vitro dissolution/release testing of novel mucosal drug delivery systems aimed for ocular, nasal, oromucosal, vaginal and rectal administration.
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The recent advancement and prevalence of wearable technologies and their ability to make digital measurements of vital signs and wellness parameters have triggered a new paradigm in ...the management of diseases. Drug delivery as a function of stimuli or response from wearable, closed-loop systems can offer real-time on-demand or preprogrammed drug delivery capability and offer total management of disease states. Here we review the key opportunities in this space for development of closed-loop systems, given the advent of digital wearable technologies. Particular considerations and focus are given to closed-loop systems combined with transdermal drug delivery technologies.
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