Microfabricated microneedles: a novel approach to transdermal drug delivery.
TL;DR: These microneedle arrays could be easily inserted into skin without breaking and were shown to increase permeability of human skin in vitro to a model drug, calcein, by up to 4 orders of magnitude.
About: This article is published in Journal of Pharmaceutical Sciences.The article was published on 1998-08-01. It has received 1181 citations till now. The article focuses on the topics: Transdermal & Drug delivery.
Citations
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TL;DR: Microneedles represent a promising technology to deliver therapeutic compounds into the skin for a range of possible applications and the ratio of microneedle fracture force to skin insertion force was found to be optimal for needles with small tip radius and large wall thickness.
1,298Â citations
TL;DR: The already significant impact this field has made on the administration of various pharmaceuticals is discussed; limitations of the current technology are explored; methods under exploration for overcoming these limitations and the challenges ahead are discussed.
Abstract: The past twenty five years have seen an explosion in the creation and discovery of new medicinal agents. Related innovations in drug delivery systems have not only enabled the successful implementation of many of these novel pharmaceuticals, but have also permitted the development of new medical treatments with existing drugs. The creation of transdermal delivery systems has been one of the most important of these innovations, offering a number of advantages over the oral route. In this article, we discuss the already significant impact this field has made on the administration of various pharmaceuticals; explore limitations of the current technology; and discuss methods under exploration for overcoming these limitations and the challenges ahead.
1,275Â citations
TL;DR: Building off a strong technology base and multiple demonstrations of successful drug delivery, microneedles are poised to advance further into clinical practice to enable better pharmaceutical therapies, vaccination and other applications.
1,271Â citations
Cites background or methods from "Microfabricated microneedles: a nov..."
...Short silicon microneedles have been prepared using a silicon dryetching process based on reactive ion etching with a chromium mask [40, 53], as well as isotropic etching in an inductively coupled plasma etcher [54]....
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...This group produced the first journal article on drug delivery using microneedles [40] and has continued to perform microneedles research since then....
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..., thereby partially plugging the pores) and was shown to increase by more than 10,000-fold when microneedles were inserted and immediately removed [40]....
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TL;DR: This review considers drug-vehicle interactions and the role of vesicles and particles and of particular interest is the synergy between chemical enhancers, ultrasound, iontophoresis and electroporation.
1,143Â citations
Patent•
10 Jun 1999TL;DR: In this article, a method for making a micromold having sidewalls which define the outer surface of the microneedle, electroplating the sidewalls to form the hollow micromolds, and then removing the micromolding from the micronule, is described.
Abstract: Microneedle devices are provided for transport of therapeutic and biological molecules across tissue barriers and for use as microflameholders. In a preferred embodiment for transport across tissue, the microneedles are formed of a biodegradable polymer. Methods of making these devices, which can include hollow and/or porous microneedles, are also provided. A preferred method for making a microneedle includes forming a micromold having sidewalls which define the outer surface of the microneedle, electroplating the sidewalls to form the hollow microneedle, and then removing the micromold from the microneedle. In a preferred method of use, the microneedle device is used to deliver fluid material into or across a biological barrier from one or more chambers in fluid connection with at least one of the microneedles. The device preferably further includes a means for controlling the flow of material through the microneedles. Representative examples of these means include the use of permeable membranes, fracturable impermeable membranes, valves, and pumps.
834Â citations
References
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TL;DR: Conventional forms of drug administration generally rely on pills, eye drops, ointments, and intravenous solutions, but a number of novel drug delivery approaches have been developed, which may revolutionize the way many drugs are delivered.
Abstract: Conventional forms of drug administration generally rely on pills, eye drops, ointments, and intravenous solutions. Recently, a number of novel drug delivery approaches have been developed. These approaches include drug modification by chemical means, drug entrapment in small vesicles that are injected into the bloodstream, and drug entrapment within pumps or polymeric materials that are placed in desired bodily compartments (for example, the eye or beneath the skin). These techniques have already led to delivery systems that improve human health, and continued research may revolutionize the way many drugs are delivered.
2,357Â citations
"Microfabricated microneedles: a nov..." refers background in this paper
...Increases of 3 to 4 orders of magnitude were observed for microneedles (1) inserted and left in skin, (2) inserted for 10 s and then removed, and (3) inserted for 1 h and then removed....
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Book•
01 Jan 1968
TL;DR: Diagnosis of skin disease neonate naevi and other developmental defects pruritus eczema lichenification, prurigo and erythroderma atopic dermatitis contact dermatitis irritants and sensitizers occupational dermatoses reactions to mechanical and thermal injury reactions to cold cutaneous photobiology.
Abstract: This latest edition continues its place as a would-be comprehensive encyclopaedia of the scope of dermatology with a vast array of disease states presented to the reader. For this new edition many chapters have been entirely rewritten to take account of the considerable advances in dermatology, and new contributors with specialized experience of the subject on which they write have joined the team.
1,738Â citations
TL;DR: Enough information has been gained from clinical trials to allow the conclusion that human gene transfer is feasible, can evoke biologic responses that are relevant to human disease, and can provide important insights into human biology.
Abstract: Enough information has been gained from clinical trials to allow the conclusion that human gene transfer is feasible, can evoke biologic responses that are relevant to human disease, and can provide important insights into human biology. Adverse events have been uncommon and have been related to the gene delivery strategies, not to the genetic material being transferred. Human gene transfer still faces significant hurdles before it becomes an established therapeutic strategy. However, its accomplishments to date are impressive, and the logic of the potential usefulness of this clinical paradigm continues to be compelling.
1,391Â citations
"Microfabricated microneedles: a nov..." refers background in this paper
...Increases of 3 to 4 orders of magnitude were observed for microneedles (1) inserted and left in skin, (2) inserted for 10 s and then removed, and (3) inserted for 1 h and then removed....
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TL;DR: Low-frequency ultrasound was shown to increase the permeability of human skin to many drugs, including high molecular weight proteins, by several orders of magnitude, thus making transdermal administration of these molecules potentially feasible.
Abstract: Transdermal drug delivery offers a potential method of drug administration. However, its application has been limited to a few low molecular weight compounds because of the extremely low permeability of human skin. Low-frequency ultrasound was shown to increase the permeability of human skin to many drugs, including high molecular weight proteins, by several orders of magnitude, thus making transdermal administration of these molecules potentially feasible. It was possible to deliver and control therapeutic doses of proteins such as insulin, interferon gamma, and erythropoeitin across human skin. Low-frequency ultrasound is thus a potential noninvasive substitute for traditional methods of drug delivery, such as injections.
803Â citations
Patent•
18 Jan 1994
TL;DR: An intradermal drug delivery device for delivering a liquid drug to a subject via the subject's skin includes a housing having a lower surface provided with an adhesive coating for adhering the housing to the subject skin this paper.
Abstract: An intradermal drug delivery device for delivering a liquid drug to a subject via the subject's skin includes a housing having a lower surface provided with an adhesive coating for adhering the housing to the subject's skin. An expansible-contractible chamber within the housing defines a reservoir which is expanded upon being filled with the drug and contracted to dispense the drug. A hollow needle extends through the lower surface of the housing and has an inner end which communicates with the reservoir and an outer end which projects outwardly of the housing a short distance to penetrate through the epidermis and into the dermis of the subject's skin when the housing is adhered thereto. The device permits delivery of drugs of relatively large molecular size and at slow rates which can be precisely controlled. A method of delivering a liquid drug intradermally includes adhering the intradermal delivery device to the skin of the subject and activating the means for actively discharging the at least one drug from the reservoir to the subject's skin via the needle.
642Â citations