Personalized medicine is of growing interest due to the increasing understanding of the pathology of disease and its link to genetics. The creation of appropriate doses on demand that could be tailored to the individual patient could help to make therapy more effective and reduce the logistical difficulties of current drug production. We decided to develop dry emulsion particles with simvastatin that would exhibit suitable properties for use in 2D printing cartridges after redispersion. The emulsion was dispersed by a spray drying process and the process was optimized by design of experiments to obtain the smallest particles. We found that particle size is affected by inlet air temperature, emulsion feed rate (pump setting), nozzle pressure, nozzle position and oil phase fraction in the oil-in-water emulsion system. Then we made oil-in-water emulsions with five different hydrophilic carriers - lactose, nanocrystalline cellulose and lactose combination, sucrose, trehalose, maltodextrin with dextrose equivalent 4,0–7,0 and maltodextrin with dextrose equivalent 16,5–19,5. For the nanocrystalline cellulose and lactose combination and maltodextrin with dextrose equivalent 4,0–7,0, leucine was added to improve the particle properties. In the case of maltodextrin, this reduced the particle size and narrowed the size distribution of the dried particles. The resulting dry emulsions were redispersed in three different ratios of propylene glycol to water. It was found that the most appropriate choice of dispersion medium depended on the carrier used. We also tested the physical stability of the dispersed systems after one month and observed that for most samples, the particle size increases in the most viscous medium and decreases in the least viscous medium. We collected the product from the cyclone and the collector separately and found that the process and formulation parameters affect them differently and that there are differences in particle size and morphological properties of the samples. When analyzed by scanning electron microscopy, it was observed that for lactose and the combination of nanocrystalline cellulose and lactose, the particles are clustered together. For both maltodextrins, wrinkled particles were formed in which smaller particles were trapped, and for sucrose and trehalose, we can see differences between the particle shape of the cyclone- and collector-derived product. We have been able to produce particles that are suitable for 2D printing. The most suitable particles in terms of physical properties were produced in the case of maltodextrin with dextrose equivalent 4,0–7,0 with leucine added, which were dispersed in a medium of propylene glycol and water in a ratio of 10 : 90. They should be used immediately after dispersion, as after one month the particles aggregated into larger agglomerates.
|
