Lactose flow properties

Many surface area studies have investigated various properties of excipients. The relationship between excipient grades, flow properties, particle sizes, and surface areas have been studied. Fast-flo lactose is manufactured to contain larger particles (approximately 50 jim) than hydrous lactose (approximately 20 /zm) [23], This has been done to improve the flow properties of the fast-flo... 

The range of application of shear cell testing methodology is seen in Tables 2-6. Table 3 relates the flow properties of mixtures of spray-dried lactose and bolted lactose. These mixtures, in combination with the excipients tested, cover a broad range of flow. Tables 4 and 5, for example, show lot to lot variations in the flow properties of several materials, and Table 6 shows the variation in flow properties of bolted starch, sucrose, and phenacetin at different relative humidities (RH). Figure 8 presents the yield loci of sucrose at four different consolidation loads. Also shown in the figure are the shear indices determined at each consolidation load. 

Zhou, Q., Armstrong, B., Larson, I., Stewart, P. J., Morton, D. A. V. Improving powder flow properties of a cohesive lactose monohydrate powder by intensive mechanical dry coating. J. Pharm. Sci., 99, 2010, 969-981. 

Controlled optimal particle size and size distribution ensures superior flow properties of coprocessed excipients and reduced reliance on addition of glidants. The volumetric flow properties of SMCC were studied in comparison with those of the physical mixture of its parent excipients (42). The particle size range of the two test samples was found to be similar, but the flow of coprocessed excipient was better than that of the physical mixture. A comparison of the flow properties of Cellactose with its parent excipients was also performed (5) by measuring the angle of repose and Hausner ratio, and Cellactose was found to have better flow characteristics than lactose or a physical mixture of cellulose and lactose. The spray-dried coprocessed product had a spherical shape and even surfaces, which resulted in improved flow properties. On similar terms, mechanically coating the 2% CSD over microfine cellulose powder resulted in improving its flow properties (43). 

Anhydrous 3-lactose (95%) and lactitol (5%) Pharmatose DCL14 DMY, Veghel, The Netherlands High compactibility, superior flowing properties, low lubricant sensitivity... 

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... 

Tablet diluent Inert substance used as filler to create desired bulk, flow properties, and compression characteristics in preparation of tablets Dibasic calcium phosphate, kaolin, lactose, mannitol, microcrystalline cellulose, powdered cellulose, precipitated calcim carbonate, sorbitol, starch...

Nqvist, H. Nicklasson, M. Flow properties of compressible lactose containing small quantities of drug substances. Drug Dev. Ind. Pharm. 1985,11 (4), 745-759. 

Anhydrous lactose is primarily anhydrous p-lactose with up to about 25% anhydrous a-lactose. It consists of agglomerates of fine crystals produced by roller drying a solution of a-lactose monohydrate. Flow properties are... 

Lactose anhydrous has been used experimentally in hydrophilic matrix tablet formulations and evaluated for dry powder inhalation applications. Partial hydration of anhydrous lactose increases the specific surface area and reduces the flow properties of powders but has no effect on compactibility. A specification for lactose is included in the Food Chemicals Codex (FCC) see Factose, Monohydrate. The EINECS number for lactose anhydrous is 200-559-2. 

Of critical importance in the development of DPI products is the evaluation, optimization, and control of flow and dispersion (deaggregation) characteristics of the formulation. These typically consist of drug blended with a carrier (e.g., lactose). The properties of these blends are a function of the principal adhesive forces that exist between particles, including van der Waals forces, electrostatic forces, and the surface tension of adsorbed liquid layers [7], These forces are influenced by several fundamental physicochemical properties, including particle density and size distribution, particle morphology (shape, habit, surface texture), and surface composition (including adsorbed moisture) [8]. In addition,... 

Chitosan (molecular weight, 19-400 kDa degree of deacetylation, 75-98%) has been evaluated as a directly compressible vehicle for tablets, but has found limited utility due to the lack of good flow properties and compressibility. The influence of excipient (lactose, sodium lauryl sulfate, sodium alginate, hydroxypropyl methyl... 

Lactose (alfa-Iactose monohydrate) (see also Sect. 23.4.4) has somewhat less favourable flow properties than microcrystaUine cellulose PH102. A disadvantage of lactose is its incompatibility with primary amines. An advantage compared to microcrystaUine cellulose is that it is water soluble, which makes lactose suitable for capsules where the contents have to be dissolved. Capsules containing lactose disintegrate as a resrrlt of the dissolution of lactose (Fig. 4.1). Its use might be limited in patients with lactose intolerance [12]. 

The preparation of the powder mixture is analogous to the preparation of single-dose powders (see Sect. 4.5), but the flow properties are less critical, because the powder mixture does not have to be distributed evenly over dose units. A diluent is generally not necessary, but in case it is required, lactose is often used. Bulk or multidose powders can be packaged in glass, plastic, metal or other containers that have a wide mouth to allow the handling of the powdermeasuring device. 

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