http://hdl.handle.net/10468/367 2013-06-20T12:30:07Z 2013-06-20T12:30:07Z McGrath, Marie G. Vrdoljak, Anto O'Mahony, Conor Oliveira, Jorge C. Moore, Anne C. Crean, Abina M. http://hdl.handle.net/10468/364 2013-03-08T03:00:48Z 2011-08-30T00:00:00Z

Determination of parameters for successful spray coating of silicon microneedle arrays McGrath, Marie G.; Vrdoljak, Anto; O'Mahony, Conor; Oliveira, Jorge C.; Moore, Anne C.; Crean, Abina M. Coated microneedle patches have demonstrated potential for effective, minimally invasive, drug and vaccine delivery. To facilitate cost-effective, industrial-scale production of coated microneedle patches, a continuous coating method which utilises conventional pharmaceutical processes is an attractive prospect. Here, the potential of spray-coating silicon microneedle patches using a conventional film-coating process was evaluated and the key process parameters which impact on coating coalescence and weight were identified by employing a fractional factorial design to coat flat silicon patches. Processing parameters analysed included concentration of coating material, liquid input rate, duration of spraying, atomisation air pressure, gun-to-surface distance and air cap setting. Two film-coating materials were investigated; hydroxypropylmethylcellulose (HPMC) and carboxymethylcellulose (CMC). HPMC readily formed a film-coat on silicon when suitable spray coating parameter settings were determined. CMC films required the inclusion of a surfactant (1%, w/w Tween 80) to facilitate coalescence of the sprayed droplets on the silicon surface. Spray coating parameters identified by experimental design, successfully coated 280 μm silicon microneedle arrays, producing an intact film-coat, which follows the contours of the microneedle array without occlusion of the microneedle shape. This study demonstrates a novel method of coating microneedle arrays with biocompatible polymers using a conventional film-coating process. It is the first study to indicate the thickness and roughness of coatings applied to microneedle arrays. The study also highlights the importance of identifying suitable processing parameters when film coating substrates of micron dimensions. The ability of a fractional factorial design to identify these critical parameters is also demonstrated. The polymer coatings applied in this study can potentially be drug loaded for intradermal drug and vaccine delivery.

2011-08-30T00:00:00Z Moore, Anne C. Crean, Abina M. O'Mahony, Conor http://hdl.handle.net/10468/306 2013-03-08T03:00:26Z 2010-12-01T00:00:00Z

Development of stabilized vaccines with needle-free devices for targeted skin immunization Moore, Anne C.; Crean, Abina M.; O'Mahony, Conor Difford, Helen Vaccination represents the primary public health measure to combat infectious diseases. However, limitations of cold-chain storage, vaccine wastage, hazardous sharps-waste and the requirements for trained personnel add significant and unsustainable financial and logistic costs to immunisation programmes. Developments of needle-free methods should aim to overcome these logistics issues from the very start of the vaccine production process. Dermal vaccine administration using microneedle-based devices promises to be one such needle-free method that addresses all of these issues. Methods of stabilisation of vaccines onto or incorporated into microneedles should be developed to permit seamless transition and cost-effectiveness from vaccine bulk-up to final product. This review examines recent developments in microneedle technology and highlights the current challenges to translate this technology into practice.

2010-12-01T00:00:00Z