Amorphization technology has been the subject of continuous attention in the pharmaceutical industry, as a means to enhance the solubility of poorly water-soluble drugs. Being in a high energy state, amorphous formulations generally display significantly increased apparent solubility as compared to their crystalline counterparts, which may allow them to generate a supersaturated state in the gastrointestinal tract and in turn, improve the bioavailability. Conventionally, hydrophilic polymers have been used as carriers, in which the amorphous drugs were dispersed and stabilized to form polymeric amorphous solid dispersions. However, the technique had its limitations, some of which include the need for a large number of carriers, the tendency to recrystallize during storage, and the possibility of thermal decomposition of the drug during preparation. Therefore, emerging amorphization technologies have focused on the investigation of novel amorphous-stabilizing carriers and preparation methods that can improve the drug loading and the degree of amorphization. This review highlights the recent pharmaceutical approaches utilizing drug amorphization, such as co-amorphous systems, mesoporous particle-based techniques, and in situ amorphization. Recent updates on these technologies in the last five years are discussed with a focus on their characteristics and commercial potential.
Ginsenosides, dammarane-type triterpene saponins obtained from ginseng, have been used as a natural medicine for many years in the Orient due to their various pharmacological activities. However, the therapeutic potential of ginsenosides has been largely limited by the low bioavailability of the natural products caused mainly by low aqueous solubility, poor biomembrane permeability, instability in the gastrointestinal tract, and extensive metabolism in the body. To enhance the bioavailability of ginsenosides, diverse micro-/nano-sized delivery systems such as emulsions, polymeric particles, and vesicular systems have been investigated. The delivery systems improved the bioavailability of ginsenosides by enhancing solubility, permeability, and stability of the natural products. This mini-review aims to provide comprehensive information on the micro-/nano-sized delivery systems for increasing the bioavailability of ginsenosides, which may be helpful for designing better delivery systems to maximize the versatile therapeutic potential of ginsenosides.
1 September 2007 in Archives of Pharmacal Research
Ginsenosides, the major active ingredients of ginseng and other plants of the genus Panax, have been used as natural medicines in the East for a long time; in addition, their popularity in the West has increased owing to their various beneficial pharmacological effects. There is therefore a wealth of literature regarding the pharmacological effects of ginsenosides. In contrast, there are few comprehensive studies that investigate their pharmacokinetic behaviors. This is because ginseng contains the complicated mixture of herbal materials as well as thousands of constituents with complex chemical properties, and ginsenosides undergo multiple biotransformation processes after administration. This is a significant issue as pharmacokinetic studies provide crucial data regarding the efficacy and safety of compounds. Moreover, there have been many difficulties in the development of the optimal dosage regimens of ginsenosides and the evaluation of their interactions with other drugs. Therefore, this review details the pharmacokinetic properties and profiles of ginsenosides determined in various animal models administered through different routes of administration. Such information is valuable for designing specialized delivery systems and determining optimal dosing strategies for ginsenosides.
Cinnamaldehyde (CA) has been known to exhibit anti-inflammatory and anticancer effects. Although numerous pharmacological effects have been demonstrated, regulatory effect of CA on the functional activation of monocytes and macrophages has not been fully elucidated yet. To evaluate its monocyte/macrophage-mediated immune responses, macrophages activated by lipopolysaccharide (LPS), and monocytes treated with proaggregative antibodies, and extracellular matrix protein fibronectin were employed. CA was able to suppress both the production of nitric oxide (NO) and upregulation of surface levels of costimulatory molecules (CD80 and CD69) and pattern recognition receptors (toll-like receptor 2 (TLR2) and complement receptor (CR3)). In addition, CA also blocked cell-cell adhesion induced by the activation of CD29 and CD43 but not cell-fibronectin adhesion. Immunoblotting analysis suggested that CA inhibition was due to the inhibition of phosphoinositide-3-kinase (PI3K) and phosphoinositide-dependent kinase (PDK)1 as well as nuclear factor-(NF-)B activation. In particular, thiol compounds with sulphydryl group, L-cysteine and dithiothreitol (DTT), strongly abrogated CA-mediated NO production and NF-B activation. Therefore, our results suggest that CA can act as a strong regulator of monocyte/macrophage-mediated immune responses by thiolation of target cysteine residues in PI3K or PDK1.