Preparation, Characterization, and Evaluation of Breviscapine Nanosuspension and Its Freeze-Dried Powder

Sorafenib tosylate-loaded nanosuspension: preparation, optimization, and in vitro cytotoxicity study against human HepG2 carcinoma cells

This study aimed to optimize nanosuspension of sorafenib tosylate (an anticancer hydrophobic drug molecule) using a central composite design. Nanosuspension was prepared using a nanoprecipitation-ultrasonication approach. FTIR and DSC analyses demonstrated that the drug and excipients were physicochemically compatible. X-ray powder diffraction analysis confirmed amorphous form of the payload in the formulation. The optimized formulation (batch NSS6) had a zeta potential of -18.1 mV, a polydispersity of 0.302, and a particle size of 97.11 nm. SEM analysis confirmed formation of rod-shaped particles. After 24 h, about 64.45% and 86.37% of the sorafenib tosylate was released in pH 6.8 and pH 1.2, respectively. The MTT assay was performed on HepG2 cell lines. IC50 value of the optimized batch was 39.4 µg/mL. The study concluded that sorafenib tosylate nanosuspension could be a promising approach in the treatment of hepatocellular cancer.

Combined Hydroxyethyl Starch Luteolin Nanocrystals for Effective Anti-Hyperuricemia Effect in Mice Model

Introduction

Although flavonoid compounds exhibit various pharmacological activities, their clinical applications are restricted by low oral bioavailability owing to their poor solubility. Nanocrystals (NCs) represent an excellent strategy for enhancing the oral bioavailability of flavonoids. Hydroxyethyl starch (HES), a biomaterial compound used as a plasma expander, could be an ideal stabilizer material for preparing flavonoid NCs.

Methods

HES was used to stabilize flavonoid nanocrystals (NCs), using luteolin (LUT) as a model drug. After full characterization, the freeze-drying and storage stability, solubility, intestinal absorption, pharmacokinetics, and in vivo anti-hyperuricemic effect of the optimized HES-stabilized LUT NCs (LUT-HES NCs) were investigated.

Results

Uniformed LUT-HES NCs were prepared with mean particle size of 191.1±16.8 nm, zeta potential of about -23 mV, drug encapsulation efficiency of 98.52 ± 1.01%, and drug loading of 49.26 ± 0.50%. The freeze-dried LUT-HES NCs powder showed good re-dispersibility and storage stability for 9 months. Notably, compared with the coarse drug, LUT-HES NCs exhibited improved saturation solubility (7.49 times), increased drug dissolution rate, enhanced Caco-2 cellular uptake (2.78 times) and oral bioavailability (Fr=355.7%). Pharmacodynamic studies showed that LUT-HES NCs remarkably lowered serum uric acid levels by 69.93% and ameliorated renal damage in hyperuricemic mice.

Conclusion

HES is a potential stabilizer for poorly soluble flavonoid NCs and provides a promising strategy for the clinical application of these compounds. LUT-HES NCs may be an alternative or complementary strategy for hyperuricemia treatment.

Freeze-drying revolution: unleashing the potential of lyophilization in advancing drug delivery systems

Lyophilization also known as freeze-drying is a technique that has been employed to enhance the long-term durability of nanoparticles (NPs) that are utilized for drug delivery applications. This method is used to prevent their instability in suspension. However, this dehydration process can cause stress to the NPs, which can be alleviated by the incorporation of excipients like cryoprotectants and lyoprotectants. Nevertheless, the freeze-drying of NPs is often based on empirical principles without considering the physical-chemical properties of the formulations and the engineering principles of freeze-drying. For this reason, it is crucial to optimize the formulations and the freeze-drying cycle to obtain a good lyophilizate and ensure the preservation of NPs stability. Moreover, proper characterization of the lyophilizate and NPs is of utmost importance in achieving these goals. This review aims to update the recent advancements, including innovative formulations and novel approaches, contributing to the progress in this field, to obtain the maximum stability of formulations. Additionally, we critically analyze the limitations of lyophilization and discuss potential future directions. It addresses the challenges faced by researchers and suggests avenues for further research to overcome these limitations. In conclusion, this review is a valuable contribution to the understanding of the parameters involved in the freeze-drying of NPs. It will definitely aid future studies in obtaining lyophilized NPs with good quality and enhanced drug delivery and therapeutic benefits.

Nanosuspension-Based Drug Delivery Systems for Topical Applications

Nanosuspensions have garnered recent attention as a promising strategy for mitigating the bioavailability challenges of hydrophobic drugs, particularly those characterized by poor solubility in both aqueous and organic environments. Addressing solubility issues associated with poorly water-soluble drugs has largely resolved the need to enhance drug absorption and bioavailability. As mucosal formulations and topical administration progress in the future, nanosuspension drug delivery, straightforward formulation techniques, and versatile applications will continue to be subjects of interest. Nanosuspensions have undergone extensive scrutiny in preparation for topical applications, encompassing ocular, pulmonary, and dermal usage. Among the numerous methods aimed at improving cutaneous application, nanocrystals represent a relatively recent yet profoundly intriguing approach. Despite the increasing availability of various nanosuspension products, primarily designed for oral administration, only a limited number of studies have explored skin permeability and drug accumulation in the context of nanosuspensions. Nevertheless, the scant published research unequivocally underscores the potential of this approach for enhancing cutaneous bioavailability, particularly for active ingredients with low to medium solubility. Nanocrystals exhibit increased skin adhesiveness in addition to heightened saturation solubility and dissolution rate, thereby augmenting cutaneous distribution. The article provides a comprehensive overview of nanosuspensions for topical application. The methodology employed is robust, with a well-defined experimental design; however, the limited sample size raises concerns about the generalizability of the findings. While the results demonstrate promising outcomes in terms of enhanced drug delivery, the discussion falls short of addressing certain limitations. Additionally, the references largely focus on recent studies, but a more diverse inclusion of historical perspectives could offer a more holistic view of the subject.

Preparation, characterization, and evaluation of the antitumor effect of kaempferol nanosuspensions

Kaempferol (KAE) is a naturally occurring flavonoid compound with antitumor activity. However, the low aqueous solubility, poor chemical stability, and suboptimal bioavailability greatly restrict its clinical application in cancer therapy. To address the aforementioned limitations and augment the antitumor efficacy of KAE, we developed a kaempferol nanosuspensions (KAE-NSps) utilizing D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) as a stabilizing agent, screened the optimal preparation process, and conducted a comprehensive investigation of their fundamental properties as well as the antitumor effects in the study. The findings indicated that the particle size was 186.6 ± 2.6 nm of the TPGS-KAE-NSps optimized, the shape of which was fusiform under the transmission electron microscope. The 2% (w/v) glucose was used as the cryoprotectant for TPGS-KAE-NSps, whose drug loading content was 70.31 ± 2.11%, and the solubility was prominently improved compared to KAE. The stability and biocompatibility of TPGS-KAE-NSps were favorable and had a certain sustained release effect. Moreover, TPGS-KAE-NSps clearly seen to be taken in the cytoplasm exhibited a stronger cytotoxicity and suppression of cell migration, along with increased intracellular ROS production and higher apoptosis rates compared to KAE in vitro cell experiments. In addition, TPGS-KAE-NSps had a longer duration of action in mice, significantly improved bioavailability, and showed a stronger inhibition of tumor growth (the tumor inhibition rate of high dose intravenous injection group was 68.9 ± 1.46%) than KAE with no obvious toxicity in 4T1 tumor-bearing mice. Overall, TPGS-KAE-NSps prepared notably improved the defect and the antitumor effects of KAE, making it a promising nanodrug delivery system for KAE with potential applications as a clinical antitumor drug.

Herbal Medicine Nanocrystals: A Potential Novel Therapeutic Strategy

Herbal medicines have gained recognition among physicians and patients due to their lower adverse effects compared to modern medicines. They are extensively used to treat various diseases, including cancer, cardiovascular issues, chronic inflammation, microbial contamination, diabetes, obesity, and hepatic disorders, among others. Unfortunately, the clinical application of herbal medicines is limited by their low solubility and inadequate bioavailability. Utilizing herbal medicines in the form of nanocrystals (herbal medicine nanocrystals) has shown potential in enhancing solubility and bioavailability by reducing the particle size, increasing the specific surface area, and modifying the absorption mechanisms. Multiple studies have demonstrated that these nanocrystals significantly improve drug efficacy by reducing toxicity and increasing bioavailability. This review comprehensively examines therapeutic approaches based on herbal medicine nanocrystals. It covers the preparation principles, key factors influencing nucleation and polymorphism control, applications, and limitations. The review underscores the importance of optimizing delivery systems for successful herbal medicine nanocrystal therapeutics. Furthermore, it discusses the main challenges and opportunities in developing herbal medicine nanocrystals for the purpose of treating conditions such as cancer, inflammatory diseases, cardiovascular disorders, mental and nervous diseases, and antimicrobial infections. In conclusion, we have deliberated regarding the hurdles and forthcoming outlook in the realm of nanotoxicity, in vivo kinetics, herbal ingredients as stabilizers of nanocrystals, and the potential for surmounting drug resistance through the utilization of nanocrystalline formulations in herbal medicine. We anticipate that this review will offer innovative insights into the development of herbal medicine nanocrystals as a promising and novel therapeutic strategy.

Nanocrystals in cosmetics and cosmeceuticals by topical delivery

The main issues with local delivery of cosmetics are their high sensitivity and limited drug loading of active pharmaceutical ingredient. Nanocrystal technology offers consumers cutting-edge and effective products and exhibits enormous development potential in the beauty business as a new delivery method to address the issue of low solubility and low permeability of sensitive chemicals. In this review, we described the processes for making NCs, along with the impacts of loading and the uses of different carriers. Among them, nanocrystalline loaded gel and emulsion are widely used and may further improve the stability of the system. Then, we introduced the beauty efficacy of drug NCs from five aspects: anti-inflammation and acne, anti-bacterial, lightening and freckle removal, anti-aging as well as UV protection. Following that, we presented the current scenario about stability and safety. Finally, the challenges and vacancy were discussed along with the potential uses of NCs in the cosmetics industry. This review serves as a resource for the advancement of nanocrystal technology in the cosmetics sector.

Formulation Strategies of Nanosuspensions for Various Administration Routes

Nanosuspensions (NSs), which are nanosized colloidal particle systems, have recently become one of the most interesting substances in nanopharmaceuticals. NSs have high commercial potential because they provide the enhanced solubility and dissolution of low-water-soluble drugs by means of their small particle sizes and large surface areas. In addition, they can alter the pharmacokinetics of the drug and, thus, improve its efficacy and safety. These advantages can be used to enhance the bioavailability of poorly soluble drugs in oral, dermal, parenteral, pulmonary, ocular, or nasal routes for systemic or local effects. Although NSs often consist mainly of pure drugs in aqueous media, they can also contain stabilizers, organic solvents, surfactants, co-surfactants, cryoprotectants, osmogents, and other components. The selection of stabilizer types, such as surfactants or/and polymers, and their ratio are the most critical factors in NS formulations. NSs can be prepared both with top-down methods (wet milling, dry milling, high-pressure homogenization, and co-grinding) and with bottom-up methods (anti-solvent precipitation, liquid emulsion, and sono-precipitation) by research laboratories and pharmaceutical professionals. Nowadays, techniques combining these two technologies are also frequently encountered. NSs can be presented to patients in liquid dosage forms, or post-production processes (freeze drying, spray drying, or spray freezing) can also be applied to transform the liquid state into the solid state for the preparation of different dosage forms such as powders, pellets, tablets, capsules, films, or gels. Thus, in the development of NS formulations, the components/amounts, preparation methods, process parameters/levels, administration routes, and dosage forms must be defined. Moreover, those factors that are the most effective for the intended use should be determined and optimized. This review discusses the effect of the formulation and process parameters on the properties of NSs and highlights the recent advances, novel strategies, and practical considerations relevant to the application of NSs to various administration routes.