Xingnaojing mPEG2000-PLA modified microemulsion for transnasal delivery: pharmacokinetic and brain-targeting evaluation

Intranasal delivery of herbal medicine for disease treatment: A systematic review

BACKGROUND

Intranasal administration has been adopted in traditional medicine to facilitate access to the bloodstream and central nervous system (CNS). In modern medicine, nasal drug delivery systems are valuable for disease treatment because of their noninvasiveness, good absorption, and fast-acting effects.

OBJECTIVE

This study aimed to systematically organize preclinical and clinical studies on intranasal herbal medicines to highlight their potential in drug development.

METHODS

A comprehensive search for literature until February 2023 was conducted on PubMed and the Web of Science. From the selected publications, we extracted key information, including the types of herbal materials, target diseases, intranasal conditions, methods of toxicity evaluation, main outcomes, and mechanisms of action, and performed quality assessments for each study.

RESULTS

Of the 45 studies, 13 were clinical and 32 were preclinical; 28 studies used herbal extracts, 9 used prescriptions, and 8 used natural compounds. The target diseases were rhinosinusitis, influenza, fever, stroke, migraine, insomnia, depression, memory disorders, and lung cancer. The common intranasal volumes were 8-50 µl in mice, 20-100 µl in rats, and 100-500 µl in rabbits. Peppermint oil, Ribes nigrum folium, Melia azedarach L., Elaeocarpus sylvestris, Radix Bupleuri, Da Chuan Xiong Fang, Xingnaojing microemulsion, and Ginsenoside Rb1 emerged as potential candidates for rapid intranasal therapy. The in vivo toxicity assessments were based on mortality, body weight, behavioral changes, mucociliary activity, histopathology, and blood tests. Most intranasal treatments were safe, except for Cyclamen europaeum, Jasminum sambac, Punica granatum L., and violet oil, which caused mild adverse effects. At lower doses, intranasal herbal treatments often show greater effects than oral administration. The actions of intranasal herbal medicine mainly involve regulating inflammation and neurotransmission, with the olfactory bulb and anterior cingulate cortex to be relevant brain regions.

CONCLUSION

Intranasal delivery of herbal materials holds promise for enhancing drug delivery efficacy and reducing treatment duration, offering a potential future perspective for developing intranasal therapies for various diseases.

Applications and research progress of Traditional Chinese medicine delivered via nasal administration

Nasal administration of Traditional Chinese medicine (TCM) has a long history of applications. With the gradual maturing of technology and pharmacological advances, nasal preparations of TCM have undergone significant changes. Nasal TCM formulations are used not only for treatment of pneumonia, asthma, sinusitis and allergic rhinitis but also Alzheimer's disease and Parkinson's disease, as antidepressants and antiepileptics, and in ischemia reperfusion. However, according to the analysis of nasal preparations of TCM currently on the market, most of them were compound preparations, which were used to treat allergic rhinitis (AR), common cold, headache and other local treatments, with a small range of diseases. At the same time, the dosage forms were mainly traditional dosage forms, aerosols and sprays, but there were no new dosage forms, which can not meet the clinical needs in terms of variety number, variety diversity and disease types. In this manuscript, we reviewed the development and applications of different nasal preparations of TCM from the aspects of nasal structure, origin, factors affecting absorption and common dosage forms, pharmacodynamics, targeting of nasal delivery and safety. In the near future, we expect that more nasal preparations of Chinese medicine with independent intellectual property rights will be marketed to meet the needs of clinical disease management.

Geniposide-Loaded Liposomes for Brain Targeting: Development, Evaluation, and In Vivo Studies

Geniposide (GE) possesses excellent neuroprotective effects but with poor brain targeting and short half-life. Liposome was considered to have great potential for brain diseases. Therefore, this research aimed to develop a geniposide liposome (GE-LP) as a brain delivery system for cerebral ischemia reperfusion injury (CIRI) therapy and evaluate its characterization, pharmacokinetics, brain targeting, and neuroprotective effects in vivo. Then, a reverse-phase evaporation method was applied to develop the GE-LP and optimize the formulation. Notably, the GE-LP had suitable size, which was 223.8 nm. Subsequently, the pharmacokinetic behavior of GE solution and GE-LP in mice plasma was investigated, and the brain targeting was also researched. The results showed that GE in plasma of GE-LP displayed three folds longer distribution half-life and a higher bioavailability and brain targeting compared to GE solution. In vivo neuroprotective effects was evaluated through the middle cerebral artery occlusion (MCAO) rat model, and GE-LP exhibited a stronger tendency in preventing the injury of CIRI, which can significantly improve neurological deficits. Overall, this study demonstrates GE-LP as a new formulation with ease of preparation, sustained release, and high brain targeting, which has significant development prospects on CIRI; this is expected to improve the efficacy of GE and reduce the frequency of administration.

Borneol: a Promising Monoterpenoid in Enhancing Drug Delivery Across Various Physiological Barriers

Incorporation of permeation enhancers is one of the most widely employed approaches for delivering drugs across biological membranes. Permeation enhancers aid in delivering drugs across various physiological barriers such as brain capillary endothelium, stratum corneum, corneal epithelium, and mucosal membranes that pose resistance to the entry of a majority of drugs. Borneol is a natural, plant-derived, lipophilic, volatile, bicyclic monoterpenoid belonging to the class of camphene. It has been used under the names "Bing Pian" or "Long Nao" in Traditional Chinese Medicine for more than 1000 years. Borneol has been incorporated predominantly as an adjuvant in the traditional Chinese formulations of centrally acting drugs to improve drug delivery to the brain. This background knowledge and anecdotal evidence have led to extensive research in establishing borneol as a permeation enhancer across the blood-brain barrier. Alteration in cell membrane lipid structures and modulation of multiple ATP binding cassette transporters as well as tight junction proteins are the major contributing factors to blood-brain barrier opening functions of borneol. Owing to these mechanisms of altering membrane properties, borneol has also shown promising potential to improve drug delivery across other physiological barriers as well. The current review focuses on the role of borneol as a permeation enhancer across the blood-brain barrier, mucosal barriers including nasal and gastrointestinal linings, transdermal, transcorneal, and blood optic nerve barrier.

Amphiphilic Block Copolymers: A Novel Substance for Bitter-Masking in Aqueous Solutions

It is a challenging task to suppress the bitterness of liquid preparations, especially for children. Bitter molecules are highly dispersible in liquids, leading to a strong and instant stimulation of the bitter receptors. At present, there is no effective way to correct this issue except for adding sweeteners, resulting in an unsatisfying taste. Based on the three-point contact theory, which is a universally accepted mechanism of bitterness formation, a new idea and application of amphiphilic block copolymers (ABCs) for bitterness suppression was proposed for the first time. We found that ABCs could widely inhibit the bitterness of four typical bitter substances. The mechanism is that ABCs self-assemble to form association colloids, which attract bitter components and reduce their distribution in the molecular form in solution. The bitter components were demonstrated to automatically embed in the spiral hydrophobic cavity of the hydrophobic chain of the ABCs, and their special interaction dispersed the positive electrostatic potential of bitter groups. The combination did not affect the pharmacokinetic parameters and pharmacodynamics of bitter drugs. These findings highlight the novel application of ABCs for the inhibition of bitterness and illuminate the underlying inhibition mechanisms.

An update on the role of nanovehicles in nose-to-brain drug delivery

A quantitative analysis has cast doubt over the limited advantages provided by particles for nose-to-brain (NTB) drug delivery. Thus, it is imperative to identify the role of nanovehicles in NTB drug delivery. If nanocarriers are used merely as an option to improve various properties of the drugs or the formulations, it is difficult for them to outperform conventional formulations, such as solutions or gels. However, nanovehicles bring about special features, such as maintenance of the solubilized state of drugs, sustained or delayed release, and enhanced penetration because of surface modifications, all of which lead to enhanced NTB delivery efficiency.