INTRODUCTION:

The most usable and important drug delivery route is undoubtedly the oral route [1-2]. It affords advantages of convenience of administration and potential manufacturing cost savings.

Drugs that are administered orally, solid oral dosage types in general, tablets and capsules in particular represent the preferred class of product. The demand for improving and developing new technologies has been increasing annually. Since the development and research cost of a new drug molecule is very high, efforts are now being made by pharmaceutical companies to focus on the development of new dosage forms for existing drugs with improved safety and efficacy together with minimized dosing frequency and good therapeutic effects, and the production of more cost-effective dosage forms having improve patients compliance and achieve higher bioavaibility. For most therapeutic agents used to produce systemic effects, the oral route still represents the preferred and most preferred route of administration, having to its several advantages and high patient compliance compared to many other routes. Tablets and hard/soft gelatin capsules constitute a major portion of drug delivery systems that are presently available. However, many patients such as the elderly, children, and patients who are mentally retarded, uncooperative, nauseated, or on decrease liquid-intake/diets have difficulties swallowing (Dysphagia) these dosage forms. Those who are traveling or have little access of water at time its similarly affected. To fulfill these medical needs, pharmaceutical technologists have developed a novel oral dosage form known as Orally Disintegrating Tablets (ODTs) defined by the Food and Drug Administration (USFDA) as “a solid dosage form containing medicinal substances which helps to rapidly disintegrates of drug, mainly within a few seconds when its placed upon the tongue”. It disintegrates rapidly in saliva, usually in a matter of seconds, without the need to take it water. Orally disintegrating tablets are also known as orodispersible tablets, quick disintegrating tablets, mouth dissolving tablets, rapid dissolving tablets, porous tablets, fast disintegrating tablets, fast dissolving tablets, and rapimelts [2-4]. Drug dissolution and absorption as well as onset of clinical effect and drug bioavailability may be significantly greater than those compared from conventional dosage forms. Although recent chewable tablets have also been on the market but, they are not the same as the new ODTs. Patients for whom chewing is difficult or may painful can use these tablets easily. ODTs can be used easily in children who have lost their primary teeth but do not have full use of their permanent teeth and also its having taste masking ingredients that’s improve the children and other patients’ compliance.

The aim of this article is to review the characteristics, advantages of ODTs, limitations, formulation challenges, manufacturing techniques, available marketed formulations and evaluation tests of ODTs.

Ideal characteristics of ODTs^[5-8]:

ODTs should depict some ideal characteristics to differ them from traditional conventional dosage forms. Important desirable characteristics of these dosage forms include:

1. No water requirement for swallowing ODTs but it should dissolve or disintegrate in the mouth within fraction of seconds.

2. Provide pleasant feeling in the mouth.

3. Be compatible with taste masking.

4. Be portable without fragility concern.

5. Leave negligible or no residue in the mouth after oral administration.

6. Allow high drug loading.

7. Adaptable and amenable to conventional processing and packaging equipment at nominal expense.

Advantages of ODTs^[9-16]:

1. Good for patients with swallowing difficulties

2. Good for paediatric compliance

3. Convenient to administer during travelling or condition without water

4. Convenience of administration and accurate dosing compared to liquids

5. Conventional manufacturing equipment

6. Cost effective

7. Good chemical stability as conventional oral solid dosage form

8. Allow high drug loading

9. No chewing needed

10. Rapid drug therapy intervention

11. As bitter pill particularly in pediatric patients

12. Rapid dissolution and absorption of drug

Disadvantages of ODTs^[15-19]:

1. ODT is hygroscopic in nature so must be keep in dry place

2. Most ODTs is that They are fragile and brittle

3. It needs to special package for protection during storage and transportation

4. It is also showing the fragile, effervescence granules property

Mechanisms of ODTs:

ODTs involve the following mechanisms to achieve the desired quick dissolving characteristics:

1. Water should shortly enter into the tablet matrix to cause rapid disintegration and instantaneous dissolution of the tablet.

2. Incorporation of a disintegrating agent or highly water-soluble excipients in the preparation of tablet.

3. There are some mechanisms by which the tablet is broken down into the smaller particles and then subsequently result a solution or suspension of the drug. The mechanisms are:

· High swellability of disintegration

· Chemical response

· Capillary action

Challenges in formulation ODTs:

1. Palatability

2. Mechanical Strength

3. Hygroscopicity

4. Amount of drug

5. Aqueous solubility

6. Size of tablet

Excipients to be used for the preparation of ODTs with range in use (% in weight):

Excipients	Function	Example
Super disintegrant 1-15%	Increases the rate of disintegration and hence the dissolution. The presence of other formulation ingredient such as water soluble excipients and effervescent agents further hasten the process of disintegration. For the success of fast dissolving tablet, the tablet having quick dissolving property which is achieved by using the super disintegrant agents	Crospovidone, Microcrystalline cellulose, Sodium starch glycolate, sodium carboxy methyl cellulose, pregelatinized Starch, carboxy methyl cellulose, and modified corn starch. Sodium starch glycolate has good flowability than croscarmellose sodium. Cross povidone is fibrous nature and highly compatable
Flavour	Increases Patient compliance and acceptability	Peppermint flavor, cooling flavor, flavor oils and flavoring aromatic oil, peppermint oil, clove oil, bay oil, anise oil, eucalyptus oil thyme oil, oil of bitter almonds. Flavouring agents include vanilla, citrus oils, fruit essences.
Sweeteners and sugar-based excipients	This is another approach to manufacture ODT by direct compression. Sugar based excipients acts as bulking agents. These exhibits high aqueous solubility and sweetness, and hence impart taste masking property and a pleasing mouth feel.	Artificial sweeteners like Aspartame, sugars derivatives. Bulking agents like dextrose, fructose isomalt lactitol, maltitol, maltose, mannitol, sorbitol, starch hydrolysate, polydextrose and xylitol
Surface Active agents	Reduces interfacial tension and thus enhances solubilization of FDT	Sodiumdoecylsulfate, sodiumlaurylsulfate, polyoxyethylene sorbiton fatty acid esters (Tweens), spans
Binder 5-10%	Maintains integrity of dosage form prior to administration	Polyvinylpyrrolidone (PVP), Polyvinylalcohl (PVA), Hydroxy propyl methylcellulose (HPMC)
Color	Enhances appearance and organoleptic properties of dosage form	Sunset yellow, Amaranth, Red iron oxide
Lubricants	Lubricant helps reduce friction and wear by introducing a lubricating film between mechanical moving parts of tablet punching machine	Stearic acid, Magnesium stearates, Zinc state, calcium state, talc, polyethylene glycol, liquid paraffin, magnesium lauryl sulfate, colloidal silicon dioxide.
Fillers 0-85%	Enhances bulk of dosage form	Directly compressible spray dried Mannitol, sorbitol xylitol, calcium carbonate, magnesium carbonate, calcium phosphate, calcium sulfate, pregelatinzed starch, magnesium trisilicate, aluminium hydroxide

TECHNIQUES FOR PREPARING: ORODISPERSIBLE TABLETS.:

Various techniques are currently used in preparing fast disintegrating/dissolving tablets; some of them are discussed briefly in the following section.

Direct compression:

The easiest and cost-effective way to prepare tablets. Conventional compression machines with common ingredients are used, by limited number of processing steps. Microcrystalline cellulose (MCC) and low substituted hydroxypropyl cellulose (HPC) are used to manufacture rapidly disintegrating tablets. Rapid disintegration can also be achieved by adding effervescent material in a tablet to generate carbon dioxide, which also helps in taste masking of a drug. Major drawback of effervescent form, is hygroscopicity i.e., the ability to absorb atmospheric moisture. Sometime super disintegrants are added in optimal concentration, to achieve good oral dispersibility with pleasant feeling. Common examples of superdisintegrants include sodium starch glycolate, crospovidone, alginic acid, calcium silicate and crosscarmellose. They provide rapid disintegration by swelling due to water absorption^[20]. Characteristics of direct compression are cost effective, much similar to the conventional dosage form with an exception of containing high amount of disintegrants in some cases which can result in low tablet hardness^[21].

Freeze drying or lyophilization:

It is a process that allows the drying of heat sensitive drugs and biological material under low temperature by the application of vacuum to remove water by sublimation. Drugs are dissolved or dispersed in aqueous solution of a carrier, transferred to preformed blister packs and subjected to nitrogen flush to freeze out, then placed in refrigerator to complete the process^[22]. Characteristics of lyophilization techniques are, they possess high porosity and specific surface area, and gets dissolve rapidly in mouth presenting high drug bioavailability^[23]. Major drawback of this system is high cost, time consuming procedure and fragility, making conventional packing inappropriate for packing this dosage form and stability issues under stress condition ^[24].

Molding method:

Tablets are designed using by hydrophilic ingredients, with the aim to get maximum drug dissolution. Powder mass is wetted with hydro alcoholic solvent and compressed into dosage form. The solvent system is then allowed to evaporate. Taste of drug particles is developed by spray congealing technique. The molten mixture of hydrogenated cottonseed oil, sodium carbonate, lecithin, polyethylene glycol with an active ingredient into lactose-based tablet triturate. Characteristics of moulding method are, very porous as solvents are removed by drying leaving porous mass which promotes rapid dissolution^[25].

Sublimation:

Rapid disintegration and dissolution is obtained by formulating into porous mass by incorporating inert solid ingredients that volatilize rapidly like urea, camphor ammonium carbonate, ammonium bicarbonate and hexamethylene-tetramine^[26]. They were mixed with other ingredients and compressed. The volatile material is evolved by reduced pressure and applying slight temperature leaving the mass in porous form. Characteristics of sublimation method are, they are porous in nature, solvents like cyclohexane and benzene can be used^[27].

Spray-drying:

By this method ingredients are integrated by mannitol as bulking agent, hydrolyzed and nonhydrolyzed gelatins as supporting agents, sodium starch glycolate or crosscarmellose sodium as disintegrating and an acidic material (e.g. citric acid) and or alkali material (e.g. sodium bicarbonate) to enhance disintegration and dissolution. Characteristics of spray-drying method is this method gives rapid dissolution (within 20 seconds) when dosage form gets in contact with aqueous medium ^[28].

Mass-extrusion:

In this the mixed ingredients are softened by water soluble ingredients i.e. polyethylene glycol, using methanol as solvent, passing through an extruder to form thin cylinders. Which further get sliced with heated blade to form small tablets. Characteristics of this method the products can be used to mask bitter tasting drugs making small granules thus enhancing oral bioavailability of drug^[29].

Nanonization:

Nanonization method is the key process for poorly water-soluble drugs. In this technique particle size of the drug is reduced by the wet media milling procedures. The approach is a water-based media milling process in which nano-sized particles are obtained by the shear fracture of the micron-sized drug particles^[30]. Stabilizers are used to prevent the agglomeration of the nano-crystals by surface adsorption. Nanoparticle dispersions are stable and typically have a mean diameter of less than 200 nm with 90% of the particles being less than 400nm^[31].

Compaction:

By compaction method the dosage form formulated by addition of hydrophilic waxy binder (super polystate) PEG-6-stearate. This binder have dual action; increasing physical strength it also enhances the disintegration. rational of compaction method is that it rapidly melts in mouth leaving no residue^[32].

Phase-transition method:

By Phase-transition method, these dosage forms are established my mixing and compressing the mixture containing two sugar alcohols one of high melting point and 2nd of low melting point and successive heating them between their melting points making the tablet harden due to amplification of bondages induced by phase transition of lower melting point sugar alcohols ^[33]. A fast dissolving tablet produced by contained erythritol (MP: 122°) and xylitol (MP: 93-95°). They were heated at about 93° for 15 min resulted in increased the median pore size along with increase in tablet hardness. Characteristics of method is this method can withstand with the rigors of manufacturing and shipping conditions. As enough hardness is gained during heating but not suitable for heat unstable drugs^[34].

Evaluation of ODTs:

Evaluation parameters of tablets mentioned in the Pharmacopoeias need to be assessed, along with some special tests are involved. The quality of tablet also depends on the quality of physicochemical properties of blends. There are many formulation and process variables are involved in mixing and all these can affect the characteristics of blends which have produced^[35-38].

A. Evaluation of blends before compression:

The various characteristics of blends to be tested before compression are:

1. Angle of repose:

Angle of repose is determined by using funnel method. The accurately weighed blend is taken in to a clean funnel. The height of the funnel is adjusted in such a way that the tip of the funnel just touches the apex of the heap of blend. The drug-excipient (as solid dispersion) blend is allow to flow through the funnel freely on to the surface. The diameter of the powder cone is measured and angle of repose is calculated using the following equation.

Tan Ө = h/r

Where h and r are the height of cone and radius cone base respectively. Angle of Repose less than 30° shows the free flowing of the material.

Table 2: Angle of repose as an indication of powder flow properties

No.	Angle of repose	% difference
1	<20	Excellent
2	20-30	Good
3	30-34	Passable
4	>34	Very poor

2. Bulk density:

It is determined by pouring a weighed quantity of mixture into graduated cylinder and measuring the volume and weight it. Bulk density can be calculated by:

Bulk density = Weight of the powder/Volume of the packing

3. Tapped density:

It is determined by placing a graduated cylinder, containing a known mass of drug-excipients blend. The cylinder is allowed to fall under its own weight onto a hard surface from the height of 10cm at 2 second intervals. The tapping is continued until no further change in volume is noted. Tapped density can be calculated by:

Tapped Density = (Weight of the powder/volume of the tapped packing)

4. Compressibility index:

The Compressibility Index of the blends is determined by compressibility index. Compressibility Index can be calculated by:

Compressibility Index (%) = [(TD-BD) X 100] /TD]

5. Hausner’s ratio:

A similar index to indicate the flow properties can be defined by Hausner’s ratio. Hausner’s ratio can be calculated by:

Hausner’s ratio = (Tapped density x 100)/(Poured density) Hausner’s ratio

B. Evaluation of Tablets:

All the formulated ODTs were subjected to the following evaluation tests:

1. Weight variation:

The weight variation test is carried out in order to ensure uniformity in the weight of tablets in a batch. First the total weight of 20 tablets from each formulation is determined and the average is calculated. The individual weight of the each tablet is also determined to find out the weight variation test^[39].

USP Specification for uniformity of weight:

Table 3: USP Specification for uniformity of weight.

S. No.	Average Weight of tablets	% difference
1	130mg or less	10
2	130mg – 324mg	7.5
3	More than 324mg	5

2. Hardness:

The hardness of tablet is an indication of its strength. Measuring the force required to break the tablet across tests it. The force is measured in kg and the hardness of about 2.5-3 kg/cm2 is considered to be satisfactory for uncoated tablets. Hardness of 10 tablets from each formulation is determined by Monsanto hardness tester, Pfizer hardness tester etc ^[40].

3. Friability test:

Friability is the loss of weight of tablet in the container due to removal of fine particles from the surface. Friability test is carried out to access the ability of the tablet to withstand abrasion in packaging, handling and transport. Roche friabilator is employed for finding the friability of the tablets. Weigh the 20 tablets from each batch and place in Roche friabilator that will rotate at 25 rpm for 4 minutes ^[41].

4. Disintegration test:

The USP disintegration apparatus contains six glass tubes that, open at the top, at the bottom end of the basket rack assembly. One tablet is placed in each tube and the basket rack is poisoned in 1-liter beaker of distilled water at 37± 2 °C, such that the tablets remain below the surface of the liquid on their upward movement and descend not closer than 2.5cm from the bottom of the beaker ^[42].

5. Uniformity of dispersion:

Keep the Two tablets in 100ml water and stir gently for 2 minutes. The dispersion is passed through 22 meshes. The tablets will consider passing the test if no residue remained on the screen.

6. In -Vitro disintegration test:

In-vitro disintegration time is measured by dropping a tablet in a beaker containing 50 ml of Sorenson’s buffer pH 6.8. Three tablets from each formulation are randomly selected and in vitro dispersion time is carried out.

7. In-Vivo disintegration test:

The test is carried out on 2 or 3 tablets in the mouth and the time in second taken for complete disintegration of the tablet is measured ^[43].

8. In-Vitro dissolution test:

In-vitro dissolution study is performed by using USP Type II Apparatus (Paddle type) at 50rpm. Phosphate buffer pH 6.8, 900 ml is used as dissolution medium which maintained at 37±0.5°C. Withdraw aliquot sample of dissolution medium (10ml) at specific time intervals (2 min) and filter it. The amount of drug dissolved is determined by suitable analytical technique.

9. Stability Studies:

The optimized formulation of ODTs is subjected to stability study as per ICH guidelines to assess their stability with respect to their physical appearance and release characteristics^[44].

REFERENCE:

1. Hirani J, Rathod D, Vadalia K. Orally disintegrating tablets. Tropical Journal of Pharmaceutical Research 2009;8(2): 161-172.

2. Konapure SA, Chaudhari PS, Oswal RJ, Kshirsagar SS, Antre RV, Chorage TV. Mouth dissolving tablets an innovative technology. International Journal of Applied Biology and Pharmaceutical Technology 2011;2(1): 496- 503.

3. Bangale SG, Shinde GV, Rathinaraj BS. New generation of orodispersible tablets: recent advances and future prospects. International Journal of Advances in Pharmaceutical Sciences 2011;2(3): 17-28.

4. Jesmeen T, Uddin R. Orodispersible tablets: A short review. Stamford Journal of Pharmaceutical Sciences 2011;4(1): 96-99

5. Clarke A, Brewer F, Johnson ES, Mallard N, Hartig F, Taylor S, et al. A new formulation of selegiline: improved bioavailability and selectivity for MAO-B inhibition. Journal of Neural Transmission 2003;110(11): 1241- 1255.

6. Bhowmik D, Chiranjib P, Krishnakanth, Chandira RM. Fast dissolving tablet: An overview. Journal of Chemical and Pharmaceutical Research 2009;1(1): 163- 177.

7. Agarval VA, Rajkumar RM, Ingale RG. Fast disintegrating tablet as new drug delivery system: A review. Pharmacophore 2011;2(1): 81-88.

8. Deshmukh VN. Mouth dissolving drug delivery system: A review. International Journal of PharmTech Research 2012;4(1): 412-421.

9. Brown D. Orally disintegrating tablets-taste over speed. Drug Delivery Technology 2003;3(6): 58-61.

10. Pilgaonkar P, Rustomjee M, Gandhi A, Badge PM. Orally disintegrating tablets. United States Patent. 2009.

11. Shukla D, Chakarborty S. Mouth dissolving tablets: An overview of formulation technology. Scientia Pharmaceutica 2009;77 (2): 309-326.

12. Kumare MM, Marathe RP, Kawade RM, Ghante MH, Shendarkar GR. Design of fast dissolving tablet of atenolol using novel coprocessed superdisintegrant. Asian Journal of Pharmaceutical and Clinical Research 2013;6 (3): 81-85.

13. Chacko AJ, Jose S, Babu N, Lucille, Michelle M. Design and development of orodispersible tablets of promethazine theoclate using coprocessed superdisintegrants and subliming materials. International Journal of Innovative Pharmaceutical Research 2010;1(2): 53-56.

14. Saxena V, Khinchi MP, Gupta MK, Agarwal D, Sharma N. Orally Disintegrating Tablets: Friendly Dosage Form. International Journal of Research in Ayurveda and Pharmacy. 2010; 1: 399-407.

15. Virely P, Yarwood R. Zydis – a novel, Fast Dissolving Dosage Form. Manuf Chem. 1990; 61: 36-37

16. Seager H. Drug delivery products and the zydis fast dissolving dosage form. Journal of Pharmacy and Pharmacology 1998;50(4): 375-382.

17. Habib W, Khankari R, Hontz J. Fast dissolving drug delivery system. Critical Reviews in Therapeutic Drug Carrier Systems 2000; 17(1):61-72.

18. Behnke K, Sogaard J, Martin S, Bauml J, Ravindran AV, Agren H, et al. Mirtazapine orally disintegrating tablet versus sertraline: a prospective onset of action study. Journal of Clinical Psychopharmacology 2003;23(4): 358-364.

19. Gafiţanu E, Dumistracel I, Antochi S. Formulations and bioavailability of propyphenazone in lyophilized tablets. Revista Medico-chirurgicala a Societatii De Medici Si Naturalisti Din Iasi 1991;95(1- 2): 127-128.

20. Kumari S, Visht S, Sharma PK, Yadav RK. Fast Dissolving Drug Delivery System: Review Article. Journal of Pharmacy Research. 2010; 3(6): 1444- 1449. 18. Bhowmik D, Chranjib B, Pankaj K, Chandira RM. Fast Dissolving Tablet: An Overview. Journal of Chemical and Pharmaceutical Research. 2009; 1(1): 163-177.

21. Ashish P, Harsoliya MS, Pathan JK, Shruti S. A review-formulation of mouth dissolving tablet. Int J Pharm Clin Sci 2011; 1:1-8.

22. Allen LV Jr. Dosage form design and development. Clin Ther 2008; 30: 2102-11

23. Kumari S, Visht S, Sharma PK, Yadav RK. Fast dissolving Drug delivery system: Review Article; Journal of Pharmacy Research 2010; 3(6): 1444-1449.

24. Mahato RI, Narang AS. Drug delivery systems. In: Pharmaceutical Dosage Forms and Drug Delivery. 2nd ed. New York: CRC Press; 2011. p. 217-34.

25. Nagar P, Singh K, Chauhan I, Verma M, Yasir M, Khan A, et al. Orally disintegrating tablets: Formulation, preparation techniques and evaluation. J App Pharm Sci 2011; 4: 35-45.

26. Pahwa R, Piplani M, Sharma PC, Kaushik D, Nanda S. Orally disintegrating tablets-Friendly to pediatrics and geriatrics. Arch Appl Sci Res 2010; 2:35-48

27. Bhowmik D, Chiranjib B, Pankaj. Fast dissolving tablet: An overview. J Chem Pharm Res 2009;1: 163-77.

28. Nagar P, Singh K, Chauhan I, Verma M, Yasir M, Khan A, et al. Orally disintegrating tablets: Formulation, preparation techniques and evaluation. J App Pharm Sci 2011;4: 35-45.

29. Sehgal P et al. Fast dissolving tablets: a new venture in drug delivery. American Journal of PharmTech Research 2012; 2(4):252-279.

30. Parkash V, Maan S, Deepika, Yadav SK, Hemlata, Jogpal V. Fast disintegrating tablets: Opportunity in drug delivery system. J Adv Pharm Technol Res 2011;2: 223-35.

31. Kuchekar BS, Badhan AC, Mahajan HS. Mouth dissolving tablets: A novel drug delivery system. Pharm Times 2003;35: 7-14.

32. Sri KV, Raj GB, Ravishanker D, Kumar CA. Preparation and evaluation of montelukast oral dispersible tablets by direct compression method. Int Res J Pharm 2012;7: 315-18.

33. Shukla D, Chakraborty S, Singh S, Mishra B. Mouth dissolving tablets I: An overview of formulation technology. Sci Pharm 2009; 77:309-26.

34. Yang D, Kulkarni R, Behme RJ, Kotiyan PN. Effect of the melt granulation technique on the dissolution characteristics of griseofulvin. Int J Pharm 2007; 329:72-80.

35. Bess WS, Kulkarni N, Ambike SH, Ramsay MP. Fast dissolving orally consumable solid film containing a taste masking agent and pharmaceutically active agent at weight ratio of 1:3 to 3:1. United States Patent; US 7067116; 2006.

36. Fatma R, Nandi PK, Gupta AK. Novel approach for patient’s compliance: fast dissolving tablets. World Journal of Pharmacy and Pharmaceutical Sciences 2014;3(7):1758-1768.

37. Tablet rapidly disintegrating in the oral cavity, Chem Pharm Bull, 1996; 44: 2121-2127.

38. Subramanian S, Sankar V, Manakadan AA, Ismailand S, Andhuvan G. Formulation and Evaluation of Cetirizine dihydrochloride Orodispersible Tablet. Pak.J.Pharm. Sci. 2010; 239 (2): 232-235.

39. Kuno Y, Kojima M, Ando S, Nakagami H. Evaluation of Rapidly Disintegrating Tablets Manufactured by Phase Trasition of Sugar Alcohol. Journal of Controlled Release. 2005; 105: 16-22.

40. Bhowmik D, Chiranjib B, Pankaj. Fast dissolving tablet: An overview. J Chem Pharm Res 2009;1: 163-77.

41. Chaudhari PD, Chaudhari SP, Kolhe SR, Dave KV, More DM. Formulation and evaluation of fast dissolving tablets of famotidine. Indian Drugs 2005; 42: 641- 649.

42. Wilson CG, Washington N, Norman S, Greaves JL, Peach JM, Pugh K. A gamma scintigraphic study to compare oesophageal clearance of “Expidet” formulation, tablets and capsules in supine volunteers. Int. J.Pharm. 1988; 46 (3): 241-246.

43. Washington N, Wilson CG, Greaves JL, Norman S, Peach JM, Pugh K. A gamma scintigraphic study of gastric coating by Expidet, tablets and liquid formulation. Int. J. Pharm. 1989; 57(1): 17-22.

44. Divate S, Kunchu K, Sockan GN. Fast Disintegrating tablet an Emerging Trend. International Journal of Pharmaceutical Science Review and Research. 2011; 6 (2): 18-22.

Received on 03.11.2020 Modified on 07.12.2020

Res. J. Pharma. Dosage Forms and Tech.2021; 13(1):66-71.

DOI: 10.5958/0975-4377.2021.00012.4