Polymeric particles represent a promising delivery system that enables the incorporation of
poorly soluble drugsand modifiestheir release.Polymer particlescan also be used to achieve
rapid onset of action, adequate maintenance of therapeutic plasma concentrations, and
reduced dosing frequency, ultimately resulting in enhanced patient compliance.
Electrospraying enables incorporation of a drug into polymeric particles in an amorphous
state, which, along with the size of the particles, increases the drug's metastable solubility.
In addition, the polymer matrix protects the drug from disintegration. The aim of this
master's thesis was to develop dry, monodisperse polycaprolactone (PCL) particles loaded
with simvastatin (SIM) using the design of experiments as the first step towards increasing
its solubility.
Polymer particles were developed by the electrospraying method and design of experiments,
within which we studied the effects of process and formulation parameters on the properties
of polymer particles. The morphology, size and size distribution of the particles were studied
using images taken with a scanning electron microscope and the program ImageJ.
In the initial experiments, we electrosprayed polymer solutions with a ratio of PCL and SIM
of 2:1 in chloroform or trifluoroethanol, which did not result in the formation of particles
regardlessof the solventor processparameters chosen.We found that the concentration ratio
of SIM and PCL significantly affected the formation of particles. Further, we have
investigated the effects of all process and formulation parameters on the size and size
distribution of polymer particles using the designs of experiments. The flow rate and
polymer concentration in the solution significantly impacted the size and size distribution of
the particles. The most optimal protocol was electrospraying polymer solution containing
9.5 % (m/V) PCL and 0.5 % (m/V) SIM with a flow rate of 300 μL/h at a relative humidity
of 40 % and a temperature of 25 °C. This resulted in particles with an average diameter of
2.15 μm.
The objective of the master's thesis was achieved by successful preparation of PCL particles
with SIM, which have to be physico-chemically evaluated in the next step.
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