Effective mucoadhesive water-soluble polymers for the solidification transformation of phospholipid-bile salts-mixed micelles.

Cucurbitacin B (Cu B), formulated in the phospholipid-bile salts-mixed micelles (PL-BS-MMs), was transformed into dry powders by solidification process. Solidification methods for this transformation included freeze-drying, spray-drying or vacuum-drying, and different grades of process parameters called conservative, moderate and aggressive have been used in each solidification method, respectively. Saccharides (mannose, trehalose and glucose), polyethylene glycol (PEG) and mucoadhesive water-soluble polymers (carrageenan, hydroxpropylmethylcellulose (HPMC) and gelatin) were selected as the stabilizer, respectively. The influence of different stabilizers on the redispersibility of solid Cu B-PL/SDC-MMs was systemically investigated, such as the redispersibility index (RDI). The results showed that there were significant differences in RDI from samples stabilized by different stabilizers. The solid Cu B-PL/SDC-MMs stabilized by mucoadhesive water-soluble polymers (carrageenan, HPMC and gelatin) have better redispersibility under different solidification approaches, compared with those samples stabilized by other stabilizers. The results indicated that the mucoadhesive water-soluble polymers could effectively counter various stresses from the solidification process and prevent the nanocrystal surface from agglomeration. The combined action between steric hindrance and increased viscosity appeared to effectively avoid irreversible particle aggregation.