(iv) Enhanced stability of bioactive compounds.
(v) High surface-to-volume ratio of the nanoscale materials results in better
bioavailability.
(vi) Both hydrophilic and hydrophobic bioactive compounds can be
encapsulated.
Electrospraying was employed to successfully encapsulate b-carotene in its
solubilized form to enhance its stability and also to improve its bioavailability
(Basar et al. 2020). When exposed under UV light, the free-b-carotene degrades
within 180 min while only 20% degradation was found with the encapsulated
b-carotene. Wide ranges of polymers are adaptable to electrodynamic processing
including polysaccharides cellulose and its derivatives, guar gum, pectin, starch,
chitosan, alginate, etc. (Wen et al. 2017b). Viscosity, surface tension, and electrical
conductivity of the polymeric solution were found to influence the morphology of
the electrosprayed capsules or fibers (Gomez-Mascaraque et al. 2016b).
20.3.2.8 Solid Dispersion and Micelles
Solid dispersion technique is one of the most commonly employed methods to
improve the solubility and bioavailability of poorly aqueous-soluble drugs.
Crystalline drugs often exhibit poor solubility in aqueous-based solvents as the
lattice energy must be overcome to bring them into solution (Li et al. 2013).
Formulation into amorphous solid dispersion helps solubilization of such crystalline
drugs as the encapsulating polymers in the solid dispersions trapped them in the
amorphous state which facilitates their dissolution once they come in contact with
the aqueous solvents. Various cellulose derivatives have been reported to exhibit
strong enhancement of curcumin dissolution while also protecting from chemical
degradation and affecting pH-dependent release (Li et al. 2013). Various formulations of curcumin such as nanocrystal solid dispersion prepared with hydroxypropyl cellulose SL (CSD-Cur), amorphous solid dispersion with hydroxypropyl
methylcellulose acetate succinate (ASD-Cur), and nanoemulsion (NE-Cur) were
prepared and the increase in oral bioavailability compared to the unformulated
curcumin was reported to be 12-folds for ASD-Cur, 16-folds for CSD-Cur and,
9-folds for NE-Cur (Onoue et al. 2010).
Self-assembled colloidal dispersion of amphiphilic surfactants, also known as
micelles, has been another important technique to enhance the solubility of
hydrophobic drugs. Certain amphiphilic polymers are also known to form micelles
and are known as polymeric micelles (Husseini and Pitt 2008). Polymeric micelles
have been shown to enhance the solubility and bioactivity of bioactive compounds.
When Pluronic P123- and Solutol HS15-based polymeric micelles were prepared
loaded with naringenin, sustained release of naringerin and significant enhancement
in its cytotoxicity against cancer cell line were observed (Zhai et al. 2013). Oral
bioavailability of paclitaxel in glycyrrhizic acid micelle was also found to enhance
sixfolds as compared to Taxol (Yang et al. 2015).
704
L. Pachuau et al.
(v) High surface-to-volume ratio of the nanoscale materials results in better
bioavailability.
(vi) Both hydrophilic and hydrophobic bioactive compounds can be
encapsulated.
Electrospraying was employed to successfully encapsulate b-carotene in its
solubilized form to enhance its stability and also to improve its bioavailability
(Basar et al. 2020). When exposed under UV light, the free-b-carotene degrades
within 180 min while only 20% degradation was found with the encapsulated
b-carotene. Wide ranges of polymers are adaptable to electrodynamic processing
including polysaccharides cellulose and its derivatives, guar gum, pectin, starch,
chitosan, alginate, etc. (Wen et al. 2017b). Viscosity, surface tension, and electrical
conductivity of the polymeric solution were found to influence the morphology of
the electrosprayed capsules or fibers (Gomez-Mascaraque et al. 2016b).
20.3.2.8 Solid Dispersion and Micelles
Solid dispersion technique is one of the most commonly employed methods to
improve the solubility and bioavailability of poorly aqueous-soluble drugs.
Crystalline drugs often exhibit poor solubility in aqueous-based solvents as the
lattice energy must be overcome to bring them into solution (Li et al. 2013).
Formulation into amorphous solid dispersion helps solubilization of such crystalline
drugs as the encapsulating polymers in the solid dispersions trapped them in the
amorphous state which facilitates their dissolution once they come in contact with
the aqueous solvents. Various cellulose derivatives have been reported to exhibit
strong enhancement of curcumin dissolution while also protecting from chemical
degradation and affecting pH-dependent release (Li et al. 2013). Various formulations of curcumin such as nanocrystal solid dispersion prepared with hydroxypropyl cellulose SL (CSD-Cur), amorphous solid dispersion with hydroxypropyl
methylcellulose acetate succinate (ASD-Cur), and nanoemulsion (NE-Cur) were
prepared and the increase in oral bioavailability compared to the unformulated
curcumin was reported to be 12-folds for ASD-Cur, 16-folds for CSD-Cur and,
9-folds for NE-Cur (Onoue et al. 2010).
Self-assembled colloidal dispersion of amphiphilic surfactants, also known as
micelles, has been another important technique to enhance the solubility of
hydrophobic drugs. Certain amphiphilic polymers are also known to form micelles
and are known as polymeric micelles (Husseini and Pitt 2008). Polymeric micelles
have been shown to enhance the solubility and bioactivity of bioactive compounds.
When Pluronic P123- and Solutol HS15-based polymeric micelles were prepared
loaded with naringenin, sustained release of naringerin and significant enhancement
in its cytotoxicity against cancer cell line were observed (Zhai et al. 2013). Oral
bioavailability of paclitaxel in glycyrrhizic acid micelle was also found to enhance
sixfolds as compared to Taxol (Yang et al. 2015).
704
L. Pachuau et al.