Department of Biotechnology
inStem (Institute for Stem Cell Science and Regenerative Medicine)

Microscale engineering of hollow microneedle tips: design, manufacturing, optimization and validation.

Publication Type

Journal Article

Date of Publication

February 1, 2022

Journal

Drug delivery and translational research

Volume/Issue

12/2

ISSN

2190-3948

Transdermal and intradermal drug delivery utilizing microneedles is an emerging front in painless therapeutics. Drug delivery using hollow microneedles is the most preferred method for delivering generic transdermal drugs in the clinical setup. The needle tip must be extremely short as the drug is administered to sub-millimeter depths. Also, they need to be sharp enough to pierce through the skin with minimal skin flexing. There are multiple challenges in engineering a tip profile that is short and sharp at the same time. Stainless steel (SS) hypodermic needles with the lancet tip profile are ubiquitous in subcutaneous and intramuscular injections. They have long bevel lengths that make them inappropriate as microneedles. Thus, designing a unique tip profile and developing the manufacturing technology for microneedle applications are necessary. This article presents the design and optimization of microneedle tip profiles through analytical models. Further, manufacturing strategies for reliably obtaining designed profiles are discussed. The article concludes with experimental validation of improved piercing performance of the optimized tip profile compared to other tip profiles. The article discusses about tip geometries of stainless steel needles for microneedle applications, where depth of delivery is less than 1 mm. Through series of analyses, the optimum needle tip geometry evolved from single plane bevel (SPB) to hex plane bevel (HPB) progressively improving piercing performance.

Alternate Journal

Drug Deliv Transl Res

PubMed ID

34664227

Authors

Kedar Badnikar
Shreyas Nataraja Jayadevi
Suman Pahal
Praveen Kumar Vemula
Mangalore Manjunatha Nayak
Dinesh Narasimhaiah Subramanyam

Keywords

Administration, Cutaneous
Microinjections
Needles
Pharmaceutical Preparations
Stainless Steel
Drug Delivery Systems
Skin