encapsulated drug (Pandey et al. 2005). As a result, polymeric nanocapsules
facilitate both oral and parenteral administration of bioactive compounds. The type
and amount of the wall formers in nanocapsules have been shown to influence the
size, surface properties, stability, drug-loading capacity, aqueous solubility, and the
release profile of the encapsulated compounds (Dos Santosa et al. 2016). Therefore,
selection of appropriate wall-forming material is crucial to impart the desired
functionality to the nanocapsules. Biocompatible and biodegradable poly(lactic
acid) (PLA), poly(glycolic acid) (PGA), and their copolymer poly
(lactide-coglycolide) (PLGA) are among the most commonly used polymers for
nanoencapsulation (Liu and Feng 2015). Encapsulation of ellagic acid in PLGA
nanoparticles was found to increase the intestinal permeability from 66% in
aqueous suspension of ellagic acid from to 87% in nanocapsules while also
exhibiting its antioxidant effects (Bala et al. 2006). PLGA-based silymarin
nanocapsule was also shown to sustain the release, improve bioavailability, and
exhibit preferential toxicity toward prostate cancer cells, thus enhancing its overall
therapeutic efficacy (Snima et al. 2014). Nanoencapsulation of curcumin with
PLGA also delayed the progression of diabetic cataract in animal model (Grama
et al. 2013) (Table 20.3).
Poorly aqueous-soluble anticancer phytochemical paclitaxel, isolated from
Taxus brevifolia, which also suffers from P-glycoprotein-mediated efflux and
metabolism by cytochrome P450 metabolic enzymes (Singla et al. 2002), had been
alleviated through nanoencapsulation. The improvement in permeability of
nanoencapsulated paclitaxel across Caco-2 monolayers was found to be 6.7–7.4
times of the lone paclitaxel and the plasma concentration time curve (AUC) and
C max following oral administration also increased up to 5.7 times and 7.3 times,
respectively (Iqbal et al. 2011).
Coating with mucoadhesive polymers is another means to improve oral
bioavailability of bioactive compounds due to their ability to bring prolonged and
intimate contact with GI tract surfaces resulting in better absorption. Chitosan has
often been used to coat the polymeric nanocapsules due to its ability to adhere to the
negatively charged mucosal surface, thus improving absorption and hence therapeutic activity (Chuah et al. 2014; Ensign et al. 2012; Mazzarino et al. 2012).
Capsaicin is a natural bioactive compound isolated from peppers with pungent
odor and quick degradation and nanoencapsulation with natural wall formers
gelatin and acacia was able to mask the pungency and instability of capsaicin
(Jincheng et al. 2010; Wang et al. 2008). pH-dependent release and thermal stabilization of bioactive compounds have also been achieved using natural-based
encapsulating materials (Akbari and Wu 2016; Pinheiro et al. 2015).
20.3.2.2 Solid Lipid Nanoparticles (SLN) and Nanostructured Lipid
Carriers (NLC)
Lipid-based nanocarriers like SLNs have become effective alternative delivery
systems to conventional colloidal carriers like emulsions, liposomes, and polymeric
20 Encapsulation of Bioactive Compound and Its Therapeutic Potential
695
facilitate both oral and parenteral administration of bioactive compounds. The type
and amount of the wall formers in nanocapsules have been shown to influence the
size, surface properties, stability, drug-loading capacity, aqueous solubility, and the
release profile of the encapsulated compounds (Dos Santosa et al. 2016). Therefore,
selection of appropriate wall-forming material is crucial to impart the desired
functionality to the nanocapsules. Biocompatible and biodegradable poly(lactic
acid) (PLA), poly(glycolic acid) (PGA), and their copolymer poly
(lactide-coglycolide) (PLGA) are among the most commonly used polymers for
nanoencapsulation (Liu and Feng 2015). Encapsulation of ellagic acid in PLGA
nanoparticles was found to increase the intestinal permeability from 66% in
aqueous suspension of ellagic acid from to 87% in nanocapsules while also
exhibiting its antioxidant effects (Bala et al. 2006). PLGA-based silymarin
nanocapsule was also shown to sustain the release, improve bioavailability, and
exhibit preferential toxicity toward prostate cancer cells, thus enhancing its overall
therapeutic efficacy (Snima et al. 2014). Nanoencapsulation of curcumin with
PLGA also delayed the progression of diabetic cataract in animal model (Grama
et al. 2013) (Table 20.3).
Poorly aqueous-soluble anticancer phytochemical paclitaxel, isolated from
Taxus brevifolia, which also suffers from P-glycoprotein-mediated efflux and
metabolism by cytochrome P450 metabolic enzymes (Singla et al. 2002), had been
alleviated through nanoencapsulation. The improvement in permeability of
nanoencapsulated paclitaxel across Caco-2 monolayers was found to be 6.7–7.4
times of the lone paclitaxel and the plasma concentration time curve (AUC) and
C max following oral administration also increased up to 5.7 times and 7.3 times,
respectively (Iqbal et al. 2011).
Coating with mucoadhesive polymers is another means to improve oral
bioavailability of bioactive compounds due to their ability to bring prolonged and
intimate contact with GI tract surfaces resulting in better absorption. Chitosan has
often been used to coat the polymeric nanocapsules due to its ability to adhere to the
negatively charged mucosal surface, thus improving absorption and hence therapeutic activity (Chuah et al. 2014; Ensign et al. 2012; Mazzarino et al. 2012).
Capsaicin is a natural bioactive compound isolated from peppers with pungent
odor and quick degradation and nanoencapsulation with natural wall formers
gelatin and acacia was able to mask the pungency and instability of capsaicin
(Jincheng et al. 2010; Wang et al. 2008). pH-dependent release and thermal stabilization of bioactive compounds have also been achieved using natural-based
encapsulating materials (Akbari and Wu 2016; Pinheiro et al. 2015).
20.3.2.2 Solid Lipid Nanoparticles (SLN) and Nanostructured Lipid
Carriers (NLC)
Lipid-based nanocarriers like SLNs have become effective alternative delivery
systems to conventional colloidal carriers like emulsions, liposomes, and polymeric
20 Encapsulation of Bioactive Compound and Its Therapeutic Potential
695