Influence of excipients on characteristics and release profiles of poly(ε-caprolactone) microspheres containing immunoglobulin G

Nanoemulsion: A novel delivery approach for thermosensitive IgG on inhibiting milk fat oxidation

IgG, a biologically active substance in bovine colostrum, is easily inactivated during heat treatment and edible process to lose its biological activity. Nanoemulsion can effectively protect IgG to maintain its biological activity from injurious treatment. In this study, a food-grade nanoemulsion system was developed to protect IgG from heat and acid damage. It can be found that the residual rate of nanoemulsion-protected IgG reaches 87.1 % after 10 min at 72 °C. After 5 min at 82 °C, the residual rate of IgG in nanoemulsion was 18.7 % higher than that in PBS. In the simulated gastric fluid at pH 2.0, the residual rate of IgG in the nanoemulsion reacted for 4 h was 21.5 % higher than that in PBS. It indicated that nanoemulsion system can improve the heat and acid resistance of IgG compared with others, which is attributed to the lowest water activity of nanoemulsion. The contents of hydroperoxide and malondialdehyde in the milk after storage for 72 h with nanoemulsion-protected IgG were 0.12 meq/kg and 0.04 mg/kg, respectively, less than that of PBS-protected IgG. IgG is protected by nanoemulsion can effectively protect its activity during processing, which provides a theoretical basis for its direct application in liquid milk.

Starches in the encapsulation of plant active ingredients: state of the art and research trends

As a natural polymer, starches and their derivatives have received widespread attention in the cosmetic and pharmaceutical industries, particularly for their use as a coating material. In this sense, as an encapsulating agent, starches stand out, considering the number of compounds that they can trap. Additionally, they provide a nutritional contribution and may improve acceptance by patients. As such, this type of material may serve as an alternative to overcome gaps such as loss of activity of the active principles, low assimilation, or deterioration under environmental and physiological conditions. In this paper, we aim to present the state of the art and research trends on the use of starch as a wall material for the encapsulation of active principles of plant origin. It was found that the most-encapsulated active principles are essential oils and polyphenols; native or modified starches are typically used, either as the sole wall material or in combination with other polymers; and the most widely used methodology is spray drying. The reviewed studies indicate the potential of starches for their use in active ingredient encapsulation processes, improving their viability and expanding their range of applications in different industries, as well as showing a clearly increasing publication trend over the last 10 years.

Graphical abstract

Polymer-based prolonged-release nanoformulation of duloxetine: fabrication, characterization and neuropharmacological assessments

OBJECTIVE

The poly D, L-Lactic-co-glycolic acid (PLGA) and Polycaprolactone (PCL) have been widely applied for developing the prolonged-release formulation. The current study explores the application of these polymers for developing prolonged-release nanosphere of Duloxetine (DLX). Developing a prolonged release parenteral nanosphere formulation of DLX would be overcoming pitfalls like acid-labile degradation, first-pass metabolism and erratic bioavailability along with long-term therapeutic benefit in the treatment of depression.

METHODS

DLX-loaded PLGA and PCL nanospheres were prepared by using the emulsion solvent evaporation technique. The developed formulation was compared with DLX oral solution concerning brain estimation. The prepared nanospheres were subjected to the morphology of the drug particles, polydispersity Index (PDI), distribution size, zeta potential, entrapment efficiency and percentage yield to generate a proof of concept.

RESULTS

DLX-loaded polymeric nanosphere exhibited the uniform size from 89.48 nm to 100.9 nm. The entrapment efficiency was in the range of 74.93 to 77.49, respectively, of PLGA and PCL formulation. The FSEM image affirmed smooth spherical morphology. A good PDI and negative zeta potential value (-31.3 mV for F1 and -30.7 mV for F2) supported the stability of the nanosphere. The brain concentration of the drug was three times enhanced supporting the effectiveness of the nanosphere during pharmacodynamic and pharmacokinetic studies.

CONCLUSION

The intramuscular DLX-loaded nanospheres signify improved brain availability relative to DLX solution. This can be a blueprint for the effective and targeted brain delivery of CNS drugs.

Clinoptilolite/PCL–PEG–PCL composite scaffolds for bone tissue engineering applications

The aim of this study was to prepare and characterize highly porous clinoptilolite/poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) composite scaffolds. Scaffolds with different clinoptilolite contents (10% and 20%) were fabricated with reproducible solvent-free powder compression/particulate leaching technique. The scaffolds had interconnective porosity in the range of 55–76%. Clinoptilolite/poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) scaffolds showed negligible degradation within eight weeks and displayed less water uptake and higher bioactivity than poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) scaffolds. The presence of clinoptilolite improved the mechanical properties. Highest compressive strength (5.6 MPa) and modulus (114.84 MPa) were reached with scaffold group containing 20% clinoptilolite. In vitro protein adsorption capacity of the scaffolds was also higher for clinoptilolite/poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) scaffolds. These scaffolds had 0.95 mg protein/g scaffold adsorption capacity and also higher osteoinductivity in terms of enhanced ALP, OSP activities and intracellular calcium deposition. Stoichiometric apatite deposition (Ca/P=1.686) was observed during cellular proliferation analysis with human fetal osteoblasts cells. Thus, it can be suggested that clinoptilolite/poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) composite scaffolds could be promising carriers for enhancement of bone regeneration in bone tissue engineering applications.