INTRODUCTION:

Oral delivery of drugs is by far the most preferable route of drug delivery due to the ease of administration, patient compliance and flexibility in formulation etc. From immediate release to site specific delivery, oral dosage forms have really progressed. Gastro retentive dosage forms significantly extend the period of time, over which drug may be released and thus prolong dosing intervals and increase patient compliance. Such retention systems are important for those drug that are degraded in the intestine like antacids or certain antibiotics, enzymes that act locally in the stomach. This systems can be retained in the stomach and assist in improving the oral sustained delivery of drugs that have an absorption window in a particular region of the gastrointestinal tract, thus ensuring optimal bioavailability^[6],[7].

Prolonged gastric retention improves bioavailability, reduces drug waste and improves solubility of drug that is less soluble in high P^H environment. The types of gastro retentive dosage forms are floating drug system^[9].

MATERIALS AND METHODS:

Collection of plant materials - The fruits of Amla, Ginger rhizomes, Fenugreek seeds and Psyllium husk were collected from local market of Pune, India.

Preparation of extracts

Preparation of Amla extract: ^{[2] [3]}

After removing seeds, fruits were washed with deionized water and dried in oven at 35-40°C for 4-5 days till weight became constant. Dried amla pulp weighing 15 gm. was pounded and soaked in 50 ml of absolute ethanol and kept in 250 ml sterile conical flask at 37°C with shaking at 120 rpm for 24 hrs. The content was filtered through Whatman filter paper No.1 and sterilized through 0.22µ member. The filtrates obtained were stored separately.

Preparation of Ginger extract: ^[4]

Ginger rhizomes were cleaned, washed, air dried and powdered for coarse particle size. 10 gm of powder was defatted using hexane in Soxhlet apparatus, 1 gm. of defatted powder was taken in 10 ml of distilled water and boiled for 5 min cooled and centrifuged at 1000 rpm for 10 min and the clear solution was separated and referred as ginger aqueous extract.

Preparation of Fenugreek extract:

Fenugreek seeds were grinded into coarse powder and then boiled with water, and mucilage was separated out.

Formulation of tablet ^[5]

All the ingredients were passed through sieve no. # 80 and weighed accurately on electronic balance according to formula mentioned in Table No. 01.

All the ingredients were mixed properly in mortar and pestle to get a uniform tablet blend and finally talc and magnesium stearate were mixed with the blend. Then tablet blend was weighed individually according to formula and compressed into tablet using single punch tablet machine according to different formula.

Table no.01 Composition of floating tablet formulation-

Sr. no.	Ingredients	F1 (mg)	F2 (mg)	F3 (mg)
1	Active ingredients	250	250	250.
	Amla extract	200	200	200
	Ginger extract	30	30	30
	Fenugreek extract	20	20	20
2	Isapgol husk	75	100	125
3	HPMC K 100 M	50	50	40
4	Sodium bicarbonate	100	90	110
5	Talc	20	20	20
6	Magnesium stearate	5	5	5

Evaluation of Floating Tablet: -^[5]

The Prepared floating tablets were evaluated for

Diameter and Thickness- Using Vernier Calipers diameter and thickness of each tablet were measured and noted.

Hardness- The tablets were evaluated using a Monsanto hardness tester. The hardness of 6 tablets were checked of each formulation and noted.

Friability: Friability was determined by using a Rochefriabilitor.

Weight variation test: Twenty tablets from each formulation were weighed and their average weight was determined.

Buoyancy time: -^[5]the time between introduction of dosage form and its buoyancy on simulated gastric fluid and the time during which the dosage form remain buoyant were measured. The time taken for dosage form to emerge on surface of medium called floating Lag Time (FLT) or Buoyancy Lag Time (BLT) and total duration of time of tablet to float on surface was determine (TFT).

RESULT:

Physical evaluation of the formulation

Table. No. 2 Physical Evaluation of Tablets

Parameter	Observation
Colour	Woody brown
Odour	Pleasant
Taste	Slightly stimulating
Shape	Circular

Evaluation of herbal floating tablets

Table No. 3 Diameter of formulated tablets

Formulation	F1 (mm)	F2 (mm)	F3 (mm)
1	1.3	1.5	1.7
2	1.3	1.5	1.7
3	1.4	1.4	2.1

Mean of tablet diameter = F1 (1.33), F2 (1.466), F3 (1.833)

Table No. 4 Thickness of formulated tablets

Formulation	F1 (mm)	F2 (mm)	F3 (mm)
1	0.5	0.7	1
2	0.5	0.8	1.2
3	0.8	0.7	1.1
4	0.7	0.6	1.1
5	0.5	0.7	1

Mean of tablet thickness: F1 (0.6), F2 (0.7), F3 (1.08).

Table No. 5 Hardness of formulated tablets

Formulation	F1 (kg/cm²)	F2 (kg/cm²)	F3 (kg/cm²)
1	4.9	5.0	4.9
2	4.9	4.9	4.8
3	4.9	4.9	4.9

Mean of tablet hardness: F1 (4.9 kg/cm2), F2 (4.9 kg/cm2), F3 (4.9 kg/cm2)

Table No. 6Uniformity of weight of formulated tablets

Formulation	F1	F2	F3
1	470	500	520
2	480	510	530
3	500	530	525
4	450	520	540
5	470	520	500

Mean of tablet weight (in mg): F1 (474), F2 (516), F3 (523).

Table No. 7 Buoyancy time of formulated tablets

Formulation	Time in min
F1	0.30
F2	2.00
F3	0.36

Figure No. 1 Buoyancy time of Formulation 1:-

Fig.no.1

Time of tablet insertion till it float to top: - 0.00-0.30 minutes

Figure No. 2 Buoyancy time of Formulation 2

Fig.no.2

Time of tablet insertion till it float to top: - 0.00-2.00minutes

Figure No. 3 Buoyancy time of Formulation 3

Fig.no.3

Time of tablet insertion till it float to top:-0.00- 0.36minutes

DISCUSSION:

The total of three batches namely F1, F2 and F3 were prepared in the form of gastroretentive herbal floating tablets. Physical evaluation of these formulations is as mentioned in Table No. 2. Further determination of diameter, thickness, hardness, uniformity of weight and buoyancy time was carried out and the results are shown in Table No. 3, 4, 5, 6 and 7 respectively. The floating drug delivery is based on the swelling property and density of the polymer as well as the gas generating agent ⁽⁸⁾. The buoyancy time of formulation are shown in table (7). Floating lag time (FLT) of all the formulation was found to be less than 2min.

CONCLUSION:

Herbal Floating tablets of amla extract using Isapgol husk, HPMC K100M, talc, sodium bicarbonate, and magnesium stearate were prepared. Formulated tablets were within the acceptable limits range for various physiochemical evaluations for tablets like tablet dimensions, hardness, uniformity of weight, friability, buoyancy time. It can be concluded that Isapgol husk, sodium bicarbonate and HPMC K100M in combination can be promising polymer for gastro retentive drug delivery systems. Floating tablets of alcoholic extract of amla can be formulated as an approach to increase gastric residence time, thereby improving its bioavailability. The results indicate a promising potential of alcoholic extract of amla floating tablets as an alternative to the conventional dosage form

REFERENCES

1. Garg R, Gupta GD. Progress in controlled gastrointestinal delivery system. Tropic J Pharma Res. 2008; 7:1055-66.

2. Abraham P, Sandhu N, Naik SR (1997). In vitro sensitivity of Helicobacter pylori in India. Indian J. Gastroenterol., 16(1):S20-21

3. Rajpal V. Vol.1. New Delhi: Eastern Publishers; 2002. Standardization Of Botanicals: Testing and extraction method of medicinal herbs; pp. 115-39.

4. Yoshikawa M, Yamaguchi S, Kunimi K, et al. Stomachic principles in ginger. III. An anti-ulcer principle, 6- gingesulfonic acid, and three monoacyldigalactosylglycerols, ginger glycolipids A, B, and C, from ZingiberisRhizoma originating in Taiwan. Chemical and Pharmaceutical Bulletin. 1994;42(6):1226–1230.

5. Basak SC, Rao KN, Manavalan R, Rao PR. Development and in vitro evalution of an oral floating matrix tablet formulation. Indian J. Pharm Sci. 2004:66:313-6.

6. Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., and Inc.

7. Timme Mans J, Andre Jm. Facter. Controling The Buoyancy And Gastric Retention Capabilities Of Floating Matrix Capsule: New Data For Recaadering The Controversy. J Pharma. Sci. 1994;83:18-24 [Pubmed:8138903]

8. Arora S, Ali J, Ahuja A, Khar R. Baboota S. Floating Drug Delivery System; A Review. AAPS Pharm Sci Tech. 2005:67:703-9.

9. Kokate CK, Purohit AP, Ghkhle SB. 22^ndEd. Pune: Nirali Prakashan; 2002. Pharmacognosy; pp 149-51.

Received on 24.02.2014 Modified on 20.05.2014

Research J. Pharm. and Tech. 7(9): Sept. 2014 Page 1034-1037