isolation and evaluation of hibiscus rosa sinensis leaf mucilage as superdisintegrant

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ISOLATION AND EVALUATION OF HIBISCUS ROSA- SINENSIS LEAF MUCILAGE
AS SUPERDISINTEGRANT
Rajni Bala, *Reecha Madaan, Vibhu, Aneesh and Dr. Sandeep Arora
Chitkara College of Pharmacy, Chandigarh-Patiala National Highway, Rajpura, Patiala, Punjab 140 401, India.
Article Received on 02/06/2016 Article Revised on 23/06/2016 Article Accepted on 14/07/2016
INTRODUCTION
Oral route of administration still continues to be the most
preferred route due to its diverse advantages including
ease of administration, precise dosage, self - medication,
versatility, pain avoidance leading to high level of patient
compliance. Tablets and capsules are the most popular
dosage forms, but main drawback of such dosage form is
dysphasia or difficulty in swallowing. [1] This leads to the
development of novel dosage forms such as fast
disintegrating/ dissolving tablets (FDT). FDT are a solid
single-unit dosage forms that are placed in mouth,
allowed to disperse/dissolve in the saliva without the
need of water and provides a quick onset of action. Some
drugs are absorbed from mouth, pharynx and oesophagus
as the saliva passes down into the stomach. In such cases
bioavailability of drug is significantly greater than those
observed from conventional tablet dosage form. [2] The
Centre for Drug Evaluation and Research (CDER), US
(FDA) defined FDT as “Asolid dosage form containing
medicinal substance or active ingredient which
disintegrates rapidly usually within a matter of seconds
when placed upon the tongue.” [3]The disintegration time
for FDTs generally ranges from several seconds to about
a minute. The bioavailability of some drugs may be
increased due to absorption of drugs in oral cavity and
also due to pregastric absorption of saliva containing
dispersed drugs that pass down into the stomach.
Recently immediate release tablets have started gaining
popularity and acceptance as a drug delivery system,
mainly because they are easy to administer, has quick
onset of action is economical and lead to better patient
compliance. They are also a tool for expanding markets,
extending product life cycles and generating
opportunities.[4] In the formulation of FDT,
superdisintegrants are added to facilitate the breakup or
disintegration of tablet content into smaller particles that
can dissolve more rapidly than in the absence of
disintegrants. Common superdisintegrants used are
croscarmellose sodium (Vivasol, Ac‐Di‐Sol),
crospovidone (Polyplasdone), carmellose (NS‐300),
carmellose calcium (ECG‐505), sodium starch glycolate
(SSG) etc.[5] Similarly, various natural polymers like gum
SJIF Impact Factor 3.628
Research Article
ISSN 2394-3211
EJPMR
EUROPEAN JOURNAL OF PHARMACEUTICAL
AND MEDICAL RESEARCH
www.ejpmr.com
ejpmr, 2016,3(8), 434-440
Corresponding Author: Reecha Madaan
Chitkara College of Pharmacy, Chandigarh-Patiala National Highway, Rajpura, Patiala, Punjab 140 401, India.
ABSTRACT
Natural polymers remain attractive primarily because they are natural products of plants, readily available,
inexpensive, and capable of multitude of chemical modification. Leaves of Hibiscus rosa- sinensis Linn (family:
Malvaceae) contains high proportion of mucilage which can be used as additives in pharmaceutical formulations.
The objective of the study is to extract mucilage from the leaves Hibiscus rosa-sinensis and examine the
disintegrant property of the dried mucilage to assess its functionality as a pharmaceutical excipient.The Present
work was carried out to study the disintergant property of Hibiscus rosa-sinensis mucilage using imipramine as a
model drug. The present work was carried out to develop fast dissolving tablet of Imipramine using natural
disintegrant isolated from Hibiscus rosasinensis leaves and its efficiency was compared with synthetic
superdisintegrant like crosspovidone. Hibiscus rosasinensismucilage was isolated and characterised for its
identification by chemical test and micrometric properties. Fast dissolving tablets of Imipramine were formulated
by direct compression method using Hibiscus rosa-sinensis mucilage (2-8% w/w), Avicel PH 102 as diluents,
mannitol to enhance mouth feel and compressibility, and aspartame as sweetener. The formulated tablets were
evaluated for their pre and post compression parameters like tablet hardness, thickness, % friability, wetting time
which was found to be in permissible limits. The in vitro disintegration time of tablet formulations containing 6%
of mucilage was found to be 24 sec and that of tablet containing 4% of crosspovidone was 42secs. Based upon in
vitro disintegration time in vitro drug release studies were carried out in phosphate buffer p H 6.8 which showed
100% drug release in 12 minutes of F3 formulation containing 6% of mucilage. Stability studies performed on F3
formulation indicated that the prepared tablets remain stable for the period of 90 days and showed no change in in
vitro drug release pattern.
KEY WORDS: Imipramine, Hibiscus rosa-sinensis, superdisintegrant, mucilage, Fast dissolving tablet.

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karaya, starch, agar, plantago ovata mucilage have been
used in the formulation of FDT. Mucilage of natural
origin is preferred over semisynthetic and synthetic
substances because they are comparatively cheaper,
abundantly available, non irritating and non toxic in
nature. [6] Hence, in the present study, mucilage of
Hibiscus rosa-sinensis linn was used to develop FDT of
the selected model drug Imipramine. Imipramine is a
tricyclic antidepressant with general pharmacological
properties similar to those of structurally related tricyclic
antidepressant drugs such as amitriptyline and doxepin A
tertiary amine, Imipramine inhibits the reuptake of
serotonin more so than most secondary amine tricyclics,
meaning that it blocks the reuptake of neurotransmitters
serotonin and nor adrenaline almost equally. It binds the
Sodium-dependent serotonin transporter and sodium-
dependent nor adrenaline transporter, preventing or
reducing the reuptake of nor epinephrine and serotonin
by nerve cells. Peak plasma levels are reached in 2 to 8
hours, and plasma half-life ranges from 11 to 25 hours. It
is excreted in the urine, mainly in the form of its
metabolites, either free or in conjugated form; small
amount are excreted in the faeces via the bile.
Imipramine is one of the less sedating tricyclics and has
moderate antimuscarinic activity. Imipramine is used for
the treatment of nocturnal enuresis in children. Tricyclic
anti- depressants are not recommended under 6 years of
age. [7]
MATERIAL AND METHODS
Material
Imipramine was received as a gift sample fromTriko
Pharmaceutical, Rohtak, India. Crospovidone, mannitol,
and Avicel were purchased from LobeChem Ltd.,
Mumbai, India. Aspartame was purchased from Himedia
Lab Pvt Ltd., Mumbai, India. Hibiscus rosa-sinensiswas
collected from Chitkara herbal garden. All other
chemicals used were of analytical grade and were used
without further purification.
Methods
Isolation and Characterization of Mucilage form
Hibiscus rosa-sinensis
The leaves of hibiscus rosa-sinensis linn were collected,
from Chitkara University, Punjab. The fresh hibiscus
rosa-sinensis linn leaves were collected and washed with
water to remove dirts and debries. Leaves were
powdered and soaked in water for 5-6 hrs, boiled for 30
minutes and left stand for 1hours to allow complete
release of mucilage into water. The mucilage was
extracted using multi-layer muslin cloth bag to remove
the marc from the solution. Acetone (in the volumes of
three times to the volume of filtrate) was added to
precipitate the mucilage. The mucilage was separated,
dried in an oven at <50º C, collected, ground, passed
through #80 sieve and stored in desiccators at room
temperature for further use. [8] Dried powdered mucilage
was characterized for various physicochemical properties
like percentage yield, particle size, swelling index, angle
of repose etc. [9]
Preformulation study
In the preparation of tablet formulations, drug and
polymer may interact as they are in close contact with
each other, which could lead to the instability of drug.
Preformulation studies regarding the drug-polymer
interaction are therefore carried out for selecting
appropriate polymers. FT-IR spectroscopy was employed
to ascertain the compatibility between Imipramine
Hydrochloride and selected polymers. The pure drug,
drug-polymers combinations and formulations were
subjected to FT-IR studies. Potassium bromide, pure
drug, and the polymers were heated to 1050C for one
hour to remove the moisture content if present in a hot
air oven. Then in presence of IR lamp, potassium
bromide was mixed with drug and /or polymer in 1:1
ratio. Grinding in smooth mortar can effect mixing. The
mixtures were then placed in the sample holder of the
instrument and the spectra were taken. The spectra were
run from 3500 cm-1 to500 cm-1 wave number. FT-IR
spectrum of Imipramine Hydrochloride was compared
with FT-IR spectrum of Imipramine Hydrochloride with
polymer. The pure drug and the drug with excipients
were scanned separately. Disappearance of Imipramine
Hydrochloride peaks or shifting of peak in any of the
spectra was studied.
Preparation of standard calibration curve of
Imipramine
Standard calibration curve of Imipramine hydrochloride
was prepared by dissolving accurately weighed 10 mg of
imipramine hydrochloride in phosphate buffer (pH 6.8)
solution in a 100 ml volumetric flask and the volume was
made up to 100 ml by using phosphate buffer (pH 6.8)
solution to obtain a stock solution of 100 μg/ml. From
stock solution, appropriate aliquots were pipetted into
different 10ml volumetric flasks and volumes were made
up to 10 ml with phosphate buffer (pH 6.8) solution so as
to get drug concentrations of 2, 4, 6, 8 and 10 μg/ml. The
absorbance of these drug solutions were measured at
250.8 nm. This procedure was performed in triplicate to
validate the calibration curve.[10]
Formulation of Fast Dissolving Tablets of
Imipramine using Hibiscus rosa-sinensis mucilage
Fast dissolving tablets of Imipramine were prepared by
direct compression method, in this powder blends of
active ingredient and suitable excipient, which flow
uniformly in the die cavity and forms a firm compact
was prepared as per the composition given in the table 1.
Powdered drug was mixed with Hibiscus rosa-sinensis
mucilage assuperdisintegrants in 2%, 4%, 6% and 8%,
microcrystalline cellulose as diluent, talc as glidant, and
magnesium stearate as lubricant and mannitol was used
as filler. All blends passed through mesh #60. Before
compression, hardness was adjusted. Each tablet
weighed 200 mg.[11]

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436
Table 1: Composition of fast dissolving tablets of Imipramine
Ingredients (mg)
Formulation batches
F1
F2
F3
F4
F5
F6
F7
F8
Imipramine
10
10
10
10
10
10
10
10
Crosspovidone
-
-
-
-
2%
4%
6%
8%
Mucilage
2%
4%
6%
8%
-
-
-
-
Avicel PH102
50
48
46
44
50
48
46
44
Mannitol
30
30
30
30
30
30
30
30
Aspartame
5
5
5
5
5
5
5
5
Magnesium stearate
1
1
1
1
1
1
1
1
Talc
2
2
2
2
2
2
2
2
Evaluation of precompression parameters
Formulation blends were evaluated for all
precompression parameters like angle of repose, bulk
density, tapped density, bulkiness, hausner’s ratio and
compressibility index. The evaluation was done using all
the methods as per specified in pharmacopoeias.[12]
Evaluation of Imipramine hydrochloride tablets [13]
Weight variation
All prepared tablets were evaluated for weight variation
as per USP XXIV monograph. Twenty tablets of each
batch were used to evaluate weight variation among
tablets and mean and standard deviation was calculated.
Friability
Tablets of all batches were used to evaluate friability as
per USP XXIV monograph. Friability testing was done
by Roche Friabilator. Twenty tablets were weighed and
placed in a Roche friabilator and rotated at 25 rpm for 4
min. The tablets were taken out, de-dusted and
reweighed. The percentage friability of the tablets was
calculated by the formula,
% friability = Initial weight – Final weight x
Initial weight
Hardness
Hardness of all batches was determined using Monsanto
hardness tester. The test was carried out in triplicate for
all batches as per USP XXIV monograph for uncoated
tablets.
Thickness
The thickness of the matrix tablets was determined using
verniercaliper (Mitutoyo Dial Thickness Gauge,
Mitutoyo, Japan) and the results were expressed as mean
values of 10 determinations, with standard deviations.
Drug content
The tablets were powdered, and 5mg equivalent weight
of Imipramine in tablet powder was accurately weighted
and transferred into a 100 ml volumetric flask. Initially,
10 ml of phosphate buffer (pH6.8) was added and shaken
for 10 min. Thereafter, the volume was made up to 100
ml with buffer. Subsequently, the solution in volumetric
flask was filtered, and 1 ml of the filtrate was diluted and
analyzed at 250 nm using UV-visible spectrophotometer
Shimadzu UV-2450, Japan).
In vitro drug release study
In vitro drug release was studied using Lab India
Dissolution Apparatus (LABINDIA DS 80 00, India), in
900 ml phosphate buffer pH 6.8, maintained at 37±1°C
for 30 minutes, at 75 rpm. 5ml of sample was withdrawn
after specified time interval, and was replaced by an
equal volume of fresh dissolution medium. Collected
samples were analyzed spectrophotometrically at
measured wavelength of 250 nm, and cumulative percent
drug release was calculated. The test was performed in
triplicate to assure significance of results. Drug release
profile was studied using percentage drug release versus
time (hr) plot. [14]
Stability studies
In order to determine the change in in-vitro release
profile on storage, stability study of batch F3 was carried
out at 40 C in a humidity chamber having 75% RH.
Samples were withdrawn at regular intervals during the
study of 60 days. Formulation is evaluated for change in
in-vitro drug release pattern, hardness and disintegration
time. [15]
RESULTS AND DISCUSSIONS
Characterization of Mucilage form Hibiscus rosa-
sinensis
Mucilage isolated from Hibiscus rosa-sinensis was
characterized for its physical and chemical properties the
results of which are given in table 2 and 3.

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Table: 2 Physical characterizations
S.No
Physical Parameters
Observations
1
Appearance
Greenish powder
2
Odor
characteristics
3
Percentage yield
26%
4
Weight loss on drying(mg)
28.56±0.159
5
Solubility
Slowly soluble in
water to produce
viscous solution
6
Density of liquid
1.058±0.018
7
pH
7.1±0.111
Table 3: Chemical characterization
S.No
Chemical characterization
Observations
1
Mounted in 90% ethanol
transparent
2
Mounted in Ruthenium red
Particles stained red
3
Mounted in iodine solution
Particles stained blue
4
Molisch test (for carbohydrates)
Positive
5
Ferric chloride test (for tannins)
Negative
6
Silver nitrate (for chlorides)
Negative
7
Barium chloride (for sulphates)
Negative
Preformulation study
To study the compatibility of the drug with various
polymers, IR spectra of drug and mucilage were carried
out. The FTIR spectra of drug, mucilage and physical
mixture of drug and mucilage (1:1) were shown in figure
1. No major differences in the FTIR patterns of pure drug
and mucilage were observed. Therefore, the FTIR studies
ruled out the possibilities of any drug excipient
interaction during the preparation of tablets.
Figure 1: FTIR Spectra of a) Imipramine b) Hibiscus rosa-sinensis c) Imipramine + Hibiscus rosa-sinensis
Preparation of standard calibration curve of
Imipramine
The standard calibration curve of Imipramine
Hydrochloride was obtained by plotting Absorbance
versus concentration as shown in figure 2. The standard
calibration curve shows the correlation coefficient of
0.990. The curve was found to be linear in the
concentration range of 2 to 10μg/ml (Beer’s range) at
250.8 nm.

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Figure 2: Standard calibration curve of Imipramine hydrochloride
Evaluation of precompression parameters
Results of evalution of precompression parameters of the
formulation blends are given in table 4 which indicated
good flow behaviour and compressibility of prepared
formulation blends.
Table 4: Precompression Parameters of blend for Imipramine-Hibiscus rosa-sinensis tablets
Parameters
Formulation Batches
F1
F2
F3
F4
F5
F6
F7
F8
Angle of repose
26.56
29.24
27.92
28.5
23.45
20.21
24.32
26.12
Bulk density (g/ml)
0.317
0.357
0.436
0.385
0.350
0.362
0.291
0.321
Tapped density(g/ml)
0.54
0.491
0.65
0.421
0.491
0.481
0.398
0.412
Carr’s index (%)
41.2
27.3
32.9
33.2
28.71
24.74
26.88
22.1
Hausnor’s ratio
1.19
1.24
1.20
1.21
1.24
1.26
1.19
1.25
Evaluation of post compression parameters of
Imipramine hydrochloride tablets
The formulated tablets were evaluated for weight
variation, hardness, thickness, in vitro disintegration
time, dissolution rate, wetting time and uniformity of
drug content. The formulated tablets were of uniform
weight with acceptable limit as per the IP specifications.
Thickness of the formulated tablets was found in the
range from 3.0±0.01 mm to 3.9±0.31mm. Uniformity in
the values suggested that formulations were compressed
without sticking to the dies and punches with uniform
compression pressure. The hardness was found to be in
the range of 3.0±0.01 to 3.9±0.01 kg/cm2 and was in
correlation with disintegration time. Friability below 1%
indicated good mechanical resistance of the tablets
Disintegration time was found to be in the range of 82-24
seconds. Formulation F3 containing 6% of mucilage
giving minimum disintegration time of 24 seconds which
facilitate fast dispersion and dissolution within the oral
cavity. In vitro drug release of all the formulations as
shown in figure 3,4 and 5 were carried out in phosphate
buffer pH 6.8 it was found that more than 85% of the
drug was released within 10 minutes; with F3
formulation containing 6% of mucilage showed
maximum release of 99.6% within 12 minutes. With
increasing concentration of mucilage in vitro
disintegration time decrease resulting in fast in vitro drug
release. Formulation containing 8% of mucilage showed
increased disintegration time with slow in vitro drug
release in comparison with F3 formulation which may be
due to binding property of mucilage in increased
concentration. Further, it was found that F7 containing
6% cross povidone showed disintegration time of 42
seconds which was greater than that of F3 containing
same level of disintegrating agent i.e 6% of mucilage.
Wetting time was found to be in the range of 13-21
seconds. Formulation F3 containing 6% of mucilage
showed fastest wetting time of 13 seconds which results
in faster disintegration. Results of evaluation of post
compression parameters are given in table 5.
Table: 5 Evaluation of post compression parameters of Imipramine hydrochloride tablets
Parameters
Formulation batches
F1
F2
F3
F4
F5
F6
F7
F8
Disintegration time
(sec)
68
35
24
82
80
60
42
34
Hardness (kg/cm2)
3.5±0.01
3.2±0.05
3.0±0.01
3.9±0.02
3.7±0.03
3.6±0.02
3.5±0.03
3.9±0.01
Thickness (mm)
3.5±0.2
3.8±0.05
3.0±0.01
3.9±0.3
3.4±0.2
3.5±0.05
3.6±0.2
3.3±0.4
Wetting time(sec)
16
14
13
21
20
19
18
15
Weight variation(mg)
96
97
95
96
101
97
98
101
Drug content
98.12±0.10
99.6±0.1
98.0±0.02
98.41±0.01
96.5±0.11
99.2±0.11
97.3±0.12
96.7±0.1
% friability
0.2
0.4
0.32
0.41
0.5
0.4
0.6
0.7

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Figure 3: In-vitro Drug Release Studies of Formulation F1, F2and F3
Figure 4: In-vitro Drug Release Studies of Formulation F4, F5 and F6
Figure 5: In-vitro Drug Release Studies of Formulation F7and F8
Stability studies
Stability studies performed on F3 formulation as per ICH
guidelines for 60 days at 40°C±2°C / 75% RH±5%.
Showed no remarkable change in the physical properties
and release profile of the prepared tablets. Results of the
stability studies are given in table 6.
Table 6: stability studies of F3 formulation at 40°C±2°C/75% RH±5%
Days
Parameter
0
15
30
60
In vitro drug release
100
99.4
99
99.6
Hardness (kg/cm2)
3.0±0.01
3.0±0.01
3.0±0.01
3.0±0.01
Disintegration time (sec)
24
23.6
24
24

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CONCLUSION
From the present study, it can be concluded that natural
super disintegrants like Hibiscus rosa sinensis Linn
mucilage powder showed better disintegrating property
than the most widely used synthetic super disintegrants
like crosspovidone in the formulations of Fast dissolving
tablets and may be used as disintegrant at the level of 6%
w/w in tablet formulations. Hibiscus rosa sinensis Linn
mucilage powder can be used as superdisintegrants in
place of currently marketed synthetic super
disintegrating agent.
REFERENCE
1. Nyol S, Gupta M. Immediate release dosage forms:
A review. J Drug Delivery Thera, 2013; 3(2): 155-
161.
2. Patel V, Patel K. Review on immediate release
dosage system. Int J Pharma Res Bio Sci, 2012;
1(5): 37-66.
3. Kumar S, Gupta SK, Sharma PK. A review on
recent trends in oral drug delivery- fast dissolving
formulation technology. Adv Biol Res. 2012; 6(1):
6-13.
4. Konapura SA, Chaudhari PS, Oswal RJ, Kshirsagar
SS, Antre RV, and Chorage TV. Mouth dissolving
tablets an innovative technology. Int J Appl Biol
Pharma Technol, 2011; 2(1): 496-503.
5. Vijaya KS, Mishra DN. Rapidly disintegrating oral
tablets of miloxicam. Indian drugs, 2006; 43:117-
121.
6. Jani GK, Shah DP. Evaluation of mucilage of
Hibiscus rosasinensis Linn as a rate controlling
matrix for sustained release of diclofenac. Drug Dev
Ind Pharm, 2008; 34(8): 807-816.
7. Tripathi KD. Essentials of medical pharmacology.
5th edition. New Delhi: Jaypee brother’s medical
publishers; 2007.
8. Swati S, Neeharika V and Lakshmi PK. Formulation
and evaluation of fast dissolving tablets of freely and
poorly soluble drugs with natural and synthetic
superdisintegrants. Drug invention today, 2011;
3(10): 250-256.
9. Gupta S, Parvez N, Sharma P. Extraction and
characterization of Hibiscus rosa sinensis mucilage
as pharmaceutical adjuvant. World applied science
journal, 2015; 33(1): 136-141.
10. Jadhav SB, Mali DA, Rajeghadage SH and Bathe
RS. Formulation and evaluation of immediate
release tablets of imipramine hydrochloride. Int J
Biomed Adv Res, 2014; 5(11): 559-560.
11. Bhupindera GP, Satish NP. Formulation evaluation
and optimization of orally disintegration tablets of
cinnarizine. J Sci Technol, 2010; 5:9-21.
12. Chang RK, Guo X, Burnside BA, Courch RA. Fast
dissolving tablets. Pharm Tech, 2000; 24: 52-54.
13. Indian Pharmacopoeia, ministry of health and family
welfare, Govt. of India 4th ed. New Delhi: the
controller of Publications; 1996.
14. Nayak AK, Manna K, Current development of orally
disintegrating tablet technology. Journal of
Pharmaceutical Education and Research, 2011; 2(1):
21-34.
15. ICH Harmonisation Tripartite Guideline. Cover note
for revision of Q1A(R) Stability testing of new drug
substances and products. Q1A (R2): pp 9.