Volume 4, Issue 5, May – 2019 International Journal of Innovative Science and Research Technology

ISSN No:-2456-2165

Nanosilica for Sustained Release of Quercetin and its

Antioxidant Activity
Manoj K. Patil1*, Siddhita S. Padhye2, Rhea M. Nair3
Haffkine Institute for Training, Research and Testing
Parel, Mumbai India.

Abstract:- This study was carried out to synthesize output is estimated is 80 million tons. So it is an eco-
silica nanoparticles for Sustained drug release. friendly process as it minimizes the paddy husk ash waste.
Synthesis of nanosilica was carried out from Rice husk Rice husk are often left to rot in field or burnt in open. Rice
ash by sol-gel method and the size distribution was husk contains silica in range of 20- 25wt%. The silica in
controlled by using different surfactants like, a cationic rice husk exists in the hydrated amorphous form like silica
(CTAB) and anionic (SDS) surfactant. The quercetin – gel. The amorphous nature of silica in rice husk makes it
a flavonoid was successfully incorporated in nanosilica extractable. Thermal degradation and pyrolysis of rice husk
synthesized using 2% SDS surfactant and was grafted followed by the combustion of the char results in a highly
with PEG 4000. The quercetin loading capacity into porous and amorphous silica with a varying percentage of
nanosilica was determined depending on different unburnt carbon. Combusted at moderate temperature, the
concentrations used for loading. The release of this white ash obtained from rice husk contains approximately
loaded quercetin was traced using UV 92-97% amorphous silica [2].
spectrophotometer for sustained release in Ethyl
acetate. The % release profile was also determined. The Highly pure, small particle-size nano silica powder
Antioxidant activity of the quercetin incorporated with high-surface area from agricultural by-product, such
nanosilica was checked using a DPPH antioxidant as rice husk ash, by using a simple user-friendly, alkali
assay. The successful nanosilica synthesis and drug extraction followed by an acid precipitation method. The
loading and grafting by PEG 4000, all were confirmed method is simple, cost-effective, reliable and reproducible.
by using characterization techniques like Dynamic light The purity obtained by this method is enhanced to
scattering for particle size analysis, Scanning electron conventional methods [3].
microscopy (SEM) and IR spectroscopy.
B. Drug Loading and PEG Grafting:
Keywords:- Silica nanoparticles, Rice husk ash, sol-gel Flavonoids are a large group of phenolic compounds
method, Surfactants, CTAB, SDS, Quercetin, PEG 4000, that are widely spread in different plant foods. Quercetin
Sustained release, Antioxidant activity, 2,2-diphenyl-1- (3,3′,4′,5,7-pentahydroxyflavone) is a common dietary
picrylhydrazyl(DPPH), UV spectrophotometer, Particle flavonol with a wide range of pharmacological activities
size analysis, SEM and IR spectroscopy. including antioxidant, antiplatelet, anti-inflammatory,
antimutagenic, anticarcinogenic, antiangiogenic,
I. INTRODUCTION antibacterial, antitumor, antiviral, and hepatoprotective.
The beneficial biological properties of quercetin make it a
A. Synthesis of Nanosilica: promising therapeutic agent. A possible approach to
Manipulation of matter on a 'nano' scale, is overcome this problem is loading of quercetin in
considered to be a key enabling technology. It is commonly appropriate drug delivery systems [4]. The possibility of a
known as nanomedicine, Medical applications of combination of controlled drug delivery and biocompatible
nanomaterials are expected to significantly improve disease properties of mesoporous silica has great advantages once
diagnostic, therapeutic modalities and subsequently reduce silica can induce bioactivity through its extrinsic properties.
health care costs [1]. Silica has a porous network with different diameters and
extensions that provide the possibility of hosting different
The nano silica powder is generally prepared by using molecules. The wall structures of silica pores are formed by
sol–gel method. In most of these methods, nano silica a disordered network of free silanol groups and silane
powder is synthesized using chemicals as a raw material. In bonds that act as reactive nuclei and can be hosts for
chemical methods, it is easy to control size, shape and chemical species [5-8].
purity of the material but the starting reagents are costly. In
industrial applications, low costs and large quantities of This paper to contribute to the development of drug
initial precursor are needed. Rice husk ash is one of the controlled release systems for the treatment of diseases like
most abundant by-products produced in the paddy field. cancer. Thus, mesoporous silica matrix were synthesized
Rice husk is a form of waste from the rice milling and characterized the flavonoid quercetin (C15H10O7) was
industries and is produced in abundance in around the incorporated to the particles.
country. All riceproducing countries have abundant
quantity of rice husk. India alone produces 12 million tons
of rice husks every year. Thus worldwide annual husk

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In this field drug delivery system utilizing polymeric constant temperature, after which drug release is assessed
carrier, which covalently conjugates molecule of interest, by sampling of the release media (filtrate or supernatant) or
plays an important role in modern therapeutics. Such the nanoparticles [13]. The use of syringe filters to achieve
polymer-based drug entities are called as “polymer physical separation between the release media and
therapeutics” The objectives for designing polymer nanoparticles, the small size of nanoparticles has separated
therapeutics are primarily to improve the potential of the by use of high energy separation techniques like
respective drug by enhancing water solubility, particularly centrifugation, ultracentrifugation, and ultrafiltration.
relevant for drugs with low aqueous solubility, targeted Generally, this method provides a direct approach to
delivery of drugs to specific site of action in the body and monitor drug release [14]. In continuous flow drug release
Stability against degrading enzymes or reduced uptake by occurs as a result of buffer or media constantly circulating
endothelial system. The smart drug delivery systems should through a column containing the immobilized dosage form
possess some important feature such as pre-scheduled rate, and is monitored by collecting the eluent at periodic
self-controlled, targeted, predetermined time and monitor intervals. Most used method is sample and separate, only a
the delivery [9]. PEG pro-drugs have been designed mostly few examples of the continuous flow have been reported
for the delivery of anticancer agents due to its overall for nano-sized dosage forms. Flow rates used in this
implications in the treatment. However it should be noted method depend on the type of pump as well as the filters
that PEG-antitumor pro-drug is expected to be stable used. This method suffer from several disadvantages
during circulation and degrade or hydrolyze only on including difficulty in set-up, instrument costs, filter
reaching the targeted site [10]. The coating or clogging, adsorption to the filter and glass beads, and
encapsulation of nanoparticles has been found to be of difficult to maintain the constant flow rate lead to variables
particular interest in sustained drug delivery. A in results. Low flow rates have been known to be a key
polyethylene Glycol as a coating steric stabilizer is factor causing slow or incomplete release from dosage
covalently bound to the particle at the one end Thus, in an forms [15]. This is the most versatile and popular method,
aqueous suspension, the aggregation among the in this method, physical separation of the dosage forms is
nanoparticles is prevented by the repulsion force of the achieved by usage of a dialysis membrane which allows for
PEG surface moiety. Some of the advantages are PEG is ease of sampling at periodic intervals. In general, the
nontoxic, and its attachment to silica nanoparticles provides volume enclosed in a dialysis bag (inner media) is
a biocompatible and protective surface. Due to high significantly smaller than the outer media. Thus, container
aqueous solubility, PEG polymer is considered as a size will depend on the total volume of release media
versatile candidate for drug conjugation [11]. required for the in vitro release study. In the regular
dialysis technique, drug released from the nanoparticles
C. Sustained Release: diffuses through the dialysis membrane to the outer
Much attention has been devoted to the development compartment from where the samples analysed [16].
of suitable apparatus to assess in vitro release from
nanoparticulates. In contrast to oral dosage forms where D. Determination of Antioxidant activity from nanosilica
release media typically mimics pH of the gastrointestinal To determine the antioxidant activity in a like manner
tract, selection of release media for nano-sized dosage by using a stable free radical α, α-diphenyl-β-
forms will vary depending on the site of administration as picrylhydrazyl (DPPH; C18H12N5O6, M = 394.33). The
well as the site of action of the formulation. In general, assay is based on the measurement of the scavenging
selection of release media for nanoparticulate preparation is capacity of antioxidants towards it. The odd electron of
generally based on drug solubility and stability, assay nitrogen atom in DPPH is reduced by receiving a hydrogen
sensitivity, and the method used. Drug releases from atom from antioxidants to the corresponding hydrazine.
nanoparticle by three categories, such as sample and DPPH can accept an electron or hydrogen radical to
separate (SS), continuous flow (CF), and dialysis become a stable, diamagnetic molecule; it can be oxidized
membrane (DM) methods [12]. only with difficulty, and then irreversibly. DPPH shows a
strong absorption band at 517 nm due to its odd electron
and solution appears a deep violet colour, the absorption
vanishes as the electron pairs off. The resulting
decolourization is stoichiometric with respect to the
number of electrons taken up.

It is a rapid, simple, inexpensive and widely used

method to measure the ability of compounds to act as free
radical scavengers or hydrogen donors, and to evaluate
antioxidant activity of foods. It can also be used to quantify
antioxidants in complex biological systems, for solid or
Fig 1:- Schematic for sustained drug release from liquid samples. DPPH method may be utilized in aqueous
nanosilica and non-polar organic solvents and can be used to examine
both hydrophilic and lipophilic antioxidants. Ascorbic acid
In the sample and separate method, the dosage form is is used here as a standard antioxidant.
introduced into the release media that is maintained at a

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II. EXPERIMENTAL SECTION of this mixture (at 375 nm) was then taken using an UV
spectrophotometer and noted down, 100 mg of silica
A. Materials: nanoparticles synthesized using 2% SDS surfactant was
Rice Husk Ash (obtained from Ahmedabad, India), weighed and added into the vial. The assembly was stirred
Sodium hydroxide (Merck grade), Surfactants CTAB for around 27 hours using a magnetic stirrer.
(Cetyltrimethylammonium Bromide and SDS (Sodium
dodecyl sulfate) (S.D.Fine Chem), Sulphuric Acid (Merck
grade), Quercetin (Sigma Aldrich), Polyethylene Glycol  PEG grafting of Quercetin loaded Silica nanoparticles:
molecular weight 4000 (PEG 4000), Whatman Filter paper, The absorbance of stirred sample was taken (at 375
L-Ascorbic acid stock, Ethyl Acetate (Merck Grade), and nm) using UV spectrophotometer, samples showed increase
DPPH (2,2-diphenyl-1-picrylhydrazyl). (Sigma Aldrich). in absorbance reading compared to the absorbance taken
for quercetin stock before loading. 100 mg of Polyethylene
B. Methods: Glycol molecular weight 4000 (PEG 4000) was weighed
and added to reaction mixture in and the assembly was then
 Extraction of Silica from Rice Husk Ash (RHA): kept on stirring for 24 hours using a magnetic stirrer. After
2.5 N NaOH solution was added in to 25 gm of RHA, stirring, the mixture was filtered out using a Whatman
mixed using a clean glass road and the beaker was kept for Filter paper. The absorbance of filtrate (at 375 nm) was
boiling for 90 minutes continuous stirring was carried out taken using an UV spectrophotometer and noted down. The
during boiling. After 90 minutes, content was allowed to PEG coated Quercetin loaded nano-silica which was
cool down and the solution was filtered using a whatman retained on filter paper was allowed to air dry and then
filter paper, obtained filtrate was sodium silicate and stored properly in sample vial and kept in dark.
residue above the filter paper is carbon. The residual carbon
was washed using distilled water and then dried in a hot air  Sustained release of Quercetin from PEG coated
oven. Quercetin loaded nanosilica:
5 mg of PEG coated quercetin loaded nano-silica was
2NaOH (aq.) + RHA (s) Na2SiO3 (aq.) weighed and added to 10 ml Ethyl acetate in a glass vial.
+H2O (g) Immediately after the addition, 2 ml aliquot was taken and
absorbance was checked at 375 nm (0 minute reading). The
Sodium Hydroxide Sodium silicate same aliquot was added back to vial and then assembly was
kept undisturbed throughout experimentation time,
 Preparation of mesoporus Nanosilica: absorbance readings (at 375 nm) were taken using an UV
Sodium silicate solution was split up into two beaker spectrophotometer after some definite time intervals in a
and adds 2% Cetyl trimethylammonium Bromide (CTAB) fashion similar to 0 minute reading. The process was
cationic surfactant in one beaker and 2% Sodium dodecyl repeated till a constant absorbance reading was obtained.
sulfate (SDS) anionic surfactant was added into another This reading indicates the maximum release of the
beaker. 5 M H2SO4 was added drop wise using separating quercetin from nanosilica.
funnel till neutral pH was achieved, after achieving neutral
pH the mixture was stirred for extra half hour. The mixture  Determination of Antioxidant activity using DPPH:
was centrifuged at 500 rpm for 6 minutes, the supernatant 10 μg/ml L-Ascorbic acid stock was prepared in
obtained was discard and warm distilled water was added, distilled water and kept for sonication for 15 minutes prior
this step repeated till all the un reacted surfactant was to use and 2 μM DPPH stock was prepared in Ethanol. The
removed. Residue was dried in hot air oven at 90 °C around stock was prepared and stored in amber coloured bottle and
8 hrs. Dried residue was grounded as fine as possible using at cold temperature (4 °C). Based on controlled release
mortar and pestle. calculations, stock of 1 μg/ml quercetin in Ethyl acetate
was prepared, dilutions of this stock served as positive
Surfactant control for released quercetin, 400 μl aliquot of released
Na2SiO3 (aq.) + H2SO4 (aq.) SiO2(s) + Na2SO4 (aq.) + H2O quercetin was taken from PEG coated quercetin loaded
Sodium silicate Sulphuric acid Silica oxide NP nano-silica sample added in Ethyl acetate after constant
absorbance reading at 375 nm taken using an UV
 Incorporation of quercetin in Silica Nanoparticles: spectrophotometer.
Quercetin was incorporated into silica nanoparticles
synthesized using 2% SDS surfactant. Quercetin stock of The dilutions of L-Ascorbic acid stock were made as
10μg/ml was prepared in ethanol. The stock was properly per the table 1.
stirred by using Sonicator for 15 minutes. The absorbance

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Concentration of Ascorbic acid Volume of Ascorbic acid Diluent/ distilled water Total volume
(μg/ml) stock (μl) (μl) (μl)
0 -- 400 400
0.3 12 388 400
0.3 13 384 400
0.6 24 376 400
0.8 32 368 400
1.0 40 360 400
Table 1:- DPPH Assay dilutions for 10 μg/ml L-Ascorbic acid

Sample Concentration Volume of sample stock Diluent/ Ethyl acetate Total volume (μl)
(μg/ml) (μl) (μl)
0.2 Quercetin 80 320 400
0.4 Quercetin 160 240 400
0.6 Quercetin 240 160 400
0.8 Quercetin 320 80 400
Released Quersetin. 400 -- 400

Table 2:- DPPH Assay dilutions for PEG coated Quercetin loaded nanosilica and Positive controls.

All the dilutions were made 3600 μl of DPPH was role in obtaining the pure quality of silica. The silica
added to each tube, all the tubes were kept on sonicator for obtained is in form of sodium silicate (solution), after
half a minute. This was done to mix all the contents well. addition of surfactants (2 % CTAB and 2% SDS) and
The tubes were incubated in dark at room temperature for treatment with sulphuric acid the sodium silicate gets
30 minutes. The absorbance was taken at 515 nm using an converted to gel. Thus, the process is sol-gel. The obtained
UV Spectrophotometer. Based on the results, % gel is filtered and dried, SiO2 in powder form.
Scavenging activity of released quercetin was calculated
with following formula. RHA (gm) Silica synthesized % Silica
(gm) yield
25 20.4 81.60%
Table 3:- The % yield of synthesized silica

B. Characterization of Nanosilica:
III. RESULTS AND DISCUSSION
 Particle Size Analysis:
A. Nanosilica Extracted from RHA: Particle size analysis was carried out, for nanosilica
The concentration of sodium hydroxide (2.5 N) used made using 2% CTAB and 2% SDS surfactant.
for extraction of silica from Rice husk ash plays significant

Fig 2:- Particle size distribution for silica made using 2% CTAB.

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Fig 3:- Particle size distribution for nanosilica made using 2% SDS.

The distribution obtained in silica made using 2% result. The particle sizes obtained during 3 iterations were
CTAB is not an ideal one. The particle sizes (diameters) 142.4 nm, 140.2 nm and 159.9 with average particle
obtained in three iterations was 5638.5 nm, 4915.7 nm and diameter of 147.5 nm. It was also found that in the
13213.4 nm. These are in micrometer ranges and thus, the dispersion 10% of scanned particles were having diameter
silica powder synthesized cannot be considered as less than 68.8 nm while 90% of scanned particles were
nanosilica. This could have been happened due to having diameter less than 172.3 nm. Thus, the width of the
agglomeration. The huge variations during 3 iterations also graph tells us that the particle falls in range of around 70 –
shows that small sized particles might be present in 170 nm. Thus, nanosilica with quite low polydispersibility
solution, but presence of large particles are hiding them index (0.109) was obtained using 2% SDS surfactant. Same
from DLS laser source. This silica sample was not used for sample was used for further experimentation.
any further experimentation.
The SEM was carried out only on nanosilica made
The particle size distribution obtained for nanosilica using 2% SDS surfactant.
sample made using 2% SDS surfactant showed an ideal

Fig 4:- The SEM result for nanosilica made using 2% SDS from 5 μm

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Fig 5:- The SEM result for nanosilica made using 2% SDS from 10 μm.

The data was collected over a selected area of 5 µm

and 10 µm surface of the sample. The difference between
two images is clear, as smaller distance (5 µm) shows less
particles but high focus, while larger distance (10 μm)
shows more particles. The results indicate that,
agglomeration of nanosilica is present. This was very well
expected as no functionalization of nanosilica or polymer
coating was carried out at this stage. The nanoparticles
obtained are irregularly shaped and thus have many cavities
over its surface. Such topography is suitable for loading a
drug moiety in it by simple physical attachment or
adsorption [17]. Thus, the nanosilica can be used for
loading of quercetin.

Fig 7:- IR results for nanosilica made using % SDS.

The CH2 bending at 1631.06 cm-1 and Si-O-Si

stretching at 1089.07 cm-1, confirms the silica particles
controlled by SDS surfactant. The shift seen in CH3
asymmetric stretching and CH2 bending (includes
scissoring and wagging) band pattern reconfirms the same.

Fig 6:- IR results for silica made using 2% CTAB.

Infra Red (IR) gives idea about the molecules

(functional groups) present in the given sample.

Broad peak at 3200 cm-1 indicates presence of OH

groups. The CH2 stretching at 2852.01 cm-1 and Si-O-Si
stretching at 1096.78 cm-1, confirms the silica particles
controlled by CTAB surfactant.
Fig 8:- IR results for nanosilica made using 2% SDS and
PEG coating.

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The intensity of peak at 1641.42 cm -1 which SDS surfactant reconfirm the same, as addition of quercetin
corresponds to peak at 1631.06 cm-1 in figure 4.2.5 is much has changed their interaction environment.
smaller. This indicates the successful grafting by Poly
ethylene glycol (PEG), as it hides the exposed groups of IV. LOADING AND RELEASE PROFILE
silica and SDS surfactant.
A. Standard graph for Quercetin loading:
In order to obtain concentration of quercetin that has
been loaded in nanosilica, it is important to first plot a
standard graph for a range of quercetin concentrations. The
slope of this graph will be used to determine the
concentration based on the absorbance obtained by UV-
spectrophotometer. For 0.01% quercetin loading, a stock of
10µg/ml in ethanol was directly used, while for 10%
loading, a stock of 10 mg/ml was used. But 10 mg/ml is
very high range of concentration for spectrophotometric
analysis and hence, was diluted 1000 times.

Fig 9:- IR results for Standard Quercetin.

Broad peak at 3200 cm-1 indicates presence of OH

groups which are largely present in quercetin structure
itself. The C=O stretching at 1666.50 cm-1 is a strong
indicator of quercetin. The expected frequencies with
respect to quercetin in presence of silica have been
considered from the literature [18].

Fig 11:- Standard graph for loading 2-10 μg/ml Quercetin

in Ethanol.

B. Standard graph for Quercetin release:

In order to obtain concentration of quercetin that has
been released from nanosilica, it is important to first plot a
standard graph for a range of quercetin concentrations. The
slope of this graph will be used to determine the
concentration based on the absorbance obtained by UV-
spectrophotometer. For 0.01% quercetin loading, a stock of
10µg/ml in ethyl acetate was used.

Fig 10:- The IR results for PEG coated 0.01% Quercetin

loaded nanosilica made using 2% SDS.

Broad peak at 3200 cm-1 indicates presence of OH

groups of quercetin. The slight shift of C-H stretching
bands of quercetin at 1648.20 cm-1 and 1640.72 cm-1 in
respective loaded nanosilica are indication of successful
loading. Also, the slight shifts in Si-O-Si stretching at Fig 12:- Standard graph for release 2-10 μg/ml Quercetin in
1092.93 cm-1 of silica and CH2 wagging at 1347.54 cm-1 of Ethyl acetate.

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C. Sustained release of Quercetin from nanosilica: taken and it thus contains 0.4115µg of Quercetin. This is
the highest amount of quercetin that can be released. The %
Sr. Time Absorbanc Sr. Time Absorbanc loading was found to be 82.30%.
No (mins e (at 375 No (mins e (at 375
. ) nm) . ) nm) 5 mg of sample was suspended in 10 ml of Ethyl
1. 0 0.0227 9. 90 0.1259 acetate. The absorbance obtained after 120 minutes was
2. 10 0.0447 10. 100 0.1402 0.0459. Based on slope value obtained from graph 12, the
3. 20 0.0559 11. 110 0.1460 released quercetin was 0.389 µg for 5 mg nanosilica. The
4. 30 0.0832 12. 120 0.1526 highest amount of quercetin that can be released is 0.4115
5. 50 0.1028 13. 150 0.1400 µg. Thus, % release was found to be 94.53%.
6. 60 0.1063 14. 180 0.1467
7. 70 0.1114 15. 210 0.1344 E. Scavenging Property of Quercetin incorporated
8. 80 0.1111 nanosilica:
Table 3:- Absorbance of released quercetin from 0.01%
Quercetin loaded nanosilica in Ethyl acetate  Standard graph for DPPH activity:
In order to obtain % scavenging activity quercetin
that has been released from nanosilica, it is important to
first plot a standard graph for a range of L-ascorbic acid
concentrations for DPPH scavenging. The slope of this
graph will be used to determine the concentration based on
the absorbance obtained by UV- spectrophotometer. For
0.01% quercetin nanosilica, a stock of 10 µg/ml L-Ascorbic
acid in distilled water was used. L-Ascorbic acid is a
standard antioxidant used for DPPH assay, and the
respective samples.

Concentration of L- Absorbance (at 515 nm)

Ascorbic acid (µg/ml)
0 0.0153
0.3 0.0111
0.4 0.0083
0.6 0.0065
0.8 0.0042
Fig 13:- Graph of sustained release from PEG coated 1.0 0.0016
0.01% Quercetin loaded nanosilica. Table 5:- DPPH assay of 0.3-1.0 μg/ml L-ascorbic acid
stock.
5 mg of PEG coated 0.01% Quercetin loaded
nanosilica particles were tested for release profile in 10 ml
of Ethyl acetate. It can be seen that sustained release of
quercetin is seen till 120 minutes as the absorbance
readings at this point are maximum and stable.

D. Amount Quercetin loaded and released:

10 ml of 10 µg/ml Quercetin stock prepared in
ethanol was taken and 100 mg nanosilica was used for drug
incorporation. For obtaining the absorbance of the same the
values were extrapolated on graph obtained in figure 13.

Sr. Sample Absorbance (at 375

No. nm)
1. Before loading 1.4363
2. Residual filtrate post 0.2532
PEG coating
Table 4:- Absorbance of quercetin for 0.01% loading
nanosilica in Ethanol Fig 14:- Standard graph of 0.3 -1 µg/ml L-ascorbic acid
antioxidant assay using DPPH.
Based on slope value obtained from graph 11, the
unloaded quercetin was 1.77µg and hence loaded amount The equation of the graph was found to be y=-0.013x
of quercetin was found to be 8.23 µg for 100 mg nanosilica. + 0.014. The y in line equation indicates absorbance
The release study, 5 mg loaded nanosilica sample was reading while x represents corresponding concentration.

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[3]. R. Yuvakkumar, V. Elango, V. Rajendran and N.
Sample concentration (µg/ml) Absorbance (at 515 Kannan, “High-purity nano silica powder from rice
nm) husk using a simple chemical method”, Journal of
0.2 Quercetin 0.0122 Experimental Nanoscience, Volume 9, Issue 3,
0.4 Quercetin 0.0076 (2014).
0.6 Quercetin 0.0058 [4]. PHARMACIA, vol. 63, No. 4/2016 D. Aluani, V.
0.8 Quercetin 0.0031 Tzankova, Y. Yordanov, A. Zhelyazkova, E.
Released Q. 0.01% 0.0097 Georgieva, K. Yoncheva Quercetin: an overview of
biological effects and recent development of drug
Table 6:- DPPH Assay for PEG coated Quercetin loaded delivery systems.
nanosilica and Positive controls [5]. ESPUELAS, S. Delivery systems for the treatment
and prevention of leishmaniosis. Gazeta Médica da
Based on equation obtained from graph 4.5.1, the Bahia, v.79, p. 134-146, 2009.
released quercetin from 0.01% nanosilica was found to be [6]. BELYAKOVA, L.A.; VARVARIN, A.M. Surfaces
0.37 µg after 120 minutes; the expected amount was 0.31 properties of silica gels modified with hydrophobic
µg and % scavenging property was found to be 36.60%. groups. Colloids and Surfaces A: Physicochem. Eng.
IC50 value for the assay was found to be 0.53µg/ml AAE. Aspects, v.154 p. 285–294, 1999.
[7]. HORCAJADA, P.; RÁMILA, A.; PÉREZ-
V. CONCLUSION PARIENTE, J.; VALLET-REGI, M. Influence of
pore size of MCM-41 matrices on drug delivery rate.
In summary, we have developed a simple approach to Microporous and Mesoporous Materials, v.68 n.1-3,
prepare an intelligent drug controlled delivery system. p. 105-109, 2004.
Nanosilica particles with irregular shape and amorphous [8]. SLOWING, I.I.; VIVERO-ESCOTO, J. L.; Wu, C.
nature were synthesized from Rice husk ash. The synthesis W.; LIN, V. S.-Y. Mesoporous silica nanoparticles as
was based on sol-gel method cationic surfactant (CTAB) controlled release drug delivery and gene transfection
and SDS anionic surfactant was used in order to guide the carriers. Advanced Drug Delivery, v.60, p. 1278–
nanoparticle production. It was found that, the use of 1288, 2008.
CTAB surfactant gave more yield by weight but the size of [9]. T. Andreani, A. L. de Souza, C. P. Kiill, E. N.
these particles was in micrometer range. Whereas, SDS Lorenzón, J. F. Fangueiro, A. C. Calpena, M. V.
yield was comparatively less than CTAB, but was in Chaud, M. L. Garcia, M. P. Gremião, A. M. Silva and
nanometer range (70-170 nm). This suggests a possibility E. B. Souto, “Preparation and characterization of
that CTAB surfactant has less control in silica particle size PEG-coated silica nanoparticles for oral insulin
than SDS surfactant. Scanning electron microscope (SEM) delivery”, Int J Pharm. Oct 1;473(1-2):627-35,
analysis on nanosilica made using SDS surfactant showed (2014).
irregularity of surface, this indicates that the adsorption of [10]. D. Bennet and S. Kim, “Polymer Nanoparticles for
quercetin on such surface is possible, thus making it a Smart Drug Delivery”, INTECH, (2014).
suitable candidate for quercetin as drug loading. The [11]. H. Xu, F. Yan, E. Monson and R. Kopelman, “Room
quercetin is known to have antioxidant properties and temperature preparation and characterization of poly
hence, both nanosilica samples (after 120 minutes release) ethylene glycol coated silica nanoparticles for
were used in antioxidant assay using DPPH. Batch-1 biomedical applications”, Wiley Periodicals, (2013).
particles showed 63.39% scavenging activity while Batch-2
showed 36.60%. The IC50 value for the given assay [12]. Susan D’Souza, “A Review of in Vitro Drug Release
concentration was found to be 0.53 µg/ml AAE. Test Methods for Nano-Sized Dosage Forms,”
Advances in Pharmaceutics, Article ID 304757, 12
ACKNOWLEDGMENT pages, (2014).
[13]. V. Sanna, A. M. Roggio, S. Siliani et al.,
The authors gratefully acknowledge the support of the “Development of novel cationic chitosan-and anionic
Director, Haffkine Institute for Training, Research and alginate-coated poly(D,L-lactide-co-glycolide)
Testing Parel Mumbai. nanoparticles for controlled release and light
protection of resveratrol,” International Journal of
REFERENCES Nanomedicine, vol. 7, pp. 5501–5516, (2012).
[14]. Y. I. Kim, L. Fluckiger, M. Hoffman, I. Lartaud-
[1]. P. Satalkar, B. S. Elger and D. M. Shaw, “Defining Idjouadiene, J. Atkinson and P. Maincent, “The
Nano, Nanotechnology and Nanomedicine: Why antihypertensive effect of orally administered
Should It Matter?” Sci Eng Ethics. Oct; 22(5):1255- nifedipine-loaded nanoparticles in spontaneously
1276, (2016). hypertensive rats,” The British Journal of
[2]. Heta Gandhi1, A.N. Tamaskar2, Harshali Parab3 and Pharmacology, vol. 120, no. 3, pp. 399–404, (1997).
Sonam Purohit4 Journal of Basic and Applied [15]. S. S. D'Souza and P. P. DeLuca, “Methods to assess
Engineering Research Print ISSN: 2350-0077; Online in vitro drug release from injectable polymeric
ISSN: 2350-0255; Volume 2, Number 4; January- particulate systems,” Pharmaceutical Research, vol.
March, 2015, pp. 330-333. 23, no. 3, pp. 460–474, (2006).

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ISSN No:-2456-2165
[16]. X. Xu, M. A. Khan, and D. J. Burgess, “A two-stage
reverse dialysis in vitro dissolution testing method for
passive targeted liposomes,” International Journal of
Pharmaceutics, vol. 426, no. 1-2, pp. 211–218,
(2012).
[17]. S. M. Haidary, E. P. Córcoles, and N. K. Ali,
“Nanoporous Silicon as Drug Delivery Systems for
Cancer Therapies,” Journal of Nanomaterials, Article
ID 830503, 15 pages, (2012).
[18]. M. Halo, A. M. Ferrari, G. Berlier, I. Miletto and S.
Casassa, “Experimental and first-principles IR
characterization of quercetin adsorbed on a silica
surface”, Theor Chem Acc, 135:123, (2016).

IJISRT19MY465 www.ijisrt.com 279