Lactose-based tablets

Figure 4.17 Van t Hoff plot for vitamin E succinate decomposition in lactose base tablets.

Microcrystalline Cellulose. Microcrystalline cellulose is a purified, partially depolymerized cellulose that occurs as a white, odorless, tasteless, crystalline powder composed of porous particles. It is widely used in pharmaceutical dosage forms, primarily as a filler-binder in oral tablets and capsules with both wet granulation and direct compression processes. Microcrystalline cellulose was marketed first in 1964 by the FMC Corporation under name Avicel PH in four different particle size grades, each with different properties.37 Addition of Avicel into a spray-dried lactose-based formulation overcame compressibility problems. At the same time, the lactose enhanced the flowability of the Avicel products available at that time. The direct compression tableting process became a reality, rather than a concept, partially because of the availability of Avicel. As of 2007, Avicel PH is commercially available in 10 types with different particle size, density, and moisture grades that have different properties and applications (Table 7.6).38 Other brands of microcrystalline cellulose are also available on the pharmaceutical market, including Pharmacel 101 and 102 from DMV International and Emcocel 50 M and 90 M from JRS Pharma. 

Whiteman, M. Yarwood, R.J. The evaluation of six 38. lactose-based materials as direct compression tablet excipients. Drug Dev. Ind. Pharm. 1988,14 (8), 1023-1040. 

Tablets of Isoprenaline Sulphate, B,P, Usually contain 10 mg of isoprenaline sulphate in a lactose base. The determination follows that given above for sprays.

Tablets of Colchicine, B.P, Generally contain 0 25 mg. of colchicine in a lactose base.

Primary and secondary amines can react readily with aldehydes and more slowly with ketones to give Schiffs bases or enamines, respectively. This reaction is particularly important with reducing sugars such as glucose, lactose and fmctose that may be incorporated in formulations with amines. For instance, if LDOPA were formulated in a tablet with lactose as a filler, the reaction shown in Figure 3.23 could occur. Such reactions, leading to discolouration of lactose-containing tablets, have been... 

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. 

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. 

Many excipients are acids or bases or have acidic or basic impurities. For this reason, the reaction of amines with aldehydes requires that the amine exist in the nucleophilic-free base, rather than the protonated cationic form. For example, the reaction of fluoxetine hydrochloride with lactose was much more rapid as potassium hydroxide was added to neutralize the hydrochloride salt. Michael addition between seproxetine and maleic acid from a tablet formulation following dissociation of the hydrochloride salt occurs because of the conversion of a salt to a free acid/base. 

Hauschild, K., and Picker-Freyer, K. M. (2004), Evaluation of a new coprocessed compound based on lactose and maize starch for tablet formulation, AAPS PharmSci, 6(2), article 16. 

Sebhatu et al. (136) studied the relationships between effective interparticulate contact area and the tensile strength of amorphous and crystalline lactose tablets with varying particle size and compression forces. They measured the area of interparticulate contact within the tablet using a model proposed by Eriksson and Alderbom (137). which is based upon measuring the deformation properties of the particles during compression. This relationship is given by ... 

In a collaborative study on the quantitative determination of cocaine hydrochloride in powders and tablets that also contain other drugs (i.a. caffeine, procaine hydrochloride and benzocaine) as well as lactose, mannitol and starch, the free cocaine base was extracted with chloroform from an aqueous solution after addition of KjHPO. Tetracosane was added... 

Ludipress . [BASF AG] Lactose/ Kollidon based direct tabletting auxiliary. 

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