Pharmaceutical Resonance 2018 Vol.1 - Issue 1
© Published by DYPIPSR, Pimpri, Pune - 411 018 ( MH ) INDIA 42
RESEARCH ARTICLE
Formulation and Evaluation of Rectal Delivery System for the
Treatment of Hemorrhoids
Suchita Dhamane1*, Aditi Kulkarni 2. Potnis Vaishali1, Manoj Modase2
1Department of Pharmaceutics, JSPM’s Jayawantrao Sawant college of Pharmacy and Research, Hadapsar, Pune.
2Department of Pharmacognosy, JSPM’s Jayawantrao Sawant college of Pharmacy and Research, Hadapsar, Pune.
1. Introduction
A conventional suppository is a semi solid dosage form
which melts in the rectum at body temperature [1]. The
patient compliance for conventional suppository is less as
it causes discomfort and sometimes refusal. Conventional
suppository may undergoes first pass metabolism as it
reaches to the end of rectum [2,3] Therefore, an attempt
was made to develop a liquid rectal dosage form which
forms a gel at body temperature, with suitable gel strength
that does not leak out of the anus after administration and
has suitable bio adhesive force so as not reach at the end
of the colon. Liquid suppositories aimed either to improve
the local effect or to enhance the drug absorption.[3,4]
Poloxamer are the base of the liquid suppositories.
Poloxamer solutions are known to exhibit phenomenon of
reverse thermal gelation remaining as solution at low
temperature (40oC) and gelling upon increasing the
temperature to 25-35oC.[5,6]
Lidocaine belongs to class of local anaesthetic.
Lidocaine increases permeability to sodium ions in
neuronal membranes, resulting in inhibition of
depolarization, blocking transmission of nerve impulses.
This helps in reducing the pain while passing bowels. It
also shows anti-inflammatory properties. Pure aloe vera is
used to treat pain and inflammation. Hence, combination
of lidocaine and aloe Vera was used for preparation of
liquid suppository.
2. Experimental
2.1 Materials
Lidocaine was obtained from Titan Laboratory, India,
Poloxamer 407 and poloxamer 188 were from BASF,
Germany; HPMC K4M from Emcure Pharmaceutical Ltd,
Pune and Carbopol 940 from New Modern Chemical
corporation, Mumbai and aloe vera juice from Patanjali
Ayurveda.
2.2 Methods
2.2.1 Pre-formulation Studies [6,7]
2.2.1.1. UV-spectrophotometric study of lidocaine
Stock solutions of Lidocaine (100 μg/ml) was prepared by
dissolving accurately weighed 10mg quantity using 100
ml distilled water. From stock solution 1 ml was diluted
with distilled water to give solutions of 10 μg/ml
concentration. The solutions were scanned in the range of
400 to 200 nm and respective λ max values were reported
in triplicate. Calibration curve of lidocaine in distilled
* Dahmane Suchita
Department of Pharmaceutics
JSPM’s Jayawantrao Sawant college of Pharmacy and
Research, Hadapsar, Pune
Email : [email protected]
ABSTRACT:The aim of this research was to introduce rapid onset of action of lidocaine in relief of pain and inflammation
in treatment of haemorrhoids. Haemorrhoids are swollen and inflamed veins in the rectum and anus that cause discomfort
and bleeding. Rectal delivery of drugs promotes rapid absorption and high bioavailability, with a subsequent immediate
onset of pharmacological effect. Conventional suppositories are solid forms which often cause discomfort during insertion.
The leakage of suppositories from the rectum also gives uncomfortable feelings to the patients. In addition, when the solid
suppositories without mucoadhesivity reach the end of the colon, the drugs can undergo the first-pass effect. To solve these
problems, we developed a novel in situ-gelling and mucoadhesive lidocaine liquid suppository with gelation temperature at
30–36°C and suitable gel strength and bioadhesive force. The mixtures of P407 (25%) and P188 (5%) existed as a liquid at
room temperature, but gelled at 30–36°C. To modulate gel strength and mucoadhesive force, mucoadhesive polymers such
as HPMC K4M and carbopol 940 was used. Optimized formulation was tested in haemorrhoids induced rats for 5 days.
After 5 days of treatment with optimized formulation histopathological studies reveals that there was significant reduction
in inflammation as compared to positive group.
Keywords: Haemorrhoids, liquid suppository, mucoadhesive, lidocaine
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water was prepared in distilled water and phosphate buffer
pH 6.8.
2.2.1.2. IR spectrometry
The IR absorption spectrum of Lidocaine was recorded by
potassium dispersion method. The drug was previously
dried in desiccator and then spectrum was recorded by
blending with potassium bromide. For this, sample of drug
and potassium bromide was mixed in a 1:3 ratio and kept
in sample cell. The cell was then fitted on sample holder
and an IR spectrum was recorded 4000-400 cm-1 after
baseline correction was made.
2.2.2 Drug-excipient compatibility studies
The compatibility of mixture of Lidocaine with or without
polymeric addition was ascertained by exposing to the
environmental conditions over the 15 days. The detection
of changes in any of the physical or physicochemical
characteristics of blends if any was carried out by visual
and FT-IR spectrophotometry (Jasco 4600, USA).
2.2.3 Preparation of liquid suppository
Formulation and evaluation of placebo liquid
Suppository
Placebo liquid suppositories were prepared to determine
optimum concentration of polymer. Prepared suppositories
were evaluated for gelling temperature, gel strength and
gelling time and gelling ability. All excipients except
poloxamer as given in table no.1 were completely
dispersed in distilled water with continuous agitation at
room temperature and cooled to 4°C. Poloxamer was then
slowly added to the solution with continuous agitation.
Temperature of liquid suppository was maintained to 4°C
until a clear solution was obtained.
Placebo liquid suppositories were evaluated for general
characteristics, pH, gelation temperature, gel strength.
2.2.4 Formulation and evaluation of medicated liquid
suppositories by using 32 factorial design [8]
Medicated liquid suppository was prepared by using
poloxamer 407 (5-25%) and poloxamer 188 (1-5%).
Concentration of polymers was selected based on
evaluation of preliminary placebo suppository batches.
Design expert version 10.0.3.1 was used for factorial
design of formulation of liquid suppository. Poloxamer
Name of ingredient
(% w/w) F1 F2 F3 F4 F5
Poloxamer 407 5 10 15 20 25
Poloxamer 188 1 2 3 4 5
Aloe vera juice Q.S. Q.S. Q.S. Q.S. Q.S.
Table 1. Formulation composition of placebo
(preliminary) batches of in situ gel.
407 and poloxamer 188 were two factors with three
different concentrations. Concentration of polymers was
selected based on evaluation of preliminary placebo
suppository batches. Formulations were optimized by
application of 32 full factorial designs, to study effect of
concentration and type of polymer on gelation temperature
and drug release at the end of 5 hrs.
All nine formulations of medicated liquid suppositories
were evaluated for colour, clarity, pH, gelation
temperature, gel strength, drug content and drug release
through dialyzing membrane.
2.3 Formulation of mucoadhesive medicated liquid
suppositories
The medicated liquid suppository formulation was
optimized using Design expert, in whichMF9 was
optimized for preparation of mucoadhesive liquid
suppository. From among the nine medicated formulation,
the MF9 demonstrating good gelling ability (+++),
physiologically acceptable pH range in rectal delivery (pH
-6.9), gellation temperature (36oC), gel strength (5mm)
and prolong diffusion (In-vitro) over 5 hrs. To reinforce
the gel strength and bioadhesive force of the liquid
suppositories, the poloxamer solutions was added with
bioadhesive polymers. Medicated Gel was found to have
weak mechanical strength. HPMC K4M, Carbopol 940
were selected as the bioadhesive polymer.
All six formulations of medicated mucoadhesive liquid
suppositories were evaluated for colour, clarity, pH,
gelation temperature, gel strength, drug content and drug
release through dialyzing membrane. Selected formulation
was evaluated for anti-haemorrhoidal activity.
Formulation
code
X1: Poloxamer
407
X2: Poloxamer
188
MF1 5 1
MF2 15 1
MF3 25 1
MF4 5 3
MF5 15 3
MF6 25 3
MF7 5 5
MF8 15 5
MF9 25 5
Table 2. Different batches with their respective
compositions as per (32) factorial design
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2.4 Evaluation of liquid suppository
2.4.1 Physical Examination
Appearance of formulation, for this 5 ml of placebo
formulation was taken into clean and dry glass test tube
and was observed carefully for clarity and presence of
suspended particle if any against black and white
background.
Colour of formulation was visually observed.
2.4.2 pH of liquid suppository
The pH of suppository formulations was determined by
using digital pH meter. The pH meter was calibrated
before each use with standard phosphate buffer ( pH 7 and
4).
2.4.3 Gelation temperature [9]
Tube tilting method was used to determine gelation
temperature of placebo, medicated and mucoadhesive
liquid suppository. For this, 2 ml aliquot of liquid was
transferred to a test tube which was sealed with aluminium
foil, and test tube was placed in a water bath at 4°C. The
temperature of water bath was increased in increments of
1°C and left to equilibrate for 5 min at each new setting.
Gelation temperature was noted when the meniscus would
no longer move upon tilting of test tube through 90°.
2.4.4 Gel strength [10,11]
For this, 100ml glass measuring cylinder containing 50gm
of liquid suppository was placed in thermostat at 36.5°C
for gelation. For measuring gel strength apparatus
weighing 35gm was placed onto gelled suppository and
time required for the apparatus to move 5cm into the bulk
of gel was noted.
2.4.5 Mucoadhesive strength [12,13]
The mucoadhesive force of in situ gels liquid suppository
was determined on tissue specimen (A section of tissue cut
from the fundus of sheep rectum). The pieces of tissue
were stored in simulated fluid having pH 6.8. For
determination of mucoadhesive force, a section of tissue
was secured (keeping the mucosal side out) to the upper
Sr.
No
Formulation
code
Drug
(%)
P 407
(%)
P 188
(%)
HPMC
K4M
(%)
Carbopol
940 (%)
Aloevera
Juice
1 MF9HP1 2 25 5 0.5 - QS
2 MF9HP2 2 25 5 0.75 - QS
3 MF9HP3 2 25 5 1.0 - QS
4 MF9CP1 2 25 5 - 0.5 QS
5 MF9CP2 2 25 5 - 1.0 QS
6 MF9CP3 2 25 5 - 1.5 QS
Table 3. Composition medicated mucoadhesive Liquid suppository
side of a glass vial using a using double sided adhesive
tape. The diameter of each exposed mucosal membrane
was 1.5 cm. The vials were equilibrated and maintained at
37° for 10 min. One vial with a section of tissue was
connected to the balance and the other vial was fixed on a
height adjustable pan. To the exposed surface of the tissue
attached on the vial, a constant amount of 0.1 g gel was
applied. The distance between two vials was adjusted in
such a way that the gel sample remained adhered to
mucosal membrane. Sufficient pressure was applied on
both of the vials for 10 seconds to allow proper adhesion
of gel to mucosa. A constant weight was added to the pan
(B) to the vial (C). The weight required for detaching the
two vials and hence, film of the sample between them was
noted down. The mucoadhesive force expressed as the
detachment stress in dyne/cm2, was determined from the
minimal weights needed to detach the tissues from the
surface of each formulation, using the following equation.
Where,
m : weight added to the balance (gm)
g : acceleration of gravity
A : area of the tissue exposed (πr2)
2.4.6 Dissolution studies (In vitro) pH 6.8Phosphate
buffer for lidocaine [13,14]
The in vitro drug release studies from medicated liquid
suppository and mucoadhesive liquid suppository was
monitored by using USP II dissolution apparatus. A 2g of
the formulation was placed in semi permeable bag and
secured with the aid of non absorbing thread. The bag was
immersed in a vessel containing dissolution medium, 500
ml phosphate buffer, pH 6.8 at 370C. The speed of rotation
was 100rpm. At predetermined time intervals 4 ml of
aliquots were withdrawn and analyzed spectro-
photometrically at 263 nm. The experiments were
conducted in triplicates.
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2.4.7 In vivo animal study (Anti haemorrhoidal
activity) [15]
To test the anti haemorrhoidal activity of optimized in situ
gel liquid suppositories,male wistar rats weighing (200-
250gm) that were housed in standard conditions of
temperature (22±3°C), relative humidity (55±5%), and
(12h light-dark cycle) before and during the study. Rats
were fed with standard pellet diet and water ad libitum.
Protocol for animal study was approved by the
Institutional Animal Ethics Committee (IAEC) of Prado
preclinical research and development organization.
2.4.8 Procedure for induction of haemorrhoids
Four groups of male wistar rats (200-250gm) were
formed, each group having 8 rats. Croton oil preparation
containing deionized water, pyridine, diethylether, and 6%
croton oil in diethylether(1:4:5:10)was used for induction
of haemorrhoids. After overnight fast, hemorrhoids were
induced by inserting sterile cotton swabs (4 mm diameter)
soaked in 100 μL of croton oil preparation into the anus
(rectoanal portion, 20 mm from anal opening) of all group
animals except normal control group. After 10 seconds
cotton swab was removed and animals were observed for
development of edema and blood in faces up to 8 hours
after induction of croton oil. Twenty-four hours after
induction of haemorrhoids, animals of respective groups
were treated for five days.G1-Distilled water, G2-positive
control, G3-test aloe vera suppository (once daily for 5
days), G4-test mixture suppository (once daily for 5 days).
On the fifth day, 1 hour after the treatment, all the animals
were sacrificed by deep isoflurane anesthesia and
rectoanal tissues (20mm in length) were isolated.
Rectoanal tissues were fixed in 10% neutral buffered
formalin solution for histological examination. The
inflammatory cells, congestion, haemorrhage,
vasodilatation, and medium to high degrees of necrosis
were the histological observations for rectoanal tissue.
Results of the animal study were expressed as mean ±
SEM and analyzed by one-way ANOVA followed by
Dunnett’s post test using GraphPad Prism version 4.01.
3. Result and Discussion
3.1 Spectrophotometric characteristics of lidocaine
The UV spectrum (λ max) of lidocaine in water and pH
6.8 phosphate buffer indicated λmax at 263 nm. The
standard calibration curve of Lidocaine in distilled water
and phosphate buffer pH 6.8 was found to be linear over
the range of 2 -10 µg/ml as shown in Fig.1.
3.2 Drug-excipient compatibility study
FT-IR spectrum (Fig 2) of lidocaine showed major peaks
at 3030cm-1, 3248 cm-1, 1667 cm-1, 2860 cm-1, 2931 cm-1,
3447 cm-1. FTIR spectrum of mixture of lidocaine and
excipients revealed that there was no interaction between
drug and excipients, as there was no major change in the
position of peaks of lidocaine.
3.3 Characteristics of placebo liquid suppositories
All placebo liquid suppositories were clear, colorless
solution. There was no gelation and colour change of any
suppository during processing. pH of all the
suppositories was found to be in range of 6.7-6.9
respectively. The pH of placebo liquid suppository
solution was near to pH of rectum (6.7-6.9). Thus
therefore formulation will not produce irritation on
instillation into the rectum.
The liquid suppository should remain liquid at room
temperature and should instantly form gel in rectum, so
the gelation temperature should be 30-36o C. Formulation
F1, F3, F5 showed gelation temperature in range of 30-36°
C.Hence, this formulation concentration used for 32
factorial design of medicated liquid suppository. The
temperature-dependent gelation of poloxamer solutions
could be explained by configuration change. Poloxamer
molecules exhibit a well-arranged zigzag configuration.
With increasing temperature, the zigzag configuration of
poloxamer may be transformed into a close-packed
meander configuration, forming a more close-packed and
more viscous gel.
3.4 Characteristics of medicated liquid suppositories
All 9 formulations were prepared by following 32 full
factorial designs. The formulations were evaluated for
Fig. 1 Calibration curve of lidocaine in distilled water
and pH 6.8 phosphate buffer
ab
so
rpti
on
ab
so
rpti
on
conc µg/ml
conc µg/ml
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physicochemical characterization and drug release study.
All formulations were clear, colourless solution. The pH
of medicated liquid suppository solution was nearing to
pH of rectum (6.7-6.9). Gelation temperature range for
liquid suppository should be 30-36o C. So that it will be a
liquid at room temperature and forms a gel instantly in the
rectum. Formulation MF2, MF5 and MF9 shown gelation
temperature between 30 to 36oC. Gel strength of all
formulation was found in the range of 6 to 45 sec. The gel
strength is an indication for viscosity of the gel at
physiological temperature. The data obtained indicates, as
the polymer grade variation increases gel strength.
Gel strength play important role in the development of
liquid suppository. Determination of gel strength allows
the easy insertion of the suppository and no leakage from
the anus. The contents of lidocaine in the medicated liquid
suppository range between 99-101% which is acceptable.
Formulation indicated comparable release profile over 5
hrs. Release of lidocaine is higher in first hrs, because it is
entered in sol form (Fig 3). Because thermo sensitivity
nature, formulation require few minutes to convert to gel
form. In the gel form retardation of release rate is less. The
probable mechanism in retardation of release may be
reduction in number and dimension of the channels in the
gel structure.
3.5 Full factorial design
Effect of formulation variables on gelation
temperature
On applying the factorial design, the quadratic model was
found to be significant with model F value of 33.00, p
value < 0.008 which implied that model was significant.
Following quadratic equation describes the effect of
concentration of polymers on gelation temperature.
Y1= 32.55 - 5.83X1 + 1.66X2 + 1.25 X1X2 + 4.16X12 +
1.66X22
Fig.2: FTIR spectrum of lidocaine & physical mixture
of lidocaine and excipient
There was significant (p<0.008) effect of individual
variable on gelation temperature. The gelation temperature
decreases with increase in concentration of Poloxamer 407
(X1). At low level of factor X1 gelation temperature is
high and at medium level gelation temperature is about
36oC. The gelation temperature increases with
concentration of factor poloxamer 188(X2), but as not
rapid as X1. The combined effect of factor X1 (poloxamer
407) and X2(Poloxamer 188) can be further elucidated
with help of response surface plot (figure). At high level
of X1 and X2 the gelation temperature was 36oC.
3.6 Contour plot and three dimensional response
surface plot of Gelation temperature
Two-dimensional contour plot and three dimensional
response surface plot is shown in Fig 4A and 4B
respectively. The contour plot does not show straight line,
it indicates that there is no linear relationship between the
factor X1 and X2. The gelation temperature decreases
with increase in concentration of Poloxamer 407 (X1). At
low level of factor X1 gelation temperature is high and at
medium level gelation temperature is about 36o C. The
gelation temperature increases with concentration of factor
X2, but as not rapid as X1. The combined effect of factor
X1 (poloxamer 407) and X2(Poloxamer 188) can be
further elucidated with help of response surface plot
(figure). At high level of X1 and X2 the gelation
temperature was 36oC.
Fig 3: Dissolution plots of cumulative drug release of
lidocaine liquid suppository of above formulation
Source Sum of
Squares
Degree
of
freedom
Mean
Square
F
value
p-value
Prob>F
Model 267.3 5 53.47 33.00 0.008
(S)
Residual 4.86 3 1.62 - -
Total 272.22 8 36.44 - -
Table 4. Summary of ANOVA for gelation
temperature parameters
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Effect of formulation variables on drug release
On applying the factorial design, the quadratic model was
found to be significant with model F value of 5.63, p
value < 0.0465 which implied that model was significant.
Following quadratic equation describes the drug release.
Y2= 86.39- 2.34X1 +0.74X2 +6.90 X1X2
The quadratic model was found to be significant with F
value 5.63 (p<0.046) that indicates that the model is
significant. Positive sign in the above equation indicates
that response increases with the factor. Negative sign
indicates negative effect on drug release, response does
not increase with factor.
Fig 5A and 5B indicate two-dimensional contour plot and
three dimensional response surface plot respectively. The
contour plot does not show straight line, it indicates that
there is no linear relationship between the factor X1 and
X2. The percentage release increases with increase in
concentration of Poloxamer 407 (X1). At low and medium
level of factor X1 drug release is less and high level
Design-Expert® SoftwareFactor Coding: ActualGelat temp
Design Points45
30
X1 = A: AX2 = B: B
-1 -0.5 0 0.5 1
-1
-0.5
0
0.5
1Gelat temp
A: conc. of Poloxamer 407
B: C
onc.
of p
olox
amer
188
30
35
40
Design-Expert® SoftwareFactor Coding: ActualGelat temp
Design points above predicted valueDesign points below predicted value45
30
X1 = A: AX2 = B: B
-1
-0.5
0
0.5
1
-1
-0.5
0
0.5
1
25
30
35
40
45
Gela
t te
mp
A: conc. of Poloxamer 407
B: Conc. of poloxamer 188
Fig. 4 b
Fig. 4 a
Fig 4 a: Contour plot showing combined effect of
Poloxamer 407 and Poloxamer 188 on Gelling
temperature.
Fig 4 b: Response surface plot showing combined effect
of Poloxamer 407 and Poloxamer 188 on Gelling
temperature.
Poloxamer 407 (X1) drug release is high. The drug release
increases with concentration of factor X2 , but as not rapid
as X1. The combined effect of factor X1 (poloxamer 407)
and X2(Poloxamer 188) can be further elucidated with
help of response surface plot (figure). At high level of X1
and X2 the drug release was maximum.
Source Sum of
Squares
Degree
of
freedom
Mean
Square
F
value
p-value
Prob>F
Model 227.6 3 75.75 5.63 0.0465
(S)
Residual 67.30 5 13.46 - -
Total 294.56 8 86.39 - -
Table 5. Summary of ANOVA for Drug release
parameters
Design-Expert® SoftwareFactor Coding: ActualInvitro
Design points above predicted valueDesign points below predicted value94.28
76.75
X1 = A: AX2 = B: B
-1
-0.5
0
0.5
1
-1
-0.5
0
0.5
1
75
80
85
90
95
Invi
tro
A: conc. of poloxamer 407
B: conc. of poloxamer 188
Fig. 5 b
Design-Expert® SoftwareFactor Coding: ActualInvitro
Design Points94.28
76.75
X1 = A: AX2 = B: B
-1 -0.5 0 0.5 1
-1
-0.5
0
0.5
1Invitro
A: conc. of poloxamer 407
B: c
onc.
of p
olox
amer
188
80
85
85
90
90
Fig. 5 a
Fig 5 a: Contour plot showing combined effect of
Poloxamer 407 and Poloxamer 188 on drug release
Fig 5 b: Response surface plot showing combined effect
of Poloxamer 407 and Poloxamer 188 on drug release
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3.7 Characteristics of medicated mucoadhesive
liquid suppositories:
The medicated liquid suppository formulation was
optimized using Design expert, in which MF9 containing
25% poloxamer 407 and 5% poloxamer 188 was
optimized for preparation of mucoadhesive liquid
suppository. To increase the gel strength and bioadhesive
force of the liquid suppositories, bioadhesive polymers
were added in optimized medicated liquid suppository.
Medicated liquid suppository gel was found to have weak
mechanical strength. HPMCK4M, Carbopol 940 were
selected as the bioadhesive polymer. These bioadhesive
polymers are water-soluble or swellable, but different in
their nature and charges. HPMC a cellulose derivative is
neutral and swelling in water. Carbopol940, a polyacrylic
acid derivative polymerized without cross-linking agent, is
anionic and water-swellable. Gelation temperature range
for liquid suppository should be 30-36°C. This allows it to
remain liquid at room temperature and gel formation in the
rectum instantly. Increase in concentration of
mucoadhesive polymer decreases gelation temperature.
HPMC K4M has less effect on gelation temperature as
compared to Carbopol 940. Mucoadhesive polymer
decreases gelation temperature of thermosensitive in situ
gel containing poloxamers, due to their ability to bind to
the polyoxyethylene chain present in the poloxamer
molecule. This promotes dehydration causing increasing
inter molecular bonding which leads to gelation at lower
temperature. As concentration of bioadhesive polymer
increases gel strength also increases.
Formulations containing carbopol 940 shows more gel
strength as compare to formulations containing HPMC
K4M. There was increase in bio-adhesive strength with
increase in concentration. Mucoadhesive force means the
force with which liquid suppository binds to mucosal
membrane. Poloxamer gels without addition of
mucoadhesive agent had less mucoadhesive force. HPMC
K4M and Carbopol 940 mucoadhesive strength increases
with concentration. But carbopol 940 have effect on
gelation temperature with increase in concentration.
Sr. No. Formulation code Gelation
temperature (oC) Gel strength
Cumulative
drug release
Mucoadhesive strength
(dyne/cm2)
1 MF9HP1 36.75±0.375 15.66±0.57 90.73±0.27 5748
2 MF9HP2 34.45±0.102 14.36±0.471 91.37±0.38 5992
3 MF9HP3 30.98±0.896 14.57±0.467 83.75±0.48 6998
4 MF9CP1 33.02±0.368 16.33±0.57 82.64±0.47 5717
5 MF9CP2 29.67±0.896 17.0±1.0 81.59±0.34 6338
6 MF9CP3 28.09±0.367 17.6±0.57 78.89±0.62 6660
Table 7. Character istics of mucoadhesive medicated liquid suppository
Fig 6: Dissolution plots of cumulative drug release of lidocaine mucoadhesive liquid suppository
Batch X1 conc. of poloxamer
407
X2 conc. of poloxamer
188
Response (Y1)
Gelation temperature
Response (Y1)
Gelation temperature
MF9 25% 5% Actual value - 36oC
Predicted value - 35.47oC
Actual value - 92.41 %
Predicted value - 91.61%
% error - - 1.47% 1.08%
Table 6. Result of exper iments for confirming optimization capability
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3.7.1 In vitro drug release study of mucoadhesive
liquid suppository
Drug release was retarded by the addition of
mucoadhesive polymers. Formulations containing HPMC
K4M showed more than 82% drug release in 5 hrs while
formulations containing carbopol 940 showed less than
80.40% drug release in 5 hrs. The retarding effect of the
carbopol 940 could be attributed to high viscosity.
Formulation MF9HP2 was selected for further study as
drug release was found to be 91.37% at the end of 5hrs
(Fig 6).
3.7.2 In vivo animal study
A. Normal rectoanal region : Fig A shows normal
architecture of recto anal region. In normal rectoanal
region mucosal layer, submucosal layer and blood
vessels are intact.
B. Haemorrhoids induced rectoanal region (Possitive
control) : The sections of rectoanal region showing
severe infiltration of inflammatory cells in mucosa as
well as submucosa of colon (Arrow). Marked to
severe inflammation, congestion, haemorrhage,
dilatation of blood vessels, degeneration, and necrosis
can be observed in the section of untreated positive
control group
C. Haemorrhoids induced recto anal region treated
with aloe vera juice in situ gel suppository: The
sections of recto anal region showing minimal
infiltration of inflammatory cells of recto anal region.
Mild inflammation, marked congestion, degeneration,
and necrosis.
D. Haemorrhoids induced recto anal region treated
with aloe vera juice+ lidocaine in situ gel
suppository: Minimal infiltration of inflammatory
cells (arrow) and degeneration of lining mucosa.
From the above findings of the study (Fig 7), it can be
concluded that after five days of treatment of prepared in
situ gel liquid suppositories containing (Lidocaine) and
aloe vera juice as a vehicle liquid suppositories (Fig.7d)
has shown near normal architecture. In situ gel liquid
suppository containing aloe vera juice has shown mild
inflammation, marked congestion, degeneration, and
necrosis. Though aloe vera juice liquid suppository has not
shown normal architecture, it is indicating positive sign
towards cure of hemorrhoids. After treatment with Aloe
vera juice-liquid suppository and combination of lidocaine
+ aloe vera juice liquid suppository shows significant
reduction in the inflammation of croton oil-induced
hemorrhoids in rats compared to positive control. This
may be due to the potent anti-inflammatory activity of the
herbs present in the tested formulation.
4. Conclusion
Liquid suppository of lidocaine MF9HP2 containing
poloxamer 407, poloxamer 188 and HPMC K4M found to
be most effective in imparting stability of formulation by
maintaining gelation temperature 30-36oC. The selected
formulation exhibited relevant drug release (in vitro). This
formulation exhibited the optimal Gelation temperature,
gelling ability, gelling time, pH, gel strength, viscosity, %
drug content, mucoadhesive strength, reduce
inflammation in croton oil-induced rats to qualify as
rectal drug delivery system for treatment of hemorrhoids.
The (MF9HP2) formulation has been successfully
formulated to offer stable, cost effective and safe delivery
system for treatment of hemorrhoids.
A
B
C
D
Fig 7: Histopathology of mucosal layerof recto anal
region treated with final formulation in hemorrhoids
induced rats
Pharmaceutical Resonance 2018 Vol.1 - Issue 1
© Published by DYPIPSR, Pimpri, Pune - 411 018 ( MH ) INDIA 50
Acknowledgments
The authors are grateful to JSPM’s Jayawantrao
Sawant College of pharmacy and research, Hadapsar,
Pune for supplying of all the basic requirements of this
research.
References
[1] Baviskara P. Drug Delivery on Rectal Absorption:
Suppositories. International Journal of
Pharmaceutical Sciences Review and Research.
2013, 21(1), 70-76.
[2] Choi et al. Development of in situ-gelling and
mucoadhesive acetaminophen liquid suppository.
International Journal of Pharmaceutics. 1998,165,
33–44.
[3] Abbas Z. Fabrication and in vitro Evaluation of
Mucoadhesive, Thermoreversible, in situ Gelling
Liquid Suppository of Chloroquine Phosphate.
Indian Journal of Novel Drug delivery. 2013, 5(2),
60-70.
[4] Jadhav U.G.. Development of In Situ-Gelling and
Mucoadhesive Liquid Suppository of Ondansetron.
International Journal of Chem Tech Research. 2009,
1(4), 953-961.
[5] Walia S. Preparation and Evaluation of In Situ
Gelling Nimesulide Loaded Liquid Suppository
using Poloxamer and Menthol. American journal of
pharmatech research. 2014, 4(3), 681-689.
[6] Jaafar I. S. and Radhi A. A. Formulation And In
Vitro Evaluation Of In-Situ Gelling Liquid
Suppository Of Promethazine Hcl. World Journal of
Pharmaceutical Research. 2015, 4(11), 273-286
[7] Indian Pharmacopeia. 6th edition. Ghaziabad: Indian
Pharmacopeia commission; 2007. P. 1085.
[8] Özgüney I. and Kardhiqi A. Properties of
bioadhesive ketoprofen liquid suppositories:
preparation, determination of gelation temperature,
viscosity studies and evaluation of mechanical
properties using texture analyzer by 4 × 4 factorial
design. Journal Pharmaceutical Development and
Technology. 2014, 19(8), 968-975
[9] Lenaerts, V, Triqueneaux, C, Quarton, M, Falson,
F.R, Couvreur, P. Temperature-dependent
rheological behavior of Pluronic F-127 aqueous
solutions. Int. J.Pharm. 1998, 31(1), 121–127.
[10] Kramaric, A., Resman, A., Kofler, B., and Zmitek, J.
Thermoreversible gel as a liquid pharmaceutical
carrier for a galenic formulation. 1992, Eur. Patent
No. 0551626 (A1).
[11] Yong C. S., Choi J. S., Quan Q. Z., Rhee J. D., Kim
C. K., Lim S. J., Kim K. M., Oh P., Choi S. H. G.
Effect of sodium chloride on the gelation
temperature, gel strength and bioadhesive force of
Poloxamer gels containing diclofenac sodium. Int J
Pharm. 2001, 226, 195–205.
[12] Leung, S.S., Robinson, J.R. Bioadhesives in drug
delivery. Polym News. 1998, 4(7), 333–342.
[13] Khan R M. A study associated risk factors of
hemorrhoids. Journal of Biological and scientific
opinion. 2015, 3(1), 36-38.
[14] Lenaerts, V, Triqueneaux, C, Quarton, M, Falson, F.
R, Couvreur, P. Temperature-dependent rheological
behavior of Pluronic F-127 aqueous solutions. Int.
J.Pharm. 1998, 31(1), 121–127. [15] Azeemuddin M, Gollapalle L, Rafiq
M, Thippeswamy A, Baig M, Kavya K, Patki P,
Shyam R, An Improved Experimental Model of
Hemorrhoids in Rats: Evaluation of
Antihemorrhoidal Activity of an Herbal
Formulation, ISRN Pharmacology, Hindawi
Publishing corporation. 2014, 7.