The aim of the present research was formulation and evaluation of anti-inflammatory drug dexibuprofen loaded chitosan-based polymeric nanoparticles (NPs) for the controlled release of dexibuprofen using different concentrations of chitosan and surfactant. Materials and Methods: Dexibuprofen, a nonsteroidal anti-inflammatory drug was encapsulated with the polymer by emulsion-droplet coalescence method (DNP1-DNP5). The NPs were characterized by drug content, particle size, zeta potential, encapsulation efficiency, and in vitro drug release. Result: DNP3 was selected as best formulation due to its ideal particle size (437.6 nm), high entrapment efficiency (88.54%), and desirable drug release (99.81 ± 0.92% at the end of 24 h). Conclusion: The present study can be concluded that the newly formulated controlled release nanoparticulate drug delivery system of dexibuprofen may be ideal and effective in the management of pain due to arthritis by allowing the drug to release continuously for 24 h.

1. Drug Invention Today | Vol 10 • Issue 2 • 2018
248
Design and development of dexibuprofen loaded chitosan
nanoparticles
B. Senthilnathan1
, K. Gopalasatheeskumar1
, A. Vijayalakshmi2
*, E. Bhavya1
, Vedhapal Jeyamani1
,
K. Masilamani1
, B. Swarnapriya1
INTRODUCTION
Nano drug delivery systems are exhibited with high
drug loading capacity. This ability reduces the amount
of the excipients such as polymers and lipids required
for drug delivery in the body.[1]
In recent years,
nanoparticles (NPs) are gaining more attention as these
systems deliver the drug controlled release of drug for
long period of time to maintain the steady-state blood
level concentration of the drug, therefore providing a
reduction in the dosing frequency and increasing patient
compliance. These systems are designed mainly for the
drugs which are required to be taken frequently.[2,3]
The NPs are attractive based on their important and
unique features, such as their surface to mass ratio,
which are much larger than that of other particles
and materials, allowing for the catalytic promotion
of reactions, as well as their ability to adsorb and
carry other compounds.[4]
The reactivity of the
surface originates from quantum phenomena and
Research Article
1
Department of Pharmaceutics, Jaya College of Paramedical Sciences, College of Pharmacy, Thiruninravur, Tamil Nadu,
India, 2
Department of Pharmacognosy, School of Pharmaceutical Sciences, Vels Institute of Science, Technology &
Advanced Studies, Pallavaram, Chennai, Tamil Nadu, India
*Corresponding author: A. Vijayalakshmi, Department of Pharmacognosy, School of Pharmaceutical Sciences, VISTAS,
Pallavaram, Chennai, Tamil Nadu, India. Tel.: 044-22662150. E-mail: avijibaskaran@gmail.com
Received on: 17-10-2017; Revised on: 21-11-2017; Accepted on: 08-02-2018
Access this article online
Website: jprsolutions.info ISSN: 0975-7619
can make NP unpredictable since, immediately after
generation, NP may have their surface modified,
depending on the presence of reactants and adsorbing
compounds, which may instantaneously change
with changing compounds and thermodynamic
conditions. Therefore, on the one hand, NP has a large
(functional) surface which is able to bind, adsorb and
carry other compounds such as drugs, probes, and
proteins. On the other hand, NP has a surface that
might be chemically more reactive compared to their
fine analogs.[5]
The aim of the present work was to prepare
dexibuprofen loaded chitosan NP to deliver the
controlled release of the drug so that its frequency of
administration and its bioavailability can be enhanced.
MATERIALS AND METHODS
Materials
Dexibuprofen, chitosan, and ethanol were purchased
from Sigma-Aldrich. Potassium dihydrogen
phosphate, orthophosphoric acid was purchased from
M/S SD Fine Chemicals, Mumbai.All other chemicals
and reagents used were of analytical grade.
ABSTRACT
Objective: The aim of the present research was formulation and evaluation of anti-inflammatory drug dexibuprofen loaded
chitosan-based polymeric nanoparticles (NPs) for the controlled release of dexibuprofen using different concentrations of
chitosan and surfactant. Materials and Methods: Dexibuprofen, a nonsteroidal anti-inflammatory drug was encapsulated
with the polymer by emulsion-droplet coalescence method (DNP1-DNP5). The NPs were characterized by drug content,
particle size, zeta potential, encapsulation efficiency, and in vitro drug release. Result: DNP3 was selected as best formulation
due to its ideal particle size (437.6 nm), high entrapment efficiency (88.54%), and desirable drug release (99.81 ± 0.92% at the
end of 24 h). Conclusion: The present study can be concluded that the newly formulated controlled release nanoparticulate
drug delivery system of dexibuprofen may be ideal and effective in the management of pain due to arthritis by allowing the
drug to release continuously for 24 h.
KEY WORDS: Chitosan, Coalescence, Dexibuprofen, Encapsulation, Nanoparticle

2. B. Senthilnathan, et al.
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Drug Invention Today | Vol 10 • Issue 2 • 2018
Preformulation
Preformulation testing is the 1st
step in the development
of a formulation of a drug to different dosage
forms. It is a process, which involves analyzing and
choosing of suitable drug delivery by determining
the physicochemical properties of a new compound,
which can influence the drug performance and its
dosage form. It gives the wide information needed to
know the character of a drug substance and suitability
of dosage form. Hence, preformulation studies were
performed to confirm the absence of interaction of the
drug with other additives. The preformulation studies
carried out for the present work were;
• Preparation of calibration graph for dexibuprofen
• Preparation of calibration curve in pH 1.2, pH 7.4,
and pH 6.8 buffer solutions.
Preparation of Calibration Curve in pH 1.2,
pH 7.4, and pH 6.8 Buffer Solutions
An accurately weighed amount of dexibuprofen
100 mg was dissolved in small volume of buffer
solutions in each of three 100 mL volumetric flask
and the volume was adjusted to 100 mL with 1.2 pH
buffer in first volumetric flask, 7.4 pH buffer in second
volumetric flask, and the third one was adjusted to
100 mL with 6.8 pH buffer. A series of a standard
solution containing in the concentration range from
10 to 50 µg/mL of dexibuprofen were prepared for
1.2 pH buffer solution, 7.4 pH buffer solution, and
6.8 pH buffer solution separately, absorbance was
measured at 222 nm, and calibration graph was plotted
using concentration versus absorbance.
Drug-excipient Compatibility Studies
Samples of individual components as well as each
drug-excipient were weighed (Mettler Electronic
balance) directly in pierced aluminum crucible pans
(5–10 mg) and scanned in the 50–300°C temperature
range under static air, with a heating rate of 10°C/min,
using Shimadzu DSC-60 equipment.[6]
Preparation of Chitosan-Based NP
Emulsion-droplet coalescence method[7-11]
was adopted
for the preparation of dexibuprofen loaded chitosan
NP using various concentration of polymer as per the
formula is given in Table 1. Chitosan was dissolved
in 1% acetic acid, and 300 mg of dexibuprofen in
phosphate buffered saline. This solution was added to
10 mL of liquid paraffin containing 5% v/v tween 20.
This mixture was stirred using a homogenizer 3 min
to form water in oil (w/o) emulsion. The resultant
dexibuprofen NPs were centrifuged at 3000 rpm
for 60 min and washed using ethanol and water,
consecutively to remove the remaining surfactant and
liquid paraffin. Later they were dried in air for 3 h
followed by hot air oven at 50° for 4 h and stored in
a desiccator. Several batches, namely, DNP1, DNP2,
DNP3, DNP4, and DNP5 were formulated by changing
the drug, and polymeric ratio and the effect of polymer
concentration on the encapsulation efficiency and the
drug loading capacity was studied.
Characterization of NP
Particle size and surface charge
Surface charge is important in adhesion and interaction
of the particle with cells. The zeta- potential is used
to measure the cell surface charge density. It can be
measured using Malvern-mastersizer.The prepared NPs
were evaluated for their particle size and surface charge
by photon correlation spectroscopy using zetasizer. The
formulations were diluted to 1:1000 with the aqueous
phase of the formulation to get a suitable kilo counts
per second (kcps). Analysis was carried out at 25°C
with an angle of detection of 90°. In this experiment,
six replicates were taken for the measurement.[12]
Drug content
1 g of dexibuprofen NP were accurately weighed
and transferred into a 25 mL volumetric standard
flask. The sample was dissolved with 5 mL of
pH 6.8 phosphate buffer weighed accurately 1 g of
budesonide NP and transferred into a 25 mL standard
flask. The sample was dissolved with 5 mL of pH 6.8
phosphate buffer and diluted to 25 mL with pH 6.8
phosphate buffer. 1 mL of this solution was diluted
to 25 mL with buffer solution. Then, the standard and
sample absorbance was measured at 253 nm using
an ultraviolet (UV)-visible spectrophotometer. The
percentage of drug content was calculated.
Drugcontent %
Weight of drugin
nanoparticles
Weight of nanopart
( ) =
i
icles
1
× 00
Entrapment efficiency
The drug-loaded NPs were exposed to centrifugation
at 15,000 rpm for 30 mine supernatant liquid was
separated, and 1 mL of this solution was diluted
Table 1: Formula used for the preparation of dexibuprofen nanoparticles
Formulation Drug (mg) Chitosan (%V/V) Tween (%V/V)
DNP1 300 1 5
DNP2 300 1.5 5
DNP3 300 2 5
DNP4 300 2.5 5
DNP5 300g 3 5

3. B. Senthilnathan, et al.
Drug Invention Today | Vol 10 • Issue 2 • 2018
250
with water, and the absorbance was measured at
253 nm.[13]
The amount of dexibuprofen unentrapped
in the supernatant was calculated. The amount of
dexibuprofen entrapped was determined by subtracting
the amount of free unentrapped dexibuprofen from the
total amount of budesonide taken for the preparation.
The formula used to calculate entrapment efficiency
was given below
Drugentrapment %
Massof drug
in nanoparticles
Massof drug used
i
( ) =
n
n formulation
×100
In vitro release
In vitro release studies were performed for 24 h using
dialysismembraneusingtheFranzdiffusioncell.[14]
The
prepared dexibuprofen NPs formulations were placed
inside a dialysis membrane and immersed in pH 6.8
phosphate buffer. At predetermined time intervals, the
samplewaswithdrawn,andtheamountofdexibuprofen
released was determined by measuring the absorbance
at 253 nm using a UV-visible spectrophotometer. From
the absorbance values, the cumulative percentage drug
release was calculated.
RESULTS AND DISCUSSION
The preformulation results obtained for the drug
dexibuprofen were found to be within the limits and
desirable standards for the preparation of dexibuprofen
NPs. Dexibuprofen loaded chitosan NPs were prepared
as per the formula is given in Table 1. Standard
calibration curve of dexibuprofen was carried out in
1.2 pH, 7.4 pH, and 6.8 pH buffer at 220 nm. The r2
value in the entire medium shows nearly 1, which
signifies linearity [Table 2 and Figure 1].
Drug-excipients Accelerated Compatibility Study
On analysis of the drug-excipient mixture for their
physical characteristics, no color change was observed.
Based on the chemical evaluation, it was found that
there was no significant change observed indicating
that the drug is compatible with the added ingredients.
The results were given in Tables 3-6.
Drug Content and Entrapment Efficiency
Particle size and entrapment efficiency of the
dexibuprofen NPs (DNP1-DNP5) were increased
with increasing chitosan concentration. This may be
due to the high amount of availability of chitosan
to encapsulate the drug, on increasing the chitosan
content, number of layers coated the drug was
increased, this resulted in increased particle size and
entrapment efficiency. Further increase in the chitosan
concentration (DNP5), there is no much increase in Figure 1: Calibration curve of dexibuprofen
Table 2: Absorbance of dexibuprofen in buffer
solutions
Concentration (µg/mL) Absorbance
pH 1.2 pH 7.4 pH 6.8
10 0.125 0.120 0.151
20 0.252 0.242 0.305
30 0.374 0.364 0.454
40 0.503 0.486 0.608
50 0.627 0.607 0.756
Table 4: Physical characteristics of individual drug
and excipients
Sample ID Initial description Final
description
Dexibuprofen White crystalline
powder
No change
Chitosan Off‑white powder No change
Table 6: Chemical characteristics of drug‑excipient
mixture
Sample ID Initial
assay (%)
Final
assay (%)
Dexibuprofen 99.80±0.64 99.79±0.65
Dexibuprofen+chitosan 99.78±0.18 99.71±0.34
n=3, mean±SEM
Table 3: Physical characteristics of dexibuprofen
Physical parameters Results
Description White crystalline powder
Melting point 98.2°C
Loss on drying 0.08%
Assay 99.80%
Table 5: Physical characteristics of drug‑excipient
mixture
Sample ID Initial
description
Final
description
Dexibuprofen White
crystalline
powder
No change
Dexibuprofen+chitosan Off‑white
powder
No change

4. B. Senthilnathan, et al.
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Drug Invention Today | Vol 10 • Issue 2 • 2018
the entrapment efficiency due to the availability of the
drug to be incorporated is low which is not enough for
further encapsulation of drug by chitosan. The results
were given in Table 7 and Figures 2 and 3.
In vitro drug release
From the in vitro drug release study results, the
maximum percentage drug release (99.81 ± 0.92) at
the end of 24 h was observed with trial DNP3 which
contains2% w/vofChitosan.Below2% w/vofChitosan
concentration as in the case of trials DNP1 and DNP 2
the maximum percentage drug release 99.79 ± 0.12 and
99.81 ± 0.29 were obtained at the end of 12 and 20,
respectively, which was not desirable. Above 2% w/v
of Chitosan concentration, reduction in drug release
was observed as in the case of trial DNP4 and DNP5.
The maximum percentage drug release for DNP4 and
DNP5 was found to be 90.67 ± 0.19 and 83.75 ± 0.76,
respectively, at the end of 24 h was obtained.
From the in vitro drug release data for DNP1-
DNP5, it was observed that increase in Chitosan
concentration delays the drug release due to
increased particle size and reduced surface area of
the prepared NPs. From all the formulations, DNP3
was selected as best formulation due to its ideal
particle size (437.6 nm), high entrapment efficiency
(88.54%), and desirable drug release (99.81 ±
0.92% at the end of 24 h). The results were shown
in Table 8 and Figure 4.
CONCLUSION
Dexibuprofen NPs were prepared by emulsion-droplet
coalescence method, and the polymer concentrations
were optimized by various trials. In the present study,
Chitosan NPs containing dexibuprofen was prepared.
The effect of increase in Chitosan concentration in
various parameters such as particle size and in-vitro
releaseprofilewasstudied.ThedexibuprofenNPswere
formulated and evaluated for its in vitro drug release
Table 8: In vitro release studies of dexibuprofen nanoparticles
Time (h) % Cumulative drug release
DNP1 DNP 2 DNP 3 DNP 4 DNP 5
0.5 51.45±0.34 45.86±0.45 25.65±0.28 15.43±0.33 10.63±0.33
1 75.87±0.67 62.18±0.73 42.76±0.14 25.42±0.11 20.45±0.85
6 88.65±0.45 79.76±0.25 55.83±0.25 40.76±0.42 35.83±0.43
12 99.79±0.12 87.73±0.87 64.64±0.46 55.47±0.24 44.63±0.41
16 99.78±0.34 96.82±0.25 75.83±0.56 66.83±0.37 60.35±0.12
20 99.79±0.25 99.81±0.29 83.79±0.27 79.85±0.54 75.72±0.35
24 99.75±0.34 99.79±0.34 99.81±0.92 90.67±0.19 83.75±0.76
Mean±SD, n=3
Table 7: Drug content and entrapment efficiency Particle size and zeta potential of dexibuprofen nanoparticles
Trials Zeta potential (mV) Particle size (nm) Entrapment efficiency (%) Drug content (%)
DNP1 15.8 450.7 67.54 99.80
DNP 2 14.6 447.8 78.83 99.82
DNP 3 12.8 437.6 88.54 99.81
DNP 4 11.7 425.4 88.61 99.78
DNP 5 10.7 414.9 88.63 99.79
Figure 2: Particle size of optimized dexibuprofen loaded
chitosan nanoparticles (DNP3)
Figure 3: Zeta potential of optimized dexibuprofen loaded
chitosan nanoparticles (DNP3)

5. B. Senthilnathan, et al.
Drug Invention Today | Vol 10 • Issue 2 • 2018
252
profile.The results showed that the in vitro drug release
for DNP1, DNP2, DNP3, DNP4, and DNP5 were
found to be 99.75 ± 0.34, 99.79 ± 0.34, 99.81 ± 0.92,
90.67 ± 0.19, and 83.75 ± 0.76, respectively, at the
end of 24 h.
Based on the in vitro drug release profile
of dexibuprofen NPs formulations (DNP1-
DNP5), formulation DNP3 was selected as the
best formulation in which the particle size was
437.6 nm. The in vitro percentage drug release of
DNP3 formulation was 99.81 ± 0.92, and it was
found to be suitable formulation to manage the
condition of rheumatoid arthritis. Hence, it can be
concluded that the newly formulated controlled
release nanoparticulate drug delivery systems of
dexibuprofen may be ideal and effective in the
management of pain due to arthritis by allowing the
drug to release continuously for 24 h.
ACKNOWLEDGMENT
Authorsacknowledgesincerethankstothemanagement
for the facilities granted for the research work.
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Figure 4: In vitro drug release of dexibuprofen loaded
chitosan nanoparticles (DNP1-DNP5)
Source of support: Nil; Conflict of interest: None Declared