Text

theses

Developing a novel smart material with tunable properties and multiple functionalities is of great interest in scientific community. Janus particles exhibit many unique chemical and physical properties due to their two distinct surfaces. They are in great demand for diverse applications across many fields including pharmaceutical, electronics, biomedical engineering (affinity with human endothelial cells was reported), magnetolythic therapy, etc. As a drug delivery carrier, Janus particles offer a platform for co-encapsulating drugs with different solubility and release kinetics. This study investigated the effects of solvents and surfactants on nanosuspensions formulation by emulsion-diffusion method. Model Biopharmaceutical Classification System (BCS) class II drug, ibuprofen was used in the preparation of nanosuspensions using three different water miscible solvents and blends of different nonionic surfactants. Surfactants with similar chemical structures but opposing hydrophilicities act synergistically. This study shows that for any set of low HLB and high HLB surfactants systems, combination of surfactants with HLB value near the mid-point produces most efficient and stable nanosuspensions. It is observed that for any combination of nonionic surfactants, the smallest particle size is achieved when surfactants with equal amounts are incorporated.
We have also performed a different study focused on a novel method of double emulsion for coencapsulation and staggered release of hydrophobic and hydrophilic drug from PLGA/PCL Janus particles were investigated. Acetaminophen (APAP) and Naproxen (NPX) were chosen as the model hydrophilic and hydrophobic drug pair for encapsulation method and drug release. Due to its poor oil solubility and tendency to escape to the outer aqueous phase, it needs a special modification during the emulsification process. Three different strategies were employed for incorporating hydrophilic drugs: a) O/W emulsion with partially-water miscible solvent, b) O/W emulsion with methanol as a co-solvent, and c) W/O/W double emulsion. Encapsulation efficiencies, percent drug loading and differential drug release kinetics were measured and compared for different methods of synthesis. It was observed that the double emulsion method resulted in the highest encapsulation efficiency, drug loading of the hydrophilic drug and highest concentration of drug release over the period of time.

ETD_9854

M.S.

Includes bibliographical references

doi:10.7282/t3-mqmt-vc58

ETD graduate

The author owns the copyright to this work.