Oil-in-Water Nanosized Emulsions for Drug Delivery and Targeting. Tamilvanan Shunmugaperumal. Читать онлайн. Newlib. NEWLIB.NET

Автор: Tamilvanan Shunmugaperumal
Издательство: John Wiley & Sons Limited
Серия:
Жанр произведения: Химия
Год издания: 0
isbn: 9781119585251
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to determine long‐term product stability.

      The o/w nanosized emulsions are nanometric‐sized emulsions, typically exhibiting diameters of up to 500 nm or often quoted as being 400–800 nm. However, particles in this range tend to be thermodynamically unstable non‐self forming requiring mechanical energy input and are opaque. Nanosized emulsions are also frequently known as miniemulsions, fine‐dispersed emulsions, submicron emulsions and so forth, but are all characterized by a great stability in suspension due to their very small size, essentially the consequence of significant steric stabilization between droplets, which goes to explain why the Ostwald ripening is the only adapted droplet destabilization process (detailed below).

       1.1.2.2. Ostwald Ripening‐Adapted Droplet Destabilization Process for the Greater Stability of Nanosized Emulsions

      Accordingly, the physical destabilization of emulsions is related to the spontaneous trend towards a minimal interfacial area between the two immiscible phases. Therefore, a minimization of interfacial area is attained by two mechanisms:

      1 Flocculation followed mostly by coalescence, and

      2 Ostwald ripening.

      [Adapted from Anton et al. (2008).]

      where C is the bulk solubility of the dispersed phase, M its molar mass, and ρ its density.

      where