In‐Solution Structural Considerations by ¹H NMR and Solid‐State Thermal Properties of Inulin‐d‐α‐Tocopherol Succinate (INVITE) Micelles as Drug Delivery Systems for Hydrophobic Drugs

Abstract

H NMR is a suitable method to clarify the kind of interactions leading to the self-assembly of amphiphilic polymers. This work shows, from 1 H NMR studies performed in solution, that the self-assembly ability of the synthesized Inulin-D -α-tocopherol succinate (INVITE) amphiphilic polymers, can be addressed to specifi c π-π interactions between the aromatic regions of D -α-tocopherol. This result suggests the use of INVITE systems for the preferential loading of aromatic group bearing drugs such as curcumin. The preparation conditions, effect of drug loading, and lyophilization on the INVITE systems are evaluated by DSC and thermogravimetric analysis (TGA) analysis to assess whether common pharmaceutical processes could infl uence the physical properties of the amphiphilic polymers, such as crystallinity, glass-transition temperature or thermal degradation, to predict the physical stability of the systems upon administration. Furthermore, the size stability of the micelle systems up to 60 days is monitored to assess the feasibility of the INVITE micelles' long-term storage upon reconstitution with water.

Enzyme controlled release of celecoxib from inulin based nanomicelles

“…DL% of CLX into INVITE micelles was 5% w/w, higher that DL% of curcumin in the same micellar systems that reached maximum value of 3.5% w/w as previously reported [31,38]. This is an interesting result that could be attributed to the specific structure of CLX which, as shown in Fig.…”

“…From the CAC values found for INVITE amphiphilic polymer it could be expected a good physical stability of the micelles as also previously confirmed [31,38].…”

“…This is an interesting result that could be attributed to the specific structure of CLX which, as shown in Fig. 3, is provided with aromatic groups that could be able to interact via the formation of π − π stacking interactions with the benzopyran-6-yl moiety of VITE [38]. Probably the aromatic structure of CLX provided a better interaction of the drug with the VITE residues with respect to curcumin at least in terms of drug loading.…”

“…administration and for the formation of a carrier-in-carrier system in which curcumin-loaded-INVITE was further loaded in mesenchymal stromal cells for the dual drug delivery in the therapy central nervous system diseases [37]. Furthermore, it has been demonstrated that in the INVITE systems, the drug loading of curcumin is a result of -stacking interaction between the drug and the aromatic region of VITE so addressing their use for the preferential loading of aromatic groups bearing molecules as CLX is [38].…”

Epothilone B-based 3-in-1 polymeric micelle for anticancer drug therapy

“…Alternatively, location of co-loaded drugs in PEG- b -PLA micelles may impact drug release. 1 H NMR analysis of m-EAR might give insights into drug location and possibly drug-drug interactions in PEG- b -PLA micelles (Catenacci et al, 2014). One limitation of this in vitro study is noteworthy: It was done above the CMC of PEG- b -PLA micelles and reflects diffusional release, but not the contribution due to micelle disassembly, owing to dilution below the CMC after injection in blood.…”