Properties of Lactose

X-ray diffraction studies are usually carried out at room temperature under ambient conditions. It is possible, however, to perform variable-temperature XPD, wherein powder patterns are obtained while the sample is heated or cooled. Such studies are invaluable for identifying thermally induced or subambient phase transitions. Variable-temperature XPD was used to study the solid state properties of lactose [20], Fawcett et al. have developed an instrument that permits simultaneous XPD and differential scanning calorimetry on the same sample [21], The instrument was used to characterize a compound that was capable of existing in two polymorphic forms, whose melting points were 146°C (form II) and 150°C (form I). Form II was heated, and x-ray powder patterns were obtained at room temperature, at 145°C (form II had just started to melt), and at 148°C (Fig. 2 one characteristic peak each of form I and form II are identified). The x-ray pattern obtained at 148°C revealed melting of form II but partial recrystallization of form I. When the sample was cooled to 110°C and reheated to 146°C, only crystalline form I was observed. Through these experiments, the authors established that melting of form II was accompanied by recrystallization of form I. 

Fell JT. The flow and compaction properties of lactose. Pharmaceutisch Weekblad 1976 111 (28) 681 685. 

Yromans H, Bolhuis GK, Lerk CF, Kussendrager KD, Bosch H. Studies on tableting properties of lactose. VI. Consolidation and compaction of spray-dried amorphous lactose. Acta Pharmaceutica Suecica 1986 23(4) 231-240. 

Given the complexity that arises from the multitude of interacting variables associated with DPI systems, there are very few excipients that have been incorporated into DPI formulations. Examples of commonly marketed products are listed in Table 2. Lactose has many benefits including a well-established safety profile, low cost, and wide availability. Physicochemical properties of lactose are also relatively desirable from a DPI formulation standpoint smooth surfaces, crystalline, and moderate flow properties. However, lactose may not be suitable for some active... 

The chemistry and physicochemical properties of lactose, a reducing disaccharide containing galactose and glucose linked by a / (l-4)-bond, were described in Chapter 2. 

The first record of isolation of lactose was in 1633, by Bartolettus, by evaporation of whey. During the Eighteenth century, lactose became a commercial commodity, used principally in medicine. Whey had been used by physicians since the time of Hippocrates to utilize the unique biochemical functions and properties of lactose. 

Because of their speed and reasonable instrumental requirements, there is continuing interest in colorimetric procedures for lactose determinations. Most procedures are based on the reducing properties of lactose samples that contain only one sugar are easily measured colori-metrically, but samples with three or four sugars may require several different colorimetric assays to determine the composition accurately. 

Herrington, B. L. 1934A. Some physico-chemical properties of lactose. II. Factors influencing the crystalline habit of lactose. J. Dairy Sci. 17, 533-542. 

Lerk, C. F., Buma, T. J. and Andreae, A. C. 1980. The effect of mechanical treatment on the properties of lactose as observed by differential scanning calorimetry. Neth. Milk Dairy J. 34, 69-73. 

Cartilier, L.H. Tawashi, R. Effect of particle morphology on the flow and packing properties of lactose. STP Pharma Sci. 1993, 3, 213-220. 

Bentham, A.C. Ghadiri, M. Influence of size reduction processes on the mechanical properties of lactose, Fifth World... 

Vromans, H. Lerk, C.F. de Biggelaar, H. Van. Bosch, H. Studies on tableting properties of lactose. VII. The effect of variations in primary particle size and percentage of amorphous lactose in spray-dried lactose products. Int. J. Pharm. 1987, 35, 29-37. 

Jones, T.M. Pilpel, N. Some physical properties of lactose and magnesia. J. Pharm. Pharmacol. 1965, 17, 440. 

Gunsel, W.C. Lachman, L. Comparative evaluation of tablet formulations prepared from conventionally processed and spray-dried lactose. J. Pharm. Sci. 1963,52 (2), 178-182. Van Kamp, H.V. Bolhuis, G.K. Kussendrager, K.D. Lerk, C.F. Studies on tabletting properties of lactose. IV. Dissolution and disintegration properties of different types of crystalline lacose. Int. J. Pharm. 1986, 28, 229-238. Ondari, C.O. Kean, C.E. Rhodes, C.T. Comparative evaulation of several direct compression sugars. Drug Dev. Ind. Pharm. 1983, 9 (8), 1555-1572. 

Many thermodynamic properties of lactose are known, including its heat of combustion," -" of solution, " and of dilution" its heat capacity," " " entropy," and free energy " its mean energy and entropy of activation through a collodion membrane and the specific heats of lactose solutions. ... 

Other physical properties of lactose solutions that have been investigated include the rate of crystallization, density, viscosity, rc-... 

Holsinger VH (1997) Physical and chemical properties of lactose. In Fox PE (ed) Advanced Dairy Chemistry 3 Lactose, Water, Salts and Vitamins. Chapman and Hall, London... 

Alpar O, Hersey JA, Shotton E. The compressions properties of lactose. ] Pharm Pharmacol 1970 22 (SuppL) 1S-7S. 

Vromans FI, de Boer AH, Bolhuis GK, et al. Studies on the tableting properties of lactose the effect of initial particle size on binding properties and dehydration characteristics of a-lactose monohydrate. In Rubinstein MH, ed. Pharmaceutical Technology Tableting Technology, vol. 1. Chichester Ellis Horwood, 1987 31-42. 

Juslin L. Yliruusi J, Effect of fluidized bed granulation on the crystal properties of lactose, glucose and mannitol. S.T.P. Hiarm Sci 1996 6(3) 173-8. 

Vromans H, De Boer AH. Boihuis GK. Lerk CF. Kussendrager KD. Studies on tabletting properties of lactose. Part I. The effect of initial particle size on binding properties and dehydration characteristics of lactose. Acta Pharm Sucica 1985 22 163-72. 

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. 

Mac Ritchie KA, Newton JM. Rowe RC. The evaluation of the rheological properties of lactose/microcrystalline cellulose and water mixtures by controlled stres.s rheometry and the relationship to the production of spherical pellets by extrusion/spheronization. Eur J Pharm... 

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