Trehalose formulation

A 1% (w/v) trehalose formulation frozen by liquid nitrogen exhibited a fine filamentous directional network, whereas freezing by placement on a —50°C shelf yielded a leafy mixed-orientation appearance. The authors state that the rapidly frozen trehalose had less resistance to vapor flow during drying and reconstituted faster than the shelf-frozen samples. 

Studies with the freeze dried DPPC liposomes in trehalose solution showed, that not Tg )f the amorphous sugar is the critical temperature during storage, but the bilayer transition emperature Tm. for the lyposomes determines the short term stability of the formulation. With trehalose as lyoprotectant and a low residual water content, Tm proved to be 10 to 30 °C below the onset of T . 30 min heating above Tm but well below T% decreased the retention of CF after rehydration. Tm< after the heating was reduced from 40 to 80 °C to below 25 °C. 

Avastin Avastin is used for the treatment of colorectal cancer. It is supplied in 100 and 400 mg dosages. The 100 mg formulation consists of 240 mg a,a-trehalose dihydrate, 23.2 mg sodium phosphate (monobasic, monohydrate), 4.8mg sodium phosphate (dibasic, anhydrous), 1.6mg polysorbate 20 and water-for-injection. 

Tonicity agents are added to injectable preparations to prevent osmotic shock at the site of injection upon administration, and thereby reduce local irritation. Typical excipients used for tonicity adjustment include saline, glycerin, mannitol, dextrose, and trehalose. Tonicity is a colligative property that depends primarily on the number of dissolved particles in solution. Hence, the amount of tonicity agent to be added depends on the specific formulation. Typically, osmolality of 280 to 320mOsm is considered iso-osmotic. 

Hageman et al. [3.13] calculated the absorption isotherms for recombinant bovine somatotropin (rbSt) and found 5-8 g of water in 100 g of protein, which was not only on the surface but also inside the protein molecule. Costantino et al. [3.72] estimated the water monolayer M0 (g/100 g dry protein) for various pharmaceutical proteins and for their combination with 50 wt% trehalose or mannitol as excipient. They compared three methods of calculating MQ (1) theoretical (th) from the strongly water binding residues, (2) from conventional adsorption isotherm measurements (ai) and (3) from gravimetric sorption analysis (gsa) performed with a microbalance in a humidity-controlled atmosphere. Table 3.5 summarizes the results for three proteins. The methods described can be helpful for evaluating RM data in protein formulations. 

Fernandez-Urrusuno et al. [30] reported on development of a freeze-dried formulation of CT/TPP nanoparticles loaded with insulin. They tested various cry-protective agents for their ability to maintain the original size/charge of particles upon reconstitution. The best medium appeared to be 5 % trehalose or sucrose. This was confirmed with unloaded nanoparticles from System 2 (Fig. 16). The original suspension, without the trehalose addition, exhibited a size of 185 nm (SD 25 nm). 

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