title: Spray congealed lipid microparticles with high protein loading: preparation and solid state characterisation.
abstract: The spray-congealing technique, a solvent-free drug encapsulation process, was successfully employed to obtain lipid-based particulate systems with high (10-20% w/w) protein loading. Bovine serum albumin (BSA) was utilised as model protein and three low melting lipids (glyceryl palmitostearate, trimirystin and tristearin) were employed as carriers. BSA-loaded lipid microparticles were characterised in terms of particle size, morphology and drug loading. The results showed that the microparticles exhibited a spherical shape, mean diameter in the range 150-300 μm and an encapsulation efficiency higher than 90%. Possible changes in the protein structure as a result of the manufacturing process was then investigated for the first time using UV spectrophotometry in fourth derivative mode and FT-Raman spectroscopy. The results suggested that the structural integrity of the protein was maintained within the particles. Thermal analysis indicated that the effect of protein on the thermal properties of the carriers could be detected. Spray-congealing could thus be considered a suitable technique to produce highly BSA-loaded microparticles preserving the structure of the protein.
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Università di Bologna, Via S. Donato 19/2, 40127 Bologna, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Di Sabatino
authors.forename: Beatrice
authors.initials: B
authors.lastname: Albertini
authors.forename: Vicky L
authors.initials: VL
authors.lastname: Kett
authors.forename: Nadia
authors.initials: N
authors.lastname: Passerini
mesh_terms: D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical; D004075:Diglycerides / Q000737:chemistry; D004337:Drug Carriers; D004339:Drug Compounding; D005240:Feasibility Studies; D008055:Lipids / Q000737:chemistry*; D010316:Particle Size; D011487:Protein Conformation; D055550:Protein Stability; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman; D013678:Technology, Pharmaceutical / Q000379:methods; D044366:Transition Temperature; D014280:Triglycerides / Q000737:chemistry
chemical_list: D004075:Diglycerides; D004337:Drug Carriers; D008055:Lipids; D014280:Triglycerides; C036694:trimyristin; D012710:Serum Albumin, Bovine; C009032:precirol; C022618:tristearin