ABSTRACT
OBJECTIVE: The objective of this work is to show the feasibility of manufacturing from a spray drying process particles containing immunoglobulin G capable of being administered by inhalation via a pressurized metered dose inhaler. METHODS: Spray drying were made from aqueous solutions containing IgG and two types of excipients, mannitol and trehalose, with two ratios: 25% w/w and 75%w/w. The physicochemical and aerodynamic properties of the powders obtained were characterized just after manufacturing and after 1 month of storage at 40°C/75% RH according to criteria defined as needed to satisfy an inhaled formulation with a pressurized metered dose inhaler. Maintain of the biological activity and the structure of IgG after atomization was also tested by slot blot and circular dichroism. RESULTS: All spray-dried powders presented a median diameter lower than 5µm. The powders atomized with trehalose showed a solid state more stable than those atomized with mannitol. All atomized powders were in the form of wrinkled particles regardless the nature and the ratios of excipients. The results showed that the aerosolisation properties were compliant with the target, independently of the excipient used at a ratio of 25% w/w IgG-excipient. Moreover, the addition of excipient during the atomization process the denaturation of IgG was limited. CONCLUSION: This study showed that the use of trehalose as excipient could satisfy the requirements of an inhaled formulation with a pressurized metered dose inhaler.
Subject(s)
Immunoglobulin G/administration & dosage , Immunoglobulin G/chemistry , Metered Dose Inhalers , Desiccation , Drug Compounding , Excipients , Feasibility Studies , Particle Size , PowdersABSTRACT
The lectin isolated from the phytopathogenic basidiomycete Rhizoctonia solani (RSA) is a homodimer of two noncovalently associated monomers of 15.5 kDa. RSA is a basic protein (pI > 9) which consists mainly of beta-sheets. A presumed relationship with ricin-B is supported by the sequence similarity between the N-terminus of RSA and the N-terminal subdomain of ricin-B. Hydrophobic cluster analysis confirms that the N-terminus of both proteins has a comparable folding. RSA exhibits specificity towards Gal/GalNAc whereby the hydroxyls at the C3', C4', and C6' positions of the pyranose ring play a key role in the interaction with simple sugars. The carbohydrate-binding site of RSA apparently accommodates only a single sugar unit. Our results demonstrate an obvious evolutionary relationship between some fungal and plant lectins, but also provide evidence for the occurrence of a lectin consisting of subunits corresponding to a single subdomain of ricin-B.
Subject(s)
Lectins/chemistry , Rhizoctonia/chemistry , Ricin/chemistry , Acetylgalactosamine , Amino Acid Sequence , Binding Sites , Dimerization , Galactose , Isoelectric Point , Lectins/classification , Lectins/genetics , Lectins/isolation & purification , Molecular Sequence Data , Molecular Weight , Plant Lectins , Plants/microbiology , Protein Structure, Secondary , Protein Structure, Tertiary , Rhizoctonia/genetics , Rhizoctonia/pathogenicity , Ricin/classification , Ricin/genetics , Sequence Homology, Amino AcidABSTRACT
The pulp of ripe bananas (Musa acuminata) contains an abundant thaumatin-like protein (TLP). Characterization of the protein and molecular cloning of the corresponding gene from banana demonstrated that the native protein consists of a single polypeptide chain of 200 amino acid residues. Molecular modelling further revealed that the banana thaumatin-like protein (Ban-TLP) adopts an overall fold similar to that of thaumatin and thaumatin-like PR-5 proteins. Although the banana protein exhibits an electrostatically polarized surface, which is believed to be essential for the antifungal properties of TLPs, it is apparently devoid of antifungal activity towards pathogenic fungi. It exhibits a low but detectable in vitro endo-beta-1,3-glucanase (EC 3.2.1.x) activity. As well as being present in fruits, Ban-TLP also occurs in root tips where its accumulation is enhanced by methyl jasmonate treatment of plants. Pulp of plantains (Musa acuminata) also contains a very similar TLP, which is even more abundant than its banana homologue. Our results demonstrate for the first time that fruit-specific (abundant) TLPs are not confined to dicots but occur also in fruits of monocot species. The possible role of the apparent widespread accumulation of fruit-specific TLPs is discussed.
