Tablet manufacture lactose

Figure 5 Scans of commonly used excipients for tablet manufacture. Key-MCC (Avicel PH101),—MCC (Avicel Ph200), Lactose (Foremost 325),—dibasic calcium phosphate (di-tab) and—Mg Stearate.

Lactose is one of the most widely used excipients in tablet manufacture. It is available in a number of different forms, differing in hydration and crystal states. Isolation and purification may involve treatment with sulphur dioxide. However, there are no reports of complications from residues of this powerful oxidizing agent. 

A faulty batch of tablets can sometimes be recovered by grinding up the tablets and recompressing them, a process which is known as reworking and is analogous to the dry granulation method of tablet manufacture. This can sometimes cause problems with a direct compression formulation. Many direct compression diluent particles are in the form of aggregates, e.g., spray-dried lactose is composed of small crystals of lactose embedded in amorphous lactose. If these aggregates are compressed, their structure may be broken down to such an extent that subsequent recompression will result in impaired tablet quality. 

For the pharmaceutical product development scientist, there is clearly a need for objective information about the practical performance of different excipients and their various grades. In this chapter we set out to bring together the results of some of our ongoing evaluations of the physical and mechanical properties of excipients commonly used for the manufacture of solid oral dosage forms. In this particular article, we have chosen to focus on the fillers that are most commonly used in the manufacture of immediate release tablets microcrystalline cellulose (MCC), lactose, calcium phosphate, and mannitol (1). 

Lactose has several applications in food products (Table 2.6), the most important of which is probably in the manufacture of humanized infant formulae. It is used also as a diluent for the tableting of drugs in the pharmaceutical industry (which requires high-quality, expensive lactose) and as the base for plastics. 

Different localized levels of molecular order can coexist in some pharmaceutical materials, giving rise to the occurrence of partially crystalline (and partially amorphous ) systems. In most cases, the properties of such materials (e.g., density) are intermediate to those of the 100% amorphous and 100% crystalline samples. By deliberately varying the level of crystallinity in such systems, their properties can be customized for a particular purpose. An example of this is with the tableting excipients microcrystalline cellulose and spray-dried lactose, which have had their compression characteristics optimized by manipulating their amorphous content. The properties of partially crystalline materials may be approximated in many instances by making physical mixtures of the totally amorphous and crystalline samples. This is known as the two-state model for partially crystalline systems.However, such experiments should be undertaken with caution as the mixed two-state material can sometimes have significantly different properties from the partially crystalline material that is manufactured directly (the real one-state system). ... 

USE Both forms of lactose are employed, with the a-form predominating as a nutrient in preparing modified milk and food for infants and convalescents (Whittier, "Lactose and Its Utilization. foe. cit review with 327 ref). In baking mixtures. Pharmaceutic aid (tablet and capsule diluent). To produce lactic acid fermentation in ensilage and food products. As chromatographic adsorbent in analytical chemistry. In culture media. For many other uses see the comprehensive review by Weisberg Recent Progress in the Manufacture and Use of Lactose, toe. cit. 

The tablet mass was fixed at 200 mg. Each unit contained 10 mg (5%) drug and 1.2% lubricant. It was considered that the lubricant level could be adjusted and optimized later as part of a process study. Thus, although there were 5 components in the mixture, 2 of them were fixed. The factor space in the remaining components, microcrystalline cellulose, lactose, and carbomer (totalling 93.8%) can be represented as a ternary diagram. The tablets were manufactured by direct compression of the powder mixture and the dissolution profiles were measured at pH 2 (0.01 M hydrochloric acid) and pH 7 (phosphate buffer). The time for 50% dissolution was measured in each case. 

For lactose production the whey is evaporated to 55-65% solid content, and the concentrate is then seeded and cooled slowly to induce sugar crystallization. The raw lactose (food quality) is recrystallized to yield a raffinade (pharmaceutical-grade lactose). Lactose is used in manufacturing of drugs (tablet filler), dietetic food products, baked products, dehydrated foods, cocoa products, beverages and ice creams. 

Manufacture of HGC dosage forms compared with tablets requires minimum formulation efforts and usually involves granulation of the API powders with diluents such as lactose, mannitol, calcium carbonate, and lubricants such as magnesium stearate. Prior to filling the capsules with the granulated API powder, the body and cap are separated. The cap is replaced after completion of the filling... 

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