Encapsulation advantages over injection

The liposome gel delivery system and liposome surface modified with fibronectin offer several advantages over other liposome formulations or gel formulations constructed only with free drug [96], Two peptide hormones, insulin and growth hormone encapsulated in vesicles sequestered within the matrix, are slowly released into the circulation from either an intramuscular or subcutaneous injection site. A maximum 3-5-d release for insulin or a 14-d growth hormone release was observed. 

The trend towards multi-material moulding has been pushed by the growing importance of added value manufacture to give moulders commercial advantages over their rivals. An increase in the importance of material recycling has also aided the growth in co-injection technologies, where encapsulation enables recyclate materials to be used. 

By the use of a breath-powered unit dose dry powder inhaler, which was adapted to the physical properties of TI, relative bioavailability was 50% for the first 3 hours and 30% over the entire 6-hour period in 12 healthy volunteers (Pfutzner et al. 2002). However, although the studies demonstrated pulmonary administration of TI has the advantages of fast onset of action, short duration of action, and lower variability over the SC injections of insulin no attempt has been made to compare pulmonary administration of insulin alone with the same inhaler device. This method of encapsulating biomacromolecules has some advantages and must be considered when electing to deliver a molecule. 

---