INTRODUCTION:

In preparation of a tablet, from a drug as a dosage form, Pharmaceutical ingredients are required. Some Pharmaceutical ingredients require a binder for tablet dosage form.¹This provides the cohesiveness necessary for bonding ingredient together. For a successful formulation binder concentration must reached to form a tablet and finally disintegrate with in specified time period. Binding agents are used to impart the structural strength required during the processing, handling and packaging of tablets. A number of plant gums have been used as binding agents in tablet formulations viz. acacia, guar gum, tragacanth etc. There are several reports about the successful use of hydrophilic polymers derived from plant, locust bean gum, karaya, guar and xanthin gum in pharmaceutical preparations.²

Moringa oleifera gum has been evaluated for its binding properties³, plantago ovata and Trigonella foenum graecum mucilage has been evaluated for its binding properties⁴.

Guar gum has been investigated for its colon specific dosage forms gum of the treemoringa oleifera been reported to have gel forming potential for topical application⁵. Gum odina have been evaluated for its binding property⁶. Plantago ovata mucilage has been evaluated in fast disintegrating tablet⁷. Cassia tora have been evaluated as a binder⁸. The present work was carried out to study the binding property ofProsopis juliflora (PJ) mucilage in tablet formulation Aceclofenac was used as a model drug.

Prosophis juliflora (Fabaceae family) is a shrub or small weed plant grows all over the world. The tree grows to a height of up to 12 m and has a trunk with a diameter of up to 1.2 m. The plant has characteristic thorns and yellow flowers. The bark exudates a good amount of gum round the year. Hence, in this study we have investigated the binder effects of Prosophis juliflora Gum on the mechanical properties of tablets and to compare the prepared tablets with standard tablets prepared using starch as binding agent.

MATERIALS AND METHODS:

Aceclofenac (Blue cross, Nasik, India), Prosophis juliflora Gum (prepared in our Laboratory), Lactose, SSG, Talc, Magnesium stearate (Loba Chemie Mumbai, India), Maize starch (S.D. Fine chemicals Ltd.). All chemicals used were of analytical reagent grade and double distilled water was used throughout the experiments.

Methods:

Extraction of gum:

The Prosophis juliflora gum was collected and soaked in water for 5–6 h, boiled for 30 minutes and left to stand for 1 h to allow complete extraction of the gum into the water. The gum was filtered using a multi-layer muslin cloth bag to remove the dirt and foreign matter from the solution. Acetone (three times the volume of filtrate) was added to precipitate the gum. The gum was separated, dried in an oven at 35°C, collected, ground, passed through a # 80 sieve and stored in desiccator at 30°C and 45% relative humidity till use.¹⁰This gum was tested for flow properties. All values were found to be satisfactory.

Evaluation of some flow properties of Prosophis juliflora gum:

Bulk and tapped densities:

A 20.0 gm bulk volume sample of Prosophis juliflora gum powder was transferred into 100 ml measuring cylinder and the volume ,which was the mean of the reading from several sides ,was calculated. The cylinder was tapped for 250 times when there was no observable decrease in volume .The bulk and tapped densities were calculated as the mean of three determinations from the equation: p= m/v

Where, p is density (g/cm³),

m is the mass ( g ) of the data gum,

v is the volume of the powder in the cylinder.

Carr’s percent compressibility and the Hausner’s ratio were calculated using the equation (t-b)/t × 100 and t/b respectively, where t and b are tapped and bulk densities respectively.

Angle of repose:

The angle of repose of powdered gum was determined by the funnel method. The accurately weighed gum powder was taken in a funnel. The height of the funnel was adjusted in such a way that the tip of the funnel just touched the apex of the heap of the powder. The powder was allowed to flow through the funnel freely onto the surface. The diameter of the powder cone was measured and angle of repose was calculated using the following equation : θ = tan ^–1 (h/r)

Where, h and r are the height and radius of the powder pile respectively.

Preparation of binder solution:

The binder solution was prepared by dissolving the Prosophis juliflora gum in water. Standard binder (starch) was prepared by dispersing a 10 g sample of the starch powder in 20 ml of distilled water and adding boiled water whilst stirring with a glass rod to make up to 100 ml. The mucilage was allowed to cool and was used for binding.

Preparation and Evaluation of the granules:

The granules were prepared by wet granulation method. Aceclofenac was used as a model drug to formulate granules. Starch was used as disintegrant; lactose used as diluents and talc as lubricant respectively. The drug, lactose, and SSG were mixed thoroughly and a sufficient volume of 8, 10 and 12 % w/w of Prosophis juliflora gum was added slowly to the powder blend and cohesive wet mass was prepared. For standard used 10%w/w of starch as a binder. The batch size was 100 g. The wet mass was then sieved through sieve number 10 and dried at not more than 60^oC in hot air oven up to LOD NMT 3%. The dried granules were resieved through sieve number 20. The prepared granules were then evaluated for moisture content analysis and flow properties (by measuring angle of repose). The bulk and tapped densities were determined using bulk density apparatus. Compressibility index of the granules was determined by Carr’s compressibility index. The lower bulk and tapped densities exhibited by Prosophis juliflora gum and starch granules shows that both granules were good flowing. From the Hausner’s ratio which are almost equal to 1.2 indicate free flowing granules. In case Carr’s compressibility index, all granules possess better flow properties. The angle of repose for granules was between 25⁰ to 28⁰ that indicate free flowing properties of granules.

Preparation and evaluation of tablets:

The granules made from Prosophis juliflora gum were compressed into flat faced tablets of mean average weight 200 mg ± 7.5%, thickness 4.2 ± 0.5 mm, and diameter 8 mm ± 0.1 mm in eight station 2D Rimek Minipress tablet compression machine (Karnavati Engineering Ltd. Khadi) at an arbitrary pressure load unit of 6 tons as per formulae given in Table 1. Magnesium stearate was used to lubricate the die and punch surfaces prior to tableting to prevent sticking as shown in table 1.

Table1: Formulation Design.

Ingredients (mg/tab)	F1	F2	F3	F4
Aceclofenac	100	100	100	100
Lactose	64	60	56	60
SSG	10	10	10	10
Maize starch	-	-	-	20
*Prosophis juliflora* gum	16	20	24	-
Talc	9	9	9	9
Magnesium stearate	1	1	1	1
Total wt.	200	200	200	200

Evaluation of tablets:

The prepared Tablets were evaluated for weight uniformity, hardness, thickness, friability, disintegration time, and assay.

Table 2: Flow properties of dried powdered Prosophis juliflora gum.*

Parameters	Value
Bulk density (g/mL)	0.612±0.06
Tapped density (g/mL)	0.741±0.02
Carr’s index (%)	17.62±0.17
Hausner’s ratio	1.21±0.03
Angle of repose (Φ)	23.53±1.46

* Average of three determinations

Table 3: Evaluation of the granules.*

Sr. no.	Parameters	Binder (%)
		*Prosophis juliflora* gum			Starch
		8	10	12	10
1	Bulk density (gm/cm³)	0.516±0.05	0.498±0.04	0.466±0.02	0.489±0.06
2	Tapped density(gm/cm³)	0.602±0.02	0.594±0.03	0.537±0.02	0.570±0.02
3	Hausner’s ratio	1.16±0.04	1.19±0.04	1.15±0.03	1.17±0.03
4	Carr’s index ( % )	14.29±0.21	16.16±0.23	13.22±0.14	14.21±0.19
5	Moisture content ( % )	3.0	4.0	3.0	3.0
6	Angle of repose	27.63±0.56	25.34±1.41	26.19±1.02	26.85±1.27

* Average of three determinations

Table 4: Evaluation of tablet.

Formulations	Weight uniformity mg (±7.5%)	Hardness (Kg/cm²)	Thickness (mm)	Friability (%)	DT (sec.)	Assay (%)
F1	205	7.84±0.04	4.2±0.2	0.33±0.06	456.8±3.2	99.7±0.79
F2	197	6.96±0.05	4.2±O.5	0.25±0.04	479.1±2.7	100.2±0.53
F3	203	7.76±0.07	4.1±0.3	0.29±0.08	493.6±2.9	99.9±0.81
F4	200	7.0±0.06	4.2±0.4	0.31±0.06	480.5±2.4	99.7±0.72

For weight uniformity test, twenty tablets from each batch were selected randomly and weighed individually using a highly sensitive electronic balance (Shimadzu corporation, Japan). Their mean weights, deviations, and coefficients of variation for each batch were calculated. The tablets were evaluated for hardness as per B.P. procedure using Pfizer hardness tester. The friable mass was determined as per B.P. procedure using Friability test apparatus. The disintegration time was determined as per B.P. procedure.

Drug-excipient compatibility studies:

Infrared (IR) spectroscopy was conducted using a FTIR 8400S Spectrophotometer (Shimadzu, Tokyo, Japan) and the spectrum was recorded in the wavelength region of 4000 to 400 cm^-1. The procedure consisted of dispersing a sample (drug alone or mixture of drug and excipients) in KBr and compressing into discs by applying a pressure of 5 tons for 5 min in a hydraulic press. The pellet was placed in the light path and the spectrum was obtained.

RESULTS AND DISCUSSION:

The Prosophis juliflora plant yield high percentage of gum using acetone as gum precipitating solvent. The isolated gum was characterized for various physicochemical properties as per Pharmacopoeial guidelines. The specifications were set and the results are shown in Table no. 2. The prepared granules were evaluated for moisture content analysis and flow properties in comparison with maize starch granules. The results are shown in Table no. 3. Four batches of 100 tablets were prepared using isolated gum of Prosophis juliflora gum at three different concentrations 8%, 10% and 12% w/w and Starch at concentration 10% w/v. Starch (10% w/w) was used as standard binder for comparison. The prepared tablets were evaluated for weight uniformity, hardness, thickness, friability, disintegration time and assay. The prepared batches (F1-F6) of tablets were evaluated for various official and non-official parameters. The hardness of tablets for each formulation was between 6-7 kg/cm2. Average thickness was found to be in the range of 4 to 4.2 mm. Friability below 1% was an indication of good mechanical resistance of the tablets. The uniformity of drug content was found to be 99%-100% w/w which was within acceptable limits. Results are shown in Table 4.

The possible interaction between the drug and the polymer (gum) was studied by IR spectroscopy. The IR spectra of pure aceclofenac and its physical mixtures revealed no considerable changes in the IR peaks of aceclofenac when mixed with polymer and it conformed absence of any chemical interactions between the drug and polymer (Fig.1).

Figure 1: FT-IR spectra of A. Pure drug (Aceclofenac), B. Prosophis juliflora gum,

C. Mixture of aceclofenac and Prosophis juliflora gum.

CONCLUSION:

The comparative result of this study has concluded that Prosophis juliflora gum (10%) may used as a binding agent in the conventional tablet formulation. Since Prosophis juliflora gum displayed good binder characteristics have greater potentialities to become the new source of binder and could also be exploited for the commercial production of gums.

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Received on 04.01.2011 Modified on 23.01.2011

Research J. Pharm. and Tech. 4(8): Aug. 2011; Page 1193-1196