아주대학교

목차

1. Introduction 1
2. Materials and Methods 5
2.1. Materials 5
2.2. Preparation of gelatin-oleic acid conjugates (GOC) 6
2.2.1. Preparation of GOC-1 via solvent-based precipitation 6
2.2.2. Preparation of GOC-2 via spray drying 7
2.3. Preparation of DDAVP-loaded formulations 7
2.3.1. Preparation of DDAVP-xanthan gum complexes 7
2.3.2. Incubation-based association of DDAVP with GOC-1 systems 8
2.3.3. Preparation of spray-dried DDAVP-GOC SDs 9
2.3.4. Preparation of gelatin-based W/O/W spray-dried formulations 12
2.3.5. Preparation of GOC-based W/O/W spray-dried formulations 13
2.4. Characterization of GOC and DDAVP-loaded formulations 14
2.4.1. Determination of degree of substitution by o-phthaldialdehyde (OPA) assay 14
2.4.2. Determination of critical micelle concentration (CMC) 14
2.4.3. Particle size and polydispersity index (PDI) analysis 15
2.4.4. Fourier-transform infrared spectroscopy (FT-IR) 15
2.4.5. Differential scanning calorimetry (DSC) 16
2.4.6. Powder X-ray diffraction (PXRD) 16
2.4.7. Morphological analysis (SEM and TEM) 16
2.4.8. Circular dichroism (CD) spectroscopy 17
2.5. HPLC analysis 18
2.6. DL and content analysis 18
2.7. In vitro stability study 19
2.8. In vitro release study 20
3. Results and discussion 21
3.1. Characterization of GOC 21
3.1.1. Structural characterization of GOC by FT-IR 21
3.1.2. Degree of substitution and self-assembly behavior of GOC 22
3.2. Formulation feasibility and physicochemical characterization of DDAVP- loaded systems 24
3.2.1 Incubation-based association of DDAVP with GOC-1 systems 24
3.2.2 FT-IR, thermal, and solid-state characterization of DDAVP-loaded formulations 27
3.2.3 CD analysis of DDAVP after formulation processing 30
3.2.4 Morphological characterization of W/O/W formulations 32
3.2.5 DL and apparent encapsulation behavior 34
3.3. Degradation behavior of free DDAVP in aqueous and simulated gastrointestinal media 36
3.4. Stabilization behavior of DDAVP-loaded formulations in SIF 38
3.4.1. Stabilization behavior of DDAVP–xanthan gum complexes 38
3.4.2. Stabilization behavior of spray-dried DDAVP–GOC-1 SD 39
3.4.3. Stabilization behavior of gelatin-based W/O/W formulations 40
3.4.4. Stabilization behavior of GOC-2-based W/O/W formulations 41
3.5. In vitro release behavior of DDAVP-loaded formulations 43
3.6. Mechanistic interpretation of DDAVP stabilization by GOC-based W/O/W systems 48
4. Conclusions 49
5. References 51
국문초록 57