This document summarizes the process of evaluating floating tablets, including preformulation studies, precompression evaluation, postcompression evaluation, in vitro studies, in vivo studies, and stability studies. Some key points covered include determining particle size and shape, bulk and tapped density measurements, drug release testing using USP apparatus 2, and conducting in vivo x-ray studies in humans to observe floating ability in fasted and fed states. The goal of developing a floating drug delivery system is to provide prolonged gastric retention for controlled release of the drug.

2. 4/20/2016 2

3. EVALUATION OF FLOATING
TABLETS
GUIDED BY-Asst. Prof. Patil M.S.
Asst. Prof.Bathe R.S.
PRESENTED BY:-SHINDE SHIVAJI VASUDEO
M.PHARM.SEM-2
(Dept. of Pharmaceutics)
4/20/2016 3

4. 1) PREFORMULATION STUDY
2) PRECOMPRESSIONAL EVALUATION
3)POSTCOMPRESSIONAL EVALUATION
4) INVITRO STUDY
5) INVIVO STUDY
6) STABILITY STUDY
7) CONCLUSION
8) REFERENCES
CONTENTS
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5. PREFORMULATION STUDY:
• Yield a key information necessary to guide the formulator and analyst toward the development
of an elegant, stable dosage form with good bioavailability.
• 1.Particle size ,shape and crystallinity: Particle size and shape characteristics can be determined
by optical microscopy and sieving method. A polarizing microscope and x-ray diffraction used
to determine crystallinity.
• 2.Colour: Generally it is a function of unsaturation. It is determined by spectroscopic methods.
Colour change under stress conditions can be used in stability study.
• 3.Odour: The odour is due to major functional group present in molecule.e.g.Garlic
• 4.Melting point: Thermodynamically defined as the temperature at which the solid and liquid
phases are in equilibrium.

6. 5.Thermal Analytical Profile: Basic technique used to study is DTA. It detect changes in
compound whether it is exothermic or endothermic. Also DSC is used to determine energy
absorbed or desorbed.
6.U.V.Spectroscopy: Molecules with structural unsaturation are able to absorb light with specific
frequency range.
Ultraviolet-400-190nm
Visible -800-400nm
Beer’s-Lambert’ Law a = A / bc. Standard calibration curve is plotted using U.V. spectroscopy
widely used for the quantitative purpose.
7.I.R.Spectroscopy: Individual compound graph is recorded for the identity of compounds with
their functional groups. Physical mixture of formulation is scanned for checking the compatibility
with other ingredients. If IR spectral differences are found then interactions should be taken.

7. PRECOMPRESSIONAL EVALUATION:
• 1. Angle of repose: Angle of repose is defined as the maximum
angle possible between the surface of pile of powder and horizontal
plane. Determined by funnel method.
•
 = tan-1
(H / R)
Angle of Repose (Degree) Nature of Flow
25-35 Good
37-40 Fair
Beyond 40 Poor

8. 2.Bulk Density: Depends upon particle size, shape and cohesiveness. May influence the
compressibility, tablet porosity and dissolution.
Bulk Density= Bulk Mass/ Bulk Volume
3.Tapped Density: Helps to determine packing geometry and floability of powder blend.
Tapped Density= Bulk Mass/Tapped Volume
4. Carr’s Index: An indirect method of measuring powder flow from bulk and tapped densities.
Compressibility= Tapped Density – Bulk Density/ Tapped Density
5.Hauner’s Ratio: Essential to determine compressibility strength of powder andto estimate flow
properties.
Hausner’s Ratio= Tapped Density/ Bulk Density

9. POSTCOMPRESSIONAL EVALUATION:
• 1. Tablet Thickness and Diameter: Important for the uniformity of tablet size
and measured by using Vernier Caliper.
• 2. Hardness: The resistance of tablet to shipping or breakage under conditions
of storage, transportation and handling before use depends upon its hardness.
Measured by Monsanto hardness tester in terms of Kg/cm2.
• 3. Friability of tablet: Friability is the measure of tablet strength. Roche
friabilator was used for testing the friability .
Initial weight of tablets – Final weight of tablets
% Loss = ------------------------------------------------------------------- x 100
Initial wt. of tablets
Not more than 0.1% weight loss takes place according to I.P.

10. 4.Weight Variation: Weigh 20 tablets selected at random and calculate the average
weight. Not more than two of the individual weights deviate from the average
weight .
I.P. Standards for weight variation
Avrg. Wt. of Tablet % of deviation
80mg or < 80mg 10
> 80mg - <250mg 7.5
>250mg or more 5

11. 5. Drug content uniformity or Assay: Twenty tablets were weighed and powdered. The powder
equivalent to 10 mg was taken and dissolved in 10 ml 0.1 N HCl. This stock solution was
shaken for 20 min. on a sonicater. This resulting solution is further diluted with 0.1 N HCl to
achieve concentration up to 10 μg /ml. and the absorbance measured at its maximum
absorbable wavelength( nm).

12. INVITRO EVALUATION:
• 1. In -Vitro Buoyancy Study: The in-vitro buoyancy was characterized by floating lag
time and total floating time. The test was performed using a USP type II paddle apparatus
(Electrolab) using 900 ml of 0.1 N HCl at paddle rotation of 50 rpm at 37 ± 0.5oC.
• 2. Swelling Characteristics (Water uptake study): Determined by placing the tablet
matrices in the dissolution test apparatus, in 900 ml of 0.1 N HCl at 37  0.5 0C.
Weight of swollen tablet – Initial weight of the tablet
WU % = -------------------------------------------------------------------------- x 100
Initial weight of the tablet

13. 3.Invitro Drug Release:
Equipment used:
1. Dissolution Test Apparatus USP Type II
(Electrolab India)
Details of Dissolution Test
2. Apparatus : USP Type II
3. Speed : 50 rpm
4. Volume of medium : 900 ml
5. Stirrer : Paddle type
6. Aliquot taken at each time interval : 5 ml
7. Medium used : 0.1 N HCl
8. Temperature : 37 ± 0.5 °C

14. INVIVO STUDY:
• The in vivo X-ray evaluation of floating ability studies in healthy human volunteers in
the fasted and fed state was carried out by administering floating tablets incorporating with
barium sulphate (BaSO 4) as X-ray opaque material.
• a) Fasted state: The subjects fasted overnight then swallowed the gastric floating tablets with
200 mL of water. No food was allowed up to 3 hrs of dosing. A glass of water (200 mL) was
given to volunteers for every one hour. All the subjects were not allowed to lay down for
sleeping.
• b) Fed state: The subjects fasted overnight and in the morning they were given a high calorie-
high fat breakfast with a total calorie value of approximately 900 KCal (Bread slice with 25
gms of butter-250 KCal, chicken tikka 75 gms-350 KCal, egg omelet 40 gms-150 KCal
and fruit juice-150 KCal). The gastric floating tablet was administered with 200 mL of water
after half an hour after the breakfast. The subjects were not allowed to eat anything up to 6 hrs
but were given a glass of water (200 mL) every hour.
In each subject, digital X-ray photograph of the gastric region was taken at
time intervals of 0.5, 3, 6 and 9 hrs.

15. STABILITY STUDY:
The storage conditions for accelerated testing (as per ICH and WHO) are 400 ± 20
C and 75 ± 5% RH for solid dosage forms for 6 months. WHO prescribed testing at 0, 1, 2, 3
and 6 months during storage. ICH has not given testing time frequency.
The tablets were packed in screw capped HDPE bottles and were
stored at 400 ± 20 C and 75 % RH for 6 months. After storage for 6 months, the products were
tested for drug content floating characteristics and drug release rate as per the methods
described earlier.

17. CONCLUSION:
• Controlled released floating drug delivery system to provide a potential approach for
gastric retention. This seminar gives an overview on the main concepts used to design
pharmaceutical dosage forms with prolonged gastric retention time.

18. REFERENCES:
1.Silverstein R.M., Webster F.X., Spectrophotometric identification of organic
compounds, Wiley J. and Sons Inc, 2003, 71 - 109.
2.Chauhan B., Mahadik K.R., Paradkar A.R. et. al., Preparation and evaluation of floating
risedronate sodium, Gelucire 39/01 matrices, Acta Pharm., 2004, 54, 205– 214.
3.Deshpande A.A., Shah N.H., Christopher T., Development of a novel controlled release
system for gastric retention, Pharmaceutical Research, 1997, 14(6), 815 – 819.
4.Li S., et al, Statistical optimization of gastric floating system for oral use controlled
release system of calcium, Pharm.Sci.Tech. 2001, 1 -12.
5.Chein Y.W., Novel Drug Delivery Systems. 2nd Edn. Marcel Dekker. Inc. New York.
1992, 50, 1 -139.