Unification of medicines and excipients: The roles of natural excipients for promoting drug delivery

INTRODUCTION

Drug delivery systems (DDSs) formed by natural active compounds be instrumental in developing new green excipients and novel DDS from natural active compounds (NACs). 'Unification of medicines and excipients'(UME), the special inherent nature of the natural active compounds, provides the inspiration and conduction to achieve this goal.

AREAS COVERED

This review summarizes the typical types of NACs from herbal medicine, such as saponins, flavonoids, polysaccharides, etc. that act as excipients and their main application in DDS. The comparison of the drug delivery systems formed by NACs and common materials and the primary formation mechanisms of these NACs are also introduced to provide a deepened understanding of their performance in DDS.

EXPERT OPINION

Many natural bioactive compounds, such as saponins, polysaccharides, etc. have been used in DDS. Diversity of structure and pharmacological effects of NACs turn out the unique advantages in improving the performance of DDSs like targeting ability, adhesion, encapsulation efficiency(EE), etc. and enhancing the bioavailability of loaded drugs.

Multifunctional Microspheres Based on D-Mannose and Resveratrol for Ciprofloxacin Release

This article describes the preparation, characterization, and performance evaluation of functional microspheres useful for the release of ciprofloxacin. The particles were obtained using D-mannose, a natural aldohexose sugar, and resveratrol, a powerful antioxidant. In particular, the above compounds were initially converted into D-mannose carboxylate and resveratrol methacrylate and, therefore, subjected to an esterification reaction. The resulting product was used for the preparation of the microspheres which were characterized by light scattering, FT-IR spectrophotometry and scanning electron microscopy (SEM). Subsequently, their degree of bloating was evaluated at pH 1.2 to simulate the pH of the stomach, at pH 6.8 and pH 7.4 to mimic the intestinal environment. The antibiotic ciprofloxacin was then loaded into the microspheres, with an encapsulation efficiency of 100%. The cumulative amount of drug released was 55% at pH 6.8 and 99% at pH 7.4. The tests conducted to evaluate the antibacterial activity demonstrated the ability of the microspheres obtained to inhibit the growth of Escherichia coli. The antioxidant efficacy, due to the presence of resveratrol in their structure, was confirmed using rat liver microsomal membranes. The results obtained have highlighted how the microspheres based on D-mannose and resveratrol can be considered promising multifunctional vectors useful in the treatment of intestinal and urinary infections.

Saponin surfactants used in drug delivery systems: A new application for natural medicine components

Saponins are a group of compounds widely distributed in the plant kingdom. Due to their amphiphilic characteristic structure, saponins have high surface activity and self-assembly property and can be used as natural biosurfactants. Therefore, saponin has become a potential drug delivery system (DDS) carrier and has attracted the attention of many researchers. Increasing studies have found that when drugs combining with saponins, their solubility or bioavailability are improved. This phenomenon may be due to a synergistic mechanism and provides a potentially novel concept for DDS: saponins may be also used for carrier materials. This review emphasized the molecular characteristics and mechanism of saponins as carriers and the research on the morphology of saponin carriers. Besides, the article also introduced the role and application of saponins in DDS. Although there are still some limitations with the application of saponins such as cost, applicability, and hemolysis, the development of technology and in-depth molecular mechanism research will provide saponins with greater application prospects as DDS carriers.