To fulfill these medical needs, pharmaceutical technologists have developed a novel oral dosage form known as orodispersible tablets (ODTs) which disintegrates rapidly in saliva, usually in a matter of seconds, without the need to take it water. Drug dissolution and absorption as well as onset of clinical effect and drug bioavailability may be significantly greater than those observed from conventional dosage forms^4-6.

Over the last decade, ODTs have grown steadily in demand and importance as a convenient, potentially safer alternative to conventional tablets and capsules⁷. Since their introduction to the market in the 1980s, ODTs have become one of the fastest growing segments of the oral drug delivery industry and their product pipeline is rapidly expanding⁸. Studies have shown that most consumers prefer ODTs to conventional tablets⁹ and that popularity is understandable.

Orodispersible tablets are also called as quick disintegrating tablets, orally disintegrating tablets, fast disintegrating tablets, mouth dissolving tablets, fast dissolving tablets, rapid dissolving tablets, porous tablets, and rapimelts. However, of all the above terms, United States pharmacopoeia (USP) approved these dosage forms as ODTs. European pharmacopoeia has used the term ODTs for tablets that disperses readily and within 3 minutes in the mouth. United States Food and Drug Administration (FDA) defined ODTs as “A solid dosage form containing drug or active ingredients which disintegrate/disperse rapidly usually within a matter of seconds when placed upon the tongue”.

ODTs are required to dissolve or disperse in the oral cavity to release the drug which comes in contact with taste buds. Many drugs are bitter in taste. A tablet of bitter drug dissolving or disintegrating in mouth with seriously affect patient compliance and acceptance for the dosage form. So effective taste masking of the bitter drugs must be done so that the taste of the drug is not felt in the oral cavity. Several taste-masking technologies, such as the addition of sweeteners and flavours, coating with water insoluble materials¹⁰, creating a wax matrix by spray congealing¹¹, adsorption to ion-exchange resin^12,13 and complexing with cyclodextrins¹⁴ had been investigated. This article presents a detailed review regarding the taste-masking technique and the evaluation measures available in literature.

TASTE MASKING TECHNIQUES:

Various techniques reported in the literature are as follows

a) Addition of flavorings and sweetening agent.

b) Microencapsulation

c) Ion-exchange

d) Inclusion complex

e) Granulation

a) Addition of flavouring and sweetening agent:

This technique is simplest approach for taste masking. But this approach is not very successful for high bitter drugs. Artificial sweeteners and flavours are generally being used along with other taste-masking techniques to improve the efficiency of these techniques.

Cooling effect of certain flavouring agent aids in reducing perception of bitterness. The physiology involved merely to numb taste buds, either rapidly or over a period of time, so that the cooling effect actually build up after ingestion. The brain perceives the coolness even though physically the temperature of the product has not changed¹⁵. Chang et al.¹⁶ prepared fast dissolving tablets and showed that sugar based excipients have negative heat of solution, dissolve rapidly in saliva and provide a pleasing mouth feel and good taste masking to the final product. The Zydis dosage form uses sweeteners and flavours to mask the unpleasant taste⁴. Floss and small spheres of saccharides containing unpleasant drugs were mixed with sweeteners and flavours to provide taste masking^17,18. Mohire et al.¹⁹ prepared metronidazole orodispersible tablets using sodium saccharin as a sweeteners in the mixture of disintegrating agent and drug. Kawano et al²⁰ prepared orally disintegrating tablets of furosemide with mannitol as an additive masking agent. Granules of furosemide and mannitol were prepared by mixing method, coating method, and mixing/coating method and finally compressed into tablets. The masking effect was favourable when granules were prepared by the mixing and mixing/coating methods. Venkataraman et al²¹. prepared zaleplon ODT where concentration dependent acceptability was observed in batches using peppermint flavour as a flavour enhancing agent and acesulfame potassium, aspartame as a taste enhancing agents. They also observed that as the concentration of peppermint flavour increased up to 1.8%, the acceptability also increased.

b) Microencapsulation:

It is important to understand that only soluble portion of the drug can generate the sensation of taste. Coating the active drug with a properly selected polymer film can reduce its solubility in saliva in thus taste could be masked. Coating the drug particles created a physical barrier between the drug and the taste buds and this taste of active could be masked. Microcapsules are made up of a polymeric skin or wall enclosing a core.

Microencapsulation is a process or technique by which thin coating can be applied to small particles of solids, droplets of liquids or dispersion, thus forming microcapsules. It differs from other coating methods because microencapsulation process is used to coat the particles having a particle size range from several tenth of a micron to 5000μ. When using a coating or encapsulation for taste masking, complete coating is necessary to prevent exposure of the taste buds to a bitter tasting drug. It is important that the coating remain intact while the dosage form is in the mouth. One of the most important factors to be considered in taste masking by microencapsulation is selection of coating polymers. Ideally, the coating polymers should be such that it prevents the release of active agent in the oral cavity, following per oral intake, but allows it in stomach or small intestine where the drug is expected to be absorbed. Polymers, which mainly insoluble at salivary pH 6.8 but readily dissolve at gastric fluid pH 1.2 could be a good candidate for taste masking. Coating polymer concentration generally used ranges from 5 to 50% (the percentage being expressed by weight relative to the weight of the coated granule). If the concentration of the polymer is less than 5% coating is not sufficient to allow effective masking of the taste. For a concentration greater than 50% the release of the drug is excessively retarded²². The coatings can dissolve, swell, or become permeable during the dissolution test depending on the selected media.

Figure below: Microencapsulation restricts dissolution of the drug in the mouth but allows rapid dissolution in the GI tract

i) Coacervation

Coacervation means the separation of a liquid or phase when solutions of two hydrophilic colloids are mixed under suitable conditions. In this method, the three immiscible phases or core material, solvent and coating material are formed followed by deposition of coating material on the core. The coating material is dissolved in a suitable solvent and the core material is uniformly dispersed in the solution of the coating material.

Then the coating material is phased out of its solution by changing the temperature of the polymer solution or by adding a salt, nonsolvent, or incompatible polymer to the polymer solution, or by inducing a polymer-polymer interaction which starts getting deposited on the particles of the core material. The coacervation process places a uniform coating of polymeric membranes of varying thickness and porosities directly onto dry crystals or granules. Coacervation technique has taste-masked a wide range of extremely poor-tasting drugs, including zolpidem, sumatriptan, ranitidine, cetrizine, theophylline, ibuprofen, acetaminophen and pseudoephedrine²³. Ndesendo et al.²⁴ taste masked chloroquine diphosphate by coacervation process.

ii) Solvent Evaporation:

Microencapsulation processes are carried out in a liquid manufacturing vehicle. The microcapsule coating is dissolved in a volatile solvent, which is immiscible with the liquid manufacturing vehicle phase. A core material to microencapsulated is dissolved or dispersed in the coating polymer solution. With agitation, the core coating material mixture is dispersed in the liquid manufacturing vehicle phase to obtain the appropriate size microcapsules. Solvent evaporation is a relatively simple and convenient method for the preparation of taste-masked microspheres. The drug particles are surrounded by a polymer which prevent leaching of the drug into the saliva but allow the release of the drug in the stomach. Anand et al.²⁵ prepared taste-masked orally disintegrating tablets of prednisolone by incorporation of microsphere in the tablets. Microspheres were prepared by solvent evaporation method and taste evaluation studies confirmed that microsphere of prednisolone having a drug to polymer ratio of 1:10 is tasteless. Meager et al.²⁶ also mask the bitter taste of metronidazole by solvent evaporation method.

iii) Spray Drying:

Microencapsulation by spray drying is conducted by dispersing a core material in a coating solution, in which the coating substance is dissolved and in which the core material is insoluble, and then by atomizing the mixture into an air stream. The air, usually heated, supplies the latent heat of vaporization required to remove the solvent from the coating material, thus forming the microencapsulated product. Mezumoto et al.^27,28 prepared oral fast disintegrating dosage form using taste masked famotidine by spray drying method. Taste-masked immediate release micromatrix powders were formed by spray drying the drug and cationic polymer.²⁹

c) Ion Exchange Resins:

Ion-exchange resins are high molecular weight polymers with cationic and anionic functional groups. The most frequently employed polymeric network is a copolymer of styrene and divinyl benzene. Drug can be bound the resin by either repeated exposure of the resin to the drug in a chromatographic column or by prolonged exposure of resin with the drug solution. Drugs are attached to the oppositely charged resin substrate, forming insoluble adsorbates or resinate through weak ionic bonding so that dissociation of the drug-resin complex does not occur under the salivary pH conditions. This suitably masks the unpleasant taste and odour of drugs.

The reaction involved during complexation of drug with resin may be indicated as follows.

Re-COO^-H⁺ + Basic Drug → Re-COO-Drug + H⁺

Re-N(CH₃)₃⁺Cl^- + Acidic Drug → Re-N(CH₃)₃-Drug + Cl^-

After administration of resinate, the release of drug from the resin depends on the properties of the resin and the ionic environment within the gastrointestinal tract(GIT). Drug molecules get released from resin by exchanging with appropriately changed ions in the GIT and free drug is available for absorption. The reactions involved in the gastrointestinal fluids may be indicated as follows.

In the stomach

Re-COO-Drug + HCl → Re-COOH + Drug Hydrochloride

Re-N(CH₃)₃-Drug + HCl → Re-N(CH₃)₃Cl + Acidic Drug

In the intestine

Re-COO-Drug + NaCl → Re-COONa + Drug Hydrochloride

Re-N(CH₃)₃-Drug + NaCl → Re-N(CH₃)₃Cl + Sodium salt of Drug

This technique has taste-masked a wide range of extremely poor tasting drugs, including ciprofloxacin³⁰, epidrin hydrochloride³¹, chloroquine phosphate¹³, and ranitidine hydrochloride³². Shukla et al.³³ prepared taste-masked resinate of risperidone orally disintegrating tablets.

d) Inclusion complex:

In inclusion complex formation, the drug molecule fits into the cavity of a complexing agent, i.e., the host molecule, forming a stable complex. Complexation with cyclodextrins can be used to mask unpleasant odour and bitter taste of drugs. Molecules or functional groups that cause unpleasant taste or odour can be hidden from the sensory receptors by encapsulating them within the cyclodextrin cavity. The resulting complexes have no or little taste or odour and are much more acceptable to the patient. β-cyclodextrin is the most widely used complexing agent for inclusion type complexes. It is a sweet, nontoxic, cyclic oligosaccharide obtained from starch. Motoyama et al.³⁴ prepared orally disintegrating tablets containing dl-α-Tocopheryl Acetate with β-cyclodextrin and 2-hydroxypropyl -β-cyclodextrin. The strong bitter taste of carbetapentane citrate was reduced to approximately 50% by preparing a 1:1 complex with cyclodextrin³⁵.

e) Granulation:

Granulation is a common processing step in the production of tablet dosage form. This step can be exploited as a mean for taste masking of slightly bitter tasting drug. Some saliva insoluble polymers can also act as binding agent, granules prepared from these polymers show less solubility in saliva and thus taste could be masked. Granulation lowers the effective surface area of the bitter substance that come in contact with the tongue upon oral intake. Taste masked granules of bitter tasting drug hyocine butylbromide has been prepared by the extrusion using aminoalkyl methacrylate copolymers³⁶. Kawan et al.³⁷ also prepared taste-mask furosemide orally disintegrating tablets by dry granulation method.

EVALUATION OF ORODISPERSIBLE TABLETS:

Weight Variation:

I.P. procedure for uniformity of weight was followed³⁸. Twenty tablets were selected randomly and their average weight was determined. Weight of the individual tablet was also determined. The tablets meet the weight variation test if not more than two of the individual weights deviate from the average weight by more than the percentage shown in Table below and none deviates by more than twice that percentage.

Table : Allowable weight variation

Average weight of tablet	Percentage deviation
80 mg or less	10
80-250 mg	7.5
More than 250 mg	5

Hardness:

The hardness of ODTs is generally kept lower than conventional tablets as increased hardness delays the disintegration of the tablet. The hardness of the tablet may be measured using conventional hardness testers. A tablet is placed in the hardness tester and load required to crush the tablet is measured.

Tensile Strength:

The tablet tensile strength is the force required to break a tablet by compressing it in the radial direction and is measured using a tablet hardness tester. Tablet tensile strength is calculated using following equation.

T = 2F/πdt

Where, T = Tensile strength of the tablet, F = Crushing load, d = diameter of the tablet, and t = Thickness of the tablet.

Friability:

Friability is a measure of mechanical strength of the tablet. If a tablet has more friability it may not remain intact during packaging, transport or handling. The friability of tablets was determined by Roche friabilator. Pre weight tablets were rotated at 25 rpm for 100 rotations. The tablets were then dusted and re-weight and the percentage of weight loss was calculated. The percentage friability of the tablets was measured as per the formula.

% friability = (loss in weight/initial weight) ×100

The pharmacopoeia limit of friability test for a tablet is not more than 1%.

Porosity:

The rate and extent of water penetration is related to the porosity it provides in the tablets. Greater the porosity of the tablets provided faster penetration of water and subsequently lesser the disintegration time. The porosity of the tablet (Ɛ) was calculated using the following equation.

Where M = Tablet weight (g), V = Tablet volume (Cm³), ρ = True density of powders.

The tablet volume was calculated from the diameter and thickness of the tablet measured with a micrometer. The true density of powder was determined using a pycnometer.

Wetting time:

Wetting time of dosage form is related to the contact angle. It needs to be assessed to give an insight into the disintegration properties of the tablets; a lower wetting time implies quicker disintegration of the tablet. Wetting time was determined by the method described by Bi et al³⁹. A piece of tissue paper folded twice was placed in small culture dish (i.d. = 6.5 cm) containing 6 ml of water. A tablet is carefully placed on the surface of the tissue paper. The time required for water to reach upper surface of the tablet is noted as the wetting time.

Water absorption ratio:⁴⁰

For measuring water absorption ratio a pre-weight tablet is placed in a petridish in the similar way as described in the wetting time test. The wetted tablet from the petridish is taken and reweight. Water absorption ratio is calculated as

R = (W_b-W_a)/W_a×100

Where R = Water absorption ratio, W_a and W_b are the weights before and after water absorption, respectively.

Moisture uptake study:

Moisture uptake studies for ODTs should be conducted to assess the stability of the formulation. In order to maintain their physical integrity and surface texture, special attention is required during the storage and packaging of these dosage forms. Ten tablets from each formulation are kept in a desiccators over calcium chloride at 37^oC for 24 h. The tablets are then weight and exposed to 75% RH at room temperature for two weeks. The required humidity (75% RH) is achieved by keeping saturated sodium chloride solution at the bottom of the dessicator for three days. One tablet as control (without superdisintegrant) is kept to assess the moisture uptake due to other excipients. Tablets are weight and the percentage increase in weight is recorded.

In-vitro disintegration:

Conventional disintegration tests for ordinary tablets may not allow precise measurement of the disintegration time of ODTs because of their fast disintegration. Although the compendia test for disintegration can be applied for ODTs, but the major limitation is it gives poor in-vitro and in-vivo correlation of disintegration data. So for better in-vitro and in-vivo correlation of disintegration time and to define a suitable disintegration apparatus some modified disintegration test methodology are recently been adopted.

a) Modified dissolution apparatus:

The disintegration apparatus was the same as the USP dissolution test apparatus II. Distilled water was chosen for the disintegration medium instead of a buffer solution. Distilled water (900 ml) maintained at 37^oC and stirred with a paddle at 100 rpm speed was as the disintegration fluid. A tablet to be tested was put on the bottom of a sinker, which was placed in the middle of the vessel with a distance of 6-8.5 cm. The opening of mesh of the sinker was 3-3.5 mm in height and 3.5-4 mm in width. The disintegration time is determined when the tablet has completely disintegrated and passed through the screen of the sinker⁴¹.

b) Wire basket method:

The apparatus consisted of a glass beaker of 1000ml capacity with the wire basket positioned in the beaker with the help of a support in a way that when the beaker contained 900 ml of simulated saliva fluid(pH 6.2), the basket had only 6 ml of it. A magnetic bead was placed at the bottom of the beaker maintained at 37^oC. Disintegration time was determined at 25 and 50 rpm and compared with results obtained from the USP disintegration test apparatus and the in-vivo disintegration test⁴².

c) Rotary shaft method:

ODTs generally receive some mechanical stress produced by the tongue in the human mouth. Narazaki et al⁴³ proposed a suitable disintegration method for ODTs. In this method, the ODT is placed on stainless steel wire gauze, which is slightly immersed in test medium, and a rotary shaft is employed to provide mechanical stress to the tablet by means of its rotation and weight. Purified water at temperature 37^oC was used as the medium. The critical parameters of the proposed method were the rotation speed and the mechanical stress. The rotary shaft crushes the ODT which disintegrates into the medium. The endpoint was measured visually using a stopwatch.

Hanada et al.⁴⁴ modified the above mentioned apparatus by placing a sponge at the surface of shaft weight to increase friction with the ODT. The weight transmits the torque of the rotating shaft to the ODT and grinds it on the stainless steel perforated plate which is used in place of wire gauge. The electrodes are attached on each side of the plate. When the weight makes contact with separated plates, the electric sensor conveys a signal that indicates the end point of the disintegration test of the ODT.

d) Texture Analyzer:

Recently, a texture analysis apparatus is commonly used to measure the start and end time points of tablet disintegration⁴⁵. In this test, a flat ended cylindrical probe penetrates into the disintegrating tablet immersed in water. As the tablet disintegrates, the instrument is set to maintain a small force for a determined period of time. The plots of some distance travelled by the probe generated with the instruments software provide disintegration profile of the tablets as a function of time. The plot facilitates calculation of the start and end point of the tablet disintegration.

e) Test tube method:

In this method, the diameter (1.5 cm) of the test tube used is smaller than the diameter of sublingual area in humans (~3-4 cm). The small volume of water (2ml) used for tablet disintegration evaluation approximates the volume of saliva secreted under normal conditions. This in-vitro disintegration time simulates the relatively small sublingual area, the small volume of saliva, and the relatively static environment under the human tongue⁴⁶.

f) Petridish method:

A petridish having a diameter of 10 cm was filled with 10 ml of water or simulated saliva fluid. The tablet was carefully put in the centre of the petridish and the time for the tablet to completely disintegrate into fine particles was noted⁴⁷.

g) Shaking water Bath method:

A simple device based on shaking water bath was designed to measure the disintegration time of ODTs⁴⁷. The device is composed of a 10-mesh sieve and a glass cylinder. The sieve is placed into the cylinder at a certain position so that 2 ml of disintegration medium fills the space below the sieve of the cylinder. Then, 1 ml of the medium is added into the device, so that it is available for an ODT to be tested. Tablet was placed on the sieve and the whole assembly was then placed on a shaker. The time at which all the particles pass through the sieve was taken as a disintegration time of the tablet.

h) CCD Camera method:

Morita et al ⁴⁸ developed CCD camera apparatus comprises two distinct sections, a disintegration component and measurement device. The disintegration apparatus consists of a plastic cell partitioned into two parts: one component comprises an inner tank containing a stirring bar, a grid fabricated from stainless steel, and a disintegration medium (distilled water, 200 ml, 37^oC); the second component is an outer tank, which functions as a water bath heated at 37^oC via circulation of thermo stated water. The grid consists of three hollow areas, equidistant from the centre, in which the tablets are positioned using a support to avoid their displacement during the test.

The mode of measurement involves the continuous monitoring of pictures by the CCD camera to record the disintegration time course; these pictures are simultaneously transferred to the computer and stored. The computer enables calculation of the surface are of each tablet at any time point, as well as the design of graphs that shows decrease in the tablet surface area as a function of time. The disintegration time and the area under the curve can be calculated from these graphs as qualitative parameters that can be correlated to the oral disintegration time.

In-vivo disintegration:

Dor et al.⁴⁵conducted in-vivo disintegration tests of ODTs on volunteers who are usually randomized to receive the treatments and then directed to clean their mouths with water. Tablets are placed on their tongue’s, and the time for disintegration is measured by stopwatch. The volunteers are allowed to move ODTs against the upper roof of the mouth with their tongue and to cause a gentle tumbling action on the tablet without being on it or tumbling from side to side. Immediately after the last noticeable granules have disintegrated, the stopwatch is stopped and the time recorded.

In-vitro drug release:

The dissolution for orodispersible tablets is the same as that of conventional tablets, and is practically identical when the orodispersible tablet does not utilize taste masking. USP II paddle apparatus at 50 rpm is suitable for dissolution testing of drugs which are not taste-masked, whereas for taste-masked drug dissolution study is performed with some apparatus at 50-100 rpm. In case of tablets approaching or exceeding one gram weight and containing relatively dense insoluble particles, there are the chances of heap formation at the bottom of the dissolution vessel. Under such a condition, although the tablet disintegrates completely, there is a significant reduction in the apparent dissolution rate. However this issue can be resolved by using higher paddle speed of 75 rpm⁴⁹.

Clinical and pharmacokinetic studies:

In-vivo studies have been performed on oral fast-disintegrating dosage forms to investigate their behaviour in the oral-esophageal tract, their pharmacokinetic and therapeutic efficacy, and acceptability. The investigation using gamma-scintigraphy showed that the dissolution and clearance of oral fast-disintegrating dosage forms was rapid³. The esophageal transit time and stomach emptying time were comparable to those of traditional tablets, capsules, or liquid forms.^50,51

Taste evaluation study:

The organoleptic properties of formulation’s like taste, mouth feel and appearance are of considerable importance in differentiating products in the market and can ultimately determine the success of a product. Pharmaceutical taste-assesment typically requires a large trained taste panel, and shophisticated interpretation. To quantitatively evaluate taste sensation following methods has been reported in literature.

a) Gustatory sensation tests (human subjects)

b) Spectrophometric method

c) Measurement of frog taste nerve responses

d) Electronic sensor array technology (E-tongue)

a) Gustatory sensation tests (human subjects):

The gustatory sensation test is a psychophysical rating of the gustatory stimuli. A group of about 5-10 human volunteers is trained for taste evaluation by using reference solutions ranging in taste from tasteless to very bitter. On placing the dosage form in the oral cavity, the disintegration time is noted after which it is further held in mouth for 60 seconds by each volunteer, and the bitterness level is recoded against pure drug(control) using a numerical scale. After 60 seconds, the disintegrated tablet is spitted out and the mouth is rinsed thoroughly with mineral water. The test was evaluated and assigned a numerical value according to the following scale: 0 = tasteless, 1 = aftertaste, 2 = slight, 3 = slight to moderate, 4 = moderate, 5 = moderate to strong, 6 = strong, 7 = very strong.

Various ODT formulation have been reported to be evaluated by this technique^33,37

b) Spectrophometric method:

A known quantity of the taste masked formulation is mixed with 5 ml of pH 6.8 phosphate buffer (to stimulate salivary pH and volume) in 25 ml glass bottles. The bottles were allowed to stand for 60 seconds and 120 seconds, respectively. The test medium is then filtered through a membrane filter, followed by spectrophotometric determination of the drug in the filtrate. If this concentration below the threshold concentration, it may be concluded that the bitter taste would be masked in-vivo. This technique has been applied to evaluate the taste masked product of risperidone with threshold concentration being 25μg/ml³³.

c) Measurement of frog taste nerve responses:

In this method, adult bull frogs are anesthetized intraperitoneally and the glossopharyngeal nerve is then located and dissected from the surrounding tissue and cut proximally. An ac-amplifier and an electronic integrator are used to respectively amplify and integrate the nerve impulses. The peak height of the integrated response is then taken as the magnitude of response. Quinine sulphate formulations have been reported to be evaluated by this method⁵²

d) Electronic sensor array technology (E-tongue):

E-tongue is a sensor device for recognition, quantitative multicomponent analysis and artificial assessment of taste and flavour. Benefits of E-tongue taste evaluation are quantify bitterness of drug when limited basic taste information is available, especially if the drug supply is limited and measuring efficiency of complexation/coating within formulation. The e-tongue represents the three levels of biological taste recognition:

1) Receptor level (taste buds in humans, probe membranes in the e-tongue)

2) Circuit level (neural transmission in humans, transducer in the e-tongue)

3) Perceptual level (cognition in the thalamus in humans, computer and statistical analysis in the e-tongue)

Receptor level: At the receptor level, the e-tongue uses a seven sensor probe assembly to detect dissolved organic and inorganic compounds. The probes consist of a silicon transistor with proprietary organic coatings, which govern the probe’s sensitivity and selectivity. Measurement is done potentiometrically against an Ag/AgCl reference electrode. Each probe is cross-selective to allow coverage of full taste profile.

Circuit level: At the circuit level system samples, quantifies, digitizes, and records potentiometer reading.

Perceptual level: At the perceptual level, taste cognition happens not in the probe, but in the computer, where the e-tongue’s statistical software interprets the sensor data into taste patterns. Depending on the study design, data analysis can produce a variety of information. E-tongue was employed for taste optimization of MDT⁵³

CONCLUSION:

With the rapid acceptance of ODTs by patients and pharmaceutical companies, the market for this dosage form is promising, and the product pipeline continues to grow rapidly. The basic approach of ODT technologies is to maximize the porous structure of the tablet matrix to achieve tablet disintegration in the oral cavity, along with good taste masking. There are so many effective techniques and methodologies that are constantly being researched and developed in the pharmaceutical field in response to the need of taste masking. Applicability of all these approaches varies from drug to drug and depends on the type of dosage form required. Apart from all techniques of taste masking, microencapsulation seems to have a bright future.

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Received on 14.04.2010

Accepted on 13.05.2010

Research Journal of Pharmaceutical Dosage Forms and Technology. 2(3): May-June 2010, 225-232