Supercritical AntiSolvent micronization of PVA by semi-continuous and batch processing

Supercritical Antisolvent Technique for the Production of Breathable Naringin Powder

Flavonoids are polyphenolic compounds largely present in fruits and vegetables possessing antioxidant properties, anti-inflammatory and antibacterial activities. Their use in clinical practice is very poor due to their low bioavailability, susceptibility to oxidation and degradation. Moreover, their slight solubility in biological fluids and a consequent low dissolution rate leads to an irregular absorption from solid dosage forms, even though, anti-inflammatory formulations could be used as support for several disease treatment, i.e. the COVID-19 syndrome. To improve flavonoid bioavailability particle size of the powder can be reduced to make it breathable and to promote the absorption in the lung tissues. Supercritical fluid based antisolvent technique has been used to produce naringin particles, with size, shape and density as well as free flowing properties able to fit inhalation needs. The dried particles are produced with the removal of the solvent at lower temperatures compared to the most used traditional micronization processes, such as spray drying. The best breathable fraction for naringin particles is obtained for particles with a d₅₀~7 µm manufactured at 35 °C-150 bar and at 60 °C-130 bar, corresponding to 32.6% and 36.7% respectively. The powder is produced using a high CO₂ molar fraction (0.99) that assure a better removal of the solvent. NuLi-1 cell line of immortalised bronchial epithelial cells adopted to evaluate powder cytotoxicity indicated after 24 h absence of toxicity at concentration of 25 µM.

Nanoparticles of Lovastatin: Design, Optimization and in vivo Evaluation

Introduction

The aim of the study was to optimize the processing factors of precipitation–ultrasonication technique to prepare nano-sized particles of Lovastatin (LA) for enhancing its solubility, dissolution rate and in vivo bioavailability.

Methods

LA nanoparticles (LANs) were prepared using precipitation–ultrasonication technique under different processing factors. LANs were characterized in terms of particle size, zeta potential and in vitro release. Stability studies at 4°C, 25°C and 40°C were conducted for optimum formulation. In addition, the in vivo bioavailability of the optimum formula was studied in comparison to a marketed product in white master rats.

Results

The optimized LAN formula (LAN15) had particle size (190±15), polydispersity index (0.626±0.11) and a zeta potential (−25±1.9 mV). The dissolution study of the nanosuspensions showed significant enhancement compared with pure drug. After 50 min, only 20.12±1.85% of LA was dissolved while 99.1±1.09% of LA was released from LAN15. Stability studies verified that nanosuspensions at 4°C and 25°C showed higher stability with no particle growth compared to the samples studied at 40°C. In vivo studies conducted in rats verified that there was 1.45-fold enhancement of C_max of LAN15 as compared to marketed tablets.

Conclusion

Nanoparticle prepared by ultrasonication-assisted precipitation method is a promising formula for enhancing the solubility and hence the bioavailability of Lovastatin.

Design of submicron and nanoparticle delivery systems using supercritical carbon dioxide-mediated processes: an overview

Supercritical carbon dioxide technology is an environmentally benign technique that allows precise control of particle morphology, while minimizing organic solvent use for a wide variety of biomedical and pharmaceutical applications. Supercritical carbon dioxide processes have benefits over the conventional particle formation methods in terms of improved control, flexibility and operational ease. This article gives an insight into a variety of supercritical fluid techniques relevant to drug formulation, recent advances and novel applications in the field of controlled delivery. These new methods have been designed to alleviate the scaling-up of the traditional methods for nanoparticle formulation either in the form of polymeric scaffolds, impregnation or nanoencapsules using a simple one-step process to produce micron-size particles.