Physical Characteristics of Liposomal Formulation Dispersed in HPMC Matrix and Freeze-Dried Using Maltodextrin and Mannitol as Lyoprotectant

Abstract

Background: The present study aims to design formulation of liposomes that are well-preserved during freeze-drying. The combination of Hydroxy Propyl Methyl Cellulose (HPMC) as dispersion matrix and lyoprotectants; maltodextrin or mannitol, was employed to prevent aggregation and/or recrystallization. The obtained dry products were investigated in terms of their physical characteristics. Methods: Liposomes were prepared using thin film method and hydrated with the lyoprotectant solution. The formed liposomes were mixed with HPMC gel and freeze-dried. The obtained solid products were characterized using Differential Scanning Calorimetry (DSC), X-Ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). Results: The DSC thermograms of formulations with maltodextrin were relatively homogenous, yet exhibiting meta-stable properties. In contrast, the formulations using mannitol showed phase separation. These results were confirmed by XRD data, in which formulations with maltodextrin showed no intensive peaks, indicating amorphous solid while the formulations with mannitol exhibited more intensive peaks, indicating the presence of crystalline solids. The SEM images of both maltodextrin and mannitol-containing formulations showed porous matrix with spherical liposomes trapped in the matrices. The SEM images also correspond to the DSC and XRD data, where crystalline solid existed in the mannitol-containing formula. Conclusion: The developed liposomes formulation using combination of HPMC matrix and maltodextrin showed potential in preserving liposomes structure, contrary to those of using mannitol.

<p>Characterization and Dissolution Study of Micellar Curcumin-Spray Dried Powder for Oral Delivery</p>

“…The saturated sucrose in the mixture has been suggested to increase the tendency of internal interactions; however, the molecular dynamics were not sufficient to recrystallize. 40,41 It can be confirmed that casein, as well as sucrose in the developed MC-SDP formulations, successfully prevented curcumin from recrystallization. Moreover, the employed ratio of polymeric casein and sucrose was sufficient to inhibit the crystallization of curcumin.…”

Formulation Design and Cell Cytotoxicity of Curcumin-Loaded Liposomal Solid Gels for Anti-Hepatitis C Virus

“…With the same manufacturing technique, the liposomes prepared using the SPC, EPC, and HSPC showed similar morphology that was spherical and homogeneously distributed in the porous solid gel matrix. Such porous structure might be initiated by the entrapped ice crystals that sublimated during the freeze-drying process and resulted in a hollow structure [ 32 , 33 ]. The entrapped liposomes were a few micrometers in size, which indicates that they aggregated during the incorporation into the solid gel matrix.…”

Development of Dry Powder Formulations of AS01Bcontaining vaccines using Thin-Film Freeze-Drying

“…e ., 1:4, 1:8, 1:15 and 1:30 w/w , respectively). Maintaining liposomal integrity during freezing and subsequent drying is challenging [54]. Formation of ice crystals in the internal aqueous compartment or the external aqueous phase during the freezing step can rapture the liposomal lipid bilayers [55].…”

“…Secondly, the applicability of using TFFD to formulate dry powders of AS01B-adjuvanted vaccines was investigated using OVA as a model antigen and different stabilizers (i.e., sucrose, trehalose, and mannitol) at different lipid to stabilizer ratios (i.e., 1:4, 1:8, 1:15 and 1:30 w/w, respectively). Maintaining liposomal integrity during freezing and subsequent drying is challenging [54]. Formation of ice crystals in the internal aqueous compartment or the external aqueous phase during the freezing step can rapture the liposomal lipid bilayers [55].…”