Formulation Strategies of Nanosuspensions for Various Administration Routes

Combatting Acinetobacter baumannii pneumonia by multidrug codelivery of curcumin nanosuspensions and sulfamethoxazole with polymyxin B for targeted pediatric pulmonary inflammation and disease management

The bacterium Acinetobacter baumannii (A. baumannii) poses a severe clinical challenge due to its high drug resistance, driven by genetic adaptability, biofilm formation, enzymatic degradation, and facilitating healthcare-associated infections. In our present study, we described and to developed an innovative strategy for A. baumannii pneumonia using multidrug codelivery of curcumin nanosuspensions and sulfamethoxazole (SZ) with polymyxin B (PB) (CNS@SZ/PB). The physicochemical properties, drug release kinetics, antibacterial efficacy, and anti-biofilm activity of CNS@SZ/PB were comprehensively evaluated. In-vitro anti-bacterial analysis of CNS@SZ/PB exhibited potent bacterial inhibition against A. baumannii with a minimum inhibitory concentration (MIC) of 60 μg/mL, it also effectively prevented biofilm formation at 50 μg/mL. Furthermore, the pediatric pulmonary targeting ability of CNS@SZ/PB demonstrated effective moderation of lung inflammation, offering a promising way for managing pulmonary-associated diseases. In-vivo studies on mice infected with multidrug-resistant A. baumannii validated the significant protective effects of CNS@SZ/PB, attributed to its regulation of inflammatory factors. Overall, our findings highlight the therapeutic potential of CNS@SZ/PB as a promising approach for combating A. baumannii infections, providing a solid foundation for further experimental analysis of pediatric pulmonary inflammation and disease.

Costunolide nanosuspension loaded in dissolvable microneedle arrays for atopic dermatitis treatment

Transdermal drug delivery systems (TDDS) have garnered increasing attention due to their potential to overcome the limitations of the traditional oral route. This study developed a novel transdermal delivery system integrating costunolide nanosuspension (COS-NS) with dissolvable microneedles (DMN) to address the poor aqueous solubility and bioavailability of COS for atopic dermatitis (AD) treatment. COS-NS was prepared via antisolvent precipitation, stabilized with PVP K30 and SDS, and freeze-dried with mannitol (COS NS-M), yielding nanoparticles (203.42 ± 1.99 nm) with enhanced solubility (388.61 ± 9.35 μg/mL) and cumulative release (93.00 ± 2.92 % over 24 h). COS NS-M was incorporated into hyaluronic acid-based DMN (COS-DMN), demonstrating robust mechanical strength (0.12 N/needle) and efficient epidermal penetration (630 µm depth, 95 % success rate in mice skin). Pharmacokinetic studies in rats revealed superior transdermal performance for COS-DMN, achieving a Cmax of 26.30 ± 3.49 ng/mL and AUC0-24h of 210.80 ± 8.15 h·ng/mL, outperforming oral administration. In the 2,4-Dinitrochlorobenzene (DNCB)-induced AD mice model, COS-DMN (less than 10 % of the oral dose) significantly reduced skin thickness, pruritus scores, and inflammatory cytokines (IgE, TNF-α, IL-13) Histological and molecular analyses confirmed attenuated epidermal hyperplasia and inflammatory infiltration. These findings highlight COS-DMN as a minimally invasive, high-efficacy platform for transdermal delivery of hydrophobic therapeutics, offering a promising strategy for AD management.

Unveiling the Potential of Nanosuspension Formulation Strategy for Improved Oral Bioavailability of Gefitinib

Gefitinib (GB), an oral tyrosine kinase inhibitor suffers major setbacks in clinical application due to limited aqueous solubility leading to poor oral bioavailability. Nanosuspension serves as a promising formulation strategy to overcome the above-mentioned drawbacks. Hence, the present study involves the development of gefitinib nanosuspension (GB-NS) using High-pressure homogenization (HPH) to increase its aqueous solubility and maximize oral bioavailability. GB-NS was optimized by utilizing the quality-by-design strategy to optimize independent variables such as homogenization pressure, drug-to-stabilizer ratio, and number of cycles. Lecithin was found to stabilize the nanosuspension with optimal particle size, PDI, and zeta potential of 157 ± 18.77 nm, 0.296 ± 0.040, and -33.25 respectively. Intriguingly, a drug-to-stabilizer ratio significantly influenced (p < 0.005) particle size and PDI, establishing its crucial role in optimization. The morphological characterization by SEM of GB-NS revealed a rod-shaped structure. Thereafter, the thermal and powder X-ray analysis depicted the crystalline nature of gefitinib in GB-NS. Additionally, GB-NS exhibited enhanced saturation solubility (~ 2.4- and ~ 3.4-fold) and dissolution rate (~ 2.5- and ~ 3.5-fold) compared to pure GB in 0.1 N HCl and PBS 6.8 respectively. GB-NS remained stable under both storage conditions ( 25°C and 4°C). Finally, the pharmacokinetic study depicted a considerable increase in Cmax (~ 2.84-fold) and AUC(0-t) (~ 3.87-fold) of GB-NS when compared to free GB. Therefore, developed formulations showed a competent solution for enhancing the oral bioavailability of poor water-soluble drugs.

Herbal Nanoformulations for Diabetes: Mechanisms, Formulations, and Clinical Impact

BACKGROUND

Diabetes mellitus remains a global health challenge, demanding innovative therapeutic strategies. Herbal remedies have garnered attention for their potential in diabetes management, and recent advancements in nanotechnology have enabled the development of herbal nanoformulations with enhanced efficacy and bioavailability.

OBJECTIVE

This review aimed to comprehensively analyze the mechanisms, formulations, and clinical impact of herbal nanoformulations in managing diabetes mellitus.

METHOD

A systematic literature search was conducted to identify relevant studies exploring the mechanisms of action, various formulations, and clinical outcomes of herbal nanoformulations in diabetes management.

RESULT

Herbal nanoformulations exert their anti-diabetic effects through multiple mechanisms, including enhanced bioavailability, improved tissue targeting, and potentiation of insulin signaling pathways. Various herbal ingredients, such as bitter melon, fenugreek, and Gymnema sylvestre, have been encapsulated into nanocarriers, like liposomes, polymeric nanoparticles, and solid lipid nanoparticles, to enhance their therapeutic potential. Clinical studies have demonstrated promising results, showing improvements in glycemic control, lipid profile, and antioxidant status with minimal adverse effects.

CONCLUSION

Herbal nanoformulations represent a promising avenue for the management of diabetes mellitus, offering improved therapeutic outcomes compared to conventional herbal preparations. Further research is warranted to optimize formulation strategies, elucidate long-term safety profiles, and explore the potential synergistic effects of herbal nanoformulations in combination therapies for diabetes management.

Updates on the conversion of nanosuspensions to solid oral dosage forms

Pharmaceutical nanosuspensions, also called nanocrystals, are heterogeneous mainly aqueous dispersions of insoluble drug particles stabilised by surfactants and/or polymers. Nanosuspensions as liquid formulations suffer from instability. Solidification of nanosuspensions to solid dosage forms is a way to combine the advantages of nanocrystals with the advantages of the solid state. In this review, advances regarding stabilisation and production of nanosuspensions are briefly covered. Updates on the methods used to convert nanosuspensions to solid oral dosage forms (e.g., powder, granules, pellets, tablets, and films) are presented in depth. From these methods, spray drying and freeze drying are widely used. Granulation and hot-melt extrusion allow straightforward downstream processing, while printing exhibits the potential for dose personalisation. Focus is given on novel formulations (e.g., nano-cocrystals, nanocrystalline solid dispersions) which could further enhance the dissolution and bioavailability of poorly soluble drugs.

Dexamethasone nanocrystals-embedded hydroxypropyl methylcellulose hydrogel increases cochlear delivery and attenuates hearing loss following intratympanic injection

Herein, dexamethasone (DEX) nanocrystalline suspension (NS)-embedded hydrogel (NS-G) was constructed using a hydroxypropyl methylcellulose (HPMC) polymer to enhance cochlear delivery and attenuate hearing loss following intratympanic (IT) injection. Hydrophobic steroidal nanocrystals were prepared using a bead milling technique and incorporated into a polysaccharide hydrogel. The NS-G system with HPMC (average molecular weight, 86,000 g/mol; 15 mg/mL) was characterized as follows: rod-shaped drug crystalline; particle size <300 nm; and constant complex viscosity ≤1.17 Pa·s. Pulverization of the drug particles into submicron diameters enhanced drug dissolution, while the HPMC matrix increased the residence time in the middle ear cavity, exhibiting a controlled release profile. The IT NS-G system elicited markedly enhanced and prolonged drug delivery (> 9 h) to the cochlear tissue compared with that of DEX sodium phosphate (DEX-SP), a water-soluble prodrug. In mice with kanamycin- and furosemide-induced ototoxicity, NS-G markedly enhanced hearing preservation across all frequencies (8-32 kHz), as revealed by an auditory brainstem response test, compared with both saline and DEX-SP. Moreover, treatment with NS-G showed enhanced anti-inflammatory effects, as evidenced by decreased levels of inflammation-related cytokines. Therefore, the IT administration of DEX NS-loaded HPMC hydrogels is a promising strategy for treating hearing loss.

Nanocrystals and nanosuspensions: an exploration from classic formulations to advanced drug delivery systems

Nanocrystals and nanosuspensions have become realistic approaches to overcome the formulation challenges of poorly water-soluble drugs. They also represent a less-known but versatile platform for multiple therapeutic applications. They can be integrated into a broad spectrum of drug delivery systems including tablets, hydrogels, microneedles, microparticles, or even functionalized liposomes. The recent progresses, challenges, and opportunities in this field are gathered originally together with an informative case study concerning an itraconazole nanosuspension-in-hydrogel formulation. The translational aspects, historical and current clinical perspectives are also critically reviewed here to shed light on the incoming generation of nanocrystal formulations.

Advanced Drug Delivery Technologies for Enhancing Bioavailability and Efficacy of Risperidone

Multidisciplinary research has been conducted on novel drug delivery technologies to maximize therapeutic advantages while curtailing undesirable reactions. Drugs under BCS Class II often have a low bioavailability because the dissolution phase limits the absorption efficiency. In this review, risperidone was used as a pharmacological model to examine the impact of solubility enhancement at the primary administration site for such pharmaceuticals. For tackling drug-related pertains like disease diagnostics, therapy, and prophylactic measures at the cellular or molecular levels, implementing nanocarriers in therapeutics has significant potential. The comprehensive pharmaceutical compositions of risperidone nano-microparticles that have been developed to alleviate psychosis are highlighted in the study, which also illustrates potential future developments in such domains.

Spanlastic Nano-Vesicles: A Novel Approach to Improve the Dissolution, Bioavailability, and Pharmacokinetic Behavior of Famotidine

Background/Objectives: Drugs exhibiting poor aqueous solubility present a challenge to efficient delivery to the site of action. Spanlastics (a nano, surfactant-based drug delivery system) have emerged as a powerful tool to improve solubility, bioavailability, and delivery to the site of action. This study aimed to better understand factors affecting the physicochemical properties of spanlastics, quantify their effects, and use them to enhance the bioavailability of famotidine (FMT), a model histamine H2 receptor antagonist (BCS class IV). Methods: FMT was incorporated into nano-spanlastics drug delivery system. The ethanol injection method, Box-Behnken design, and mathematical modeling were utilized to fabricate famotidine-loaded nano-spanlastics and optimize the formula. Spanlastics were characterized for their particle size, polydispersity index, zeta potential, entrapment efficiency, drug loading, compatibility of the excipients (using DSC), in vitro drug release, and in vivo pharmacokinetics. Results: Span 60 (the non-ionic surfactant) and tween 60 (the edge activator) gave rise to spanlastics with the best characteristics. The optimal spanlastic formulation exhibited small particle size (<200 nm), appropriate polydispersity index (<0.4), and zeta potential (>-30 mV). The entrapment efficiency and drug loading of the optimum formula assured its suitability for hydrophobic drug entrapment as well as practicability for use. DSC assured the compatibility of all formulation components. The drug release manifested a biphasic release pattern, resulting in a fast onset and sustained effect. Spanlastics also showed enhanced Cmax, AUC0-24, and bioavailability. Conclusions: Spanlastics manifested improved FMT dissolution, drug release characteristics, membrane permeation, and pharmacokinetic behavior.

Tailoring Mesalazine Nanosuspension Using Chitosan Polyelectrolyte Complexes with Alginate and Alginate/Hydroxypropyl-Methylcellulose Phthalate

Background/Objectives: This study evaluated how the relative proportion of chitosan (CS) to the polyanions alginate (ALG) and hydroxypropyl-methylcellulose phthalate (HP) affects the colloidal properties of mesalazine (MSZ) nanosuspensions as a strategy to produce particles with specific characteristics. Methods: Nanosuspensions were prepared using a bottom-up approach based on acid-base reactions and were modified with CS in a binary mixture with ALG or a ternary mixture with ALG and HP. The particle size, polydispersity index (PDI), zeta potential, morphology, and drug association efficiency were analyzed. Results: Higher proportions of CS relative to the polyanions resulted in smaller, less polydisperse particles. The zeta potential inversion was influenced by the relative proportion of CS in the system. These results were consistent over 30 days and pH exerted an influence on the magnitude of the observed effect. The optimized NS modified with binary CS/ALG blends had the following properties at pH 6.0: an average particle size of 324.9 nm, PDI of 0.5, and zeta potential of +40.8 mV; at pH 4.0, it had an average particle size of 310.4 nm, PDI of 0.4, and zeta potential of +43.6 mV. The optimized NS modified with ternary CS/ALG/HP had the following properties at pH 6.0: an average particle size of 316.7 nm, PDI of 0.5, and zeta potential of +33.9 mV; at pH 4.0, it had an average particle size of 363.5 nm, PDI of 0.6, and zeta potential of +33.9 mV. Conclusions: CS-based polyelectrolyte complexes with ALG and ALG/HP offer an approach to modulating the properties of MSZ nanosuspensions, enabling the production of particles with tailored characteristics.

Contemporary strategies in glioblastoma therapy: Recent developments and innovations

Glioblastoma multiforme (GBM) represents one of the most prevailing and aggressive primary brain tumors among adults. Despite advances in therapeutic approaches, the complex microenvironment of GBM poses significant challenges in its optimal therapy, which are attributed to immune evasion, tumor repopulation by stem cells, and limited drug penetration across the blood-brain barrier (BBB). Nanotechnology has emerged as a promising avenue for GBM treatment, offering biosafety, sustained drug release, enhanced solubility, and improved BBB penetrability. In this review, a comprehensive overview of recent advancements in nanocarrier-based drug delivery systems for GBM therapy is emphasized. The conventional and novel treatment modalities for GBM and the potential of nanocarriers to overcome existing limitations are comprehensively covered. Furthermore, the updates in the clinical landscape of GBM therapeutics are presented in addition to the current status of drugs and patents in the same context. Through a critical evaluation of existing literature, the therapeutic prospect and limitations of nanocarrier-based drug delivery strategies are highlighted offering insights into future research directions and clinical translation.

Therapeutic efficiency of Tamoxifen/Orlistat nanocrystals against solid ehrlich carcinoma via targeting TXNIP/HIF1-α/MMP-9/P27 and BAX/Bcl2/P53 signaling pathways

BACKGROUND

Orlistat (Orli) is an anti-obesity medication that has been approved by the US Food and Drug Administration. It has relatively limited oral bioavailability with promising inhibitory effects on cell proliferation as well as reducing the growth of tumors.

AIMS

This investigation was done to evaluate the potential protective effect of Tamoxifen/Orlistat nanocrystals alone or in combination against Solid Ehrlich Carcinoma (SEC) and to clarify the possible underlying influences.

MATERIALS AND METHODS

The liquid antisolvent precipitation technique (bottom-up technology) was utilized to manufacture Orlistat Nanocrystals. To explore potential causes for the anti-tumor action, female Swiss Albino mice bearing SEC were randomly assigned into five equal groups (n = 6). Group 1: Tumor control group, group 2: Tam group: tamoxifen (0.01 g/kg, IP), group 3: Free-Orli group: orlistat (0.24 g/kg, IP), group 4: Nano-Orli: orlistat nanocrystals (0.24 g/kg, IP), group 5: Tam-Nano-Orli: Both doses of Tam and Nano-Orli. All treatments were administered for 16 days.

KEY FINDINGS

The untreated mice showed development in the tumor volume and weight. As well as histopathology results from these mice revealed many tumor large cells as well as solid sheets of malignant cells. Also, untreated mice showed raised VEGF and TGF-1beta content. Moreover, results of gene expression in the SEC-bearing mice noted upregulation in HIF-1α, MMP-9, Bcl-2, and P27 gene expression and downregulation of TXNIP, BAX, and P53 gene expression. On the other hand, administrated TAM, Free-Orli, Nano-Orli, and a combination of Tam-Nano-Orli distinctly suppressed the tumor effects on estimated parameters with special reference to Tam-Nano-Orli.

SIGNIFICANCE

The developed Tamoxifen/Orlistat nanocrystals combination could be considered a promising approach to augment antitumor effects.

Exploring Hydrogel Nanoparticle Systems for Enhanced Ocular Drug Delivery

Drug delivery to the ocular system is affected by anatomical factors like the corneal epithelium, blinking reflex, aqueous blood barrier, and retinal blood barrier, which lead to quick removal from the site and inefficient drug delivery. Developing a drug delivery mechanism that targets specific eye tissue is a major hurdle for researchers. Our study examines the challenges of drug absorption in these pathways. Hydrogels have been researched as a suitable delivery method to overcome some obstacles. These are developed alone or in conjunction with other technologies, such as nanoparticles. Many polymer hydrogel nanoparticle systems utilizing both natural and synthetic polymers have been created and investigated; each has pros and cons. The complex release mechanism of encapsulated agents from hydrogel nanoparticles depends on three key factors: hydrogel matrix swelling, drug-matrix chemical interactions, and drug diffusion. This mechanism exists regardless of the type of polymer. This study provides an overview of the classification of hydrogels, release mechanisms, and the role of controlled release systems in pharmaceutical applications. Additionally, it highlights the integration of nanotechnology in ocular disease therapy, focusing on different types of nanoparticles, including nanosuspensions, nanoemulsions, and pharmaceutical nanoparticles. Finally, the review discusses current commercial formulations for ocular drug delivery and recent advancements in non-invasive techniques. The objective is to present a comprehensive overview of the possibilities for enhancing ocular medication delivery through hydrogel nanoparticle systems.

Recent Advances in Nanotechnology for the Treatment of Dry Eye Disease

Dry eye disease (DED) incidence is continuously growing, positioning it to become an emergent health issue over the next few years. Several topical treatments are commonly used to treat DED; however, reports indicate that only a minor proportion of drug bioavailability is achieved by the majority of eye drops available on the market. In this context, enhancing drug ability to overcome ocular barriers and prolonging its residence time on the ocular surface represent a new challenge in the field of ocular carrier systems. Therefore, research has focused on the development of multi-functional nanosystems, such as nanoemulsions, liposomes, dendrimers, hydrogels, and other nanosized carriers. These systems are designed to improve topical drug bioavailability and efficacy and, at the same time, require fewer daily administrations, with potentially reduced side effects. This review summarizes the different nanotechnologies developed, their role in DED, and the nanotechnology-based eyedrops currently approved for DED treatment.

Minoxidil Nanosuspension-Loaded Dissolved Microneedles for Hair Regrowth

Minoxidil (MIN) is used topically to treat alopecia. However, its low absorption limits its use, warranting a new strategy to enhance its delivery into skin layers. The objective of this study was to evaluate the dermal delivery of MIN by utilizing dissolved microneedles (MNs) loaded with MIN nanosuspension (MIN-NS) for hair regrowth. MIN-NS was prepared by the solvent-antisolvent precipitation technique. The particle size of MIN-NS was 226.7 ± 9.3 nm with a polydispersity index of 0.29 ± 0.17 and a zeta potential of -29.97 ± 1.23 mV. An optimized formulation of MIN-NS was selected, freeze-dried, and loaded into MNs fabricated with sodium carboxymethyl cellulose (Na CMC) polymeric solutions (MIN-NS-loaded MNs). MNs were evaluated for morphology, dissolution rate, skin insertion, drug content, mechanical properties, ex vivo permeation, in vivo, and stability studies. MNs, prepared with 14% Na CMC, were able to withstand a compression force of 32 N for 30 s, penetrate Parafilm M® sheet at a depth of 374-504 µm, and dissolve completely in the skin within 30 min with MIN %recovery of 95.1 ± 6.5%. The release of MIN from MIN-NS-loaded MNs was controlled for 24 h. MIN-NS-loaded MNs were able to maintain their mechanical properties and chemical stability for 4 weeks, when kept at different storage conditions. The in vivo study of the freeze-dried MIN-NS and MIN-NS-loaded MNs proved hair regrowth on rat skin after 11 and 7 days, respectively. These results showed that MIN-NS-loaded MNs could potentially improve the dermal delivery of MIN through the skin to treat alopecia.

Novel nano-drug delivery system for natural products and their application

The development of natural products for potential new drugs faces obstacles such as unknown mechanisms, poor solubility, and limited bioavailability, which limit the broadened applicability of natural products. Therefore, there is a need for advanced pharmaceutical formulations of active compounds or natural products. In recent years, novel nano-drug delivery systems (NDDS) for natural products, including nanosuspensions, nanoliposomes, micelle, microemulsions/self-microemulsions, nanocapsules, and solid lipid nanoparticles, have been developed to improve solubility, bioavailability, and tissue distribution as well as for prolonged retention and enhanced permeation. Here, we updated the NDDS delivery systems used for natural products with the potential enhancement in therapeutic efficiency observed with nano-delivery systems.

Comparison of the pharmacokinetic characteristics and bioequivalence between two nanosuspension formulations of megestrol acetate in healthy Korean male subjects

Megestrol is commonly used to address appetite loss, cachexia, and significant weight loss in cancer or acquired immune deficiency syndrome patients. This study aimed to assess the pharmacokinetics and determine the bioequivalence of two orally administered megestrol acetate suspensions (625 mg/5 mL) in healthy Korean male subjects. A randomized, open-label, single-dose crossover study was conducted involving fifty-four healthy male subjects who were randomized into two sequence groups. Each subject received either a test or reference drug formulation of 625 mg/5 mL megestrol acetate with a two-week washout period between treatments. Plasma samples were collected before and up to 120 hours after administration, and their plasma drug concentrations were analyzed using validated liquid chromatography-mass spectrometry/mass spectrometry. The pharmacokinetic parameters were calculated, and bioequivalence was confirmed if the 90% confidence intervals of the geometric mean ratios were within the specified bounds of 80.00% to 125.00%. In total, fifty-two subjects completed the study, contributing to the pharmacokinetic analysis. The 90% confidence intervals for the geometric mean ratios of the test formulation compared to the reference formulation were 93.85% to 108.90% for maximum plasma concentration and 91.60% to 101.78% for area under the concentration-time curve from the point of administration to last time point of blood sampling. Throughout the study, no serious or unexpected adverse events were observed. The pharmacokinetic profiles of both formulations of megestrol acetate (625 mg) were comparable and well tolerated in healthy Korean male adult subjects. The test formulation met regulatory criteria for bioequivalence.

Trial Registration

ClinicalTrials.gov Identifier: NCT06147908.

Nanomedicines: Emerging Platforms in Smart Chemotherapy Treatment-A Recent Review

Cancer continues to pose one of the most critical challenges in global healthcare. Despite the wide array of existing cancer drugs, the primary obstacle remains in selectively targeting and eliminating cancer cells while minimizing damage to healthy ones, thereby reducing treatment side effects. The revolutionary approach of utilizing nanomaterials for delivering cancer therapeutic agents has significantly enhanced the efficacy and safety of chemotherapeutic drugs. This crucial shift is attributed to the unique properties of nanomaterials, enabling nanocarriers to transport therapeutic agents to tumor sites in both passive and active modes, while minimizing drug elimination from delivery systems. Furthermore, these nanocarriers can be designed to respond to internal or external stimuli, thus facilitating controlled drug release. However, the production of nanomedications for cancer therapy encounters various challenges that can impede progress in this field. This review aims to provide a comprehensive overview of the current state of nanomedication in cancer treatment. It explores a variety of nanomaterials, focusing on their unique properties that are crucial for overcoming the limitations of conventional chemotherapy. Additionally, the review delves into the properties and functionalities of nanocarriers, highlighting their significant impact on the evolution of nanomedicine. It also critically assesses recent advancements in drug delivery systems, covering a range of innovative delivery methodologies. Finally, the review succinctly addresses the challenges encountered in developing nanomedications, offering insightful perspectives to guide future research in this field.

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.

Key Challenges, Influencing Factors, and Future Perspectives of Nanosuspensions in Enhancing Brain Drug Delivery

Many brain diseases pose serious challenges to human life. Alzheimer's Disease (AD) and Parkinson's Disease (PD) are common neurodegenerative diseases that seriously threaten human health. Glioma is a common malignant tumor. However, drugs cannot cross physiological and pathological barriers and most therapeutic drugs cannot enter the brain because of the presence of the Blood-brain Barrier (BBB) and Bloodbrain Tumor Barrier (BBTB). How to enable drugs to penetrate the BBB to enter the brain, reduce systemic toxicity, and penetrate BBTB to exert therapeutic effects has become a challenge. Nanosuspension can successfully formulate drugs that are difficult to dissolve in water and oil by using surfactants as stabilizers, which is suitable for the brain target delivery of class II and IV drugs in the Biopharmaceutical Classification System (BCS). In nanosuspension drug delivery systems, the physical properties of nanostructures have a great impact on the accumulation of drugs at the target site, such as the brain. Optimizing the physical parameters of the nanosuspension can improve the efficiency of brain drug delivery and disease treatment. Therefore, the key challenges, influencing factors, and future perspectives of nanosuspension in enhancing brain drug delivery are summarized and reviewed here. This article aims to provide a better understanding of nanosuspension formulation technology used for brain delivery and strategies used to overcome various physiological barriers.

A New Approach for Preparing Stable High-Concentration Peptide Nanoparticle Formulations

The subcutaneous administration of therapeutic peptides would provide significant benefits to patients. However, subcutaneous injections are limited in dosing volume, potentially resulting in high peptide concentrations that can incur significant challenges with solubility limitations, high viscosity, and stability liabilities. Herein, we report on the discovery that low-shear resonant acoustic mixing can be used as a general method to prepare stable nanoparticles of a number of peptides of diverse molecular weights and structures in water without the need for extensive amounts of organic solvents or lipid excipients. This approach avoids the stability issues observed with typical high-shear, high-intensity milling methods. The resultant peptide nanosuspensions exhibit low viscosity even at high concentrations of >100 mg/mL while remaining chemically and physically stable. An example nanosuspension of cyclosporine nanoparticles was dosed in rats via a subcutaneous injection and exhibited sustained release behavior. This suggests that peptide nanosuspension formulations can be one approach to overcome the challenges with high-concentration peptide formulations.

Novel tetrahydrocurcumin integrated mucoadhesive nanocomposite κ-carrageenan/xanthan gum sponges: a strategy for effective local treatment of oral cancerous and precancerous lesions

Oral cancer is one of the leading causes of death worldwide. Oral precancerous lesions (OPL) are the precursors of oral cancer, with varying degrees of progression. Tetrahydrocurcumin (THC) is a major metabolite of curcumin with superior anticancer properties against various types of cancer. However, THC's clinical outcome is limited by its poor aqueous solubility. Herein, we developed novel mucoadhesive biopolymer-based composite sponges for buccal delivery of THC, exploiting nanotechnology and mucoadhesion for efficient prevention and treatment of oral cancer. Firstly, THC-nanocrystals (THC-NC) were formulated and characterized for subsequent loading into mucoadhesive composite sponges. The anticancer activity of THC-NC was assessed on a human tongue squamous carcinoma cell line (SCC-4). Finally, the chemopreventive activity of THC-NC loaded sponges (THC-NC-S) was examined in DMBA-induced hamster OPL. The selected THC-NC exhibited a particle size of 532.68 ± 13.20 nm and a zeta potential of -46.08 ± 1.12 mV. Moreover, THC-NC enhanced the anticancer effect against SCC-4 with an IC50 value of 80 µg/mL. THC-NC-S exhibited good mucoadhesion properties (0.24 ± 0.02 N) with sustained drug release, where 90% of THC was released over 4 days. Furthermore, THC-NC-S had a magnificent potential for maintaining high chemopreventive activity, as demonstrated by significant regression in the dysplasia degree and a decline in cyclin D1 (control: 40.4 ± 12.5, THC-NC-S: 12.07 ± 5.2), culminating in significant amelioration after 25 days of treatment. Conclusively, novel THC-NC-S represent a promising platform for local therapy of OPL, preventing their malignant transformation into cancer.

Overview of Recent Advances in Nano-Based Ocular Drug Delivery

Ocular diseases profoundly impact patients' vision and overall quality of life globally. However, effective ocular drug delivery presents formidable challenges within clinical pharmacology and biomaterial science, primarily due to the intricate anatomical and physiological barriers unique to the eye. In this comprehensive review, we aim to shed light on the anatomical and physiological features of the eye, emphasizing the natural barriers it presents to drug administration. Our goal is to provide a thorough overview of various characteristics inherent to each nano-based drug delivery system. These encompass nanomicelles, nanoparticles, nanosuspensions, nanoemulsions, microemulsions, nanofibers, dendrimers, liposomes, niosomes, nanowafers, contact lenses, hydrogels, microneedles, and innovative gene therapy approaches employing nano-based ocular delivery techniques. We delve into the biology and methodology of these systems, introducing their clinical applications over the past decade. Furthermore, we discuss the advantages and challenges illuminated by recent studies. While nano-based drug delivery systems for ophthalmic formulations are gaining increasing attention, further research is imperative to address potential safety and toxicity concerns.

Intravenous nanocrystals: fabrication, solidification, in vivo fate, and applications for cancer therapy

INTRODUCTION

Intravenous nanocrystals (INCs) have shown intrinsic advantages in antitumor applications, particularly their properties of high drug loading, low toxicity, and controllable size. Therefore, it has a very bright application prospect as a drug delivery system.

AREAS COVERED

The ideal formulation design principles, fabrication, solidification, in vivo fate of INCs, the applications in drug delivery system (DDS) and the novel applications are covered in this review.

EXPERT OPINION

It is vital to select a suitable formulation and fabrication method to produce a stable and sterile INCs. Besides, the type of stabilizers and physical characteristics can also influence the in vivo fate of INCs, which is worthy of further studying. Based on wide researches about applications of INCs in cancer, biomimetic INCs are concerned increasingly for its favorable compatibility. The output of these studies suggested that INCs-based drug delivery could be a novel strategy for addressing the delivery of the drug that faces solubility, bioavailability, and toxicity problems.