Malvern Mastersizer

A Malvern Mastersizer (Malvern Instruments Ltd, Malvern, UK) with optical parameters defined by the manufacturer s presentation code 0505 was used to determine the droplet size distribution. The measurement was made in triplicate at room temperature. Water was used to disperse the emulsion droplets. 

Particle size was measured using a Malvern Mastersizer, and nitrogen porosymmetry undertaken using a Sorpty 1750 instrument. 

Grinding was performed using Retsch ball-mill. Particle size distribution was measured using Malvern (Mastersizer) laser particle sizer. BET surface area measurements were carried out using ASAP (Micromeritics) surface area analyzer. 

Figure 7.17 Influence of i-carrageenan on the state of flocculation of BSA-stabilized emulsions (20 vol% oil, 1.7 vt% protein. pH = 6, ionic strength = 0.005 M) stored at 25 °C for 40 hours. The average droplet size measured by static light scattering (Malvern Mastersizer), d32, is plotted against the polysaccharide concentration ch added to the freshly made emulsion. Reproduced from Dickinson and Pawlowsky (1997) with permission.

Figure 7.18 Protein-polysaccharide interactions in emulsions subjected to high pressure treatment (HPT). Influence of pH on average effective particle diameter d43 determined by static light scattering (Malvern Mastersizer) in emulsions (20 vol% soybean oil, 0.5 wt% p-lactoglobulin) prepared with untreated protein (open symbols) and high-pressure-treated (800 MPa for 30 min filled symbols) protein in the absence (O, ) and presence (A, ) of 0.5 wt% pectin. Reproduced from Dickinson and James (2000) with permission.

Figure 2. The normalized particle size distribution of the salt grains used to produce tissue scaffolds can be obtained by light scattering (Malvern Mastersizer series 2600c).

Particle size distribution and classifier selectivity have been determined, using kernel density estimations, to data from (two) classifier flow streams. The procedure has been applied to hydrocyclones using platey particles whose sizes were determined with a Sedigraph 5100 and spheroidal particles whose size distributions were determine using the Malvern Mastersizer and the Coulter Counter [8] Svarovsky s equation was used [9,10]. 

Malvern Mastersizer is a fixed configuration model to lower cost. A range of small volume accessories are available along with the standard Mastersizer E tank that is suitable for volumes of 1 liter. The wide size range of 0.1 pm to 600 pm makes it ideal for routine analysis and quality control. 

Malvern Mastersizer X operates in the size range 0.1 to 2000 pm. A wide choice of modules can handle dry powders, suspensions, emulsions, aerosols and sprays in manual or fully automatic mode. 

Malvern Mastersizer S uses Mie theory to cover the size range 0.05 to 900 pm using a single lens, and up to 3500 pm with an extended range system. Scattering angles from 0.01 ° to 150° are detected in order to cover this wide size range. The system handles measurements of particles, droplets or gas bubbles. 

Malvern Mastersizer Micro, which uses a folded optics configuration, is the most compact MALLS instrument presently available. In its basic form it has a size range of 0.3 to 300 pm. 

Malvern Mastersizer Microplus extends this range to 0.05 to 550 pm. This instrument is intended where low sample throughput, a limited size range or well-defined user needs makes the flexibility of the more sophisticated versions unnecessary. Roberts has presented a discussion of low cost sizing using these two instruments [160]. 

Comparison tests between the PSS Accusizer 770 (light blockage), API Aerosizer (time of flight) and MALLS instruments (Malvern Mastersizer and Coulter LS) indicated that the MALLS instruments gave results that differ from each other and from microscopy whereas the other two instruments gave results in agreement with each other and with microscopy [167]. The choice of the Fraunhofer or Mie theory model affected the calculated size distribution in an unpredictable manner and the use of Mie... 

Three particle systems were examined by image analysis and their aspect ratio and particle size distributions were measured [197,198]. The data were then used as a reference method for neural networking using a Malvern Mastersizer X and concentrations from 2 g f to 60 g I" . Particle shapes ranged from an ellipsoidal cracking catalyst, needle shaped asbestos and monoclinic sucrose crystals. 

A Malvern MasterSizer X light scattering granulometer mounted in the direct Fourier configuration was used for Particle Size Distribution (PSD) measurements. 

With this powder, cake filtration seems possible. It is always prudent to check the powder properties of each batch received. With static light scattering (for example, a Malvern Mastersizer) we find d90 7 pm... 

Shelf-life specifications of a suspension dosage form include redispersabihty upon storage. However, there is no official method to test this, and most manufacturers design their own methods, chiefly requiring some t q)e of subjective shaking. The stability of the suspensions is partly dependent on the particle size in suspension. This can be measured using techniques, such as laser diffraction or Malvern Mastersize (19). As the stabilized suspension is mostly in a flocculated form due to the electrolytes added to it, it may be necessary to apply sonification in the study of particle sizes. 

The efficiency of homogenization may be assessed by microscopic examination or more effectively by a particle sizer, e.g. Malvern Mastersizer. 

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