Precise Dissolution Control and Bioavailability Evaluation for Insoluble Drug Berberine via a Polymeric Particle Prepared Using Supercritical CO₂

Current Advances in Nanotechnology-Mediated Delivery of Herbal and Plant-Derived Medicines

Phytomedicine has been used by humans since ancient times to treat a variety of diseases. However, herbal medicines face significant challenges, including poor water and lipid solubility and instability, which lead to low bioavailability and insufficient therapeutic efficacy. Recently, it has been shown that nanotechnology-based drug delivery systems are appropriate to overcome the above-mentioned limitations. The present review study first discusses herbal medicines and the challenges involved in the formulation of these drugs. The different types of nano-based drug delivery systems used in herbal delivery and their potential to improve therapeutic efficacy are summarized, and common techniques for preparing nanocarriers used in herbal drug delivery are also discussed. Finally, a list of nanophyto medicines that have entered clinical trials since 2010, as well as those that the FDA has approved, is presented.

Optimization of Hyaluronate-Based Liposomes to Augment the Oral Delivery and the Bioavailability of Berberine

Various perspectives had been utilized to enhance the poor intestinal permeability and bioavailability of drugs with low water solubility. Berberine (Brb) is a unique molecule that possesses multiple therapeutic activities such as antimicrobial, anti-inflammatory, antioxidant and anti-hyperglycemic effects. To improve Brb permeability and bioavailability, this study presents a newly developed formulation, namely Brb hyaluronate-based liposomes, prepared by using film hydration method and characterized by dynamic light scattering measurements, entrapment efficiency percentage (EE%), transmission electron microscope (TEM), in vitro drug release and physical stability. The bioavailability of the selected formulations was assessed in vivo after oral administration to rats. The results revealed an enhanced effect of hyaluronic acid on the entrapment efficiency, reaching 78.1 ± 0.1% with mean size 520.7 ± 19.9 nm. Sustained release of Brb was recorded up to 24 h in comparison to Brb solution. Physical stability was maintained for three months at refrigeration temperature. Results of pharmacokinetics studies indicated the potential of the liposomal formulation to increase the oral bioavailability of Brb and to accelerate its entry into the bloodstream. The obtained results are accredited to the lipophilic nature of the prepared system, resembling the structural features of bio-membrane, in addition to their small size that enhances intestinal penetration.

Berberine: A Promising Natural Isoquinoline Alkaloid for the Development of Hypolipidemic Drugs

Berberine, as a representative isoquinoline alkaloid, exhibits significant hypolipidemic activity in both animal models and clinical trials. Recently, a large number of studies on the lipid-lowering mechanism of berberine and studies for improving its hypolipidemic activity have been reported, but for the most part, they have been either incomplete or not comprehensive. In addition, there have been a few specific reviews on the lipid-reducing effect of berberine. In this paper, the physicochemical properties, the lipid-lowering mechanism, and studies of the modification of berberine all are discussed to promote the development of berberine as a lipid-lowering agent. Subsequently, this paper provides some insights into the deficiencies of berberine in the study of lipid-lowering drug, and based on the situation, some proposals are put forward.

Supercritical Carbon Dioxide as a Green Alternative to Achieve Drug Complexation with Cyclodextrins

Cyclodextrins are widely used in pharmaceutics to enhance the bioavailability of many drugs. Conventional drug/cyclodextrin complexation techniques suffer from many drawbacks, such as a high residual content of toxic solvents in the formulations, the degradation of heat labile drugs and the difficulty in controlling the size and morphology of the product particles. These can be overcome by supercritical fluid technology thanks to the outstanding properties of supercritical CO₂ (scCO₂) such as its mild critical point, its tunable solvent power, and the absence of solvent residue after depressurization. In this work the use of scCO₂ as an unconventional medium to achieve the complexation with native and substituted cyclodextrins of over 50 drugs, which belong to different classes, are reviewed. This can be achieved with different approaches such as the “supercritical solvent impregnation” and “particle-formation” techniques. The different techniques are discussed to point out how they affect the complexation mechanism and efficiency, the physical state of the drug as well as the particle size distribution and morphology, which finally condition the release kinetics and drug bioavailability. When applicable, the results obtained for the same drug with various cyclodextrins, or different complexation techniques are compared with those obtained with conventional approaches.

Formation of Rutin-β-Cyclodextrin Inclusion Complexes by Supercritical Antisolvent Precipitation

In this work, rutin (RUT)–β-cyclodextrin (β-CD) inclusion complexes are prepared by Supercritical AntiSolvent (SAS) precipitation. Well-defined composite microparticles are obtained at guest:host ratios equal to 1:2 and 1:1 mol:mol. The dimensions of composite particles range between 1.45 ± 0.88 µm and 7.94 ± 2.12 µm. The formation of RUT–β-CD inclusion complexes has been proved by different analyses, including Fourier transform infrared spectroscopy, Differential Scanning Calorimetry, X-ray diffraction, and UV-vis spectroscopy. The dissolution tests reveal a significant improvement in the release rate of RUT from inclusion complexes. Indeed, compared to the unprocessed RUT, the dissolution rate is about 3.9 and 2.4 times faster in the case of the complexes RUT–β-CD 1:2 and 1:1 mol:mol, respectively. From a pharmaceutical/nutraceutical point of view, CD-based inclusion complexes allow the reduction of the polymer amount in the SAS composite formulations.