Tablet/capsule diluents

In pharmaceutical applications, sorbitol is used as a tablet diluent in wet granulation or dry compression formulations. It is commonly used in chewable tablets because of its sweet taste, and it is also used as a plasticizer for gelatin in capsule formulations. Sorbitol is utilized in sugar-free liquid preparations and as a stabilizer for drug, vitamin, and antacid suspensions. When it is used in syrups, crystallization around bottle caps is prevented. 

Cellulose (Figure 8.19) may be extracted from wood pulp, and is usually partially hydrolysed with acid to give microcrystalline cellulose. These materials are used as tablet diluents. Semi-synthetic derivatives of cellulose, e.g. methylcellulose, hydroxymethylcellulose, and carboxymethylcellulose, are used as emulsifying and suspending agents. Cellulose acetate phthalate is cellulose with about half the hydroxyl groups acetylated, and the remainder esterified with phthalic acid. It is used as an acid-resistant enteric coating for tablets and capsules. 

Allen LV. 2000. Featured excipients capsule and tablet diluent. Int. J. Pharm. Compound... 

Allen LV. Featured excipient capsule and tablet diluents. Int J Pharm Compound 2000 4(4) 306-310, 324-325. 

Powdered cellulose is used as a tablet diluent and a hard gelatin capsule filler see Table I. In both contexts it acts as a bulking agent to increase the physical size of the dosage form for formulations containing a small amount of active substance. 

Uses Emollient in cosmetics textile lubricant pharmaceutical intermediate, diluent, crystallization promoter, m.p. modifier, bodying agent, lubricant, moisturizer emulsifier mold release agent buffing compd. filler in capsules, tablets, and suppositories in food-pkg. adhesives defoamer in food-contact paper/paperboard in food-contact textiles Regulatory FDA21CFR 175.105,176.180,176.210,177.2800,182.70, 182.170 BP, EP compliance... 

Uses of lactose production by appHcation include baby and infant formulations (30%), human food (30%), pharmaceuticals (25%), and fermentation and animal feed (15%) (39). It is used as a diluent in tablets and capsules to correct the balance between carbohydrate and proteins in cow-milk-based breast milk replacers, and to increase osmotic property or viscosity without adding excessive sweetness. It has also been used as a carrier for flavorings. 

Excipients are sub-divided into various functional classifications, depending on the role that they are intended to play in the resultant formulation, for example, fillers, disintegrants, binders, lubricants and glidants. An added complexity is the fact that certain excipients can have different functional roles in different formulation types. Thus, lactose is widely used as a filler or diluent in solid oral dosage forms, for example, tablets and capsules [2] and as a carrier for inhalation products [3]. 

Sorbitol is a hexahydric alcohol that is isomeric with mannitol, and which has been described as a humectant, plasticizer, sweetening agent, and tablet and capsule diluent. It is used extensively in the pharmaceutical, cosmetics, and food industries, since it has a sweet taste and approximately 50-60% the sweetness of sucrose. 

Lactose has a sweetish taste, and is used extensively in the pharmaceutical industry. It is the second most widely used compound and is employed as a diluent, filler or binder in tablets, capsules and other oral product forms, a-lactose is used for the production of lactitol, which is present in diabetic products, low calorie sweeteners and slimming products. As lactose is only 30 per cent as sweet as sugar it is used as a sugar supplement, and also in food and confectionery. It is used in infant milk formulas. 

Tablet and capsule diluents inert substances incorporated to increase the bulk, to make the tablet or capsule of practical size. 

Take, for example, dextrose. When dextrose is used as a sweetener in baked goods, it is a food ingredient and subject to the requirements of food products. When dextrose is used as a sweetener or diluent in tablet, capsule, or liquid preparations, it is an excipient. When it is used in the manufacture of sterile dextrose injection, it is an active drug substance and an API but now... 

Microcrystalline cellulose (Avicel) is purified partially depolymerized cellulose, prepared by treating a-cellulose with mineral acids. In addition to being used as a filler, it is also used as dry binder and disintegrant in tablet formulations. Depending on the preparation conditions, it can be produced with a variety of technical specifications depending on particle size and crystallinity. It is often used as an excipient in direct compression formulations but can also be incorporated as a diluent for tablets prepared by wet granulation, as a filler for capsules and for the production of spheres. 

Talc —OH Anticaking agent, glidant, tablet and capsule diluent, and lubricant... 

Lactose, cellulose —O—, —OH Diluent for dry-powder inhalers, tablets, and capsules... 

In reality, no single excipient would satisfy all the criteria therefore, a compromise of the different requirements has to be made. For example, although widely used in pharmaceutical tablet and capsule formulations as a diluent, lactose may not be suitable for patients who lack the intestinal enzyme lactase to break down the sugar, thus leading to the gastrointestinal tract symptoms such as cramps and diarrhea. The role of excipients varies substantially depending on the individual dosage form. 

For tablets and capsules, excipients are needed both for the facilitation of the tableting and capsule-filling process (e.g., glidants) and for the formulation (e.g., disintegrants). Except for diluents, which may be present in large quantity, the level of excipient use is usually limited to only a few percent and some lubricants will be required at <1%. Details of the types, uses, and mechanisms of action of various excipients for tablet and capsule production have been discussed at length in other articles in this encyclopedia. The types and functions of excipients for tablet production are summarized in Table 1. Although binders. 

Buffering agent coating agent opacifier tablet and capsule diluent therapeutic agent. 

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