Evaluation of nano spray drying as a method for drying and formulation of therapeutic peptides and proteins

Citation: Haggag YA and Faheem AM (2015) Evaluation of nano spray drying as a method for drying and formulation of therapeutic peptides and proteins. The high sensitivity of peptides and proteins to physicochemical stresses during processing and storage is the major hurdle against its pharmaceutical applications. Peptide-based drug formulations are commonly prepared as solid dosage forms because more stability can be achieved in the solid rather than in the liquid state (Ameri and Maa, 2006). The most common methods to increase the stability of peptides and proteins are drying and the use of stabilizing excipients (Maltesen and van de Weert, 2008). So far, spray drying and freeze drying are the most popular methods of drying peptides and protein solutions in the Pharmaceutical industry. Other drying methods, like spray coating, spray freeze drying (SFD), and supercritical fluid technology and their different modifications, are mostly used on a small scale, especially for research purposes (Franks et al., 1991; Marreto et al., 2006). The optimum choice of drying technique will depend mainly on the economics of drying and on the intended route of drug administration (Webb et al., 2002). Compared to freeze drying, spray drying is a faster and more economical, single step, drying method which can be designed as a continuous drying process (Masters, 1972). Spray drying is suitable for heat-sensitive materials, despite the high temperatures of the drying gas, owing to the cooling effect of the evaporating solvent which keeps the droplet temperature relatively low (Masters, 1972). Another advantage of spray drying technique is its ability to control the particle size and the morphology of the dried powder by varying the process parameters and the formulation factors (Masters, 1972). Moreover, spray dried powders are commonly prepared when the intended route of administration is via inhalation, so that this technique is of prime importance for pulmonary delivery of protein pharmaceuticals (Maaand and Prestrelski, 2000; Lee, 2002). However, low powder yield is still the major drawback in the development of spray dried pharmaceuticals because of small amounts of expensive active ingredients which are available after the early stages of development (Broadhead et al., 1994). Other instability problems encountered when spray drying an aqueous solution of a pure protein, include aggregation and subsequent loss of activity (Adler and Lee, 1999; Tzannis and Prestrelski, 1999). These instabilities can be ameliorated by formulation measures, such as the inclusion of disaccharides or surfactants in the liquid feed …