Methotrexate delivering microneedle patches for improved therapeutic efficacy in treatment of rheumatoid arthritis.

Arthritis is an inflammatory disorder that leads to degeneration and swelling in the joints thereby severely affecting mobility. Till date, a complete cure for this disorder remains elusive. Administration of disease modifying anti-rheumatic drugs has not proved effective owing to poor retention of drugs at the site of inflammation in the joints. In most cases, lack of adherence to the therapeutic regimen further aggravates the condition. Localized administration of the drugs through intra-articular injections is highly invasive and painful. A possible solution to overcome these issues will be to ensure sustained release of the anti-arthritic drug at the site of inflammation through a minimally invasive method. The present work focuses on the development of a microneedle patch for localized and minimally invasive delivery of methotrexate to arthritic joints in guinea pig model. The microneedle patch was found to elicit minimal immune response and ensured sustained release of the drug that was manifested through faster restoration of mobility and a distinct reduction in inflammatory and rheumatoid markers at the joints when compared to untreated and those treated through conventional hypodermic injections. Our results demonstrate the promise of microneedle-based platform for an effective arthritic therapy.

Single step fabrication of hollow microneedles and an experimental package for controlled drug delivery.

Hollow microneedle arrays (HMNs) are an excellent choice for managing chronic diseases requiring the administration of multiple drug doses over a prolonged duration. However, HMNs have gained partial success due to limitations in their manufacturing capabilities, and cumbersome processes. In the present study, polymeric HMNs were fabricated using a novel single-step drop-casting process without needing cleanroom facilities, and sophisticated instrumentation. When drop casted on the pyramidal tip stainless steel needles, the optimized polymer solution allowed the reproducible formation of desired height HMMs on a detachable acrylic base. To enable broader applications, the base with HMNs was integrated into an experimental package built to deliver a dose of âˆ¼ 5 µL per 30° clockwise rotation of the actuator, allowing multiple metered drug dose administrations. The fabricated HMNs were optically imaged, and tested for mechanical integrity and stability. The working and functional utility of the HMNs package in delivering metered drug doses was demonstrated by delivering vitamin B12 (ex vivo) and insulin (in vivo), respectively. The optimized process can be used for the large-scale manufacturing of HMNs and the experimental package shows the potential to be further developed into a wearable device.

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

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.

Microneedles for Extended Transdermal Therapeutics: A Route to Advanced Healthcare.

Sustained release of drugs over a pre-determined period is required to maintain an effective therapeutic dose for variety of drug delivery applications. Transdermal devices such as polymeric microneedle patches and other microneedle-based devices have been utilized for sustained release of their payload. Swift clearing of drugs can be prevented either by designing a slow-degrading polymeric matrix or by providing physiochemical triggers to different microneedle-based devices for on-demand release. These long-acting transdermal devices prevent the burst release of drugs. This review highlights the recent advances of microneedle-based devices for sustained release of vaccines, hormones, and antiretrovirals with their prospective safe clinical translation.