In vivo evaluation of solid lipid microparticles and hybrid polymer-lipid microparticles for sustained delivery of leuprolide.

This study aims to investigate the potential of solid lipid microparticles (MP) and hybrid polymer-lipid MPs for sustained delivery of a peptide drug, leuprolide. A peptide-phospholipid complex was prepared to increase the compatibility of the peptide with triglyceride (TG) and poly (lactide-co-glycolide) (PLGA). Peptide loaded solid lipid MPs, PLGA MPs, and hybrid MPs were prepared using a spray drying method and characterized in terms of particle size, morphology and encapsulation efficiency.

Qualitative and quantitative analysis of the biophysical interaction of inhaled nanoparticles with pulmonary surfactant by using quartz crystal microbalance with dissipation monitoring.

Understanding the interaction between inhaled nanoparticles and pulmonary surfactant is a prerequisite for predicting the fate of inhaled nanoparticles. Here, we introduce a quartz crystal microbalance with dissipation monitoring (QCM-D)-based methodology to reveal the extent and nature of the biophysical interactions of polymer- and lipid-based nanoparticles with pulmonary surfactant. By fitting the QCM-D data to the Langmuir adsorption equation, we determined the kinetics and equilibrium parameters [i.

Effect of excipients on encapsulation and release of insulin from spray-dried solid lipid microparticles.

The study aimed at investigating the potential of spray drying method for encapsulation of protein drugs into solid lipid microparticles (MP) and evaluating effects of excipients on encapsulation and release of protein from MP. After transformation of model protein insulin to insulin-phospholipid complex, it was dissolved together with lipid excipients in organic solvent, which was spray-dried to form solid lipid MP. Polymeric MP with D, L-lactic-co-glycolic acid (PLGA) were prepared similarly.

Lipid Shell-Enveloped Polymeric Nanoparticles with High Integrity of Lipid Shells Improve Mucus Penetration and Interaction with Cystic Fibrosis-Related Bacterial Biofilms.

Nanoparticle (NP) mediated drug delivery into viscous biomatrices, e.g., mucus and bacterial biofilms, is challenging.

Electrospinnability of Poly Lactic-co-glycolic Acid (PLGA): the Role of Solvent Type and Solvent Composition.

Purpose: In this study, the electrospinnability of poly(lactic-co-glycolic acid) (PLGA) solutions was investigated, with a focus on understanding the influence of molecular weight of PLGA, solvent type and solvent composition on the physical properties of electrospun nanofibers.

Method: Various solvents were tested to dissolve two PLGA grades (50 KDa-RG755, 100 KDa-RG750). The viscoelasticity, surface tension, and evaporation rate of the PLGA solutions were characterized prior to the electrospinning process.

Modulating protein release profiles by incorporating hyaluronic acid into PLGA microparticles Via a spray dryer equipped with a 3-fluid nozzle.

Purpose: The purpose of this study was to modulate the release profiles of the model protein drug from spray dried poly(DL-lactic-co-glycolic acid) (PLGA) microparticles by incorporating hyaluronic acid (HA) in the formulation.

Methods: Bovine serum albumin (BSA)-loaded PLGA microparticles with or without HA were prepared using a spray dryer equipped with a 3-fluid nozzle. The effects of HA on the surface tension and the rheological behavior of the inner feed solution were investigated.

Property profiling of biosimilar mucus in a novel mucus-containing in vitro model for assessment of intestinal drug absorption.

Oral delivery of drugs, including peptide and protein therapeutics, can be impeded by the presence of the mucus surface-lining the intestinal epithelium. The aim of the present project was to design and characterize biosimilar mucus compatible with Caco-2 cell monolayers cultured in vitro to establish a more representative in vitro model for the intestinal mucosa. The rheological profile of a biosimilar mucus mixture composed of purified gastric mucin, lipids and protein in buffer was optimized by supplementing with an anionic polymer to display viscoelastic properties and a microstructure comparable to freshly isolated porcine intestinal mucus (PIM).

The influence of size, structure and hydrophilicity of model surfactants on the adsorption of lysozyme to oil-water interface--interfacial shear measurements.

The flexibility and aggregation of proteins can cause adsorption to oil-water interfaces and thereby create challenges during formulation and processing. Protein adsorption is a complex process and the presence of surfactants further complicates the system, in which additional parameters need to be considered. The purpose of this study is to scrutinize the influence of surfactants on protein adsorption to interfaces, using lysozyme as a model protein and sorbitan monooleate 80 (S80), polysorbate 80 (T80), polyethylene-block-poly(ethylene glycol) (PE-PEG) and polyglycerol polyricinoleate (PG-PR) as model surfactants.

Adsorption of proteins at the oil/water interface--observation of protein adsorption by interfacial shear stress measurements.

The interfacial adsorption of proteins is a problem during processing and formulation. The flexibility and aggregation of the protein cause the formation of a viscoelastic multilayer upon adsorption to the oil/water interface. Protein adsorption is a complex process and therefore it is difficult to elaborate which protein characteristics are important for the interfacial protein adsorption.

Rheological characterization and turbidity of riboflavin-photosensitized changes in alginate/GDL systems.

Riboflavin (RF) in combination with light, in the wavelength range of 310-800 nm, is used to induce degradation of alginic acid gels. Light irradiation of alginate solutions in the presence of RF under aerobic conditions causes scission of the polymer chains. In the development process of a new drug delivery system, RF photosensitized degradation of alginic acid gels is studied by monitoring changes in the turbidity and rheological parameters of alginate/glucono-delta-lactone (GDL) systems with different concentrations of GDL.

Characterization of riboflavin-photosensitized changes in aqueous solutions of alginate by dynamic light scattering.

The effect of irradiation, in the wavelength range of 310-800 nm, on aqueous solutions (pH = 7.4) of alginate in the presence of the photosensitizer riboflavin (RF) has been investigated with the aid of dynamic light scattering (DLS). Under aerobic conditions light irradiation of RF causes scission of the polymer chains which affects the polymer dynamics.

Riboflavin-photosensitized changes in aqueous solutions of alginate. Rheological studies.

Interactions between photoexcited riboflavin (RF), promoted by irradiation in the range of 310-800 nm, and alginate have been studied in air equilibrated aqueous solutions with the aid of rheological methods. Light irradiation of RF causes under aerobic conditions fragmentation of alginate and a decrease in the shear viscosity and other rheological parameters of its solutions. The decrease is most pronounced in concentrated polymer solutions.