Scholarly article on topic 'Development and evaluation of orodispersible tablets using a natural polysaccharide isolated from Cassia tora seeds'

Development and evaluation of orodispersible tablets using a natural polysaccharide isolated from Cassia tora seeds Academic research paper on "Chemical sciences"

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{" Cassia tora " / "direct compression" / "orodispersible tablets" / "patient compliance" / "sodium starch glycolate"}

Abstract of research paper on Chemical sciences, author of scientific article — Harshal Pawar, Chhaya Varkhade, Pravin Jadhav, Kavita Mehra

Abstract Background Orodispersible tablets or fast dissolving tablets dissolve or disintegrate immediately on the patients’ tongue or buccal mucosa. This drug delivery system is suitable for drugs undergoing high first pass metabolism. It improves bioavailability, reduces dosing frequency, and thereby minimizes the side effects and also makes the dosage form more cost-effective. In this study, polysaccharide isolated from the seeds of Cassia tora was investigated as a superdisintegrant in the orodispersible tablets. The model drug chosen was valsartan, an antihypertensive drug. Methods Valsartan tablets were prepared separately using different concentrations (1%, 2.5%, 5%, and 7.5% w/w) of isolated C. tora seed polysaccharide (natural) and sodium starch glycolate (synthetic) as superdisintegrant by the direct compression method. Evaluation of tablets was done for various pre- and postcompression parameters. The stability studies were performed on optimized formulation F4. The disintegration time and in vitro drug release of the formulation F4 were compared with marketed formulations (conventional tablets). Results The drug excipient interactions were characterized by Fourier transform infrared studies. The formulation F4 containing 7.5% polysaccharide showed good wetting time and disintegration time as compared to a formulation prepared using a synthetic superdisintegrant at the same concentration level. Hence, batch F4 was considered optimized formulation. Conclusion The present work revealed that C. tora seed polysaccharide has a good potential as a disintegrant in the formulation of orodispersible tablets. Because C. tora polysaccharide is inexpensive as compared to synthetic superdisintegrants, nontoxic, compatible, and easy to manufacture, it can be used in place of currently marketed superdisintegrants.

Academic research paper on topic "Development and evaluation of orodispersible tablets using a natural polysaccharide isolated from Cassia tora seeds"

Author: Harshal Pawar Chhaya Varkhade Pravin Jadhav Kavita Mehra

Accepted Manuscript

Title: Development and evaluation of orodispersible tablets using a natural polysaccharide isolated from Cassia tora seeds

PII: DOI:

Reference:

S2213-4220(14)00022-5

http://dx.doi.org/doi:10.1016/j.imr.2014.03.002

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Received date: Revised date: Accepted date:

13-1-2014 10-3-2014 10-3-2014

Please cite this article as: Harshal PawarChhaya VarkhadePravin JadhavKavita Mehra Development and evaluation of orodispersible tablets using a natural polysaccharide isolated from Cassia tora seeds (2014), http://dx.doi.org/10.1016/jimr.2014.03.002

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Title Page

Development and evaluation of orodispersible tablets using a natural polysaccharide isolated from Cassia tora seeds

Harshal Pawar*, Chhaya Varkhade, Pravin Jadhav, Kavita Mehra

Department of Quality Assurance, Dr. L. H. Hiranandani College of Pharmacy, Ulhasnagar,

Maharashtra, India.

"Corresponding Author:

Harshal Ashok Pawar,

Assistant Professor and Head of Department (Quality Assurance), Dr. L. H. Hiranandani College of Pharmacy, Smt.CHM Campus, Opp. Ulhasnagar Railway Station, Ulhasnagar-421003, Maharashtra, India Contact No. +91-8097148638, Email: harshal.dlhhcop@gmail.com

Abstract Background:

Orodispersible tablets or Fast dissolving tablets dissolve or disintegrate immediately on the patients tongue or buccal mucosa. This drug delivery system is suitable for drugs undergoing high first pass metabolism. It improves bioavailability, reduces dosing frequency and thereby minimizes the side effects and also makes the dosage form more cost effective. In this study polysaccharide isolated from the seeds of Cassia tora was investigated as superdisintegrant in the orodispersible tablets. The model drug chosen was Valsartan, an antihypertensive drug. Method:

Tablets of Valsartan were prepared separately using different concentrations (1, 2.5, 5 and 7.5%w/w) of isolated Cassia tora seed polysaccharide (Natural) and sodium starch glycolate (synthetic) as superdisintegrant by direct compression method. Evaluation of tablets was done for various pre-compression and post-compression parameters. The stability studies were performed on optimized formulation F4.The disintegration time and in vitro drug release of the formulation F4 were compared with the marketed formulation (Conventional tablets). Results:

The drug excipient interactions were characterized by FTIR studies. The formulation F4 containing 7.5% polysaccharide showed good wetting time and disintegration time as compared to formulation prepared using synthetic superdisintegrant at the same concentration level. Hence batch F4 was considered as optimized formulation. Conclusion:

The present work revealed that Cassia tora seed polysaccharide has good potential as disintegrant in the formulation of orodispersible tablets. Since Cassia tora polysaccharide is

inexpensive as compared to synthetic superdisintegrant, non-toxic, compatible and easy to manufacture, it can be used in place of presently marketed superdisintegrants. Keywords: Orodispersible tablets, Cassia tora, Direct compression, Patient compliance, Sodium starch glycolate.

1. Introduction

Tablets and capsules are most extensively used and widely acceptable dosage forms. However they face a drawback for some patients because of the difficulty to swallow. Tablets that dissolve rapidly in the oral cavity have become very popular in the recent times. Orodispersible tablet (ODT) is a rapidly emerging drug delivery system with better patient compliance. ODT are used for people who have swallowing difficulties as well as for active people [1, 2, 3].

ODT disintegrate in patient's mouth within a few seconds and are ideal for patients having dysphasia [4, 5]. Some drugs are absorbed from the mouth, pharynx and esophagus as the saliva passes down the stomach which leads to increase in bioavailability. The advantages of mouth dissolving dosage form are increasingly being acknowledged in both industry and academia [6].ODT are commonly known as Orally disintegrating tablets, Mouth dissolving tablets, Fast dissolving tablets or Rapid melt tablets.

The additives used to convert active pharmaceutical ingredients into pharmaceutical dosage form are known as excipients [7]. Excipients from Natural sources have advantage over synthetic excipients as they are locally accessible, non-polluting, biocompatible and cheap as compared to imported synthetic products. Herbs are renewable resources for maintainable supplies of cheaper pharmaceutical products [8-15].

Fast disintegrating tablets are made by direct compression method using superdisintegrants as an important component. Disintegrants are the substances or mixture of substances added to the drug formulation that helps in disintegration of tablet content into smaller particles that dissolve more rapidly than tablets without disintegrants. Examples of superdisintegrants are croscarmelose, crospovidone, sodium starch glycolate which symbolize

example of crosslinked cellulose, crosslinked polymer and a crosslinked starch respectively [16,

17, 18]. These are the commonly used synthetic origin superdisintegrants. Various natural origin

substances like karaya, modified starch and agar have been used in the formulations of ODTs.

The natural origin substances are comparatively cheaper with desired properties like abundantly

available, non-irritating and non-toxic in nature [19].They have several advantages over

synthetic superdisintegrants like ease of isolation, local availability and biocompatibility.

Cassia tora (Family: Leguminosae) is an annual under shrub commonly found in India and other tropical countries [20]. Seeds of Cassia tora contain several anthraquinones and sennosoids [21, 22, 23]. It has been used for treatment of asthma and to improve visual activity [24]. It has antiinflammatory and hepatoprotective activity [25].Gum obtained from the seeds of Cassia tora is known as 'Panwar gum'. Chemically it is neutral heteropolysaccharide of galactose and mannose (i.e. galactomannans). The pH of the Panwar gum mucilage is approximately 7 [20]. Literature survey revealed that the Cassia tora polysaccharide has not been used till date as disintegrant and hence this polysaccharide was selected for present investigation. The present study deals with investigation of polysaccharide isolated from the seeds of Cassia tora as a superdisintegrant in Orodispersible tablets and comparing its disintegrating potential with synthetic superdisintegrant.

The model drug used for the study was Valsartan, which is an antihypertensive drug belongs to the category of Angiotensin II receptor antagonist. The molecular weight of Valsartan is 435.5, its half-life is 4-6h, with poor oral bioavailability ranging from 10-35 because of poor solubility, dissolution, 95% of the drug undergoes protein binding and most importantly extensive first pass hepatic metabolism [26, 27]. The present research work was aimed at the development and characterization of Orodispersible tablets of Valsartan using novel superdisintegrant to produce rapid onset of action and patient compliance.

2. Materials and Methods

2.1. Materials

Valsartan was obtained from Unichem Laboratories Ltd., Mumbai as a gift sample. Microcrystalline Cellulose (MCC PH 102), Sodium starch glycolate (SSG), Magnesium Stearate (Mg-stearate), Talc, Aspartame and Vanilla flavor were obtained from Colorcon Asia Pvt. Ltd., Mumbai. Cassia tora seeds were collected from Maharashtra region (India) in the month of October. The plant material was authenticated from Blatter herbarium. The specimen sample of the plant is preserved with department of Quality Assurance, Dr. L. H. Hiranandani College of Pharmacy, Ulhasnagar. All the chemicals and reagents were of analytical grade.

2.2. Isolation of polysaccharide from Cassia tora seeds

The seeds of Cassia tora were dry milled in a mixer to separate the endosperm from the seed coat. The endosperm of Cassia tora seeds (100gm) were soaked in distilled water and shaken for 4-5 hrs. The viscous solution obtained was filtered through Muslin cloth. Precipitation of the mucilage (Polysaccharide) was carried out by the addition of 95% ethanol (1:1 ratio) by continuous stirring. The precipitated polysaccharide was transferred to an evaporating dish and treated consecutively with ethanol. The polysaccharide obtained was dried in oven at 40-45°C. It was then powdered and passed through sieve no. 60 and stored in airtight container. The isolated polysaccharide was characterized for various physicochemical properties such as solubility, pH (1% w/w in water), swelling index, loss on drying, ash value, bulk and tapped density, compressibility index, Hausner's ratio and angle of repose as per reported method [28, 29].

2.3. Formulation of Orodispersible tablets

ODTs of Valsartan were prepared by the direct compression method using isolated polysaccharide and synthetic superdisintegrant at concentration of 1, 2.5, 5, 7.5% w/w. All the ingredients were passed through 60 mesh sieve. Weighed quantity of each ingredient was taken and the blend (Powder mix) was uniformly mixed and compressed into tablets of 200mg using 9mm round flat punches on single rotary tablet machine (Royal artist).The composition of each formulation is given in table 1.

2. 4. Evaluation of powder blend (Pre-compression parameters)

The powder mix was evaluated for various flow properties such as angle of repose, bulk and tapped density, Hausner's ratio and Carr's index. 2. 4.1. Angle of repose

The angle of repose of powder was carried out by the fixed funnel method. The accurately weighed quantity of powder mix was taken in a funnel. The height of the funnel was maintained in such a way that the tip of the funnel just touched the apex of the heap of the powder. The powder was allowed to flow through the funnel without any resistance on to the surface. The diameter and height of the powder cone was measured. Angle of repose was determined using the subsequent equation:

Tan 9 = h /r

Where, h and r are the height and radius of the powder cone. 2.4.2. Bulk density and tapped density

Powder weighing 5g from each formula was introduced into a 25-mL measuring cylinder. It was initially shaken lightly to break any agglomerates formed. Initial volume was noted and the cylinder was allowed to fall under its own weight onto a hard surface from the height of 2.5

cm at 2-second intervals. The tapping was continued until a constant volume was observed [30].

LBD and TBD were calculated using the following formulas:

LBD = Weight of the powder/volume of the packing

TBD = Weight of the powder/tapped volume of the packing

2.4.3. Compressibility index and Hausners ratio

The following formula was used to determine the compressibility index of granules:

Carr's compressibility index (Carr's index) = [(TBD - LBD) x 100]/TBD Hausner's ratio was calculated by the following formula:

Hausner's ratio = Tapped density / Bulk density 2.5. Evaluation of tablets (Post compression parameters)

2.5.1. Tablet hardness

Hardness is a vital parameter which prevents breakage of tablets during transportation, handling and storage. The hardness of tablet was measured by Monsanto hardness tester and was expressed in terms of Kg/cm2'

2.5.2. Tablet thickness

The tablet was placed between the two arms of the Vernier Caliper and thickness was determined. Five measurements were taken.

2.5.3. Weight variation

Twenty tablets were selected arbitrarily from each formulation and weighed individually using a Shimadzu digital balance (BL-220H). The individual weights were noted and compared with the average weight for the weight variation [31].

2.5.4. Friability

Twenty tablets were weighed then they were placed in a plastic chambered friabilator USP type Roche friabilator (Pharmalab, Ahmedabad, India)attached to a motor revolving at a speed of 25 rpm for 4 min. The tablets were reweighed and percentage weight loss (friability) was calculated using the following formula.

Friability = [(Initial weight- Final weight) / (Initial weight)] x 100%

2.5.5. Drug content

Ten tablets were weighed and crushed to a fine powder, a quantity of powder equivalent to 40 mg of Valsartan was introduced into 100mLvolumetric flask and extracted using PH 6.8 phosphate buffer. The solution obtained was filtered and the filtrate was suitably diluted with pH 6.8 phosphate buffer. The Valsartan content was determined by measuring the absorbance at 250 nm using UV-Visible Spectrophotometer (Shimadzu 1800). The drug content was determined using standard calibration curve [32]. The mean percent drug content was calculated as an average of three determinations.

2.5.6. Wetting time and water absorption ratio (R)

A tissue paper was taken and folded twice and placed in a petri dish having an internal diameter of 5 cm containing 6 ml of water. A tablet was cautiously placed on the top of the tissue paper in the Petri dish. Wetting time was noted as the time required for water to reach the upper surface of the tablet and to completely wet it [33]. Water absorption ratio (R) was then determined according to the following equation: R = 100 x (wa - wb)/ wb

Where 'wb' and 'wa' were tablet weights before and after water absorption, respectively.

2.5.7. In vitro disintegration time

The tablet disintegration test apparatus was used to determine disintegration time for all formulations. Six tablets were placed individually in each tube of disintegration test apparatus. The medium was maintained at a temperature of 37°±2°C and time was noted for the entire tablet to disintegrate completely.

2.5.8. In-vitro dissolution

USP dissolution test apparatus (Electrolab TDT - 08 L Dissolution testers USP) type 2 (paddle) was used for study. Nine hundred milliliter of phosphate buffer pH 6.8 was taken in vessel and the temperature was maintained at 37 ± 0.5°C. The speed of the paddle was fixed at 50 rpm. Dissolution samples were withdrawn at two minutes time interval and drug content was determined by measuring the absorbance at 250 nm [34]. Drug concentration was calculated from the standard calibration curve and expressed as cumulative percent drug dissolved. In vitro dissolution study was also performed similarly on conventional tablet formulation (Valzaar).

2.5.9. Drug-excipient interaction study

The pure drug, mixture of drug with polysaccharide (1:1) and the optimized formulation (Mixture of drug with various excipients used in the preparation of ODT formulation) were characterized by FT-IR spectroscopy to know the compatibility. The scanning range was 500 to 4000 cm-1 and the IR spectra of samples were obtained using KBr disc method.

2.5.10. Stability studies

The stability study of the tablets was carried out by keeping the samples in stability chamber at 40° ± 20°C/75% ± 5% RH for three months as per the ICH guidelines. The optimized batch was selected for stability studies. Tablets were evaluated for hardness, friability, drug content (Assay), disintegration time, in-vitro drug release profile after one month interval.

3. Results

The polysaccharide isolated from Cassia tora seeds was a light brown colored powder (Yield =18.56% w/w).The polysaccharide was soluble in hot water forming colloidal solution and practically insoluble in organic solvents. The pH of 1% w/w solution of polysaccharide was found to be near neutral. Polysaccharide showed good swelling and water absorption capacity. The Carr's index and angle of repose indicated that the polysaccharide has a good flow with moderate compressibility. The loss on drying and ash values were well within official limits. The results of the physicochemical characterization of polysaccharide are reported in table 2.

Drug-excipient interaction studies revealed that there was no physicochemical interaction between Valsartan and other excipients (Fig.1). All the major peaks of Valsartan were found in the sample. The functional peaks include C-H stretch (Aliphatic) at 2962.66, N-H stretch at 3444.87, Carboxylic acid stretch at 1732.08cm-1, C=O stretch at 1600.02 cm-1 and C-N stretch at 1273.02, 1205.51, 1064.71cm-1, the complex region of 900-600cm-1indicates skeletal vibration and an aromatic ring in the drug structure. Weights of all the tablets prepared were within the acceptable limit for uncoated tablets as per United States Pharmacopoeia. The results of pre-compression parameter evaluation indicated good free flowing properties of the powder blend (Table 3).

The hardness of tablets was determined and was found to be in the range of 4.20 to 4.56 kg/cm2. Friability was observed between 0.49% to 0.79%, which was less than 1% indicating that tablets had good mechanical resistance. Percentage drug content of all the formulations was found between 98.36%w/w and 100.04%w/w. The results of post compression parameter are summarized in Table 4 and 5.The wetting time and water absorption ratio are important criteria for understanding the capacity of disintegrant to swell in presence of little amount of water. The

wetting time for all the formulations was found between 26.2±0.25 and 54.17±0.48 seconds (Table 5)..In vitro disintegration time for formulations F1 to F8is summarized in Table 5.In vitro drug release rate from the formulations containing polysaccharide was found to be rapid as compared to the formulations containing sodium starch glycolate. The in vitro drug release profiles of the formulations F1 toF8 are represented in fig 2 and 3.The results of stability study indicated that there was no significant change in physical and chemical characteristics of the tablet and the optimized formulation F4 containing 7.5% of polysaccharide was stable at 40° C / 75%RH for 3 month (Table 6).

4. Discussion

It was reported that seeds of Cassia tora contain galactomannans [35].Certain gums having galactomannan like locust bean gum and Guar gum have been used as superdisintegrant [35, 36]. Hence on similar basis Cassia tora gum has been studied for its superdisintegrant property. It was observed that Cassia tora has good swelling properties [37]. Therefore we have attempted to develop orodispersible tablets from polysaccharide isolated from the seeds of Cassia tora in order to investigate its potential as a superdisintegrant. There are various reported mechanisms of superdisintegrants like swelling, wicking, deformation and electrostatic repulsion[38]. Orodispersible tablets of Valsartan were prepared by direct compression method using different concentrations of Cassia tora gum as a natural disintegrant and sodium starch glycolate as synthetic superdisintegrant in the same concentration. The excipients were selected depending upon preformulation studies and their concentrations were established on basis of extensive literature survey. Microcrystalline cellulose was selected as a directly compressible diluent [39]. Aspartame was selected as a sweetening agent [40] and vanilla was used as flavor. Since direct compression method was used for preparation of tablets, Magnesium stearate was chosen as lubricant to improve flow properties of the blend [41].

Tablets prepared using Polysaccharide isolated from Cassia tora took lesser time for wetting of tablet as compared to the formulations containing sodium starch glycolate. This might be due to rapid penetration of water into the pores of tablets. Water absorption ratio of polysaccharide was higher as compared to that of sodium starch glycolate. It was observed that water absorption ratio increased with an increase in concentration of superdisintegrant. Because of higher swelling property, formulations containing polysaccharide disintegrated quickly and completely as compare to formulations containing sodium starch glycolate. Rapid increase in

dissolution of drug with increased in polysaccharide content may be attributed to swelling of polysaccharide powder which leads to penetration of water in the pores of tablets and generation of hydrodynamic pressure for quick and complete disintegration of tablets. However incase of tablet prepared by sodium starch glycolate, disintegration takes place by rapid uptake of water followed by quick and enormous swelling into smaller particles but dissolution occurs slowly due to formation of a viscous gel layer by sodium starch glycolate [42].

The drug release of F4 formulation was rapid and better than marketed formulation. The formulation F4 containing 7.5% of polysaccharide showed rapid wetting time and disintegration time as compared to formulation prepared using synthetic superdisintegrant at the same concentration level. Hence batch F4 was considered as optimized formulation. 5. Conclusion

The present work revealed that Cassia tora seed polysaccharide is a potential candidate for use as disintegrant in the formulation of orodispersible tablets. Since Cassia tora polysaccharideis inexpensive as compared to synthetic superdisintegrant, non-toxic, compatible and easy to manufacture, it can be used in place of commercially available synthetic superdisintegrants. The prepared tablets also gives advantage in terms of patient compliance, quick onset of action, high bio-availability and good stability which make these tablets as a better dosage form for the treatment of hypertension. Acknowledgment

Author is very much thankful to Dr. (Mr.) Parag Gide, Principal of Hyderabad Sindhi National Collegiate Boards (HSNCB's) Dr. L. H. Hiranandani College of Pharmacy, Ulhasnagar for his continuous support and encouragement. Conflict of Interests

The authors declare that there is no conflict of interests regarding the publication of this article. References

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Figures and Table Legends

Figure 1

FTIR Spectrum of pure drug (A), pure drug + polysaccharide (B) and optimized formulation

F4(C).

Figure 2

In vitro drug release profile of formulations (F1-F4 and marketed formulation) Figure 3

In vitro drug release profile of formulations (F5-F8)

Table 1. Composition of orodispersible tablet

Table 2. Physicochemical parameters of polysaccharide

Table 3. Pre-compression parameters of powder blend

Table 4. Post-compression parameters of orodispersible tablets of Valsartan

Table 5. Post-compression parameters of orodispersible tablets of Valsartan

Table 6.Stability study data for F4 batch

FIGURES

Fig.1. FTIR Spectrum of pure drug (A), pure drug + polysaccharide (B) and optimized

formulation F4(C).

10 15 2D 25 30 TimcCmin)

F 1=1% cassia tora gum

Fj=5%;a33iEtorra zum

-FJ=7.i%;a3 3iatoi,a gum

nurkstsd ionnul=.ticn

Fig.2. In vitro drug release profile of formulations (F1-F4and marketed formulation)

--F 3=1%5 3 dium itEfdi

gtymiate —F 7=5 /¿.sodium starch glycDlats -n— F 6=2.5%a odium

atydi dycolats ■M— FS=;.5%3odtUHL stsrdi idycolalE

10 15 20 25 Time(min)

Fig.3.In vitro drug release profile of formulations (F5-F8)

TABLES

Table 1 Composition of orodispersible tablet

Formulation code

Components mg/tablet _

F1 F2 F3 F4 F5 F6 F7 F8

Drug 40 40 40 40 40 40 40 40

Microcrystalline cellulose

151.2 148.2 143.2 138.2 151.2 148.2 143.2 138.2

Cassia tora polysaccharide 2 5 10 15 - - - -

Sodium starch glycolate - - - - 2 5 10 15

Aspartame 2.8 2.8 2.8 2.8 2.8 2.8 2.8 2.8

Vanilla 1 1 1 1 1 1 1 1

Talc 1 1 1 1 1 1 1 1

Magnesium stearate 2 2 2 2 2 2 2 2

Total weight 200 200 200 200 200 200 200 200

Table 2.Physicochemical parameters of polysaccharide

Parameters

Results

Solubility

Swelling factor

Practical yield

Total Ash

Moisture content

Total polysaccharide content

Angle of repose

Bulk density

Tapped density

Carr's index

Hausners ratio

Light brown 7.2 -7.5

Soluble in hot water forming colloidal solution

insoluble in organic solvent

11.5mL

18.56 %w/w

72.12%w/w

29.24°

0.64 g/cc

0.53 g/cc

Table 3.Pre-compression parameters of powder blend

Formulation Parameters

code Angle of repose (0) Bulk density(g/cm3) Tapped density (g/cm3) Carr's index (%) Hausners ratio

F1 30.15±1.21 0.50±0.005 0.646±0.009 22.67±1.40 1.28±0.025

F2 29.20±0.42 0.508±0.002 0.637±0.0098 20.37±1.61 1.24±0.031

F3 28.78±1.29 0.493±0.03 0.654±0.012 24.7±1.66 1.32±0.030

F4 28.03±1.20 0.491±0.015 0.651±0.009 24.54±0.78 1.32±0.015

F5 27.65±1.27 0.522±0.003 0.649±0.008 19.55±1.40 1.23±0.025

F6 26.28±0.91 0.515±0.005 0.635±0.005 18.89±0.39 1.22±0.005

F7 30.84±0.81 0.547±0.003 0.627±0.004 13.12±0.005 1.14±0.010

F8 29.20±1.78 0.539±0.003 0.629±0.004 14.39±0.54 1.16±0.005

Results are Mean ±SD, n= 5

Table 4. Post-compression parameters of orodispersible tablets of valsartan

Formulation code Parameters

Thickness (mm)* Hardness (kg/cm2)* Friability (%) *** Weight Variation***

F1 2.43±0.11 4.56±0.208 0.68±0.01 200.2±0.63

F2 2.33±0.15 4.40±0.173 0.71±0.01 200.2±0.61

F3 2.46±0.05 4.43±0.11 0.77±0.01 199.7±1.05

F4 2.40±0.12 4.2±0.251 0.79±0.01 200.5±1.35

F5 2.2±0.11 4.33±0.15 0.49±0.015 200.2±0.63

F6 2.23±0.20 4.53±0.05 0.57±0.017 200.2±0.61

F7 2.23±0.057 4.46±0.152 0.58±0.069 199.7±1.05

F8 2.26±0.014 4.3±0.057 0.70±0.015 200.5±1.35

All values are expressed as Mean ±SD, n=5* /20***

Table 5.Post-compression parameters of orodispersible tablets of valsartan

Parameters

Formulation In vitro Water

code disintegration Wetting time (sec)* absorption Drug content**

time(sec)* ratio*

F1 60.27±0.62 46.73±0.39 110.88±0.24 100.00±002

F2 57.29±0.62 42.39±0.35 119.04±0.33 99.86±0.1

F3 47.68±0.53 37.05±0.56 126.80±1.02 99.81±0.18

F4 32.34±0.78 26.2±0.25 133.55±0.28 98.36±0.43

F5 70.56±1.82 54.17±0.48 99.67±0.49 98.54±0.85

F6 61.32±0.58 50.46±0.76 99.24±0.24 99.5±0.77

F7 55.16±1.44 47.90±0.44 104.66±0.70 99.84±0.33

F8 46.96±0.70 39.18±0.43 109.52±0.99 100.04±0.20

All values are expressed as Mean ±SD, n =6*/10**

Table 6. Stability study data for F4 batch Parameters 1 month 2 month 3 month

Hardness (kg/cm2) 4.08±0.09 4.22±0.1 4.1±0.12

% Friability 0.76±0.09 0.79±0.03 0.77±0.05

Drug content (%) 99.53±0.45 100.3±0.1 99.95±0.19

Disintegration time(sec) 31.84±0.6 30.12±0.9 32.28±0.1