Pharmaceuticals play an important role in the treatment and prevention of disease, both in humans and animals. In recent years there are more and more pharmaceuticals emerging in the environment that can have negative effects on the environment. They are found in surface waters such as lakes and rivers, as well as in groundwater, soil and even drinking water. Pharmaceuticals that have a major environmental impact include antibiotics, antidepressants, anti-inflammatory drugs and analgesics, beta-blockers, oral contraceptives and hormonal medicines. Scientists are trying to find ways to prevent the presence of pharmaceuticals in the environment, for example by improving wastewater treatment, by proper waste management of pharmaceuticals, and by their advanced design and functions. One of the eco-friendlier forms of pharmaceuticals is the controlled drug delivery system. The advantage of this kind of system is that there is optimal dosage of the active substance, so less pharmaceuticals can be dosed and a smaller excess will be eliminated, which in turn leads to less environmental pollution.
In this master's thesis, we evaluated laser used for creating aperture in OROS (osmotic-controlled release oral delivery system) tablet coating which is a form controlled drug delivery system and we studied laser device parameters that could affect the diameter and thickness of aperture. We used DoE method to conduct the experiments, which is a systematic approach for understanding the influence of process parameters on response - in our case, the properties of the drilled aperture. With DoE, we studied multiple input process parameters simultaneously and identified significant interactions between parameters. Obtained results were analysed using the Umetrics Modde program.
We determined that the power and speed of the laser have a key influence on the dimensions (diameter and thickness) of the drilled aperture. We also determined that in the studied area, the diameter and thickness of the aperture do not affect the rate of release of the active substance and the release is most likely dependent on the solubility of the active substance and swelling rate of polymers. Subsequent review of the influence of individual parameters on the dimensions of drilled apertures confirmed the expectation that the more energy invested in the processing of the aperture, the larger the aperture. Using DoE, we actually optimized the parameters of the laser beam energy supply for drilling aperture of suitable dimensions into tablets.
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