y-to-use manner. Optimal MNP design balances multiple interdependent parameters that determine mechanical strength, skin-insertion reliability, drug delivery efficiency, painlessness, manufacturability, and other features of MNPs that affect their performance. MNPs can be made by adapting various microfabrication technologies for delivery of small-molecule drugs, biologics, and vaccines targeted to the skin, which can have pharmacokinetic and immunologic advantages. A small number of human clinical trials, as well as a large and growing market for MNP products for cosmetics, indicate that MNPs can be used safely, efficaciously, and with strong patient acceptance. More advanced clinical trials and commercial-scale manufacturing will facilitate development of MNPs to realize their potential to dramatically increase patient access to otherwise-injectable drugs and to improve drug performance via skin delivery.
Grayson, Amy C. Richards; Choi, Insung S.; Tyler, Betty M.; Wang, Paul P.; Brem, Henry; Cima, Michael J.; Langer, Robert
Controlled-release drug delivery systems have many applications, including treatments for hormone deficiencies and chronic pain. A biodegradable device that could provide multi-dose drug delivery would be advantageous for long-term treatment of conditions requiring pulsatile drug release. In this work, biodegradable polymeric microchips were fabricated that released four pulses of radiolabelled dextran, human growth hormone or heparin in vitro. Heparin that was released over 142 days retained on average 96 +/- 12% of its bioactivity. The microchips were 1.2 cm in diameter, 480-560 μm thick and had 36 reservoirs that could each be filled with a different chemical. The devices were fabricated from poly(L-lactic acid) and had poly(D,L-lactic-co-glycolic acid) membranes of different molecular masses covering the reservoirs. A drug delivery system can be designed with the potential to release pulses of different drugs at intervals after implantation in a patient by using different molecular masses or materials for the membrane.
Szabó, Barnabás; Hetényi, Gergely; Majoros, Klaudia; Miszori, Veronika; Kállai, Nikolett; Zelkó, Romána
Application of buccal dosage forms has several advantages. Buccal route can be used for systemic delivery because the mucosa has a rich blood supply and it is relatively permeable. This route of drug delivery is of special advantages, including the bypass of first pass effect and the avoidance of presystemic elimination within the GIT. Buccal delivery systems enable the systemic delivery of peptides and proteins. In our previous study the physiological background of this application and the excipients of the possible formulations were reviewed. In the present work the formulation and ex vivo examination aspects of buccal drug delivery systems are summarized.
Nguyen, Thao M; Lee, Sebin; Lee, Sang Bok
To uptake and release hydrophilic model drugs and insulin in a novel conductive polymer (CP) nanotube transdermal patch. The externally controlled transdermal delivery of model drugs and insulin were tested ex vivo and results were compared with CP films. The unique intrinsic properties of CPs provide electrostatic interaction between the model drugs and polymer backbone. When a pulsed potential was applied, the drug delivery release profile mimics that of injection delivery. With a constant potential applied, the release rate constants of the patch system were up to three-times faster than the control (0 V) and released approximately 80% more drug molecules over 24 h. The CP nanotube transdermal patch represents a new and promising drug method, specifically for hydrophilic molecules, which have been a large obstacle for conventional transdermal drug delivery systems.
Kotrotsiou, O; Kotti, K; Dini, E; Kammona, O; Kiparissides, C
Selective recognition requires the introduction of a molecular memory into a polymer matrix in order to make it capable of rebinding an analyte with a very high specificity. In addition, targeted drug delivery requires drug-loaded vesicles which preferentiall