Development of novel formulations for mucosal delivery of protein ...

Figure 3.15: CD spectra of insulin released from TG-chitosan xerogels in 0.01M HCl
(pH 2.3) ..................................................................................................................................... 99
Figure 3.16: CD spectra of insulin released from TG-chitosan xerogels in 0.01 M PBS (pH
6.8) ............................................................................................................................................ 99
Figure 3.17: Calibration curve of BSA in 1% acetic acid. .................................................... 102
Figure 3.18: Calibration curve of BSA in 0.01 M PBS ......................................................... 102
Figure 3.19: Calibration curve of INS in 0.01 M HCl .......................................................... 103
Figure 3.20: Representative SEM micrographs of lyophilised xerogels (magnification x 200).
................................................................................................................................................ 105
Figure 3.21: High magnifications of undialysed chitosan-BSA xerogel showing crystals of
NaAc (Magnification: (I) x2000), (II) x10000). ..................................................................... 106
Figure 3.22: SEM micrographs of xerogel loaded with insulin (magnification x200). ........ 106
Figure 3.23: High magnification SEM micrographs of impervious EC laminate to be used as
a backing membrane for xerogels (magnification x200 – x10000). ....................................... 107
Figure 3.24: SEM micrographs of ‘A’ porous xerogel with an impervious EC laminate as a
backing membrane and ‘B’ Stereo-paired image of laminated xerogel viewed with red/green
filters (magnification x200). ................................................................................................... 107
Figure 3.25: Stability curves obtained by Bradford’s assay. (A) and (B) show the content for
BSA while (C) and (D) show the content of INS in TG-chitosan xerogels after six months
storage in the refrigerator (RF) and under ICH conditions. ................................................... 109
Figure 3.26: BSA ‘A’ and INS ‘B’ calibration curves using SE-HPLC and RP-HPLC
respectively. ............................................................................................................................ 110
Figure 3.27: Stability curves obtained by SE-HPLC and RP-HPLC for BSA and INS
respectively. (A) and (B) show the content for BSA while (C) and (D) show the content of
INS in TG-chitosan xerogels after six months storage in the refrigerator (RF) and under ICH
conditions. .............................................................................................................................. 110
Figure 3.28: SE-HPLC chromatograms ‘A’ shows BSA powder peak (retention time around
6.γ minutes), ‘B’ BSA released from TG-chitosan xerogels stored at 5 °C and ‘C’ BSA and
degraded BSA products released from TG-chitosan xerogel stored under ICH accelerated
stability conditions for six months. The RP-HPLC chromatogram ‘D’ shows the peak of pure
INS powder (retention time around 5 minutes), ‘E’ the peak of INS from TG-chitosan stored
in a refrigerator and ‘F’ INS and degraded INS products from xerogels stored under ICH
conditions. .............................................................................................................................. 112
Figure 4.1: (a) Schematic diagram of texture analyser with xerogel attached to the probe and
the mucosal substrate on the platform (b) Typical texture analysis force-distance plot. ....... 118