incorporated into phytosomes to attain their synergistic effects (Rathee and Kamboj
2018; Sharma and Sahu 2016).
20.3.2.4 Self-emulsifying Systems
Both micro- and nano-self-emulsifying systems are capable of enhancing oral
bioavailability of poorly aqueous-soluble drugs by enhancing their solubility and
dissolution rate. They are composed of a lipid, surfactant, bioactive compound, and
a co-surfactant, and following oral administration, they swiftly form microemulsions with particle size less than 100 nm within the GI fluid bringing the drug into
solution for enhanced absorption (Cui et al. 2009; Dwivedi et al. 2014). Micro- and
nano-self-emulsifying systems have been demonstrated to enhance the oral
bioavailability of various phytochemicals including curcumin (Cui et al. 2009),
arteether (Dwivedi et al. 2014), silymarin (Li et al. 2010; Wu et al. 2006), curcumin,
and thymoquinone (Alwadei et al. 2019), naringenin (Khan et al. 2015) as well as
plant extracts (Arun and Maneesh 2016).
20.3.2.5 Niosomes
Niosomes are self-assembled non-ionic surfactant vesicles analogous to phospholipid vesicles of liposomes where hydrophilic drugs are encapsulated and
hydrophobic drugs are partitioned into the hydrophobic tails of the non-ionic surfactant (Hu and Rhodes 1999; Uchegbu and Vyas 1998). Niosomes are more stable
than liposomes and are more economical to prepare from a wide range of surfactants which make them an attractive alternative to liposomes (Song et al. 2015).
Niosomal preparations are reportedly initiated from the cosmetic industry in the
1970s and gradually expanded toward drug delivery applications including phytochemicals (Muzzalupo and Mazzotta 2019). Niosomes of poorly soluble
D-limonene were reported to prolong the release of D-limonene and its cytotoxicity
toward HepG2, Macf-7, and A549 cancer cells was significantly enhanced
(Hajizadeh et al. 2019). Niosome also facilitates the solubilization of Lawsone and
compared to free Lawsone solution, the antitumor activity of Lawsone noisome
against MCF-7 breast cancer cells was increased significantly (Barani et al. 2018).
Studies have shown that niosomes are also effective carrier for the delivery of
bioactive phytochemicals across the skin. Compared to their solutions, more efficient delivery of ellagic acid across the human epidermis and dermis was observed
when it was formulated as niosomes and this penetration of the skin was reported to
be dependent on the vesicle size (Junyaprasert et al. 2012).
Niosomes may suffer from the issue of aggregation, fusion, and leakage of the
encapsulated bioactive compounds. To alleviate this problem, proniosomes have
been prepared which are dry and free-flowing type that spontaneously form niosomes on gentle agitation with hot water. Proniosomes were demonstrated to
20 Encapsulation of Bioactive Compound and Its Therapeutic Potential
701
2018; Sharma and Sahu 2016).
20.3.2.4 Self-emulsifying Systems
Both micro- and nano-self-emulsifying systems are capable of enhancing oral
bioavailability of poorly aqueous-soluble drugs by enhancing their solubility and
dissolution rate. They are composed of a lipid, surfactant, bioactive compound, and
a co-surfactant, and following oral administration, they swiftly form microemulsions with particle size less than 100 nm within the GI fluid bringing the drug into
solution for enhanced absorption (Cui et al. 2009; Dwivedi et al. 2014). Micro- and
nano-self-emulsifying systems have been demonstrated to enhance the oral
bioavailability of various phytochemicals including curcumin (Cui et al. 2009),
arteether (Dwivedi et al. 2014), silymarin (Li et al. 2010; Wu et al. 2006), curcumin,
and thymoquinone (Alwadei et al. 2019), naringenin (Khan et al. 2015) as well as
plant extracts (Arun and Maneesh 2016).
20.3.2.5 Niosomes
Niosomes are self-assembled non-ionic surfactant vesicles analogous to phospholipid vesicles of liposomes where hydrophilic drugs are encapsulated and
hydrophobic drugs are partitioned into the hydrophobic tails of the non-ionic surfactant (Hu and Rhodes 1999; Uchegbu and Vyas 1998). Niosomes are more stable
than liposomes and are more economical to prepare from a wide range of surfactants which make them an attractive alternative to liposomes (Song et al. 2015).
Niosomal preparations are reportedly initiated from the cosmetic industry in the
1970s and gradually expanded toward drug delivery applications including phytochemicals (Muzzalupo and Mazzotta 2019). Niosomes of poorly soluble
D-limonene were reported to prolong the release of D-limonene and its cytotoxicity
toward HepG2, Macf-7, and A549 cancer cells was significantly enhanced
(Hajizadeh et al. 2019). Niosome also facilitates the solubilization of Lawsone and
compared to free Lawsone solution, the antitumor activity of Lawsone noisome
against MCF-7 breast cancer cells was increased significantly (Barani et al. 2018).
Studies have shown that niosomes are also effective carrier for the delivery of
bioactive phytochemicals across the skin. Compared to their solutions, more efficient delivery of ellagic acid across the human epidermis and dermis was observed
when it was formulated as niosomes and this penetration of the skin was reported to
be dependent on the vesicle size (Junyaprasert et al. 2012).
Niosomes may suffer from the issue of aggregation, fusion, and leakage of the
encapsulated bioactive compounds. To alleviate this problem, proniosomes have
been prepared which are dry and free-flowing type that spontaneously form niosomes on gentle agitation with hot water. Proniosomes were demonstrated to
20 Encapsulation of Bioactive Compound and Its Therapeutic Potential
701