International Journal of Chemical and Pharmaceutical Sciences Formulation and Evaluation of oral controlled release matrix tablets of Paroxetine
Mahendar R *, Sambashiva D, Valmiki R and Ramakrisha K
MRR College of B. Pharmacy, Nadergul village, Saroornagar, Andhra Pradesh, India.
*Corresponding Author: E-Mail: [email protected] ABSTRACT
The purpose of the present study was to formulate and evaluate oral extended release matrix
tablets of Paroxatine using hydroxy propyl methylcellulose (HPMC) and polyethylene oxide (PEO) as the
release rate retardant polymers. The study includes in vitro characterization of tablets such as physico
chemical properties, in vitro dissolution, DSC and FTIR. Selected formulations based on the in-vitro drug
release study were packed in HDPE containers and kept for accelerated stability condition at 40°C and 75
% relative humidity. In vitro release studies revealed that the release rate decreased with increase in
polymer concentration, polymer viscosity. In-vitro release kinetics indicated that the drug release from
the matrix tablets was followed first order kinetics with diffusion mechanism. Results of Differential
scanning calorimetry (DSC) and Fourier Transforms Infrared Radiation measurement (FT-IR) of initial
and stability samples have shown that there was no incompatibility observed between the drug and
excipients used in the formulation of matrix tablets. The developed controlled release matrix tablets of
were stable up to three months. The release rate of the matrix tablets for prolonged periods of time can
be advantageous than conventional Paroxatine tablets. Key words: Paroxatine, matrix tablets, controlled release, stability, DSC, FTIR. 1. INTRODUCTION
hydrochloride upon oral administration, the
Extended release is a kind of controlled
development of controlled release delivery system
release system that provides the medication for
is required, that can maintain therapeutic drug
most popular route of drug administration
because of its ease of administration and patient
as rate-controlling polymers for extended release
compliance [2]. Even though oral route is preferred
matrix-type dosage forms. Hydroxy propyl methyl
by the patients, in case of chronic situations the
cellulose (HPMC) is a hydrophilic polymer used in
dosage form should be administered in divided
the matrix type systems for the prolonged drug
doses for longer periods of time and again this is a
release. HPMC matrix tablets may be affected by
non compliance to patients. There are several
several formulation variables, such as polymer
disadvantages if the drug is administered
concentration [9] molecular weigh [10] drug levels
frequently [3]. Dose modification is required in
and solubility [11], type of excepient and tablet
such situations [4]. Extended release (XR)
shape and size [12]. The Hydrophilic polymer
formulations are preferred because they offer
matrix swells as water diffuses into the tablet.
better patient compliance, maintain uniform drug
Usually HPMC upon contact with aqueous media
levels, reduce dose and side effects, and increase
begin to hydrate, swell, coalesce, and form a
viscous phase around the surface of the tablet. For
hydrophilic matrix tablets comprised of water-
phenylpiperidine antidepressant agent which
soluble, swellable polymers such as HPMC, the
selectively inhibits serotonin reuptake (SSRI)
release kinetics are described by drug diffusion
Paroxetine hydrochloride is heavily prescribed
and polymer dissolution, i.e surface erosion. Drug
drugs and effective in patients with various
release is dependent on the relative contribution
psychiatric disorders. However, there were
of diffusion and erosion release mechanisms [13].
adverse effects associated with SSRI. Certain
The matrix geometry is also one of the important
adverse effects are thought to be linked to
factors for drug releases from extended-release
increased serotonin in the CNS (e.g. sexual
dosage forms [14]. Specifically for HPMC matrix
dysfunction and somnolence) and periphery
tablets, the effect of matrix geometry on drug
decrease these adverse effects of paroxetine
release has also been studied in detail [15]. Poly
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(ethylene oxide) (PEO) is a hydrophilic polymeric
excipient that can be used in formulations for
characterized for drug content. The lubricated
different purposes [16]. PEO s are mostly used to
granules were directly compressed on 16-station
produce controlled release solid dosage forms
tablet compression machine using 7 mm flat faced
such as matrices, reservoirs, or coated cores. Due
round (FFR) punch. (Cadmach Machinery Co,
to their chemical structure, in the presence of
Ahmedabad, India). Three batches were prepared
water, control the release of the active moiety
for each formulation and compressed in to tablets
either by swelling or by eroding and swelling
form each batch for the characterization study.
forming a hydrogel. In both cases, the water
2.3. Characterization of the Designed Tablets
triggers the process starting the erosion and/or
the swelling processes. PEO has been used in
2.3.1. Drug content estimation
association with HPMC to delay the release of a
The drug content of the prepared matrix
drug by controlling the extent and rate of swelling
tablets was determined in triplicate. For each
batch, 20 tablets were taken, weighed, and finely
powdered. An accurately weighed 150 mg of this
literature available on XR formulations of
powder was taken and suitably dissolved under
Paroxatine. The purpose of this study was to
sonication (Power sonic 505, HWASHIN
design oral XR tablet formulations of Paroxatine
technology co) in pH 7.2 tris phosphate buffer and
using HPMC and PEO as the retarding polymer.
filtered through 0.45 µ (Millipore) filter. The
The tablets were formulated by direct
sample was analyzed after making appropriate
compression method, and their physical and in
vitro release characteristics were evaluated. The
(Schimadzu, UV-1700 E 23) at 290 nm against
effect of formulation factors such as polymer
proportion, polymer type on the release
2.3.2. Hardness, weight variation and friability
characteristics was studied in order to optimize
determination
The weight variation was determined by
2. MATERIALS AND METHODS
taking 20 tablets using an electronic balance (type
Paroxatine was obtained as a gift sample
ER182A, Mettler Toledo). Tablet hardness was
from Alkem laboratories Ltd (Mumbai, India).
determined for 10 tablets using a Monsanto tablet
Hydroxypropyl methylcellulose (HPMC K 100 M)
hardness tester (MHT-20, Campbell Electronics,
were obtained from Colorcon Asia Private Ltd ,
Mumbai, India). Friability was determined by
Poly (ethylene oxide) (Polyox WSR 303) was
testing 10 tablets in a friability tester (FTA-20,
obtained from The DOW Chemical Company,
Campbell Electronics) for 300 revolutions at 25
Micro crystalline cellulose (Avicel PH 200) was
obtained form FMC Biopolymers, USA, colloidal
2.3.3. In Vitro Drug Release Studies
silicon dioxide ( Aerosil ) was obtained form
Degussa, Germany, talc was obtained form
The in vitro dissolution studies were
Luzenac, France and magnesium stearate was
performed for the prepared tablets using
obtained form Ferro Industrial Chemicals USA. All
dissolution apparatus (LABINDIA, DISSO-2000,
other chemicals and reagents used in the study
Mumbai, India). The dissolution medium
consisted of pH 7.2 tris phosphate buffer (900
mL), 150 rpm speed, maintained at 37 ±0.5 °C. The
2.1 Analytical method
samples were with drawn at different time
method was used for the determination of
spectrophotometer as per the method specified in
Paroxatine using Schimadzu, UV-1700 E 23 in pH
7.2 tris phosphate buffer at 290 nm. 2.3.4. Fourier transforms infrared radiation measurement (FT-IR) 2.2. Formulation of Paroxatine matrix tablets
The FT-IR spectra acquired were taken
from dried samples. A FT-IR (Thermo Nicolet 670
spectrometer) was used for the analysis in the
prepared using various proportions of HPMC and
frequency range between 4000 and 400 cm-1,
PEO as the retarding polymer. The tablets were
with 4 cm-1 resolution. A quantity equivalent to 2
manufactured by the direct compression. The
mg of pure drug and matrix tablets were selected
drug, polymer(s) and all other excipients sifted
through 425 μm sieve (ASTM mesh no 40) and
mixed uniformly. The dry mix blend was mixed
2.3.5 Differential scanning calorimetry (DSC)
with aerosil and talc followed by magnesium
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Differential scanning calorimetry (DSC)
study of matrix tablets was performed using a
Diamond DSC (Mettler Star SW 8.10) to determine
the drug excepient compatibility study. The
analysis was performed at a rate 5 0 C min -1 from
500 OC to 2000 OC temperature range under
Formulation physical characteristics of designed controlled release matrix tablets of Paroxatine Time (hrs)
Differential scanning calorimetry (DSC)
study of pure Paroxatine showed a sharp
endothermic peak at 132.5° C. The thermograms
of Paroxatine matrix tablets showed similar
endothermic peak at 132° C. This further confirms
that there is no drug to polymer interaction. This
was further conformed by FTIR Figure -2: DSC thermogram of (A) pure Paroxatine (B) Paroxatine matrix tablets prepared with HPMC (C) Paroxatine matrix tablets prepared with PEO . 3. RESULTS AND DISCUSSION
Prepared tablets were evaluated to weight
variation study. The results of weight variation
test are shown in the Table 1 and the values are
around 120 mg. The tablets thickness of the
prepared formulations was observed in the range
of 3.5mm to 3.6 mm. The hardness of all the
tablets was found to be in the range of 6 kg/cm2.
The friability of the prepared tablets was below
1% clearly indicates the good mechanical strength
of the tablets. The drug content ranged from
99.82 to 100.85 in formulation clearly indicating
good content uniformity. The formulations were
summarized in Table 1. The in vitro dissolution
study showed that the drug release was extended
Figure -3: FTIR Spectrum of (A) pure
up to 18 hours. The release for the formulations
Paroxatine (B) Paroxatine matrix tablets
prepared with HPMC K 100 M was faster when
prepared with HPMC (C) Paroxatine matrix
compared with the tablets prepared with
tablets prepared with PEO .
Polyethylene oxide (PEO), The mainly depends up
on the polymer type and the polymer
concentration. The release kinetics form the
dissolution data was followed zero order release
with diffusion mechanism. Table 1 shows the
release kinetics of the prepared paroxatine matrix
tablets. Figure -1: Cumulative percent drug release vs time plot of Paroxatine tablets
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4. CONCLUSION
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The prepared formulations have potential
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Aurobindo Pharma for providing providing the
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