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FORMULATION AND EVALUATION OF SOLID LIPID NANOPARTICLES( SLNs)
OF ETHANOLIC EXTRACT OF ALOE VERA LEAF POWDER AND ITS
NEUROPHARMACOLOGICAL EFFECTS IN MICE
Corresponding Author: K. Sampath Kumar, M. Pharmacy(Ph.D)(Department of
Pharmaceutics),Assoc.Professor, [email protected]
Co-Author: 1. B.V Ramana M.Pharm., (Ph.D) (Department of Pharmacology), Assoc.Professor,
2. N. Srinivas Reddy , M.Pharm., (Department of Pharmacognosy), Assoc.Professor.
3. D. Maheswar Reddy, M.Pharm.,( Ph.D)(Department of Pharmaceutics), Assoc.Professor.
4. S. Usha Rani, M. Pharmacy (Department of Pharmaceutics), [email protected]
ABSTRACT:
Solid lipid nanoparticles are typically spherical with an average diameter between 1 and 1000
nm. It is an alternative carrier system to tradition colloidal carriers, such as, emulsions,
liposomes, and polymeric micro and nanoparticles. Aloe Vera (Aloe barbandensis Miller) , of
liliaceous family is having high potential medicinal values and mostly preferred for the
traditional medication. Ethanolic leaf extract of Aloe verawas prepared and it is formulated in the
form of Solid Lipid Nanoparticles (SLNs).four formulations of SLNs were prepared (SLNs1-
SLNs4) with varying percentages of steric acid (4% & 6% w/v) as a lipid, and two varying
amounts of Ethanolic extract of Aloe veraleaf. All prepared formulations were subjected to in-
vitrorelease studies, and in-vivo studies for neuropharmacological studies in mice.
KEY WORDS: Nanoparticles, Aloe Vera, Neuropharmacology, Ethanolic extract,
INTRODUCTION
Aloe Vera (Aloe barbandensis Miller) , of liliaceous family is having high potential
medicinal values and mostly preferred for the traditional medication ,which originally
found in Asian countries like, Pakistan ,Bangladesh ,India and in few parts of south
African(1).So it is a tropical and subtropical succulent plant with lance shaped leaves
along with jagged edges with sharp points(2).The plant contains flowers and fruits which
contains numerous seeds. It contains active substances such as vitamins, enzymes, amino
acids, lignin, saponins, minerals, anthraquinone glycosides, sugar, saccharide, fatty acids
etc. (3). Aloe vera plant extract is affordable and cheap, in order to treat different types of
diseases and conditions(4).According to WHO the fast growing disorder is type2 diabetes
mellitus which have the prevalence to cause severe complications even disabilities ,where
as an Aloe vera has shown significant results over Hypoglycemic condition(5).Aloe vera
extract is used to treat type 2 Streptozocin induced diabetes mellitus which shown better
effect than glimepiride by decreasing malondialdehyde and superoxide dismutase ,by
increasing the blood glutathione. And also used to control the hypoglycemic effect with
early metabolism in women, have significant effect by decreasing HbA1c levels. (6-7).
Alloxan induced diabetes mellitus In Adult male Wister albino rats treated by Aloe vera
extract which shown more activity than metformin (8-9). High molecular fractions of
Aloe vera having more Hypoglycemic effect than Glibenclamide for the treatment of
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Type 2 Diabetes mellitus (10).It is used as Daily supplementary source, in order to
regulate the hypoglycemic effect (11).
Methods of preparation of Solid Lipid Nanoparticles
There are widely 2 broad methods are there for the formulation of SLN. They are high energy
approaches and low energy approaches.
1.1 High energy approaches
1.1.1 High Pressure Homogenization Technique (HPH)
HPH is a powerful technique for the large scale production. It has been used for years for the
preparation of Nano emulsions and SLN. Recently it is adapted for the preparation of NLC also.
In this, liquid or dispersion has been pushed with a high pressure range of 100-2000 bars through
a micron size tiny gap.
Due to this the liquid attains a velocity of 1000km/hr. and the shear stress was applied
subsequently and due to this the particles were cleaved into submicron size. It can be performed
either at elevated temperatures (Hot homogenization) or at below room temperatures (cold
homogenization) . In both cases the drug is melted above the melting of lipid (above 5 - 100C of
lipid melting point).
1.1.2 Hot Homogenization
In hot HPH, lipid and drug are melted in the presence of surfactant at the same temperature. This
mixture is sheared by hot shear device, to form a pre emulsion (Pre em). The hot Pre em was
cooled to recrystallize in order to generate NLCs. However this technique increases the
temperature (1080C for each 500 bar pressure) of the dispersion which may leads to degradation
of the API.
1.5.1.3 Cold Homogenization
In this, similar to hot HPH the lipid was melted by the use of heat and the drug was dissolved or
dispersed in the matrix. This mixture of drug and lipid was rapidly cooled by dry ice or liquid
nitrogen to get solidified. The resulting solid is ground into micro particles and added to cool
surfactant solution. This was subjected to HPH to get Nano sized particles.
1.2 Low energy approaches
1.2.1 Micro emulsion Technique
In this method, the lipids are melted and mixed with hot surfactant solution, the mixture is
subjected to gentle stirring until the micro emulsion is formed. The hot micro emulsion is
dispersed in a high volume of cold water (2 – 30C) with moderate stirring. This results in the
solidification of liquid droplets. The NLCs obtained by this method are spherical in nature and
have narrow size distribution.
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1.2.2 Membrane Contactor Technique
Suitable surfactant was added to the aqueous phase and circulated in the internal channel of the
membrane. On the other hand, the melted lipid is pressed through pores of the membrane into the
internal water flow to form small droplets which are swept away by the aqueous phase. NLCs are
formed by cooling the formulation at room temperature. This method is scalable and the
variation in the particle size was attributed to different pore sizes of the membrane.
1.2.3 Phase inversion technique
In this method, lipid, drug, surfactant and water are mixed together on magnetic stirrer. Repeated
heating and cooling cycles were performed to the resulting dispersion up to three cycles and it is
then diluted with cold water causing phase inversion of the emulsion.
1.2.4 Coacervation technique:
Acidification of a micellar solution of fatty acid alkaline salts produces Nanoparticles. First of
all, a polymeric stabilizer was dissolved in water by heating. Sodium salt of fatty acid is
homogenously dispersed in the polymeric stabilizer and it is heated to get clear solution. On the
hand the drug is dissolved in the ethanol and it is again added to clear solution with constant
stirring. Then, gradual addition of coacervation solution yields phase separation. Cooling of the
suspension will result in drug loaded Nanoparticles.
1.2.5Double emulsion technique:
This method is suitable for hydrophilic active pharmaceutical ingredients and peptides. The
aqueous solution of drug is added to melted lipid to form a primary emulsion with a suitable
stabilizer. The resulting emulsion is W/O type. This is again dispersed in aqueous solution of
hydrophilic emulsifier to form W/O/W type of emulsion. It is subjected to ultra-sonication to get
the Nanoparticles. Comparatively large particles are obtained by this method.
1.2.6 Micro emulsion cooling technique
This method was patented by mumper and jay in the year 2006. In this o/w micro emulsion was
prepared in which emulsifying wax is melted at 37 – 550C followed by the addition of water.
This is subjected to heating at the same temperature with minimal stirring so as to form a
homogeneous milky slurry. A suitable polymeric surfactant is added to get a clear and stable o/w
micro emulsion in form of a liquid matrix. This is cooled at 40C to precipitate the lipid
Nanoparticles from it.
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Physicochemical Properties:
Table 1: chemicals present in ethanolic extract of ALOE VERA
constituents Ethanol extract Methanol extract
Saponins + +
Reducing sugar + +
Terpenoids + +
Tannins + +
Phenols - +
Quinones - -
Glycosides + -
Flavonoids + +
Alkaloids + -
Detected (+); Not detected (-)
MATERIALS AND METHODS
TABLE 2: LIST OF MATERIALS
S.NO MATERIALS MANUFACTURER
1 Aloe vera plant
Sreevidhyanikethan college of
pharmacy, (garden).
2 Methyl paraben
Yucca chemicals
3 Tween 80
Yucca chemicals
4 Stearic acid
Merck
5 Lecithin
Merck
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Formulation table of NLCs:
Table 3: Formulation table for Solid Lipid Nanoparticles of ethanolic extract of Aloe vera
leaf
Formulati
on code
Ethanolic
extract of Aloe
vera leaf
(Drug)mg
Lecithin(Sta
bilizer)
%w/v
Stearic
acid
(solid lipid)
%w/v
Tween 80
%v/v
Ethanol
(solvent)
mL
Water
(solvent)
mL
SLN1 100 1 4 2 25 45
SLN2 100 1 6 2 25 45
SLN3 200 1 4 2 25 45
SLN4 200 1 6 2 25 45
Method of preparation of NLCs:
SLNs were prepared by micro emulsion method. Lipid phase containing weighed quantity of
solid lipid (stearic acid) , Ethanolic extract of Aloe vera leaf and stabilizer (soya lecithin) are
dissolved in 25 ml of ethanol and were melted at 80ºC.Aqueous phase containing 2% tween 80
and water were melted at 80ºC . After attaining 80ºC of the above mixtures aqueous phase is
added slowly to the lipid phase and is stirred continuously for 2 hours with the help of
mechanical stirrer. After mechanical stirring, the prepared formulation is kept for ultra-
sonication for 10mins at 60 watts power and 30% pulse. Thus SLNs are prepared and stored in
cool temperature.
RESULTS AND DISCUSSION
1.Preformulation studies for Aloe vera LEAF POWDER
Figure No. 1 FTIR spectrum of Aloe vera leaf powder
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Table 4: Interpretation of FTIR spectrum ofAloe vera leaf powder
Figure No.2 FTIR Spectrum of Stearic acid
S.NO Frequency range Observed frequency Functional group
1 3000-3700cm-1 3263.749
O-H stretching
C-H stretching
N-H stretching
2 2700-3300cm-1 2927.391
C-H stretching
3 2100-2400cm-1 2342.297 C≡Cstretching
C≡N stretching
4 1600-1900cm-1 1705.204 C=O stretching
5 1500-1700cm-1 1598.424 N-H Bending
6 1200-1500cm-1 1375.225
O-H Bending
7 1000-1400cm-1 1026.671 C-f stretching
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Table 5: Interpretation of FTIR Spectrum of Stearic acid
SNO Frequency range Observed frequency Functional group
1 3700-3500 cm-1
3628.185 O-H stretching
2
3100-3000 cm-1
3023.983 C-H stretching
3
2260-2100 cm-1
2171.715 C≡C stretching
4
2140-1900 cm-1
2033.516 C=C stretching
5
1820-1795 cm-1
1798.622 C=O stretching
6
1570-1500 cm-1
1537.266 N=O stretching
Figure No.3 FTIR Spectrum of Lecithin
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Table 6: Interpretation of FTIR Spectrum of Lecithin
SNO Frequency range Observed frequency Functional group
1
3700-3500 cm-
3745.930
O-H stretching
2
2700-3300 cm-1
2912.694
C-H stretching
3
1600-1900 cm-1
1783.307
C=O stretching
4
1600-1700 cm-1
1696.151
N-H Bending
C=N stretching
5
1500-1700cm-1
1428.780
O-H Bending
N-H Bending
C=N stretching
6
1200-1500 cm-1
1292.986
O-H Bending
Table 7: Comparative FTIR Interpretation
Functional groups Frequency
of Aloe
vera
Frequency
of Stearic
acid
Frequency
of lecithin
Frequency
of Tween 80
Frequency of
mixture
C-H
Stretching(alkene)
3263.749
3023.983
2912.694
2855.593 2917.306
C=O
Stretching(amide)
1705.204
1798.622
1783.307
1734.337 3293.765
N-H bending
1598.424
- 1696.151
1582.227 1596.019
C-O
Stretching(phenols)
- - - - 1236.188
C≡Cstretching
C≡ N stretching
2342.297 - - 2171.715
2343.934
C-F stretching
1026.671 - - 1104.704 -
O-H Bending
1375.225 - 1292.986 1457.077 1404.219
N=O stretching - 1537.266 - - -
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Construction of standard calibration curve
TableNo. 8 Standard calibration curve
s.no Concentration (mcg/mL) Absorbance
0 0 0
1 20 0.2029
2 40 0.3945
3 60 0.5951
4 80 0.8622
5 100 0.9950
Figure No.6 Standard calibration curve of Ethanolic extract of Aloe vera leaf powder
Evaluation studies:
Percent Entrapment Efficiency (%EE):
%EE = Total amount of drug – amount of drug present in supernatant X 100
Total amount of drug
y = 0.010x - 0.021
R² = 0.995
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
0 2 0 4 0 6 0 8 0 1 0 0 1 2 0
AB
SRO
BA
NC
E
CONCENTRATION(MCG/ML)
CALIBRATION CURVE
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Table No.9 Percent Entrapment Efficiency (%EE)
Formulation code %EE
SLN1 96.23%
SLN2 97.43%
SLN3 98.06%
SLN4 98.03%
Percent drug loading
%DL = Total amount of drug – amount of drug present in supernatant X 100
Total amount of lipid
Table No.10 Percentdrug loading (%DL)
Formulation code %DL
SLN1 24.05%
SLN2 16.23%
SLN3 49.51%
SLN4 33.00%
Invitro release studies
Table No 11: In-vitro release studies of Solid Lipid Nanoparticles of ethanolic
extract of Aloe vera leaf
Time
(hrs)
SLN1
%CDR
SLN2
%CDR
SLN3
%CDR
SLN4
%CDR
0 0 0 0 0
1 32.1 31.4 21.2 22.3
2 37.2 35.7 22.3 23
3 42.4 41.5 23.0 23
4 46.9 44.5 24 25.1
5 47.4 48.5 24.4 26.1
6 48.3 52.2 25.9 27.9
7 49.5 54.6 27.3 28.8
8 50.3 57.5 27.8 29.3
10 71.3 65.0 34.2 33.1
12 75.4 68.8 38.3 36
18 82.6 78.8 43.4 42.4
24 93.1 86.8 45.4 43.4
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In vitro release studies for SLN1
Figure No.7:Zero order plot for SLN1
Figure No 8: First order plot for SLN1
0
20
40
60
80
100
0 2 4 6 8 10 12 14
%C
DR
TIME(HRS)
ZERO ORDER PLOT
0
0.5
1
1.5
2
0 5 10 15 20 25 30
Log
%C
DU
D
TIME(HRS)
FIRST ORDER PLOT
0
50
100
0 2 4 6 8 10 12 14
%C
DR
SQUARE ROOT OF TIME
HIGUCHI PLOT
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Figure No: 9 Higuchi’s plot for SLN1
Figure No: 10 Peppa’s plot for SLN1
Invitro release studies for SLN 2:
Figure No: 11 Zero order plot for SLN2
0
1
2
3
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
Log
%C
DR
Log time
PEPPA'S PLOT
0
20
40
60
80
100
0 2 4 6 8 10 12 14
%C
DR
TIME(HRS)
ZERO ORDER PLOT
0
0.5
1
1.5
2
0 5 10 15 20 25 30
Log
%C
DU
D
TIME(HRS)
FIRST ORDER PLOT
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Figure No: 12 First order plot for SLN2
Figure No: 13 Higuchi’s plot for SLN2
Figure No: 14 Peppa’s plot for SLN2
Invitro release studies for SLN 3:
0
20
40
60
80
100
0 2 4 6 8 10 12 14
%C
DR
SQUARE ROOT OF TIME
HIGUCHI PLOT
0
0.5
1
1.5
2
2.5
3
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
Log
%C
DR
Log time
PEPPA'S PLOT
0
10
20
30
40
50
0 2 4 6 8 10 12 14
%C
DR
TIME(HRS)
ZERO ORDER PLOT
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Figure No: 15 Zero order plot for SLN3
Figure No.16 First order plot for SLNs3
Figure No: 17 Higuchi’s plot for SLN3
1.7
1.75
1.8
1.85
1.9
1.95
0 5 10 15 20 25 30
Log
%C
DU
D
TIME (HRS)
FIRST ORDER PLOT
0
10
20
30
40
50
0 2 4 6 8 10 12 14
%C
DR
SQUARE ROOT OF TIME
HIGUCHI PLOT
0
0.5
1
1.5
2
2.5
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
Log
%C
DR
Log Time
PEPPA'S PLOT
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Figure No: 18 Peppa’s plot for SLN3
Invitro release studies for SLN 4:
Figure No: 19Zero order plot for SLN4
Figure No: 20 first order plot for SLNs4
1.7
1.75
1.8
1.85
1.9
0 5 10 15 20 25 30
Log
%C
DU
D
TIME (HRS)
FIRST ORDER PLOT
0
10
20
30
40
50
60
0 5 10 15 20 25 30
%C
DR
TIME (HRS)
ZERO ORDER PLOT
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Figure No: 21 Higuchi’s plot for SLNs4
Figure No: 22 Peppa’s plot for SLNs4
In vitro kinetic studies:
Table no.12 Invitro kinetic studies
Formulation
Code
Zero order
K 0 r2
First order
K1
r2
Higuchi’s plot
KH r2
Peppa’s plot
n
r2
SLN1 5.0430.9887 0.042
0.9571
5.0430.9571 0.647 0.8887
SLN2 5.4540.9054 0.036
0.9989
5.4540.9054 0.669 0.4929
SLN3 2.700
0.9283
0.007
0.9604
2.700 0.8283 0.709 0.4744
SLN4 1.3280.9023 0.006 0.9676 2.496
0.8018
0.809 0.4470
0
10
20
30
40
50
0 2 4 6 8 10 12 14
%C
DR
SQUARE ROOT OF TIME
HIGUCHI PLOT
0
0.5
1
1.5
2
2.5
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
Log
%C
DR
Log TIME
PEPPA'S PLOT
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Particle size and Zeta potential
Table No.13 Particle size and Zeta potential of SLN 1
Formulation No. Particle size Zeta potential
SLN 3 45 nm -52.5Mv
Figure No.23Particle size of SLN 3
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SEM STUDIES:
Figure No 24: SEM image of SLNs 3 at 400nm
Figure No 25: SEM image of SLNs 3 at 100nm
Neuropharmacological studies:
Learning and Memory: Table No. 14
S.NO GROUP DOSE
1 I CONTROL
2 II STANDARD
3 III 200mg SLN
4 IV 200mg AVE
Figure No 24: SEM image of SLNs 3 at 400nm
Figure No 25: SEM image of SLNs 3 at 100nm
Neuropharmacological studies:
Table No. 14 Morris water maze
Escape latency(S)
CONTROL 55.75
STANDARD 58.38
200mg SLN 74.99
200mg AVE 86.16
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Figure No.26 Learning and memory
Anxiolytic activity:
Table No.15 Elevated plus maze
Figure No.27 Anxiolytic activity
0
10
20
30
40
50
60
70
80
90
100
CONTROL STANDARD 200mg SLN 200mg AVE
Esc
ap
e la
ten
cy
Dose(mg)
LEARNING AND MEMORY
0
10
20
30
40
CONTROL STANDARD 200mg SLN 200mg AVENO
OF
EN
TR
IES
DOSE
ANXIOLYTIC ACTIVITY
No. of Entries No. of Entries
S.NO Group Dose No. of Entries Time spent(S)
Open arm Closed
arm
Open arm Closed arm
1 I CONTROL 5.83 22.17 34.33 265.67
2 II STANDARD 33.83 13.34 132.33 167.67
3 III 200mg SLN 5.75 11.33 66.33 230.33
4 IV 200mg AVE 1.75 2.10 160.00 140.83
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Figure No.28 Anxiolytic activity
Locomotor activity:
Table No. 16 Photoactometer
S.NO
Group Dose No. of
Counts
1 I CONTROL 203.60
2 III 200mg SLN 298.58
3 IV 200mg AVE 143.66
Figure No.29 Locomotor activity
0
50
100
150
200
250
300
CONTROL STANDARD 200mg SLN 200mg AVE
TIM
E S
PE
NT
(S)
Dose(mg)
ANXIOLYTIC ACTIVITY
Time spent(S) Time spent(S)
0
50
100
150
200
250
300
350
CONTROL 200mg SLN 200mg AVE
NO
OF
CO
UN
TS
Dose(mg)
LOCOMOTOR ACTIVITY
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Exploratory behavior:
Table No.17 Hole board test
S.NO TIME
(MINS)
GROUPS DOSE NO. OF
HEAD
DIPPINGS
HEAD DIP
TIME SPENT
1 5 I CONTROL 20.80 19.80
2 5 II STANDARD 50.40 39.40
3 5 III 200mg SLN 90.83 126.25
4 5 IV 200mg AVE 24.91 39.58
Figure No.30 Exploratory behaviour
Muscle relaxant activity:
Table No. 18 Rota rod test
S.NO
Group Dose Time intervals
45(min) 60(min) 90(min)
1 I CONTROL 169.00 149.33 144.00
2 II STANDARD 54.33 47.50 39.16
3 III 200mg SLN 112.0833 120.58 123.66
4 IV 200mg AVE 67.58333 77.75 87.50
0
20
40
60
80
100
120
140
CONTROL STANDARD 200mg SLN 200mg AVE
No
of
he
ad
dip
pin
gs
Dose(mg)
EXPLORATORY BEHAVIOUR
NO. OF HEAD DIPPINGS HEAD DIP TIME SPENT
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Figure No.31 Muscle relaxant activity
DISCUSSION:
The extraction was done by using the solvent Ethanol because it extract most of the chemical
active components in Aloe vera. The chemical components in Ethanolic extract of Aloe vera
includes flavonoids saponins, reducing sugars, glycoside, alkaloids, terpenoids, tannins were
identified and confirmed by various physicochemical tests.
Compatibility studies for Drug and Excipients were performed by the use of FTIR (Fourier-
Transform Infrared) spectroscopy. The results shown that all the functional groups which were
present in the individual drug and excipients were repeated in the admixture. This confirms that
there is a compatibility between drug and excipients.
Total 4 SLNs formulations were prepared in which F1 and F3 formulation contains solid lipid in
0.4%w/v and next F2 and F4 formulations contain solid lipid in 0.6%w/v.
Four formulations were prepared (SLNs1, SLNs2, SLNs3, and SLNs4). They are subjected to in-
vitro drug release studies by using dialysis bag method. The percentage cumulative drug release
for SLNs1 and SLNs2 was found to be above 85% at the end of 24th
hour, whereas it is observed
that 42% and 45% of cumulative drug release for SLNs3 and SLNs4 respectively. This may be
due to the variation in the amount of extract (SLNs1, SLNs2-100mg) and (SLNs3, SLNs4-
200mg). The SLNs3 formulation was considered as optimized formulation which releases the
Active Pharmaceutical Ingredient (API) up to 43% within 24 hours which is suitable for more
controlled release.
The percentage entrapment efficiency of SLNs 3 was found to be 968.06%, which is highest
among all other formulations. This may be due to the presence of steric acid. Further, it was
explored that there is no significant difference in the percentage entrapment efficiency due to the
varying %w/v of steric acid i.e: 4% & 6% w/v respectively.
Particle size of SLN3 was found to be low 45nm. Zeta potential of SLN3 was found to be
-52.5Mv.
0
50
100
150
200
CONTROL STANDARD 200mg SLN 200mg AVE
fall
off
tim
e(s
)
Dose(mg)
MUSCLE RELAXANT ACTIVITY
Time intervals Time intervals Time intervals
High Technology Letters
Volume 27, Issue 2, 2021
ISSN NO : 1006-6748
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Page 23
The TEM results of SLN3 reveals that the vesicles are spherical in shape and they may be
smooth in texture.
Effect of aloe vera leaf powder and its formulations on escape latency in MWM test:
In the present study, the effect of formulations of aloe vera leaf powder and its formulations on
neuropharmacological effects were evaluated using different exteroceptive behavioral models
like Morris water maze (MWM), elevated plus maze tests and locomotor activity using
actophotometer whereas muscle relaxant property was recorded using rotarod apparatus. These
tasks have been extensively used to measure learning and memory in different animal models
particularly, behavioral manipulations especially in rodents and other neuropharmacological
effects.
ELT as a measure of effective learning was measured and shown in Tab 21 & figure 26.Results
from MWM test, showed that animals treated with formulations of aloe vera were showed more
prolonged escape latencies than control and standard groups which indicates that there was no
significant effect of the tested formulations on memory and learning process.
Effect of aloe vera leaf powder and its formulations on transfer latency in Elevated plus
maze
In the study, the time required to reach the closed arm from the open arm by each animal was
considered as the transfer latency period. From the results, there was a significant (p<0.05)
anxiolytic activity were noted in AVE (100 mg/kg ) treated animals as the average time spent in
open arm were significantly raised when compared to control and standard groups. The same
trend was observed in standard drug-treated animals also.
Effect of aloe vera leaf powder and its formulations on locomotions and exploratory
behavior
Results from the rotarod test showed that significant differences between locomotor activities of
different groups were noticed. The locomotions of control groups were found to be 203s whereas
it was significantly increased in SLN treated groups when compared to AVE and control groups
which indicated the altered behavior of the preparations. The same trend (differences between
No.of head dippings of different groups) were observed in hole board test also. In hole board test
there was a significant increase in head poking were observed in SLN treated animals at the
doses of
(100 mg/kg) which indicates that the given drug has alleviated the anxiety and depression to
some extent possibly by interfering with the inhibitory neurotransmitter like GABA
(Table.25,25).
Rota rod test
In rota rod test, between the control and experimental group at 45 Min (post-treatment),
there was no significant increase in muscle grip strength was noticed but results at 90 Min (Post-
treatment) shows that there was a gradual significant increase in muscle grip strength were
noticed (P<0.05), particularly in SLN, treated animals when compared to control groups
(Fig.31).
High Technology Letters
Volume 27, Issue 2, 2021
ISSN NO : 1006-6748
http://www.gjstx-e.cn/341
Page 24
Conclusion:
In this research work Ethanolic leaf extract of Aloe verawas prepared and it is formulated in the
form of Solid Lipid Nanoparticles (SLNs).four formulations of SLNs were prepared
(SLNs1-SLNs4) with varying percentages of steric acid (4% & 6% w/v) as a lipid, and
two varying amounts of Ethanolic extract of Aloe veraleaf. All prepared formulations
were subjected to in-vitrorelease studies, % entrapment efficiency and % drug loading. In
the above studies SLNs 3 was considered as optimized and best formulation. This SLNs 3
was subjected to particle size, zeta potential and TEM studies. The above formulation is
subjected for the in-vivo studies for neuropharmacological studies in mice. Since, the
prepared formulation shown better effects in mice, it may be recommendable for
neuropharmacological effects after further studies.
CONFLICTS OF INTEREST:
There were no conflicts of interest in the development of this study.
BIBLIOGRAPHY:
1) Amar surjushe, rashemvasani and D G saple; aloe vera a short review;Indian journal of
dermatology 2008(53)4;page 163-166.
2) Sigrid sanzana,Maria Luisa Gras,DanielVidel-Brotons;Functional foods enriched in
Aloeveraeffects of vacuum impregnational temperature on the respiration rate and the
respiratory quotient of one vegetable; Procardia food science 1(2011);page-1528-1533.
3) NinadR.Jawade, Abhijeet R.chavan; Ultrasonic assested extraction of aloin from aloe
vera gel; procedia engineering 51(2013); page-487-493.
4) Shashi Sharmaa,*Dinesh kumarSinghb, Yam Bahadur GurungbK, Swoyam Prakash
Shresthaa, ChiranjibiPanthab; Immunomodulatory effect of Stinging nettle
(Urticadioica) and Aloe vera (Aloe barbadensis) in broiler chickens;veterinary and
animal science 6 2018;page 56-63.
5) Akira yogi, saharhegazy, amalkabbash, engryAbd.Elwahabi; possible hypoglycemic
effect of Aloe vera L.high molecular weight fraction of type 2 diabetic patients;Saudi
pharmaceutical journal 2009(17);page-209-215.
6) Amira Mourad Hussein Abo-Youssef, Basim Anwar Shehata Messiha; Beneficial
effects of Aloe vera in treatment of diabetes: Comparative in vivo and in vitro studies;
Bulletin of Faculty of pharmacy; Cairo university (2013) 51; Page-7-11.
7) Lilia Cardenas-Ibarra, Jesus Z. Villarreal-Perez, J. Calos Lira-Castillo, Aram Nava-
Aleman; Randomized double blind crossover trial of Aloe vera,
Cnidoscoluschayamansa and placebo for reducing hyperglycemia in women with early
metabolic syndrome; Clinical Nutrition Experimental 14(2017) 1-12.
8) Enas Ali Kamel Mohamed; Antidiabetic, Antihypercholestermic and Antioxidative
Effect of Aloe Vera Gel Extract in Alloxan Induced Diabetic Rats; Australian Journal
of Basic and Applied Sciences, 5(11): 1321-1327, 2011 ISSN 1991-8178.
9) Akira Yagi, Sahar Hegazy, Amal Kabbash, Engy Abd-EI Wahab; Possible
hypoglycemic effect of Aloe vera L. high molecular weight fractions on type 2 diabetic
patients; Saudi Pharmaceutical Journal (2009) 17, Page 209-215.
High Technology Letters
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ISSN NO : 1006-6748
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10) ManjunathK, Bhanu Prakash G, Subash KR, Tadvi NA, Manikanta M, Umamaheswara
Rao K; Effect of Aloe vera leaf extract on blood glucose levels in alloxan induced
diabetic rats; National Journal of Physiology, Pharmacy and Pharmacology.
11) Ken Jones; Dietary Aloe vera Supplematation and Glycaemic control in diabetes;
Townsend Letter for Doctors and patients May, 2007.
High Technology Letters
Volume 27, Issue 2, 2021
ISSN NO : 1006-6748
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