The concept of formulating oral disintegrating tablets containing Aceclofrenac offers a suitable and practical approach in serving desired objective of faster disintegration and dissolution characteristics with potential increased bioavailability.

MATERIALS AND METHODS:

Aceclofenac (SR Drugs and Intermediates Pvt Ltd, Hyderabad). The leaves of Annona squamosa. L, Leucaena leucocephala bark gum and Moringa oleifera bark gum were collected from trees locally. Loctus bean gum (LBG) (Olin chemicals, Mumbai, India), Sodium starch glycolate (SSG) (DMV International) Micro crystalline cellulose (MCC) (Mylochem, Mumbai, India), Mannitol (Thermo Fisher Scientific India Pvt Ltd, Mumbai, India), Talc (Kemphasol, Mumbai, India), Magnesium stearate (MS) (S.D. Fine Chem. Limited, Mumbai, India). All other solvents and chemicals were of analytical-reagent grade. Distilled water was used throughout the study.

Extraction of Annona sqamosa L leaves mucilage (ASLM):

The fresh leaves of Annona sqamosa L was collected and washed with water to remove dirt and debris. The leaves were chopped and soaked in water for 5–6 h, boiled for 30 min, and kept aside for 1 h for complete release of the mucilage into water. The material was squeezed from an eight‐fold muslin cloth bag to remove the marc from the solution. Alcohol in a quantity of three times the volume of the total filtrate was added to the filtrate to precipitate the mucilage. The mucilage was separated, dried in an oven at a temperature < 50 °C, collected, dried‐powdered passed through a sieve (number 80), and stored in desiccators, until further use^{(3, 4)}.

Extraction of Lacuenae lucopholia bark gum (LLBG):

LLBG was obtained from the bark of Leucaena leucocephala trees grown around locally. The gum was collected around mid- February during the day time. For the processing of the gum, the method of Femi- Oyewo et al, was adopted with some modifications. The gum was dried in an oven at 40°C for 2 h and size reduced using a blender. It was hydrated in double strength chloroform water for 5 days with intermittent stirring to ensure complete dissolution and then, strained through a fourfold muslin cloth to obtain particulate free slurry which was allowed to sediment. Thereafter, the gum was precipitated from the slurry using absolute ethanol, filtered and defatted with diethyl ether. The precipitate was dried in the oven at 40°C for 48 h. The dried flakes were pulverized using a blender and stored in an air tight container⁽⁴⁾.

Extraction of Moringa oleifera bark gum (MOBG):

The gum was collected from trees (Injured site). It was dried, ground and passed through sieve no 80. Dried gum was stirred in distilled water for 6-8 hours at room temperature and subjected for centrifugation at 2000 rpm for 5 min. The supernatant liquid was separated and the residue is further washed 2 – 3 times with water and added to the supernatant liquid. To this twice the quantity of acetone is added with continuous stirring until the gum gets precipitated. The precipitated material was washed with distilled water and dried at 50- 60⁰C and stored in desiccators until further use ^{(5, 6)}.

Physicochemical Properties of Dried Powdered Extracts:

Dried powdered Annona squamosa L Leaves mucilage, Leucaena leucocephala bark gum, Moringa oleifera bark gum and Loctus Bean gum were studied for percentage yield, colour, pH of solutions.

Acute Toxicity Studies for Extracts:

Experiments were performed complied with the rulings of the Committee for the Purpose of Control and Supervision of Experiments on Animals (CPCSEA) New Delhi, India, and the study was permitted by the institutional ethical committee of the Krishna Teja Pharmacy College, Tirupati, India. Male albino mice weighing 20-35gm were used for the study according to the OECD guide lines 423 ⁽⁷⁾. The dose of 2000mg/kg body weight p.o of ASLM, LLBG, MOBG and LBG were administered to overnight fasted mice’s. Food was withheld for a further 3-4 hours after administration of and observed for signs for toxicity.

Compatibility Study Drug-Excepient by IR Spectroscopy:

The samples of Aceclofenac (drug) and drug + excipients (disintegrants) were prepared in to pellets using Potassium Bromide at ratio (1: 100) and standard pure Potassium Bromide subjected for scanning from 3500 cm^-1to 500 cm^-1 using IR spectrophotometer.

Physical Properties of Pre-compressed Formulations:

The physical properties such as angle of repose, bulk density, tapped density, Compressibility Index (Carr’s Consolidation Index) and Hausner Ratio were been evaluated for all the formulations ⁽⁸⁾.

Formulation of Aceclofenac ODT’S:

Dispersible tablets of Aceclofenac were prepared by the conventional direct compression technique using ASLM, LLBG, MOBG, LBG and SSG as disintegrants. All the required ingredients as per the formulation table were weighed and passed through Size 40# sieve. The Mixture was then blended for 15 mins. The blend was then compressed on a Cadmach 16 stage punch machine⁽^{9, 10, 11)}. The composition of each formulation is given in table 1.

TABLE 1. FORMULATIONS FOR PREPARATION OF ACE- ODT’S:

S. NO	INGREDIANTS (mg)	FORMULATIONS
S. NO	INGREDIANTS (mg)	F1	F2	F3	F4	F5
1	Aceclofenac	10	10	10	10	10
2	Mannitol	12	12	12	12	12
3	MCC	150	150	150	150	150
4	ASLM	10	-	-	-	-
5	LLBG	-	10	-	-	-
6	MOBG	-	-	10	-	-
7	LBG	-	-	-	10	-
8	SSG	-	-	-	-	10
9	Talc	9	9	9	9	9
10	MS	9	9	9	9	9
TOTAL		200mg	200mg	200mg	200mg	200 mg

ACE- ODT’S – Aceclofenac oral disintegrating tablets

Evaluation of ODT’S:

Tablets were evaluated for hardness, weight variation, thickness, diameter, friability, drug content, wetting time, disintegrating time, moisture uptake studies and stability studies. The Monsanto hardness tester and Roche friabilator were used to test hardness and friability loss respectively. In weight variation test, twenty tablets were selected at random and average weight was determined using electronic balance (Shimadzu Philippines Manufacturing INC). Thickness and diameter of tablets were determined by using Verniear calliperus (Atlas Tools Center, Chennai, India). To determine drug content of tablets, twenty tablets were weighed and powdered. An amount of the powder equivalent to 10mg of Aceclofenac was dissolved in 10ml of pH 7.4 PBS, filtered, diluted suitably and estimated for the drug content at 274 nm using UV-Visible spectrophotometer (UV -Analytical Technologies Limited). To measure wetting time of tablet, a piece of tissue paper was folded twice and placed in a small Petri dish containing sufficient water. A tablet was kept on the paper and the time for complete wetting of tablet was measured. Disintegrating time was determined using USP tablet disintegrating test apparatus (Thermonic, Campbell Electronics, Mumbai, India) using 900 ml of distilled water at 37^o c.

Dissolution studies:

In- vitro drug release studies of all the formulations were carried out using tablet dissolution test apparatus (Electrolad (USD) Model- TDT08L) at 75rpm. Phosphate buffer (PBS) pH 7.4 was used as the dissolution media with temperature maintained at 37±0.5ºC. Samples were withdrawn at different time intervals and analyzed at 274nm for percentage drug release using Analytical Technologies Limited UV-Visible spectrophotometer. The sample after each withdrawal was replaced with same volume of fresh media ^{(12, 13)}.

Moisture uptake studies:

Ten tablets from each formulation were kept in a dessicator over calcium chloride at 37⁰C for 24h. The tablets were then weighed and exposed to 75% relative humidity, at room temperature for 2 weeks. Required humidity was achieved by keeping saturated sodium chloride solution at the bottom of the dessicator for 3 days. One tablet as control (without super disintegrants) was kept to assess the moisture uptake due to other excipients. Tablets were weighed and the percentage increase in weight was recorded ⁽¹⁴⁾.

Stability Studies:

Stability studies were carried out at 40^oC ± 2^oC / 75% RH ± 5% RH for a period of six months. The tablets were stored in High density Polyethylene (HDPE) containers and evaluated at 3^rd month for the changes in hardness, Weight variation, thickness, diameter, friability, drug content and dissolution at 15 min.

RESULTS AND DISCUSSION:

The extracts of ASLM, LLBG and MOBG were extracted and purified. The percentage yield of extracts was 10.2, 79.41 and 84.5% respectively. The colours of ASLM, LLBG, MOBG and LBG were green, brown, dark brown, creamy white respectively and pH values are 6.3, 4.2, 5.9 and 5.8 respectively. The acute toxicity studies evaluated in albino mice’s not showed any mortality and other side effects. The compatability studies on drug- excepient by IR spectroscopy had shown no interactions. The IR spectra are shown in figures 1 to 11. The angle of repose was found to be in the range of 29.98⁰ to 31.44⁰, which indicates moderate flow. Bulk density and tapped density varied from 0.472 gm/cc to 0.486 gm/cc and 0.582 gm/cc to 0.593 gm/cc respectively. The percentage compressibility is within the range of 18.04% to 19.28% and the Hausner ratio is within the range of 1.22 to 1.238, which indicates flow of powder is fair in flow. The average hardness of all the batches is in the range of 2.51 to 2.68Kg/cm² and possesses sufficient hardness. As the % weight variation was within the limits of ± 7.5% USP in range from 204±7.37 to 208.4± 5.67 mg. The thickness and diameter for all formulations are within the limits. The % friability is in the range of 0.543 % to 0.711 %, which was found to be in limit. The drug content is in the range of 99.87±0.151 to 102.44±0.939 %. The wetting is in the range of 23 to 136.3. The disintegrating time is in the range of 7.96 to 64.86 sec. The results were shown in the table 2.

Figure: 1.IR spectra of Aceclofenac

Figure: 2.IR spectra of Annona sqamosa L leaves mucilage

Figure: 3.IR spectra of Annona sqamosa L leaves mucilage + Aceclofenac

Figure: 4.IR spectra of Leucaena leucocephala bark gum

Figure: 5.IR spectra of Leucaena oeucocephala bark gum + Acecofenac

Figure: 6.IR spectra of Moringa oleifera bark gum

Figure: 7.IR spectra of Moringa oleifera bark gum + Aceclofenac

Figure: 8.IR spectra of Loctus Bean gum

Figure: 9.IR spectra of Loctus Bean gum + Aceclofenac

Figure: 10.IR spectra of Sodium starch glycolate

Figure: 11.IR spectra of Sodium starch glycolate + Aceclofenac

Figure: 12. Comparative in-vitro% drug release for F1, F2, F3, F4, F5 formulations

Tablets of all formulations achieved 100% drug release with in 15 min and met the requirements of in vitro dissolution. But the rate of release of drug is faster in formulations F1, F3 and F4 comparable to F5 formulation. The results are shown in table 3 and figure 12. The moisture uptake studies shown that formulation F1 absorbed more moisture then all other formulations when compared with control (without disintegrating agent). The stability studies had shown no magnificent change in the evaluation parameters after 3 months at (40^oC ± 2^oC / 75% RH ± 5% RH). The results of stability studies were shown in table 4.

TABLE 2. EVALUATION OF FORMULATED ODT’S

S.NO	PARAMETER	FORMULATIONS
S.NO	PARAMETER	F1	F2	F3	F4	F5
1	Hardness^** (Kg/cm²)	2.68± 0.109	2.58± 0.192	2.51± 0.2	2.59± 0.151	2.51± 0.1
2	Weight variation^***(mg)	206.2±6.99	204±7.37	205.9±6.32	208.4± 5.67	206.1± 6.99
3	Thickness^* (mm)	2.18 ±0.216	2.19± 0.114	2.19± 0.089	2.18± 0.089	2.19± 0.228
4	Diameter^* (cm)	1.1 ± 0	1.13 ± 0.04	1.1 ± 0	1.13 ± 0.02	1.1 ± 0
5	Friability^** (%)	0.711 ±0.007	0.543 ±0.42	0.65±0.021	0.574 ±0.014	0.69 ±0.028
6	Drug content^*** (%)	101.14 ±0.17	99.87 ± 0.151	102.44 ± 0.939	102.21 ± 0.095	100.07 ± 0.646
7	Wetting time^* (sec)	23 ± 2	114.6± 2.51	30.6 ± 2.08	136.3±3.21	24.6 ± 1.15
8	Disintegrating time^* (sec)	7.96 ± 0.4163	37.03 ± 0.2517	12.86 ± 0.3215	64.86 ± 0.8083	9.0 ± 0.3

ODT’S - Oral disintegrating tablets. The data represented as mean ± SD (*n - 5, **n - 10, ***n – 20)

TABLE 3: COMPARITIVE % DR FOR F1, F2, F3, F4, F5 FORMULATIONS

Time (min)	Percentage drug release (%) of formulations
Time (min)	F1	F2	F3	F4	F5
0	0	0	0	0	0
1	44 ± 1.414	5 ± 7.071	39 ± 1.414	35.5 ± 0.707	66 ± 4.242
3	97 ± 2.828	33.5 ± 3.535	92 ± 2.828	82.5 ± 2.121	91 ± 1.414
5	98 ± 1.414	83 ± 2.828	99 ± 0	91 ± 1.414	94.5 ± 6.363
10	99.1 ± 5.656	103.5 ± 6.363	101.2 ±1.414	99 ± 0	99.1 ± 6.363
15	102.3 ± 2.828	103.7 ± 0.707	102 ± 2.828	103.5 ± 6.363	99.7 ± 0.12

% DR- Percentage drug release. The data represented as mean ± SD (n- 6)

TABLE 4. STABILITY STUDIES (40^oC ± 2^oC / 75% RH ± 5% RH)

PARAMETER	AFTER 3^rd MONTH
PARAMETER	F1	F2	F3	F4	F5
Hardness^*** (Kg/cm²)	2.57±0.051	2.61±0.11	2.54±0.047	2.57±0.043	2.55±0.08
Weight variation^*** (mg)	206.6±6.65	204±6.24	205.7±6.8	204.3±6.8	206±4.58
Thickness^* (mm)	2.18±0.1	2.19±0.02	2.18±0.025	2.19±0.015	2.19±0.011
Diameter^* (mm)	1.13±0.051	1.1±0	1.1±0	1.1±0.005	1.1±0
Friability^*** (%)	0.79±0.045	0.58±0.2	0.65±0.025	0.59±0.045	0.7±0.028
Drug content^**** (%)	101.9±0.32	99.6±0.28	102.9±0.4	98.88±0.28	101.5.±0.64
% drug release at 15min^**	100.5±1.5	99.2±2.25	100.9±1.79	99.2±0.36	101.2±0.85

The date represented as mean ± SD (*n- 5, **n- 6, ***n- 10, ^****n- 20)

CONCLUSION:

From the present study, it can be concluded that natural super disintegrants like Annona squamosa L Leaves mucilage, Leucaena leucocephala bark gum, Moringa oleifera bark gum and Loctus Bean gum had showed good disintegrating property as the most widely used synthetic super disintegrants like Sodium Starch Glycolate in the formulations of ODTs and may be used as disintegrant in tablet formulations. As primary ingredients are cheap, biocompatible, biodegradable and easy to manufacture. They can also be used as superdisintegrants in place of currently marketed synthetic superdisintegrating agents.

REFERENCES:

1. Zatz, J.L. and G.P. Kushla; Pharmaceutical Dosage Forms-Disperse Systems, M. M. Reiger and G.S. Banker, Ed; Marcel Dekker Inc., New York. 2: 1989; pp.508.

2. British National Formulary ISBN 978-0-85369-776-3. 55, March 2008; pp.537.

3. Femi- Oyewo M, Musiliu O, Taiwo O; Evaluation of the Suspending Properties of Albizia zygia gum on Sulphadimidine Suspension. Tropical journal of pharmaceutical Research.

4. Vijetha Pendyala et.al., Studies On Some Physicochemical Properties of Leucaena leucocephala Bark Gum: Journal of Advanced Pharmaceutical Technology and Research. Vol- 1, 2010; pp.253-259.

5. PRP Verma et.al; Studies on Disintegrant Action of Leucaena leucocephala Seed Gum in Ibuprofen Tablet and its Mechanism; Journal of Scientific and Industrial Research. Vol. 66, July- 2007; pp. 550- 557.

6. Panda D., Swain S., Gupta R., Indian J. Pharm. Sci. 68(6): 2006; pp.777-780.

7. OECD guidelines for testing of chemicals; 423: 17^th Dec 2001.

8. C.V.S. Subrahmanyam, Textbook of Physical Pharmaceutics, pp. 224-227.

9. Viral Shah et.al; Studies on Mucilage from Hibuscus rosasinensis Linn as Oral Disintegrant; International Journal of Applied Pharmaceutics. Vol– 2, Issue 1: 2010; pp.18-21.

10. Schiermeier S, Schmidt PC. Fast dispersible ibuprofen tablets, Eur. J. Pharm. Sci. 15: 2002; pp.295‐305.

11. Mizumoto T, Masuda Y, Yamamoto T, Yonemochi E, Tarada K. Formulation design of a novel fast‐disintegrating tablet, Int J Pharm. 306: 2005; pp.83‐90

12. B V Patel et. al; Study of Disintegrant Property of Moringa Oleifera Gum and its Comparison With Other Superdisintegrants; International Journal of Chemtech Research. Vol. 3, No.3, July-Sept 2011; pp. 1119-1124.

13. Yunxia B, Yorinobu Y, Kazumi D, Akinobu. O. Preparation and evaluation of oral tablet rapidly dissolving in oral cavity. Chem. Pharm. Bull. 44(11): 1996; pp. 2121-2127.

14. Velmurugan. S and Sundar Vinushitha; Oral Disintegrating Tablets: An Overview; IJCPS. Vol.1 (2): 2010- Dec.

Received on 21.09.2013

Modified on 02.10.2013

Accepted on 06.10.2013

Research Journal of Pharmaceutical Dosage Forms and Technology. 5(6): November-December, 2013, 327-333