title: Effect of hydroxypropyl beta-cyclodextrin on the self-assembling and thermogelation properties of Poloxamer 407.
abstract: This paper deals with the rheological and thermal characterisation of the self-assembling behaviour of different Poloxamer 407 systems (15-30%, w/v), both alone or after the addition of various amounts of hydroxypropyl beta-cyclodextrin (5-20%, w/v). The knowledge of the interactions existing between the two kinds of molecules could allow the development of systems for parenteral administration containing also proteins or peptides drugs. A rheology (temperature sweep and frequency sweep test) study has been performed to characterise the thermogelation process while thermal analysis (nanoDSC) allowed the determination of both micellization and sol/gelation transition processes. These two techniques were also utilised to outline the variation in the critical micelle temperature (cmT) or in the sol/gel temperature (sgT,) of the systems containing also hydroxypropyl beta-cyclodextrin (HP beta-CD). Both the rheology and thermal analysis showed the presence of interesting interactions between the HP beta-CD and the Poloxamer 407, which cause a shift of both cmT and sgT. The presence of HP beta-CD modified also Poloxamer samples elastic characters and microrheological structure as demonstrated by the G'-G'' mechanical spectra. Rheological and thermal results outlined how these new systems could open the possibility to join the thermogelling behaviour offered by Poloxamer 407 with the well-known stabilization and protection ability of HP beta-CD, which could make possible the formulation of systems for the parenteral delivery of peptides and proteins.
authors.affiliation: Department of Chemical Sciences, University of Camerino, Via S. Agostino 1, I-62032 Camerino (MC), Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Bonacucina
authors.forename: Michele
authors.initials: M
authors.lastname: Spina
authors.forename: Monica
authors.initials: M
authors.lastname: Misici-Falzi
authors.forename: Marco
authors.initials: M
authors.lastname: Cespi
authors.forename: Stefania
authors.initials: S
authors.lastname: Pucciarelli
authors.forename: Mauro
authors.initials: M
authors.lastname: Angeletti
authors.forename: Giovanni F
authors.initials: GF
authors.lastname: Palmieri
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical; D005079:Excipients / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D008823:Micelles; D020442:Poloxamer / Q000737:chemistry*; D012212:Rheology; D013696:Temperature; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D005079:Excipients; D005782:Gels; D008823:Micelles; D047392:beta-Cyclodextrins; D020442:Poloxamer; D000073738:2-Hydroxypropyl-beta-cyclodextrin