Content uploaded by Prof. Dr. Ahmed Hashim Hussein
Author content
All content in this area was uploaded by Prof. Dr. Ahmed Hashim Hussein on Apr 12, 2014
Content may be subject to copyright.
Kerbala Journal of Pharmaceutical Sciences Number 62013
Preparation and In-vitro Evaluation of Metoprolol Tartrate Proniosomal Gel
1Hayder K. Abbas, Ienas F. Ahmed H. Hussein, 2Mohammed D. Al-yousuf, 3Dhurgham Q.
Shaheed
1Department of Pharmaceutics, Faculty of Pharmacy, University of Kufa, Iraq. 2Department of
Clinical Pharmacy, Faculty of Pharmacy, University of Kufa, Iraq. 3Department of Pharmaceutical
Chemistry, Faculty of Pharmacy, University of Kufa, Iraq
Correspondence Author: Hayder K. Abbas
E-mail:hayderkadhim@ymail.com
Keyword: metoprolol tartrate, noisome, span, tween
(Received: Nov2013Accepted: Dec2013 )
Abstract
The aim of this research is to prepare metoprolol tartrate niosomal gel as transdermal drug delivery
system and also to evaluate procedure related variables like type of surfactant and release of drug
from niosomes. Metoprolol tartrate niosomes are formulated by coacervation-phase separation
method using different types of non-ionic surfactant (Span or Tween of different HLB value),
lecithin and cholesterol. The prepared formulations are estimated for its entrapment efficiency,
vesicle size (optical microscope and ABT-9000 NANO Laser particle size analyzer), the
compatibility of the drug and additives used (Fourier Transform Infra Red -FT-IR spectroscopy)
and morphological characters (Scanning Electron Microscopy- SEM). Fourier Transform Infra Red
(FT-IR) studies, confirm that there is no interaction between drug and other formulation
components of niosome. Higher entrapment efficiencies are obtained with Span 40 and span 60
(86.6%±8.07 and 78.09±15.44 respectively) and the release rate at 11 hr from span 40 niosomes is
found to be 31.18%. In conclusion, the niosomal gel formulation could be a promising transdermal
delivery system for metoprolol tartarate with prolonged drug release profiles.
-1
HLB
78.09±15.44
Kerbala Journal of Pharmaceutical Sciences Number 62013
Introduction
The oral bioavailability depends on numerous factors including, drug permeability, dissolution rate,
aqueous solubility and first-pass metabolism (1). Metoprolol tartrate is a cardio-selective β1blocker.
It is used in the management of hypertension and it is ready and completely absorbed after oral
administration, however it is subject to substantial first metabolism, with bioavailability (38%)(2).
The mean plasma half-life is about three to four hours; as a result the short half life makes frequent
dosing to keep the level of drug in blood(2). Transdermal drug delivery system is applied to give a
range of advantages over other conventional dosage forms. It may get rid of several variables
factors related to the oral intake and it avoids the first pass effect, influence of food, gastric
emptying and intestinal motility and transit times (3).
The skin impermeability of human being is regarded as the most important problem for transdermal
drug delivery system(4). The rate of penetration across the skin is specified by Fick’s first law
equation which explains passive drug move through biomembranes (5). There are many approaches
for overcoming the barricade offered by an intact stratum corneum, but vesicles and particles (as
liposomes and niosomes) can play the most important part in representation of biological
membranes, and in carrying and targeting of therapeutic agents. The basic structures of vesicles are
amphiphilic molecules in a bilayer arrangement. In an excess of aqueous phase, these amphiphilic
molecules can form either unilamellar or multilamellar vesicles (6). A large range of lipids and
surfactants can be used to organize vesicles. The majority of these vesicles are composed of
phospholipids or non-ionic surfactants (7). These are referred to as liposomes and niosomes or
nonionic surfactant vesicles. The objective of the present study was to develop and evaluate
different Noisomal gels as transdermal formulations for Metoprolol tartrate.
Materials and methods
Materials
Metoprolol tartrate powder was supplied by Hexia-chemical, China .cellophane membrane M.WT
cut-off of 12000 was from "Sigma Company". Potassium dihydrogen phosphate and Lecithin were
from -BDH chemical Ltd-Pool, England. Span 20 (Sorbitan monolaurate) Span 40 (Sorbitan
monopalmitate) were from- Fluka Chemi U.S.A. Span 60 (Sorbitan monostearate) Tween 60
(Polysorbate 60) were from -Merck-shuchardt, Germany. Tween 20 (polysorbate 20) was from
Thomas Baker, India. Tween 40 (polysorbate 40) was from -Sigma- Aldrich company , Fluka
analytical, Germany. Other materials used were of analytical grade.
Niosomal gel Preparation
Different formulas were prepared using coacervation-phase separation method (8) in which
specified amount of surfactant (Sorbitan esters or their ethoxylated derivatives), lecithin, cholesterol
and drug were mixed in dry 10 ml glass vials as given in table 1.The components were warmed on a
water bath at 60–700C for few minutes until the surfactants were dissolved completely. The aqueous
phase (0.1% w/v glycerol solution) was added and warmed till clear solution is formed which on
cooling converts into a niosomal gel. The obtained gel was kept in dark place for description.
Kerbala Journal of Pharmaceutical Sciences Number 62013
Table (1): Different Formulas of Proniosomal Gel
Physical manifestation
The manifestation for each formula was tested which include color, consistency and fluidity and
comparison of each one with the other.
Entrapment efficiency
Sample of 100 mg of proniosomal gel was dispersed in distilled water and warmed to 40 oC using
water bath to ensure the formation of niosomes. The dispersion was centrifuged at 15000 rpm for 50
min at 5oC (9) and the supernatant layer was used for the determination of free drug. The percentage
entrapment was calculated according to the following equation (10):
Amount of drug entrapped
% Entrapment = ------------------------------------ X 100
Total amount of drug used
Microscopic observation
A thin layer of proniosomal gel sample was prepared on microscope slide. The sample was
evaluated under optical microscope before and after adding a drop of water to it (11). Surface
morphology of prepared noisomal gel of different formulations were further studied also by using
scanning electron microscopy. One drop of dispersion system was mounted on a stub covered with
clean glass. The drop was spread out on the glass homogeneously. The samples were examined
under a scanning electron microscope (Quanta Inspect-Netherland) at suitable accelerating voltage
(12).
Fourier transform, infrared (FTIR) study
One to one ratio of pure drug metoprolol tartarate and the other components of niosmes were
mixed separately (span 40, tween 40, and cholesterol and soya lecithin) with infrared (IR) grade
KBr disc. The corresponding disc was prepared by applying a pressure in a hydraulic press. The
KBr disc was scanned in an inert atmosphere over a wave number range of 4000–400 cm–1FTIR
instrument(IR Affinity- 1- Shimadzu, Japan) (113).
Vesicle Size Analysis
Vesicle size examination was achieved by adding phosphate buffered saline solution (pH 7.4) to
100 mg of proniosomal gel in 5 ml glass vial. After shaking for 10 min, the sizes of 150-200
vesicles were calculated using a calibrated ocular and stage micrometer fixed in the optical
microscope at100, 40 and 10 x magnifications (14). Poly dispersity index (PI) was calculated from
the square of the standard deviation divided by mean diameter. A reduction in vesicle size may be
achieved by a number of methods. proniosomal gel of span 60 and tween 60 were exposed to
ultarsonication. The range size of niosomes in nanometer that obtained after sonication was
measured using ABT-9000 NANO Laser particle size analyzer (Angstrom Advanced Inc).
Formulation
code
Surfactant type
(mg)
Lecithin
(mg)
Cholesterol
(mg)
Metoprolol
tartarate
(mg)
F1
Span 20
800
100
100
100
F2
Span 40
800
100
100
100
F3
Span 60
800
100
100
100
F4
Tween 20
800
100
100
100
F5
Tween 40
800
100
100
100
F6
Tween 60
800
100
100
100
Kerbala Journal of Pharmaceutical Sciences Number 62013
In vitro drug release
Dialysis tubing method was used to study the in-vitro release rate. A Cellophane dialysis membrane
with molecular weight cut-off of 12000 Dalton (Sigma- Aldrich) was used as dialysis tube. Dialysis
tube was washed and soaked in phosphate buffered saline solution (pH 7.4) for 24 hrs. One end of
dialysis tube (3.0 cm2 diameter) was closed then a specified amount of proniosomal gel of different
compositions was spread on the surface of membrane and hydrated by phosphate buffered saline
then the second end was also closed. The tube containing the vesicles is putted in a beaker
containing saline phosphate buffer (pH 7.4) at 37°C. At suitable time intervals, the buffer was
analyzed for the drug content by UV method at 243 λ max (15).
Result and discussion
Physical manifestation
All formulas gave a white and yellow semisolid state, except F1and F4 showed a brown liquid state;
this is due to the property of span and tween such as color and phase transition point. The pH of
each formula was determined in order to investigate the possibility of any irritant effects in vivo
since acidic or alkaline pH may irritate skin. The pH was found between 5.2 (for F1) and 6.2 (for
F3), as shown in table 2 and this range of pH is within the physiologically skin surface pH (8).
Microscopic observation
The combination of proniosome formed appears as lamellar liquid crystals resembling palisades and
vesiculating lamellas stacked together which may be termed as compact niosomes as seen in SEM
image (figure1). These compact niosomes when shaken with excess aqueous phase leads to swelling
bilayers as well as the bilayers tend to form spherical structures (16) as shown in figures 2-3.
Table (2): Physical Properties of the Prepared Noisomal Gel
Figure (1): SEM image of compact niosomes
Entrapment
efficiency %
(PI) poly
dispersity
index
Size ±SD
(µg)
pH
Physical
state
Color
Formula
code
68.32±19.73
0.425
4.558±1.94
5.2
Liquid
Brown
F1
86.60±8.07
0.410
6.753±2.77
5.5
Semisolid
White
F2
78.09±15.44
0.340
6.816±2.32
6.2
Semisolid
White
F3
59.42±16.53
0.471
5.215±2.46
5.3
Liquid
Brown
F4
68.45±9.20
0.584
5.188±3.03
5.3
Semisolid
yellow
F5
74.03±22.00
0.301
5.433±1.64
5.6
Semisolid
yellow
F6
Kerbala Journal of Pharmaceutical Sciences Number 62013
Figure (2): Nisomes under ordinary light microscope x40
Figure (3): SEM image of niosomes
Entrapment efficiency and size distribution
The results obtained were scheduled in table 2, which shows that the less fluid the bilayer (higher
the gel to liquid phase transition temperature) the higher the encapsulation efficiency, the
entrapment efficiency is higher for vesicles prepared by solid to semisolid type of span and tween
than those prepared by liquid type. This may be attributed to the fact that spans 40, span 60,tween
40 and tween 60 are solids to semisolids at room temperature and showed a higher phase transition
temperatures [Tc] (17). The transition temperatures of surfactants are increased as the hydrocarbon
length is increased (span 20 and tween 20 are liquid at room temperature; this stability decreases
leakage of the vesicles and stabilizes against osmotic gradients (18).
Entrapment of drug in niosomes increases vesicle size, probably by interaction of solute with
surfactant head groups, increasing the charge and mutual repulsion of the surfactant bilayers,
thereby increasing vesicle size as seen with vesicles prepared by span 40 and span 60 (19). Span 40
and span 60 are spans with highest phase transition temperature and high HLB values, which
enhanced formation of large vesicles with higher entrapment of drug (20). Smallest vesicles were
achieved after sonication the dispersion of vesicles which may be due to the effect of applied energy
during sonication resulted in breakage them into smaller vesicles (21). Figure 4-5 shows the effect of
ultrasonication on vesicles size of span 60 and tween 60 niosomes.
Kerbala Journal of Pharmaceutical Sciences Number 62013
Figure (4):Tween 60 niosomes size after sonication
Figure (5): Span 60 niosomes size after sonication
Fourier transform, infrared (FTIR) study
Figure 6 show the IR spectrum of metoprolol tartarate, while figures 7, 8, 9 and 10 show the
physical mixture of drug with each of the following materials span 40, tween 40, and cholesterol
and soya lecithin, respectively. The spectrums in mixture of span 40 or tween 40 and metoprolol
tartrate are similar to that of span 40 or tween 40 alone. The usual occurrence of 1398.39 cm-1 and
1593.2cm-1 for O-H and N-H bending of metoprolol, respectively were present in their positions.
The O-H bending of span 40 was appeared at normal frequency 1419.61cm-1 as well as the C=O
and C-O stretching was appeared at 1734.01cm-1 and 1244.09 cm-1 respectively. The O-H bending
of tween was occurred at 1350.17 cm-1 with broad of C-O stretching due to high number of ether in
tween. The same result was observed for cholesterol and drug or lecithin and drug mixture. There is
no appearance of bands for new functional group or disappearance of essential bands. In general, no
predominant drug interaction was detected. The compounds span 40, tween 40 and lecithin have
numerous polar groups ( C═O, OH and NH3+)in each molecule that may be involved in intra H-
bonding , thus no chance for inter H- bonding with the drug was observed.
Kerbala Journal of Pharmaceutical Sciences Number 62013
Figure (6): Fourier Transform Infra Red (FTIR) of metoprolol tartrate.
Figure (7): Fourier Transform Infra Red (FTIR) of physical mixture of metoprolol tartrate
and span 40 .
Kerbala Journal of Pharmaceutical Sciences Number 62013
Figure (8): Fourier Transform Infra Red (FTIR) of physical mixture of metoprolol tartrate
and tween 40 .
Figure (9): Fourier Transform Infra Red (FTIR) of physical mixture of metoprolol tartrate
and cholesterol.
Kerbala Journal of Pharmaceutical Sciences Number 62013
Figure (10): Fourier Transform Infra Red (FTIR) of physical mixture of metoprolol tartrate
and lecithin.
In-vitro release
The percentage release of metoprolol tartrate at 11 hr from span surfactants was found to be in the
following order: F1>F3>F2 with 93.6%, 37.8%, and 31.18% of drug release respectively. The lag
phase for drug to be release was about 4 hrs as illustrate in figure 11; this may be attributed to the
certainty that the molecules of spans 40 and 60 are in a structured gel state at the in vitro release
circumstances. On the other hand, the result obtained at 11 hr indicates that the release percent of
drug from F4 was higher than F5 and F6 .Moreover, the percents of release were 94.8%, 94.0%and
32.7% for tween 20, tween 60 and tween 40 respectively, as explained in figure 12. The exact lag
phase difference between spans and tween cannot determine, because of the minimum sampling
time of one hour. Formulations F1 and F4 showed higher release, since spans 20 and tween 20 are
in the disorganized liquid crystalline state under the identical conditions (22). In addition to that the
release of drug from tween surfactant is faster than the release of drug from span surfactant, in view
of the fact that tween is more hydrophilic than span and less hydrophobicity (23).
Figure (11): In-vitro release of metoprolol tartrate from span niosomal gels at 37±0.5 ºC.
Kerbala Journal of Pharmaceutical Sciences Number 62013
Figure (12): In-vitro release of metoprolol tartrate from tween niosomal gels at 37±0.5 ºC.
Conclusion
According to the achieved results, the preparations of niosomes from proniosome by coacervation-
phase separation method appear to be simple and straightforward method. It does not involve more
difficult procedures. Transdermal drug delivery system with vesicles systems appears possible with
metoprolol tartrate drug with prolonged release.
References
1-Sakaeda T, Okamura N, Nagata S, Yagami T, Horinouchi M, et al. Molecular and
pharmacokinetic properties of 222 commercially available oral drugs in humans. Biol Pharm Bull;
(24): P.935-940 (2001).
2-Naga Raju K, Velmurugan S, Deepika B, Sundar Vinushitha Formulation and Invitro Evaluation
of Buccal Tablets of Metoprolol Tartrate Int J Pharm Pharm Sci.vol 3;(2):P.239-246 (2011)
3- Inayat Bashir Pathan, C Mallikarjuna Setty.Chemical Penetration Enhancers for Transdermal
Drug Delivery Systems. Trop J Pharm Res. 8; (2): P.173-179 (2009).
4- Challa Tarakaramarao, K. Srinivasareddy. Transdermals as Novel Drug Delivery System: A
Review. Int. J of Pharma Research & Review. 2;(7):P.64-69 (2013).
5-Barry BW. Reflections on transdermal drug delivery, Pharm Sci Technol Today. vol. 2;( 2):P 41–
43 (1999).
6-Upadhyay N, Mandal S, Bhatia L, Shailesh S, Chauhan P. A Review on “Ethosomes: An
Emerging Approach for Drug Delivery through the Skin” Rec Res Sci Tech. 3; P.19-24 (2011).
7-Sakthivel M, Kannan K, Manavalan R, Senthamarai R. Non Ionic Surfactant Vesicles – A
Review. RJPBCS. Vol 3 ;(1): P. 604-614 (2012).
Kerbala Journal of Pharmaceutical Sciences Number 62013
8-Runeman B, Faergemann J, Larko O. Experimental Candida albicans lesions in healthy humans:
Dependence on skin pH. Acta Derm Venereol; (80):P.421–424 (2000).
9-Schmid-Wendtner MH, Korting HC. The pH of the Skin Surface and Its Impact on the Barrier
Function. Skin Pharmacol Physiol; (19):P.296–302 (2006).
10-Aranya Manosroi,Romchat Chutoprapat, Masahiko Abe, Worapaka Manosroi, and Jiradej
Manosroi. Transdermal Absorption Enhancement of Rice Bran Bioactive Compounds Entrapped in
Niosomes.AAPS PharmSciTech.; 13(1): P. 323–335 (2012).
11-Barry Brian W. Is transdermal drug delivery research still important today. Drug Discovery
Today; (7):P.6-19 (2001).
12-Dubey V, Mishra D, Jain NK. Melatonin loaded ethanolic liposomes: Physicochemical
characterization and enhanced transdermal delivery.Eur J Pharm Biopharm; (67):P.398–405 (2007).
13-Biswajit Mukherjee, Balaram Patra, Buddhadev Layek, and Arup Mukherjee. Sustained release
of acyclovir from nano-liposomes and nano-niosomes: An in vitro study. Int J Nanomedicine ;
2(2):P. 213–225 (2007).
14-Yoshioka T, Florence AT.Vesicle (niosome)-in-water-in-oil (v:w:o) emulsions-an in-vitro study.
Int J Pharm; (108):P.117–123 (1994).
15-Mohamed Aqil, Yasmin Sultana, Asgar Ali. Matrix type transdermal drug delivery systems of
metoprolol tartrate: In vitro characterization Acta Pharm.;(53):P. 119–125 (2003).
16-Vora B, Khopade AJ, Jain NK. Proniosome based transdermal delivery of levonorgestrel for
effective contraception. J Control Rel; (54):P.149–165 (1998).
17-Varghese V, Vitta P, Bakshi V, Agarwal S, Pandey S. Niosomes of primaquine. Effect of
sorbitan esters (spans) on the vesicular physical characterstics. Indian Drugs; 41(2):P.101-103
(2004).
18-Bouwstra JA, van Hal DA, Hofland HEJ, et al. Preparation and characterization of nonionic
surfactant vesicles. Colloids Surf A; P. 71-80 (1997).
19-Gayatri Devi S., Venkatesh P. and Udupa N. Niosomal sumatriptan succinate for nasal
administration. Int J Pharm. Sci;62(6):P.479-481 (2000).
20- Neeraj Bhandari, Pooja Verma, Hussandeep Singh, Santanu Rc Proniosomes – A Surrogate For
Transdermal Drug Delivery. Ijprbs; Vol 1(6): P.10-26 (2012)
21-Gupta A, Prajapati SK, Balamurugan M, Singh M, Bhatia D. Design and Development of a
Proniosomal Transdermal Drug Delivery System for Captopril. Trop J Pharm Res; 6 (2):P.687-693
(2007).
22-Yoshioka T, Stermberg B, Florence AT. Preparation and properties of vesicles (niosomes) of
sobitan monoesters (Span 20, 40, 60, and 80) and a sorbitan triester (Span 85). Int J Pharm;
(105):P.1-6 (1994).
23-Alsarra IA, Bosela AA, Ahmed SM, Mahrous GM. Proniosomes as a drug carrier for
transdermal delivery of ketorolac. Eur J Pharm Biopharm; (59):P.485–490 (2005).
