INTRODUCTION:

Nowadays, Oro dispersible drug delivery systems are comprehensively used to expand bioavailability and patient compliance. Over the past three years, Oro dispersible tablet (ODTs) have gained considerable attention as a desired substitute to conventional tablet and capsules due to better patient compliance, improved solubility and stability profiles. ODTs are solid dosage forms containing medicinal substances that disintegrate rapidly, usually within a seconds, When placed on the tongue with without the used of water. Usually, super disintegrate are added to a drug formulation to breakup or disintegration of tablet that can dissolved more rapidly. The faster the dissolution of the drug onto the solution, The quicker is the absorption and onset of clinical effect.

Natural polymer is utilized in most of the preparation and additional advantageous over synthetic polymerises they are economical, Low cost, and easily accessible in sufficient amount. Natural polymer has non-toxic, they do not have adverse effect. The disintegrate has major function to oppose the efficiency of tablet binder and physical forces that act compression to form a tablet. Normal disintegrant include starch and celluloid based such as a corn starch. Gum (tragacanth, alginate, agar, gaur). Some clays (vee gum). Various mechanisms are responsible for breaking of the tablet into smaller particles. Mechanism of action of disintegrant include swelling, Capillary action, wicking, combined action and deformation etc.¹

The various technologies are used to prepare ODTs include direct compression, sublimation, tablet molding, spray drying, freeze- drying and mass extrusion.

1. Freez Drying (Lyophilizatio):

Freeze drying is a process in which water is sublimated from the product after freezing is called as freez drying. Freeze drying forms offer more rapid dissolution than other availabke solid product. The lyophilisation process imparts glossy amorphous structure to the bulking agent and sometimes to the drug, thereby enhancing the dissolution characteristics of the formulation. A typical procedure involved in the manufacturing of ODT usng this technique mentioned here. The active drug is dissolved or dispersed in an aqueous solution of a polymer. The mixture is done by weight and poured in the walls of the preformed blister pack. The trays holding the blister packs are passed through liquid nitrogen freezing tunnel to freeze the drug solution or dispersion. Then the frozen blister packs are placed in refrigerated cabinate to continue the freeze drying. After freeze drying the aluminium foil backing is applied on a blister sealing machine. Finally, blister are packed and shipped. The freeze drying technique has demonstrated improved absorbtion and increased in bioavailability.

2. Spray Drying:

Spray drying is used in pharmaceutical industries to produce highly porous powdres. The pocessing solvents is evaporated rapidly by spray drying, which renders the product highly porous and thus can be used in manufacturing ODT. In this technique, gelatin can be used as a supporting agent and as a matrix, mannitol as a bulking agent and sodium starch glycolate or cross carmellose or crospovidone are used as superdisintegrants. Tablets manufactured form the spray-dried powder have been reported to disintegrate in less than 20 seconds in aqueous medium. Allen and wang have reported this technique for preparing fast dissolving tablets. The formulation contained bulking agent like mannitol and lactose, a superdisintegrant like sodium starch glycolate and crosscarmellose sodium and acidic ingredients (citric acid) and/or alkaline ingredients (e.g. sodium bicarbonate). This spray dried powder, which compressed into tablets showed rapid disintegration and enhanced dissolution.

3. Mass Extrusion:

This technology involves softening the active mass using the solvent mixture of water soluble PEG, methanol and expulsion of softened mass through the extruder or syringe to get a cylinder of the product into even segment using heated blade to form a tablet.

Properties of natural disintegrants after processing of Freeze drying:

1. Millet Starch by Freeze Drying²

Botanical name: Pennistum glaucum

Family: Poaceae

Application: Binder and Disintegrants

Modification: By Pregelatinized

Table No.01

Sr. No	Properties	Millet	Pregelatinized
1.	Bulk density (kg/cc)	0215	0.353
2.	Tapped (kg/cc)	0.380	0.457
3.	Carr’s Index (%)	43.42	22.870
4.	Housner ratio	1.76	1.30
5.	Swelling Index	11	133
6.	pH	6.0	6.4
7.	Loss on drying (LOD)	4.06	12.0
8.	Effective pore radius	1.62	1.96

2. Sorghum Starch After Freeze Drying²

Botanical name: Sorghum bicolor L. Moench

Family: Graminae

Application: Binder and Disintegrant

Table No. 02

Sr. No	Properties	Natural	Pregelatinized
1.	Bulk Density(kg/cc)	0.268	0.359
2.	Tapped Density(kg/cc)	0.439	0.529
3.	Carr’s Index (%)	38.95	32.10
4.	Hausner ratio	1.64	1.47
5.	Swelling Index (%)	17	73
6.	pH	6.0	6.4
7.	Loss on Drying (LOD)	4.09	82

3. Properties of Freeze-Drying Fenugreek Seed³

Botanical name: Trigonella Fornum Graecum

Family: Legumes

Application: Disintegrant

Table No.03

Sr. No	Properties	Result
1.	Bulk Density (kg/cm³)	0.42-0.48
2.	Tapped Density (kg/cm³)	0.45-0.65
3.	Compressibility Index (%)	12.45-17.40
4.	Housner’s Ratio	1.14-1.22
5.	Angle of Repose ⁰	19.50-23.65 ⁰
6.	Swelling Index %	26
7.	pH	6.5
8.	Loss on Drying (LOD)	2.5

4. Properties of Spray Dried Mango Kernel Starch⁴

Botanical Name: Mangifera Indica

Family: Anacardiaceae

Application: Disintegrant

Table No.04

Sr. No	Properties	Results
1)	Tap density (kg/cm³)	0.43
2)	Angle of repose (⁰)	23.1
3)	Apparent density (kg/cc)	0.30
4)	Starch Content (%)	69
5)	Liquid Content (%)	2.30
6)	(%) yield	39.1

5. Spray Dried Rice Starch³

Botanical Name: Oryza Sativa

Family: Graminae

Sr. No	Properties	Result
1)	Solubility	1.26
2)	Swellabillity (%)	3.13
3)	pH	7.2
4)	Bulk density (kg/cm³)	0.4
5)	Tapped density (kg/cm³)	0.6
6)	True density (kg/cm³)	1.5154
7)	Moisture content (%)	5.77
8)	Particle size	22.80
9)	Carr’s index (%)	20-24%

6) Spray Dried Lactose⁵

Lactose is diasaccharide derived from the condensation of glucose and galactose.

Application- Used as binder and diluent

Sr. No	Properties	Improved spray dried lactose	Regular spray dried lactose
1)	Bulk density (kg/cm³)	0.610±0.000	0.628
2)	Tapped density (g/cm³)	0.713±0.004	0.736
3)	True density (g/cm³)	1.541±0.005	1.548
4)	Water activity	0.19	0.22
5)	Β-lactose (%)	13	12
6)	Primary mean particle size (µm)	22	34
7)	Surface area	0.335 to 0.008	0.236 to 0.001

7) Spray- dried pink Guave powder with maltodextrin 15%⁷

Botanical name: Psidium guajava

Sr. No	Properties	Value
1)	Bulk Density (kg/cm³)	449.33
2)	Tapped Density (kg/cm³)	510.14
3)	Carr’s Index (%)	15%
4)	Hausner Ratio	1.18
5)	Loss on drying (%)	2.9%
6)	Particle Size	12
7)	Powder yeild (%)	52

8) Spray dried maize starch and maize starch with carbapol ⁶

Botonical name: Zea mays

Family : Poaceae

Application : Disintegrant, Diluent, Binder

Sr. No	Property	Maize starch	film coated m. starch
1)	Bulk density (kg/cc)	0.43	0.45
2)	Carr’s index (%)	34.80	17.30
3)	Moisture uptake (%)	38	62
4)	Angle of repose (°)	43.50	13.50
5)	Swelling capacity (%)	0	35
6)	Tapped density (kg/cc)	0.67	0.55

CONCLUSION:

The spray drying and freeze drying techniques are the first generation techniques used to prepared orodispersible tablet. After processing of spray drying the powder of material shows the the better dissolution and disintegrating property. The porous powder was obtained by spray drying and the above suspension has compressed into tablet thereby increase the disintegration time and dissolution time of natural disintegrant. Mass extrusion are used to coat granules of bitter tasting drugs and thereby masking their taste. freez drying process imparts glossy amorphous structure to the bulking agent of the dru and this technique is improved absorption and increase bioavalability. It conclude that we can use freeze and spray dried natural disintegrant in fast dissolving tablet for better disintegration property.

REFERENCES:

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Received on 25.03.2021 Modified on 10.05.2021

Asian Journal of Pharmacy and Technology. 2021; 11(3):249-251.

DOI: 10.52711/2231-5713.2021.00041