Figure 1: FTIR Spectroscopy of pure drug

Figure 2: FTIR Spectroscopy of HPMC K4M

Figure 3: FTIR Spectroscopy of pure drug+ HPMC K4M

Figure 4: (A) In vitro buoyancy studies of optimized formulation.

Figure 4: (B) Comparison of swelling index of all the formulation

Figure 5: In vitro dissolution profile of F1 to F3 formulations

Figure 6: In vitro dissolution profile of F4to F6 formulations.

Figure 7: Zero order kinetic model

Figure 8: First order kinetic model

Figure 9: Higuchi model.

Figure 10: Korsemeyer Peppa’s

Figure 11: Hixon-crowell plot.

Ingredients(mg/tablet)

F1

F2

F3

F4

F5

F6

Venlafaxine HCl

75

75

75

75

75

75

HPMC K 4M

100

120

140

160

180

200

Lactose

100

80

60

40

20

00

Ethyl Cellulose

20

20

20

20

20

20

Sodium bicarbonate

50

50

50

50

50

50

Citric acid

50

50

50

50

50

50

Magnesium stearate

3

3

3

3

3

3

Talc

2

2

2

2

2

2

Total weight

400 mg

400 mg

400 mg

400 mg

400 mg

400 mg

Table 1: Composition of floating tablets of Venlafaxine HCl
Formulation
Angle of repose
Bulk Density (gm/cc)
Tapped density(gm/cc)
Compressibility index (%)

F1

28 .1±0.493

0.372±0.027

0.452±0.01

17.699±1.06

F2

29. 3±0.435

0.381±0.034

0.472±0.01

19.279±0.850

F3

30. 1±0.057

0.386±0.003

0.469±0.005

20±1.2

F4

30 .2±0.216

0.368±0.005

0.457±0.007

17.584±0.856

F5

32. 7±0.230

0.372±0.003

0.465±0.003

19.474±1.42

F6

33. 3±0.230

0.389±0.009

0.472±0.011

20.524±1.42

Table 2: Evaluation parameters of powder blend
Formulation
Thickness   ( mm)
Hardness   (kg/cm2)
Friability        (%)
Average weight variation(mg)
Drug content

F1

3.36±0.005

5.32±0.01

0.64±0.01

401.2±0.005

98.25±0.14

F2

3.48±0.01

5.60±0.01

0.57±.005

400.7±0.01

97.45±0.05

F3

3.32±0.005

5.42±0.02

0.52±0.02

401.5±0.005

98.26±0.15

F4

3.49±0.01

5.40±0.01

0.51±0.12

399.2±0.01

98.35±0.05

F5

3.46±0.02

5.55±.005

0.53±0.005

398.7±0.02

98.45±0.12

F6

3.36±0.01

5.64±.02

0.51±0.012

401.4±0.01

97.95±0.02

Table 3: Evaluation parameters of formulations
Swelling index (%)
Swelling index (%)

F1

F2

F3

F4

F5

F6

1

43.2±2.64

41.3±0.7

38.8±0.15

24.2±0.57

18.8±0.17

15.8±0.02

2

75.88±3.39

72.36±0.38

70.2±.15

35.9±0.057

37.9±0.20

33.2±0.057

4

115.45±5.04

109.7±0.41

107.7±0.41

70.5±0.05

68.2±0.15

57.4±0.38

6

148.5±3.25

141.1±0.75

134.7±0.2

115.9±0.05

99.7±0.1

87.9±0.012

8

166.4±8.90

162.2±0.3

159.1±0.50

125.6±0.1

110.5±0.1

109.7±0.021

10

178.8±2.41

172.4±0.25

168.6±0.15

136.8±0.17

124.1±0.12

119.5±0.023

12

184.3±0.60

178.5±0.35

176.3±0.05

138.1±0.1

132.9±0.15

128.3±0.01

Table 4: Swelling index (%) of the formulations
Formulation code
Floating lag time (sec)
Floating duration (hrs)

F1

29

>12

F2

33

>12

F3

38

>12

F4

26

>12

F5

24

>12

F6

32

>12

Table 5: Buoyancy studies of formulation
Formulation
Zero order(R2)
&First order(R2)
Higuchi(R2)
Korsemeyer Peppa’s
&Hixson- Crowell (R2)
(R2) n value

F5

0.929

0.996

0.997

0.994

0.55

0.965

Table 6: Correlation coefficients of different mathematical models for F-5