Bulk Micromachined Titanium Microneedles

Parker, E.R.; Rao, Masaru P.; Turner, Kimberly L.; Meinhart, Carl; MacDonald, N.C.

doi:10.1109/jmems.2007.892909

Cited by 96 publications

(58 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The insertion force of microneedles depends on microneedles spacing (Parker et al, 2007). This accords well where the insertion force of microneedles depends on microneedles spacing as well as microneedle length .…”

Section: Effects Of Microneedle Spacingsupporting

confidence: 77%

Transdermal drug delivery by coated microneedles: Geometry effects on effective skin thickness and drug permeability

Davidson

Al-Qallaf

Das

2008

Chemical Engineering Research and Design

146

View full text Add to dashboard Cite

can potentially allow the transdermal delivery of many medicaments including large macromolecules that typically cannot diffuse through the skin. This paper addresses the use of microneedles coated with a drug solution film. In particular, we identify how the geometries of various microneedles affect the drug permeability in skin. Effective skin permeability is calculated for a range of microneedle shapes and dimensions in order to identify the most 20 efficient geometry. To calculate effective permeability (P eff ), the effective skin thickness (H eff ) is calculated. These are then plotted for insulin as a model drug to see how various microneedle parameters affect the profiles of both H eff and P eff . It is found that the depth of penetration from the microneedle array is the most important factor in determining P eff , followed by the microneedle spacings. Other parameters such as microneedle diameter and 25 coating depth are less significant.

show abstract

Section: Effects Of Microneedle Spacingsupporting

confidence: 77%

Transdermal drug delivery by coated microneedles: Geometry effects on effective skin thickness and drug permeability

Davidson

Al-Qallaf

Das

2008

Chemical Engineering Research and Design

146

View full text Add to dashboard Cite

show abstract

Section: Microneedlesmentioning

confidence: 99%

“…MN have been produced in various geometries. These microstructure geometries can be in the form of needle-like (most common MN geometries which can be sharp-, tapered-, conical-or bevel-tipped), microblades, and blunt-projections or shaped in an arrow-head [47][48][49][50][51].In addition, MNs as a parenteral route of administration could provide the relatively easy and patient-friendly administration of therapeutics with potential efficacy at low cost. And some studies have shown that MNs can penetrate the skin, cross the stratum corneum into the viable epidermis, and reside primarily in the dermal layer, avoiding contact with blood vessels and nerve fibres.…”

mentioning

confidence: 99%

Review on Transdermal Drug Delivery Systems

Pang¹,

Han²

2014

Journal of Pharmaceutics and Drug Development

View full text Add to dashboard Cite

ISSN: 2348-9782 During the past decades, intensive studies have focused on the technologies in drug delivery, and with the rapid developments and explorations in technologies, traditional drug delivery means are being replaced by the more effective and advanced ones. The creation of transdermal drug delivery system (TDDS) has been one of the most sophisticated and innovative approaches of drug deliveries. The transdermal drug delivery system has attracted considerale attention because of its many potential advantages, including better patient compliance, avoidance of gastrointestinal disturbances, hepatic first-pass metabolism and sustained delivery of drugs to provide steady plasma profiles, particularly for drugs with short half-lives, reduction in systemic side effects and enhanced therapeutic efficacy [1][2][3][4][5][6].Recently, transdermal drug delivery system (TDDS) has become a more and more important approach to administering drugs. Based on its advantages, which are not achievable by other modes of administration, many researchers are dedicated to the study of it, and have made great progress. Although the skin offers a painless interface for systemic drug delivery, it also presents limitations which are mainly caused by the stratum corneum. In this work, we state the increasingly impact of TDDS, discuss the limitations of it, and last but not least, we highlight the methods for overcoming these limitations by using permeation enhancers, microneedles, iontophoresis.Despite these advantages, most of the transdermal candidates have low permeability. The drugs administered across skin should have the three constraining characteristics: appropriate partition coefficient, low molecular mass (<500Da), and small required dose (upto milligrams) [3]. The limitations of transdermal drug delivery are caused by skin which protects against and is impermeable to foreign molecules. The human skin is consisted of two main layers: the layer of epidermis and the layer of dermis. Stratum corneum is the epidermis's outermost layer that composed of stratified keratinocytes, multiple lipid bilayers of ceramidas, fatty acids, cholesterol and cholesterol esters. Stratum corneum provides an extremely effective physical barrier for the control of drug penetration [2,[7][8][9][10]. Therefore, attempts to overcome this skin barrier is presently an important area of pharmaceutical and toxicological research. The techniques that weaken the barrier have included permeation enhancers , microneedles and iontophoresis [69][70][71][72][73][74][75][76][77][78][79][80][81][82][83][84]. Chemical permeation enhancersIn the last 50 years, a large number of chemical permeation enhancers (CPEs) which are defined as substances that interact with the major constituents of skin barrier, stratum corneum, to promote penetration of drugs into skin.The ideal enhancer should have the following conditions: 1. Non-pharmacological activities. 2. Nontoxic,. Rapid-acting with predictable and reproducible activity. 4. When removed from the skin...

show abstract

“…The most common materials used for fabricating MN are metal, silicon and polymer (Zhao et al, 2006;Memon et al, 2011;Kim et al, 2012). The primary metals used for MNs are stainless steel (Martanto et al, 2004;Bal et al, 2008;Quan et al, 2010;Kim et al, 2012) and titanium (Parker et al, 2007;Fernandez et al, 2009;Kim et al, 2010). Metal MNs have the advantages of low cost, tougher hardness, ease of penetration into the tissue and they are not easily broken in the tissue.…”

Section: Gas Pressure and Particle Velocitymentioning

confidence: 99%