Excipients for Tablets with examples

Excipients are an integral part of any pharmaceutical product necessary for manufacturing as well as performance. So, a formulator should have proper knowledge about excipients for tablets to make them properly. Drugs are rarely given as pure chemical substances only and are always administered in formulated dosage form with active pharmaceutical ingredients and inactive ingredients. These therapeutically inactive ingredients of pharmaceutical preparation are known as excipients.

Functional classifications of excipients for tablets and other pharmaceutical products are qualitative, broad, and descriptive. An excipient may be used in diverse ways or for diverse purposes in pharmaceutical preparation and hence may require different material attributes to achieve the desired performance.

In most cases, it is not necessary to use all of the excipients for tablets because some excipients serve two or more functions. For example, starch is a multi-functional excipient for tablets. It may serve as a diluent, binder, and disintegrating agent. Besides, the function of some excipients is not necessary for some formulations. For example, a sweetener is necessary for chewable tablets, sublingual tablets, dispersible tablets, but not for film-coated tablets.

Common Excipients for Tablets

1. Diluents:  essential excipients for tablets to increase weight or volume.
2. Binders: vital excipients for tablets to facilitate the agglomeration of powder into granules.
3. Disintegrants: essential excipients for tablets to assist dosage form’s breakup or disintegration into small units/fragments.
4. Lubricants: vital excipients for tablets to reduce the frictional forces between particle-particle as well as particles and metal-contact surfaces.
5. Glidant: to promote the flow properties of tablet granules or power materials.
6. Coloring agent: to give a color or identification of the tablets as either pigment or coating materials.
7. Flavoring agent: used only in some types of tablets such as chewable tablets or dispersible tablets or in coating suspension for bad smelled tablets such as Amlodipine + Olmesartan Medoxomil tablet.
8. Sweetener or Sweetening agent: especially used in the chewable, dispersible, sublingual tablet.
9. Surfactant: used for low solubility tablets to improve wetting and deaggregation of drug particles to get a rapid and improved dissolution.
10. Release-Modifying Agents: especially used to control drug release in modified-release formulations (prolonged-release or controlled-release tablet).
11. Coating materials:

•   Film former which may be enteric or non-enteric
•   Solvent
•   Plasticizer
•   Colorant
•   Opaquant-Extender
•   Miscellaneous coating solution components. READ: TABLET COATING DEFECTS AND REMEDIES

Firstly have a look at the definition of excipients, classification, and ideal properties of excipients.

Definition of Excipient

An excipient is an inactive substance other than the active pharmaceutical ingredient(s) used in the formulation of a pharmaceutical product to bring functionality to the formulation. The desired function of an excipient is to guarantee the required biopharmaceutical and physicochemical properties of the pharmaceutical product. Also, excipients for tablets are known as auxiliary substances.

According to British Pharmacopoeia (BP), “Excipient is any constituent of a medicinal product that is not an active substance. Adjuvants, stabilizers, antimicrobial preservatives, diluents, and antioxidants are excipients” ^[1].

Classification of Excipients

Based on the pattern of uses and their manufacturing

1. Standard Excipients

It is either a compendial or non-compendial inactive substance. For example, Lactose as a diluent and Magnesium Stearate as a lubricant etc. Here, compendial means the excipient is indexed in the pharmacopoeia.

2. Mixed Excipients

It is a simple physical mixture of two or more compendial or non-compendial excipients. Mixed excipients may be either liquid or solid. For example, Opadry, Opadry II, and Eudragit (Grades) etc.

3. Co-processed Excipients

It is a combination of two or more compendial or non-compendial excipients by various methods such as granulation, melt extrusion, spray drying, milling etc. For example, Cellactose® 80 (75% alpha-lactose monohydrate with 25% cellulose powder), StarLac® (85 % alpha-lactose monohydrate and 15 % maize starch (corn starch)) Ludipress, (combining of three excipients: lactose as carrier and filler, binding agent Kollidon® 30, and disintegrants Kollidon® CL).

Based on their origin ^[2]

1. Animal sources: such as Lactose, Stearic acid, Gelatin, Beeswax, and Lanolin etc.
2. Vegetable sources: such as Starch, Peppermint, Guar gum, and Acacia etc.
3. Mineral sources: such as Calcium phosphate, Silica, Asbestos, Talc, Kaolin, and Paraffin, etc.
4. Synthetic sources: such as Boric acid, Lactic acid, Saccharin, Polysorbates, Povidone, and Polyethylene glycols etc.

 According to the functionality

The excipients are several types such as Binders, Diluents/Fillers, Disintegrants, Lubricants, Glidants, Wetting agents, Solvents, Suspending agents, Emulsifiers, Antioxidant, Preservatives, Sweeteners, Stabilizing, Coating Agent, Surfactant, Coloring agent, and Flavoring agents.

Based on chemical nature excipients are classified as:

1. Organics and their salts: for example, Mannitol as diluent.
2. Inorganics excipients: such as calcium phosphate as filler, and iron oxide as pigments.
3. Polymeric excipients: that can be fully synthetic or naturally derived such as hypromellose.

Characteristics of ideal excipients for tablets

The ideal excipients must have the following characteristics:

1. An excipient must be physiologically inert.
2. Physically and chemically stable by themselves and in combination with drug(s) or other excipients in a formulation.
3. Commercially available in an acceptable chemical and physical grade.
4. Compatible with drug(s).
5. Nontoxic and acceptable by FDA or regulatory agencies.
6. It should have accepted organoleptic properties such as colorless or white to off-white color, odorless.
7. Economical (acceptably low).
8. Free from any impurities and microbial hazards.
9. They may not be contraindicated among them.
10. Do not hamper the bioavailability of drugs

Common Excipients for Tablets Manufacturing

Diluents/ Fillers/ Bulking Agents

According to USP, Diluents are components that are incorporated into tablet or capsule dosage forms to increase dosage form volume or weight ^[3].

Diluents are fillers designed to make up the required bulk of the tablet when the drug dosage itself is inadequate to produce this bulk ^[4].

Also, Diluents are known as Fillers or Bulking Agents. Other reasons to provide better tablet properties like to provide improved cohesion, improve flow, allow direct compression manufacturing, and adjust tablet thickness or weight. The most important note is that only diluent is adjusted with the total quantity of active drug after potency calculation. Diluents are vital excipients for tablets with a small weight. 

List of Diluent for tablets and Capsules ^{[3, 5]}

1. Microcrystalline Cellulose [trade name: Avicel 101, 102, 200; Celex, MCC Sanaq],
2. Powdered Cellulose [5–40% for wet granulation and 10–30% for dry granulation]
3. Anhydrous Lactose
4. Lactose Monohydrate
5.  Spray-Dried Lactose,
6. Mannitol [preferable for chewable tablet]
7. Starch
8. Pregelatinized Starch
9. Maize Starch
10. Corn Starch
11. Sorbitol
12. Sucrose
13. Compressible Sugar (20–60% for chewable tablets)
14. Confectioner’s Sugar (10–50%)
15. Sugar Spheres
16. Dextrates
17. Dextrin
18. Dextrose
19. Calcium Phosphate, Dibasic, Anhydrous
20. Calcium Carbonate
21. Maltose
22. Maltodextrin
23. Kaolin
24. Calcium Phosphate, Dibasic, Dihydrate
25. Tribasic Calcium Phosphate,
26. Calcium Sulfate
27. Cellaburate
28. Calcium Lactate
29. Cellulose Acetate
30. Silicified Microcrystalline Cellulose,
31. Cellulose Acetate
32. Corn Syrup
33. Pregelatinized Starch and Corn Starch
34. Corn Syrup Solids
35. Erythritol (30.0–90.0%)
36. Ethylcellulose (1.0–3.0%)
37. Ethyl Acrylate and Methyl Methacrylate Copolymer Dispersion
38. Fructose
39. Isomalt
40. Alpha-Lactalbumin
41. Lactitol
42. Magnesium Carbonate (direct compression ≤45)
43. Magnesium Oxide
44. Methacrylic Acid and Ethyl Acrylate Copolymer
45. Methacrylic Acid and Methyl Methacrylate Copolymer
46. Polydextrose
47. Sodium Chloride (Capsule diluent 10–80%)
48. Simethicone
49. Pregelatinized Modified Starch
50. Starch, Pea
51. Hydroxypropyl Pea Starch
52. Starch, Pregelatinized Hydroxypropyl Pea
53. Potato Starch
54. Starch, Hydroxypropyl Potato
55. Pregelatinized Hydroxypropyl Potato Starch,
56. Starch, Tapioca
57. Wheat Starch
58. Starch Hydrolysate, Hydrogenated
59. Pullulan
60. Talc (Tablet and capsule diluent 5.0–30.0%)
61. Amino Methacrylate Copolymer
62. Trehalose
63. Xylitol

Binders

According to USP, Tablet, and capsule binders are substances that incorporated into formulations to facilitate the agglomeration of powder into granules during mixing with a granulating fluid such as water, hydroalcoholic mixtures, or other solvents ^[3].

Tablet binders or binding agents are substances that are added either in dry or liquid form during wet granulation to form granules or to promote cohesive compacts for directly compressed tablets ^[4].

Binders are agents used to impart cohesive qualities to the powdered material are referred to as binders or granulators ^[6]. They impart cohesiveness to the tablet formulation that ensures the tablet remains intact after compression, as well as improving the free-flowing qualities by the formulation of granules of desired hardness and size. Binders are vital excipients for tablets. READ TABLET BINDERS: TYPES AND EXAMPLES WITH CONCENTRATION.

List of Binder used in Pharmaceutical Preparations ^{[3, 5]}                          

1. Polyvinylpyrrolidone  is also known as Povidone, [grade: Povidone K-15, K-30, K-60, K-90 (trade name: Kollidon®)]
2. Copovidone (2.0 – 5.0 % in direct compression and 2.0 – 5.0% in wet granulation)
3. Carbomer (0.75 – 3.0%)
4. Corn Starch and Pregelatinized Starch (Commercially known as STARCH 1500)
5. Pregelatinized starch (5-10%)
6. Carboxymethylcellulose Sodium, Carmellose Sodium (1.0–6.0%)
7. Hypromellose/ hydroxypropyl methylcellulose (HPMC), Methocel (2-5%)
8. PEG (Polyethylene Glycol)
9. Hydroxyethyl Cellulose
10. Hydroxypropyl Cellulose (2.0 – 6.0%)
11. Hydroxyethyl methyl Cellulose
12. Calcium carboxymethylcellulose/ Calcium cellulose glycolate /Carmellosum calcium (5-15%)
13. Guar Galactomannan/ Guar Gum (up to 10.0%)
14. Ethylcellulose
15. Chitosan Hydrochloride
16. Dextrin
17. Low-Substituted Hydroxypropyl Cellulose
18. Hydroxypropyl Starch
19. Ceratonia (0.15 – 0.75 %)
20. Inulin
21. Magnesium Aluminum Silicate (2.0 – 10.0%)
22. Maltodextrin (2–40% for direct compression and 3–10% for wet granulation)
23. Methylcellulose (1.0–5.0%)
24. Dextrates
25. Polyethylene Oxide (5.0 – 85.0%)
26. Povidone (0.5 – 5.0%)
27. Sodium Alginate (1.0 – 3.0%)
28. Starch (3–20% w/w usually 5–10%)
29. Liquid Glucose (5.0 – 10.0%)
30. Sucrose (2–20% dry granulation and 50–67% wet granulation)
31. Compressible sugar (5–20% as a dry binder in tablet formulations)
32. Zein (30% for wet granulation)
33. Gelatin (1–3% for wet mix)
34. Polymethacrylates (10–35 % for dry mix and 15–35 % as a solution and 4.5–10.5% w/w solids)
35. Sorbitol (2–10% for wet mix)
36. Glucose (2–25% for wet mix)
37. Sodium alginate (1–3% for wet mix)
38. Zein
39. Acacia (1.0 – 5.0%)

Disintegrants

A disintegrant is a substance or a mixture of substances added to a tablet to facilitate its breakup or disintegration into small units/fragments and allow a drug substance to fast dissolution.

According to USP, Disintegrants are functional components that are added to formulations to promote rapid disintegration into smaller units and to allow a drug substance to dissolve more rapidly ^[3].

When disintegrants come in contact with water or stomach or intestinal fluid, they absorb the liquid and start to swell, dissolve, or form gels. This causes the tablet structure to rupture and disintegrate, making increased surfaces for improved dissolution of the drug substance. Disintegrants are vital excipients for tablets.

Examples of common and most used disintegrants are L-HPC (Low-Substituted Hydroxypropyl Cellulose), Microcrystalline Cellulose, Starch Pregelatinized Modified etc.

Examples of Super-disintegrant are Crospovidone (commercial name- Kollidon CL) [cross-linked povidone], Croscarmellose Sodium (Trade name Ac-Di-Sol, Primellose) [cross-linked cellulose], Sodium Starch Glycolate (Commercial name Primogel, Explotab) [cross-linked starch] etc.

List of Disintegrants Used in pharmaceutical preparations ^{[03, 05]}

1. Crospovidone (commercial name- Kollidon CL) (2–5%)
2. Croscarmellose Sodium (Commercial name Ac-Di-Sol, Primellose) (10–25% in capsules and 0.5–5.0% in tablets) Croscarmellose sodium at concentrations up to 5% w/w may be used as a tablet disintegrant. 2% w/w is used in direct compressed tablets and 3% w/w in wet-granulation processed tablets.)
3. Low-Substituted Hydroxypropyl Cellulose
4. Sodium Starch Glycolate (Commercial name Primogel, Explotab) (2-8%, Optimum concentration is about 4%, although 2% is sufficient in many cases).
5. Chitosan Hydrochloride
6. Corn Starch and Pregelatinized Starch
7. Calcium Alginate & Calcium Sodium Alginate (<10%)
8. Docusate Sodium (≈ 0.5%)
9. Microcrystalline Cellulose (5–15%)
10. Hydroxypropyl Starch
11. Magnesium Aluminum Silicate (2-10%)
12. Methylcellulose (2.0–10.0%)
13. Sodium Alginate (2.5–10%)
14. Starch (3–25% w/w)
15. Pregelatinized Starch (5–10%)
16. Calcium carboxymethylcellulose/calcium cellulose glycolate/carmellose calcium (1–15%)
17. Powdered Cellulose (5–20%)

Lubricants: vital excipients for tablets

Lubricant is a non-toxic, pharmacologically inactive substance added to the formulation to prevent adhesion of the tablet material to the surface of the dies and punches, reduce interparticle friction, facilitate the ejection of the tablets from the die cavity, and may improve the rate of flow of the tablet granulation ^[6].

According to USP, Lubricants are substances that typically are used to reduce the frictional forces between particles and between particles and metal-contact surfaces of manufacturing equipment such as tablet punches and dies used in the manufacture of solid dosage forms.  Before compaction, liquid lubricants may be absorbed into the tablet granule matrix. Lubricants are vital excipients for tablets. Magnesium stearate, Sodium Lauryl Sulphate, and calcium stearate are the most widely used lubricant.

List of lubricants used in pharmaceutical solid dosage form ^{[3, 5]}

1. Magnesium stearate
2. Magnesium silicate
3. Calcium stearate
4. Sodium Lauryl Sulphate
5. Sodium Stearyl Fumarate
6. Magnesium Lauryl Sulphate
7. Stearic Acid
8. Calcium Stearate
9. Glyceryl Behenate
10. Behenoyl Polyoxylglycerides
11. Glyceryl Dibehenate
12. Lauric Acid
13. Glyceryl Monostearate
14. Glyceryl Tristearate
15. Myristic Acid
16. Palmitic Acid
17. Poloxamer
18. Polyethylene Glycol
19. Polyethylene Glycol 3350
20. Polysorbate 20
21. Polyoxyl 10 Oleyl Ether
22. Polyoxyl 15 Hydroxystearate
23. Polysorbate 40
24. Polyoxyl 20 Cetostearyl Ether
25. Polyoxyl 40 Stearate
26. Polysorbate 60
27. Polysorbate 80
28. Potassium Benzoate
29. Sodium Benzoate
30. Sorbitan Monolaurate
31. Sorbitan Monooleate
32. Sodium Stearate
33. Sorbitan Monopalmitate
34. Sorbitan Monostearate
35. Zinc Stearate
36. Sorbitan Sesquioleate
37. Sorbitan trioleate
38. Talc

Glidant / Anticaking Agent

Glidant is a non-toxic, pharmacologically inactive substance used to promote the flow properties of tablet granulation or powder materials by decreasing interparticle friction and cohesion. These always are added in the dry state during the lubrication step before compression. Compression vs Compaction

According to USP, Glidants and anticaking agents are used to promote powder flow and to reduce the caking or clumping that can occur when powders are stored in bulk. Besides, glidants and anticaking agents reduce the incidence of bridging during the emptying of powder hoppers and powder processing.

Colloidal silicon dioxide (Aerosil 200/Cab-o-sil) is the most commonly used glidant and generally is used in low concentrations of 1% or less. Talc (asbestos-free) also is used as a glidant. Glidants are vital excipients for tablets. READ: DIFFERENCE BETWEEN LUBRICANT AND GLIDANT

List of glidants used in pharmaceutical solid dosage form ^{[3, 5]}

1. Colloidal Silicon Dioxide (trade name: Aerosil 200/ Cab-o-sil)
2. Talc
3. Tribasic Calcium Phosphate
4. Calcium Silicate
5. Cellulose, Powdered
6. Magnesium Oxide
7. Sodium Stearate
8. Magnesium Silicate
9. Silica, Dental-Type
10. Magnesium Trisilicate
11.  Hydrophobic Colloidal Silica

Coloring Agents / Colorant

Coloring agents are inactive substance(s) added into dosage forms to produce a distinctive appearance that may serve to differentiate a product from others that have a similar physical appearance or in some instances, to protect photolabile components of the dosage form. Also, Coloring agents are called colorants.

Coloring agents are categorized into:

1. Dyes: Water-soluble coloring substances,
2. Lakes: Insoluble forms of a dye that result from its irreversible adsorption onto a hydrous metal oxide,
3. Inorganic pigments: Substances such as titanium dioxide or iron oxides, and
4. Natural colorants: Colored compounds not considered dyes, such as riboflavin.

List of coloring agents used in a pharmaceutical solid dosage form such as tablets ^[3]

1. Caramel
2. Ferric Oxide
3. Titanium Dioxide
4. Ferrosoferric Oxide
5. Aluminum Oxide
6. FD & C Red #40 /Allura Red AC
7. Amaranth
8. FD & C Blue #1 /Brilliant Blue FCF
9. Canthaxanthin
10. Carmine
11. Carmoisine (Azorubine)
12. Curcumin (Tumeric)
13. FD & C Red #3 /Erythrosine
14. Fast Green FCF
15. Green S (Lissamine Green)
16. D & C Red #30 /Helendon Pink
17. FD & C Blue #2 /Indigo Carmine
18. Iron Oxide Black
19. Iron Oxide Red
20. D & C Red #7 / Lithol Rubin BK
21. Patent Blue V
22. D & C Red #28 / Phloxine B
23. Iron Oxide Yellow
24. D & C Red #27 / Phloxine O
25. Ponceau 4R (Cochineal Red A)
26. Quinoline Yellow WS
27. D & C Yellow #10
28. Riboflavin (Lactoflavin)
29. FD & C Yellow #5 /Tartrazine
30. FD & C Yellow #6 / Sunset Yellow FCF

Flavoring agent and Fragrance

According to USP, a flavor is a single chemical entity or a blend of chemicals of synthetic or natural origin that can produce a taste or aroma (i.e. fragrance) response when orally consumed or smelled ^[3]. Flavoring agents are consumed orally and appreciated by both smell and taste while fragrances are only for external use and appreciated only by smell. Generally, flavors are vital excipients for chewable tablets, oral disintegrating tablets, dispersible tablets, oral solutions, and oral suspensions to mask the unpleasant smell as well as taste and to make the product more palatable, thus increasing patient compliance.

List of Flavoring agents used in pharmaceutical solid dosage form ^{[3, 5]}

1. Vanillin
2. Peppermint flavor powder
3. Berry flavor powder
4. Strawberry flavor powder
5. Orange flavor powder
6. Lemon flavor powder
7. Orange essence
8. Ethyl Maltol (It has a flavor and odor 4–6 times as intense as maltol)
9. Eucalyptus Oil
10. Isobutyl Alcohol
11. Sodium Succinate
12. Adipic Acid
13. Almond Oil
14. Anethole
15. Benzaldehyde
16. Denatonium Benzoate
17. Ethyl Acetate
18. Ethyl Vanillin
19. Ethylcellulose
20. Fructose
21. Fumaric Acid
22. l-Glutamic Acid, Hydrochloride
23. Lactitol
24. Leucine
25. Malic Acid
26. Maltol
27. Menthol / Racementhol (Tablets 0.2–0.4%)
28. Methionine
29. Methyl Salicylate
30. Monosodium Glutamate
31. Peppermint Oil
32. Strawberry flavor, liquid
33. Peppermint Spirit
34. Racemethionine
35. Rose Oil
36. Rose Water, Stronger
37. Sodium Acetate
38. Sodium Lactate Solution
39. Tartaric Acid
40. Thymol
41. Fumaric Acid
42. Inulin
43. Isomalt
44. Neohesperidin Dihydrochalcone

Sweetener or Sweetening agent

Sweeteners are substances used to mask the unpleasant taste and sweeten oral dosage forms and also to mask unpleasant flavors. It binds to receptors on the tongue that are responsible for the sensation of sweetness. Sucrose is the standard for sweetness. Sweeteners are vital excipients for chewable tablets, lozenges, oral disintegrating tablets, dispersible tablets, oral solutions, emulsions, and oral suspensions.

List of sweetening agents used in tablets and other pharmaceutical products ^{[3, 5]}

1. Sucralose
2. Saccharin Sodium
3. Neotame
4. Sucrose
5. Acesulfame Potassium
6. Aspartame
7. Aspartame Acesulfame
8. Corn Syrup
9. Corn Syrup Solids
10. Dextrates
11. Dextrose
12. Dextrose Excipient
13. Erythritol
14. Fructose
15. Galactose
16. Glucose,
17. Glycerin
18. Inulin
19. Invert Sugar
20. Isomalt
21. Lactitol
22. Maltitol
23. Maltose
24. Mannitol
25. Saccharin
26. Saccharin Calcium
27. Sorbitol
28. Starch Hydrolysate, Hydrogenated
29. Sugar, Compressible
30. Sugar, Confectioner’s
31. Tagatose
32. Trehalose
33. Xylitol

Surfactant

Surfactants are compounds with well-defined polar and non-polar regions that allow them to aggregate in solution to form micelles and non-polar drugs can partition into these micelles and be solubilized ^[6]. They may decrease the surface tension (or interfacial tension) between a liquid and a solid or between a gas and a liquid or two liquids.

For example, Sodium lauryl sulphate used as a surfactant to dissolve aspirins. Polysorbate 80 in tablet formulations containing starch, had elicited faster drug dissolution rates despite the prolonged disintegration.

Surfactants used in the solid formulation ^{[4, 5]}

1. Behenoyl Polyoxylglycerides
2. Polysorbate 20
3. Polysorbate 40
4. Docusate Sodium
5. Polysorbate 60
6. Polysorbate 80
7. Benzalkonium Chloride
8. Caprylocaproyl Polyoxylglycerides
9. Cetylpyridinium Chloride
10. Lauroyl Polyoxylglycerides
11. Linoleoyl Polyoxylglycerides
12. Octoxynol 9
13. Oleoyl Polyoxylglycerides
14. Poloxamer
15. Polyoxyl 10 Oleyl Ether
16. Polyoxyl 15 Hydroxystearate
17. Nonoxynol 9
18. Polyoxyl 20 Cetostearyl Ether
19. Polyoxyl 40 Stearate
20. Pullulan
21. Polyoxyl Lauryl Ether
22. Polyoxyl Stearyl Ether
23. Sodium Lauryl Sulfate
24. Sorbitan Monolaurate
25. Sorbitan Monooleate
26. Polyoxyl Stearate
27. Sorbitan Monopalmitate
28. Sorbitan Monostearate
29. Stearoyl Polyoxylglycerides
30. Sorbitan Sesquioleate
31. Sorbitan trioleate
32. Tyloxapol

Release-Modifying Agents

Release-modifying agents are substances used as an excipient to control drug release in a modified-release dosage form such as in prolonged-release or controlled-release tablets. They are vital excipients for modified-release tablets.

List of Release-Modifying Agents used in tablets ^{[3, 5]}

1. Carbomer Copolymer
2. Shellac
3. Carbomer Homopolymer
4. Hypromellose
5. Carbomer Interpolymer
6. Carboxymethylcellulose Sodium
7. Carrageenan
8. Cellaburate
9. Ethylcellulose
10. Glyceryl Monooleate
11. Starch, Pregelatinized Modified
12. Glyceryl Monostearate
13. Guar Gum
14. Hydroxypropyl Betadex
15. Hydroxypropyl Cellulose
16. Polyethylene Oxide
17. Polyvinyl Acetate Dispersion
18. Sodium Alginate
19. Starch, Pregelatinized
20. Xanthan Gum
21. Alginic Acid

Coating materials

The substance used to coat tablets or particles. Any film-coating formulation consists mostly of a polymer, colorant, plasticizer, and solvent (or vehicle). Coating materials are vital excipients for tablets but not for all tablets. A proper coating formulation consists of the following materials:

• Film formers, which may be enteric or non-enteric
• Solvents
• Plasticizers
• Colorants
• Opaquant-Extenders
• Miscellaneous coating solution components

So, you are now well-informed about excipients for tablets. Only proper knowledge regarding API and excipients for tablets helps to make proper tablets.

References