Crystalline lactose

The approximate times of osazone formation in minutes are given in Table 111,139. The product from mannose is the simple hydrazone and is practically white. Arabinose osazone separates first as an oil, whilst that from galactose is highly crystalline. Lactose and maltose give no precipitate from hot solution. 

Lactose is normally encountered as a component of any skim milk that is used in bakery products. Small quantities of crystalline lactose are sometimes used in baked goods. If a product is made with too much lactose then a metallic taste appears. The amount of lactose that can be consumed without this taste appearing varies between individuals. 

H.V, Van Kamp, G.K. Bolhuis and C.F. Lerk, Effect of both lubrication and addition of disintegrants on properties of tablets prepared from different types of crystalline lactose. Act. Pharm. Suec., 23 (1986) 217. 

Riepma KA, Lerk CF, De Boer AH, Bolhuis GK, Kussendrager KD. Consolidation and compaction of powder mixtures. I. Binary mixtures of same particle size fractions of different types of crystalline lactose. Int J Pharma 1990 66(l-3) 47-52. 

Partly delactosed whey is produced by concentrating cheese whey or casein whey sufficiently to exceed the solubility limit of lactose, followed by cooling, seeding with lactose crystals and removal of the crystalline lactose. The resulting liquor fraction is recovered and dryed. 

Other systems make use of the sticking tendency of acid whey. Partially dried whey powder coats the inner wall of the drying chamber, whence it falls when the crystalline lactose content of the powder becomes high. However, sticking of the product on the hot metal surfaces can be a problem unless sufficient moisture is present so that lactose crystallization proceeds to the point where the powder no longer adheres to the equipment (Pallansch 1973). 

Manufacture of crystalline lactose from permeate derived by ultrafiltration of lactic casein whey presents special problems because of the low pH, high lactate concentration, and high calcium and phosphate concentrations (Hobman 1984). Research at the New Zealand Dairy Research Institute has led to a pilot-scale process whereby calcium phosphate complexes are partially removed before evaporation by an alkali and heat treatment to precipitate them, followed by centrifugation to clarify the treated permeate. Removal of about 50% of the calcium is sufficient to avoid problems during evaporation. 

Harper (1979) and Doner and Hicks (1982) have reviewed the various methods for analysis of lactose and its derivatives. More recently, Roetman (1981) has described methods for the quantitative determination of crystalline lactose in milk products. The reader should consult these reviews for information on specific procedures. 

Polarimetric analysis is useful for determining the anomeric form of crystalline lactose or related compounds. Quantitation by polarimetric analysis is limited to samples free of other optically active compounds. 

Four methods, based on different principles, are used to measure crystalline lactose (Roetman 1981) ... 

Estimation of water of crystallization. When lactose is crystallized as the a-lactose hydrate in a product, the fraction crystallized can be determined from the weight of water of crystallization lost. Water of crystallization accounts for 5% by weight of the crystalline lactose. 

Other approaches use Laser-Raman spectra to differentiate five conformational states of lactose, including a-lactose monohydrate, /3-lactose, and lactose glass (Susi and Ard 1974). Differential thermal analysis has also been used to measure the concentration of crystalline lactose, especially a-lactose hydrate (Ross 1978B). The specialized equipment required by these procedures may limit their use. 

Berlin, E., Kliman, P. G., Anderson, B. A. and Pallansch, M. J. 1971. Calorimetric measurement of the heat of desorption of water vapor from amorphous and crystalline lactose. Therm. Acta 2, 143-152. 

Roetman, K. 1981. Methods for the quantitative determination of crystalline lactose in milk products. Neth. Milk Dairy J. 35, 1-52. 

The Maillard reaction is more susceptible with amorphous lactose than with crystalline lactose therefore, this reaction is expected to be more of a concern for spray-dried material (80). Since the reaction is acid/base catalyzed, it is ideal to maintain a neutral pH environment with lactose-based products. 

Campina BV. Stabilization of crystalline lactose. Netherlands Patent Application NL8301220A841101 and NL83-1220 830407. DMV. 

Physical state of lactose—amorphous lactose protects free fat from being extracted while crystalline lactose promotes extraction. 

Addition of crystalline lactose—when crystallized lactose is added, it must be dissolved completely. 

Sebhatu, T., and Alderborn, G. (1999), Relationships between the effective interparticulate contact area and the tensile strength of tablets of amorphous and crystalline lactose of varying particle size, Ear. J. Pharm. Sci., 8,235-242. 

Gustafsson et al. used SSNMR and isothermal microcalorimetry to investigate the amorphous component of lactose. In general, the detection limits for crystalline forms are much better than for amorphous forms due to the much broader resonances characteristic of disordered systems. The two techniques were found to be in agreement with each other in the characterization of the degree of disorder in the system. Completely amorphous lactose (prepared by spray drying) was mixed with completely crystalline lactose monohydrate... 

Adhesion, sticking, picking, and filming on punches and dies can in many cases be avoided by a suitable surface finish of the tooling. In some cases, the surface is smoothened during continuous use of punches, whereas in other cases, depending on the material compressed, e.g., in the case of crystalline lactose, small scratches may occur on the punch tips after a few thousand compression events. On those small scratches and defects in the surface, corrosion will start. 

Nakai, Y. Fukuoka, E. Nakajima, S. Morita, M. Physico- 34. chemical properties of crystalline lactose. I. Estimation of... 

Oligosaccharides can be formed during acid hydrolysis by a process known as reversion, in which residues of lactose or its hydrolysis products are combined by condensation reactions. " The extent of reversion is dependent upon various factors, including the temperature, the concentrations of lactose and of acid, and the length of reaction time. The reversion tends to increase with increasing concentrations of carbohydrate and can be conveniently followed by paper chromatography. - When crystalline lactose containing 0.3% of water was placed in an atmosphere of hydrochloric acid fumes for 7 days at room temperature, a polymer was formed in 21 % yield. 2... 

Vromans H. De Boer AH. Boihuis GK, Lerit CF. Kussendrager KD, Bosch H. Studies on tabletting properties of lactose. Part II. Consolidation and compaction of different types of crystalline lactose. Hiarm Week Sci Ed 1985 7 186-93. 

Vromans H. Boihuis GK. Leric CF, Kussendrager KD. Studies of tableting properties of lactose. IX. The relationship between particle structure and compactibility of crystalline lactose. Int J niarm 1987 39 207-12. 

Riepma KA. Vromans H, Zuurman K. Lerk CF. The effect of dry granulation on the consolidation and compaction of crystalline lactose. Int J Pharm 1993 97 29-38. 

Amorphous lactose produced tablets of higher tensile strength than crystalline lactose and there was a tendency for reduced particle size to increase tablet strength. Hence tablet strength was correlated with the effective area of contact for each material. 

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 ... 

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