International Journal of Current Pharmaceutical Research

Research Article
FORMULATION AND EVALUATION OF FAST DISSOLVING TABLETS OF SOME AYURVEDIC
CHURNAS BY VACUUM DRYING TECHNIQUE
N. G. RAGHAVENDRA RAO 1 , UPENDRA KULKARNI 2 , BASAWARAJ S. PATIL 2 , GURURAJ V. WADAGERI 2
1Department of Pharmaceutics. Luqman College of Pharmacy, Gulbarga­585102, Karnataka, India, 2Department of Pharmaceutics. RME’s
College of Pharmacy ­585102, Karnatka, India. E mail: nraghu@rediffmail.com
Received 17 Dec 2009, Revised and Accepted 06 Jan 2010
ABSTRACT
Patient compliance can be increased and adulteration can be decreased in ayurvedic powders by formulating them into tablets. An attempt has
been made for the development of fast dissolving tablets of the ayurvedic powders like Sudarshan churna and Bhaskar lavan churna. Sudarshan
churna was indicated for fever, and Bhaskar lavan churna is used in the gastrointestinal disorders like digestive impairment, dyspepsia and
constipation. In the present work, fast dissolving tablets of Sudarshan churna and Bhaskar lavan churna were designed with a view to enhance
patient compliance employing vacuum drying technique. The blend was examined for the pre‐compressional parameters. The prepared
formulations were evaluated for hardness, weight variation, tablet thickness, friability, disintegration time, wetting time, and stability studies.
Stability studies were carried out as per ICH guidelines for three months. The values of pre‐compression parameters evaluated were within
prescribed limits and indicated good free flowing property. In all the formulations, friability is less than 1%, indicated that tablets had a good
mechanical resistance. Hardness of the tablets was found to be in the range of 4.00‐4.50 kg/cm2 which is within acceptable limits. The wetting time
of the formulations BLC3 and SC3 were shows 20 sec and 18 sec respectively. The formulation BLC3 shows less in vitro dispersion time 18 sec and
formulation SC3 shows less in vitro dispersion time 20 sec. In vitro dispersion time decreases with increase in concentration of ammonium
bicarbonate. The stability studies results revealed that disintegration time and wetting time of all tablets decreased significantly (p

MATERIALS AND METHODS
Sudarshan churna (SC) and Bhaskar lavan churna (BLC) were
procured from local market. Crospovidone was gift sample from
MAPLE biotech Pvt. Ltd. Pune, India and other substances used in
the study ammonium bicarbonate, spray dried lactose, talc, poly
vinyl pyrrolidone (PVP), and sodium lauryl sulphate (SLS) were
purchased from S.D. Fine Chemicals, Mumbai. Aspartame was
obtained from Cipla Pharma. Ltd. Vikroli, Mumbai. Other reagents
were of analytical grade.
Methods
Preparation of fast dissolving tablets of sudarshan and bhaskar
lavan churnas by vacuum drying technique: The fast dissolving
tablets of sudarshan and Bhaskar lavan churnas were prepared by
wet granulation method using aqueous solution of 1% w/w PVP as
binder for all formulation. The granules are prepared by passing the
damp mass through sieves # 16. The wet granules were then dried
at 60 0C in hot air oven. Dried granules (22/44) were taken and
mixed with spray dried lactose, aspartame, superdisintegrant and
different concentration of ammonium bicarbonate in a plastic
container followed by compression of blend on a 10‐station rotary
punch‐tabletting machine (Rimek mini Press‐1) using 12mm
concave punches at hardness of 4 to 4.50 kg/cm 2 prior to
compression of granules in to tablets, tabletting properties such as
angle of repose, % compressibility were determined for all the
formulations. After compression the tablet were collected and
vacuum dried at 60 0 C until a constant weight was obtained to ensure
the compete removal of sublimable compound to make the tablet
porous. Schematics figure of Vacuum drying method for designing of
fast dissolving tablets is shown in Fig 1. Different formulations were
prepared by vacuum drying technique compositions of which are
given in Table 1.
Table 1: Formulae used in the preparation of tablets containing sudarshan churna (sc) and bhaskar lavan churna (blc).
Ingredients (mg/tab) SC1 SC2 SC3 BLC1 BLC2 BLC3
SC/BLC 500 500 500 500 500 500
Crospovidone 32.5 32.5 32.5 32.5 32.5 32.5
Spray dried Lactose 75.25 62.25 36.25 75.25 62.25 36.25
Ammonium bicarbonate 13 26 52 13 26 52
PVP 6.5 6.5 6.5 6.5 6.5 6.5
Talc 6.5 6.5 6.5 6.5 6.5 6.5
Aspartame 13 13 13 13 13 13
SLS. 3.25 3.25 3.25 3.25 3.25 3.25
Total weight 650 650 650 650 650 650
Evaluation of tablets
All the formulated tablets were evaluated for weight variation,
hardness, thickness, friability, wetting time, disintegration time and
stability study. In the weight variation test, 20 tablets were selected
at random and the average weight was calculated. Then, individual
tablets were weighed and the weight was compared with an average
weight. Pfizer hardness tester was used for the determination of
hardness of the tablet. The tablet was placed in contact b/w the
plungers and the handle pressed. The force of fracture was recorded.
The thickness of the tablet was recorded during the process of
compression using calipers (Mitotoyo Japan). The friability of tablets
was determined using a Roche friabilator (Electrolab, EF2
friabilator). Two tablets from each batch takened and placed in the
friabilator then operated for 100 revolutions. Then the tablets were
dedusted and reweighed. Percentage friability was calculated using
the formula,
F = (1‐W0 / W) X 100
In the disintegration time study, the tablets were taken and
introduced in each tube of disintegration apparatus and the tablet
rack of the disintegration apparatus was positioned in to a 1 liter
beaker containing 900ml of distilled water and time of
disintegration was recorded at 37±20C. internal diameter 6.5cm) containing 5ml of distilled water. A tablet
was placed on the paper and time for complete wetting of the tablets
was measured in seconds. The stability study of the tablets was
carried out according to ICH guidelines, by storing the tablets in
stability chamber (Lab‐Care, Mumbai) at 40±2
In the wetting time study, a
piece of tissue paper folded twice was placed in a petridish (with
0C/75 ± 5%RH for
three months. At the end of each month tablets were tested for
disintegration time and wetting time.
RESULTS AND DISCUSSION
Flow properties of sudarshan and bhaskar lavan powders were
analyzed before compression to tablets. The high values of angle of
repose (SC≥42.22 and BLC≥41.17) and % compressibility (SC≥55.66
and BLC≥52.48) clearly indicates that both churnas were not free
flowing powders. So in order to improve flow properties of powders
a lubricant (talc) and glident (SLS) were incorporated into the
churna powders. Even after addition of lubricant and glident also,
there was no improvement in flow property of churnas. That is why,
the powder blends of sudarshan and bhaskar lavan churnas were
converted into the granules by using aqueous solution of 1% w/w
PVP. The values of pre‐compression parameters of both churnas
granules evaluated were within prescribed limits and indicated good
free flowing property (Table 2). Then granules were compressed
into tablets on a 10‐station rotary punching machine (Rimek mini
Press‐1) using 12mm concave punch.
Table 2: Precmpressional parameters of granules
Formulation Angle of repose
Compressibility
Bulk density Tapped density Hausner’s Ratio
Code
(Ө) (±SD), n=3
(%) (±SD), n=3
(gm/cc) ± SD, n=3 (gm/cc) ± SD, n=3 ± SD, n=3
SC 1 23.65 (0.22) 16.66 (0.72) 0.43 (0.006) 0.55 (0.02) 1.27 (0.03)
SC 2 24.22 (0.52) 17.72 (0.52) 0.44 (0.007) 0.52 (0.02) 1.18 (0.04)
SC 3 23.70 (0.62) 19.54 (0.55) 0.45 (0.004) 0.51 (0.01) 1.13 (0.03)
BLC 1 22.49 (0.92) 18.59 (1.22) 0.44 (0.006) 0.54 (0.02) 1.22 (0.03)
BLC 2 23.52 (0.72) 18.33 (0.92) 0.42 (0.004) 0.53 (0.01) 1.26 (0.03)
BLC 3 21.58 (0.55) 19.22 (0.99) 0.44 (0.002) 0.55 (0.02) 1.25 (0.04)
Note: Values in parenthesis are standard deviation (±SD)
In all formulations, the hardness test indicates good mechanical
strength. Hardness of tablets decreased with increase in the amount
of volatile component 14 (Fig 2‐3). Friability of all the formulations
less than 1%, it indicates that the tablets had good mechanical
resistance. The wetting time and disintegration time values
decreased with increase in the concentration of volatile component
(Fig 2‐3). It may be due to their lowest hardness and the maximum
porous structure was responsible for faster water uptake, hence it
facilitates wicking action of crospovidone in bringing about faster
disintegration 15 (Table 3). Vacuum drying techniques use to prepare
highly porous compressed tablets (mentioned in Fig 1) that were
rapidly soluble in saliva. Crospovidone containing tablets rapidly
exhibit high capillary activity and pronounced hydration with a little
tendency to gel formation 16 and thus disintegrate tablets rapidly.
37

Hardness(kg/cm)
5
4
3
2
1
0
SC1 SC2 SC3
Formulation Code
Fig 2: Graphical representation of hardness and disintegration whiletablets containing sudarshan churna
Hardness(kg/cm)
5
4
3
2
1
0
BLC1 BLC2 BLC3
Formulation Code
Fig. 3: graphical representation of hardness and disintegration while tablets containing bhaskar lavan churna.
Table 3: post­compression parameters of fast dissolving tablets
Formulation code Weight variation
(%)
(±SD), n=20
Hardness
(kg/cm 2) (±SD),
n=6
Friability
(%)
(±SD), n=10
SC1 0.7 (2.22) 4.50 (0.00) 0.12 (0.06) 55 (0.35) 30 (0.03)
SC2 0.3 (1.00) 4.25 (0.40) 0.16 (0.01) 48 (0.05) 28 (0.22)
SC3 0.9 (0.92) 4.00 (0.50) 0.24 (0.04) 20 (0.18) 18 (0.25)
BLC1 0.3 (0.52) 4.55 (0.19) 0.29 (0.01) 45 (0.44) 40 (0.30)
BLC2 0.7 (1.50) 4.50 (0.25) 0.32 (0.06) 37 (0.40) 38 (0.40)
BLC3 0.8 (2.25) 4.00 (0.70) 0.50 (0.10) 18 (0.03) 20 (0.50)
Note: Values in parenthesis are standard deviation (±SD)
Table 4: Weight of tablet before and after vacuum drying
Formulation Before vacuum drying(mg) After vacuum drying(mg)
SC1 650 638
SC2 650 625
SC3 650 600
BLC1 650 639
BLC2 650 622
BLC3 650 601
70
60
50
40
30
20
10
0
60
50
40
30
20
10
0
Disintegration
time(sec)
(±SD), n=6
Disinegration time(sec)
Disinegration time(sec)
Wetting time
(sec)
(±SD), n=3
38

The prepared tablets were subjected for weighing before and after
vacuum drying the weight may be slightly decreased with increase
in the concentration of volatile component after vacuum drying
results are shown in Table 4. Stability studies results (Table 5)
revealed that the disintegration time of all the formulations were
decreased (P