Transdermal delivery of potassium chloride with solid microneedles

Hypokalemia is one of the most common types of electrolyte imbalance. It presents as a serum potassium level of <= 3.5 mEq/L. Potassium is essential for proper nerve and muscle functioning. If left untreated, hypokalemia can lead to arrhythmias, muscle twitching, vomiting and even neuropathies. To prevent or manage these adverse reactions, it is important to develop a drug delivery system that can restore and possibly maintain potassium levels in the body. Currently, there are several potassium supplements, but they are marked by several shortcomings e.g. oral potassium tablets take a longer time to achieve peak plasma concentration and parenteral administration can cause pain, swelling, trypanophobia with the additional risk of hyperkalemia. Knowing these problems, it is crucial to develop a suitable alternative for potassium supplementation. Transdermal drug delivery is a promising approach. The transdermal route has a large surface area which supports drug administration and has the ability to impart sustained-release properties that can help maintain potassium levels. In conjunction with microneedles, drug permeation can be greatly increased. The objective of this research project was to investigate the influence of microneedle rollers on the permeation of potassium chloride across porcine skin. Permeation studies were carried out in vitro using the Franz diffusion apparatus. The transdermal flux of potassium chloride was investigated using inductively coupled plasma optical emission spectrometry. Microchannel characterization was carried out using digital microscopy, brightfield stereomicroscopy and confocal laser scanning microscopy. The mean transdermal flux of potassium chloride obtained via passive diffusion was 0.637 +/- 0.02 mg/cm(2)/h while the mean transdermal flux of potassium chloride obtained via microneedle-enhanced permeation was 6.33 +/- 18.70 mg/cm(2)/h. This increase in transdermal flux was found to be statistically significant with p < 0.05. The micro conduits created by microneedle rollers measured [173 +/- 26.94 mu m].