Preparation and in vitro / in vivo evaluation of flurbiprofen nanosuspension-based gel for dermal application

Assessment of Flurbiprofen Suspension and Composite Gel Pre- and Post Skin Perforation: Effectiveness in Managing Inflammatory Responses in Ear Tags and Periocular Piercings

(1) Background: Controlled skin perforations, such as ear tags, piercings, and microdermal implants, induce inflammation and stress in individuals undergoing these procedures. This localized trauma requires care to optimize healing, reduce inflammation, and prevent infections. (2) Methods: Two formulations were developed: an FB-suspension and an FB-gel. Their in vivo efficacy was evaluated, along with drug retention in porcine and human skin after 30 min of administration, chemical stability at different temperatures, cytotoxicity, histological changes induced via transdermal application, and irritative potential, assessed using the HET-CAM assay. (3) Results: Both formulations reduced inflammation when applied 30 min before perforation compared to the positive control. The FB-suspension demonstrated no cytotoxicity and exhibited greater efficacy than the free flurbiprofen solution, highlighting the advantages of using nanoparticle-mediated drug delivery. Moreover, the FB-gel maintained chemical stability for up to 3 months across a temperature range of 4 to 40 °C. Histologically, no significant changes in skin composition were observed. (4) Conclusions: The FB-suspension is viable for both pre- and post-perforation application, as it is a sterile formulation. In contrast, the FB-gel is a convenient and easy application, making it a practical alternative for use in both clinical and veterinary settings.

Investigation of flurbiprofen pharmacokinetics in rats following dermal administration of optimized cyclodextrin-based nanogel

PURPOSE

The main purpose of this study was to optimize a cyclodextrin-based nanogel of flurbiprofen (FP) for prolonged dermal administration and evaluate its stability, in vitro release, ex vivo skin permeation, and in vivo pharmacokinetic profile.

METHODS

The nanogels were prepared via emulsification/solvent evaporation process and optimized through design of experiments. Optimal formulation was characterized via particle size (PS), polydispersity index (PDI), zeta potential (ZP), differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD), solubility, stability, in vitro release/ex vivo permeation studies and mathematical modeling, and pharmacokinetic studies conducted in rats. Results were compared to HPMC-based gel that was not nano-sized (i.e.FP-HPMC gel).

RESULTS

The PS, PDI and ZP values of optimal FP-loaded nanogel were 295.5 nm, 0.361 and -31.9 mV, respectively and it was stable for 12 months. In in vitro release studies, the flux from the optimal FP-loaded nanogel (96.3 µg/hcm2) was three times slower (i.e.more controlled) than that of the FP-HPMC gel (287 µg/hcm2); the permeability coefficient of the nanogel (0.015 cm/h) was slightly less than that of FP-HPMC gel (0.046 cm/h). Rat skin studies showed FP-loaded nanogel provided higher drug retention in the skin, compared to FP-HPMC gel. Mathematical modeling from rat skin permeation showed the Hixson-Crowell model was the best fitting model for FP-loaded nanogel, suggesting surface area of the nanogel is changing during the release process. In rat pharmacokinetic studies, the FB-loaded nanogel exhibited prolonged and flatter plasma profile than the FP-HPMC gel, consistent with the higher drug retention in the skin.

CONCLUSION

The optimized nanogel provided prolonged drug permeation and more sustained pharmacokinetic performance compared to FP-HPMC gel.

Nanotechnological Advances in Burn Wound Care: Silver Sulfadiazine-Loaded Nanosuspension-Based Chitosan-Incorporated Nanogel for Partial Thickness Burns

Burn lesions damage the skin's outermost defensive layer, allowing pathogenic microbes including Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli to infiltrate. Silver sulfadiazine (SSD) is an effective antibacterial agent approved by U.S. Food and Drug Administration (US-FDA) and is considered as the gold standard for burn wound treatment. Despite the high degree of efficacy of SSD in burn wound management, it possesses some drawbacks, such as poor solubility, low topical bioavailability and skin irritations. The present study endeavors to develop nanosuspension based SSD nanogel for improving the deliverability of SSD and its therapeutic outcomes for the management of partial thickness burn. The SSD nanosuspension was formulated employing controlled nanoprecipitation approach using various surfactants. The formulation was optimized utilizing one-factor-at-a-time approach and to fetch the optimized formulation of 134.6 nm size. The optimized nanosuspension was incorporated into chitosan gel that offer superior drug release potential, and also offered better spreadability (5.21 ± 0.38 g) and extrudability (152.27 ± 0.22 gm) that represents the easy application over the skin and extrusion of gel from the tube. The formulation was well tolerated as shown by skin irritation study and offered a superior burn lesion healing characteristics vis-à-vis the marketed product, even at a lower concentration. Hence, the formulation offers a huge potential in enhancing the clinical outcomes of SSD, especially in the management of partial thickness burn. The developed system with the above mentioned outcomes could be a promising delivery system for partial thickness burn wound management.

Olive oil and castor oil-based self-nanoemulsifying drug delivery system of flurbiprofen can relieve peripheral pain and inflammation through reduction of oxidative stress and inflammatory biomarkers: a comprehensive formulation and pharmacological insights

Flurbiprofen (FBP) is poorly water-soluble BCS class II drug with anti-inflammatory and analgesic effects, used to treat arthritis and degenerative joint diseases. This study was aimed to develop SNEDDS loaded with FBP. Six SNEDDS using two oils olive oil (F1OLV, F2OLV, F3OLV) and castor oil (F4CAS, F5CAS, F6CAS) with three different Smix ratios consisting of Tween 20 and PEG 400 (1:1, 1:2, 2:1) were prepared and characterized. Compatibility between FBP and polymers was investigated using FTIR. SNEDDS were characterized for physicochemical attributes. Two optimized formulations were investigated at 10 mg/kg dose given orally in Wistar rats for analgesic activity by hot plate and tail flick methods, and anti-inflammatory activity by carrageenan induced paw edema method. Anti-inflammatory activity was further explored by motor coordination and motility by Rota rod and cage activity tests. Following anesthesia blood samples were collected before dissection to measure inflammatory mediators and oxidative stress markers. Sciatica nerves and hind paws of rats were also removed for histopathological evaluation. FTIR studies revealed compatibility of FBP with other components. Droplet size of F1OLV, F2OLV, F3OLV was 128.5 ± 0.7 nm, 202.5 ± 1.3 nm, and 541.5 ± 1.7 nm, whereas it was 142.5 ± 1.1 nm, 215.4 ± 1.2 nm and 349.9 ± 1.8 nm for F4CAS, F5CAS, F6CAS. %EE of F1OLV, F2OLV, F3OLV was found 85 ± 4.89%-91 ± 4.67%, whereas the %EE F4CAS, F5CAS, F6CAS was 84 ± 4.15%-90 ± 4.21%. DSC curves of F1OLV and F4CAS revealed amorphous nature of the FBP. SEM showed spherical shape of globules. % of drug released in the pH medium 1.2 for plain FBP, F1OLV and F4CAS was 25%, 59% and 57%. % drug released in the pH 6.8 for plain FBP, F1OLV and F4CAS was 59%, 85% and 83%. Oral administration of FBP-loaded SNEDDS (F1OLV and F4CAS) significantly decreased paw diameter and enhanced motor coordination in rats when compared to the disease control group. This was linked to the ability of FBP to reduce inflammation and oxidative stress, with histological studies indicating decreased tissue damage in SNEDDS treated groups, implying the possibility of tissue recovery. Administration of both formulations started to demonstrate analgesic and anti-inflammatory effects after one hour of administration. In addition to anti-inflammatory effect, both formulations improved motor coordination, motility, and reduced infiltration of inflammatory cells in the inflamed paws. The anti-inflammatory and analgesic activities were attributed to decreased serum levels of IL-6 and TNF-α, increased activity of SOD and reduced nitrite content in sciatic nerves. Histopathological evaluation revealed reduced vascularity, inflammation and synovial hyperplasia. The overall findings suggest that the FBP loaded SNEDDS can be used as carriers for improved delivery of FBP which can effectively be used to cure pain and inflammation.

Development of Dermal Lidocaine Nanosuspension Formulation by the Wet Milling Method Using Experimental Design: In Vitro/In Vivo Evaluation

Lidocaine (LID), frequently used in dermal applications, is a nonpolar local anesthetic agent that is practically insoluble in water. The main aim of this study is to develop the nanosuspension formulation of LID using the design of experiments (DoE). The improved solubility and dissolution rate provided by nanosizing are expected to result in enhanced dermal bioavailability. Nanosuspension formulations were developed by a wet media milling method using different stabilizer types [poloxamer (POL) and poly(vinyl alcohol) (PVA)]. Characterization studies of the nanosuspensions were carried out using DSC, FTIR, XRD, and SEM in vitro release from the dialysis membrane and ex vivo permeation studies using rat skin were performed. Analgesic/anesthetic effects were evaluated using the tail-flick test in in vivo studies. Particle size (PS), polydispersity index (PDI), and zeta potential (ZP) values were found as 171.7 ± 3.52 nm, 0.251 ± 0.036, and -32.2 ± 0.907 mV for POL/LID nanosuspensions and 262.1 ± 29.42 nm, 0.453 ± 0.071, and -20.2 ± 3.50 mV for PVA/LID nanosuspensions, respectively. Compared to the coarse suspension of LID, it was determined that it accumulated in the skin approximately 1.81 times more in the POL/LID nanosuspension formulation and 1.79 times more in the PVA/LID nanosuspension formulation. According to analgesic effect and related AUC data, nanosuspension formulation was found to be statistically more effective than coarse suspension. It is concluded that DoE is a useful tool in determining process parameters when developing nanosuspensions by the wet media milling method, and POL is a suitable nonionic polymer to stabilize nanosuspensions.

Nanocrystals in Dermal Drug Delivery: A Breakthrough for Enhanced Skin Penetration and Targeted Skin Disorder Treatments

One of the major challenges in dermal drug delivery is the adequate penetration of the active compound into the skin without causing any skin irritation and inflammation. Nanocrystals (NCs) are nanoscale particles, and their sizes are below 1000 nm. NCs are made up of drug particles only, which are used to improve the aqueous solubility and bioavailability of poorly water-soluble drugs. NCs are typically prepared either by bottom-up or top-down techniques. The advantages of using NC-based formulations in enhancing dermal drug delivery include increased drug loading capacity, easier and deeper penetration into the skin tissue, and increased passive diffusion. NC-based formulations with the capacity of enhanced dermal drug delivery can be effectively used to treat a wide range of skin disorders, including melanoma, inflammation, psoriasis, acne vulgaris, bacterial infections, fungal infections, eczema, skin aging, herpes simplex virus infections, skin manifestations of tick bites, frostbite-related infections, hyperpigmentation, and diabetic foot ulcer. In this review, major challenges in dermal drug delivery across the skin barrier, mechanism of action of dermal NCs, advantages of using NCs in enhancing dermal drug delivery, NC preparation methods, and applications of NCs in the treatment of various skin disorders have been discussed.

Preparation and characterization of soluplus-based nanosuspension for dissolution enhancement of indomethacin using ultrasonic assisted precipitation method for formulation and Box-Behnken design for optimization

OBJECTIVES

Nanosuspensions are increasingly recognized as a valuable technology for enhancing poorly water-soluble drugs' solubility and dissolution rate, thereby improving their bioavailability. In this study, we employed ultrasonic-assisted precipitation to fabricate nanosuspensions of indomethacin (IND), utilizing Soluplus® (Sol) as a stabilizing agent. Our objectives were driven by hypotheses centered on optimizing formulation variables and developing predictive models for optimal IND formulations.

SIGNIFICANCE

This research highlights the Box-Behnken design (BBD) as a powerful tool that optimizes the properties of IND nanosuspensions, thus significantly enhancing their dissolution rate.

METHODS

The impacts of the independent variables on the mean particle size (MPS), polydispersity index (PDI), and zeta potential (ZP) were investigated using BBD. The optimized nanosuspension was freeze-dried with 3% trehalose to produce a dry nanosuspension (DNS). The DNS was characterized by SEM, DSC, XRPD, solubility, and dissolution.

RESULTS

The IND: Sol ratio and sonication power significantly affected the MPS and ZP of the nanosuspensions. The optimized formulation showed MPS, PDI, and ZP of 144.77 ± 6.68 nm, 0.26 ± 0.08, and -24.6 ± 1.90 mV, respectively. The DNS exhibited spherical particle morphology. The DSC and XRPD confirmed the amorphous state of IND with enhanced solubility and dissolution of IND. DNS showed a 3.7-fold increase in drug release in the first 15 min compared with raw IND.

CONCLUSIONS

This study demonstrated the critical role of BBD in accurately predicting the values of independent variables essential for formulating optimal nanosuspensions. These formulations possess specific properties that can be effectively integrated into various dosage forms tailored for different routes of administration.

Repurposing of Nano-Engineered Piroxicam as an Approach for Cutaneous Wound Healing

Drug repurposing is a potential strategy to overcome the huge economic expenses of wound healing products. This work aims to develop a topical gel of piroxicam encapsulated into a nanospanlastics vesicular system as an effective, dermal wound dressing. Firstly, piroxicam was entrapped into nanospanlastics formulations and optimized utilizing 23 full factorial experimental designs. The scrutinized factors were Span 60: Edge activator ratio, edge activator type, and permeation enhancer type. The measured responses were vesicle size (VS), polydispersity index (PDI), and% entrapment efficiency (EE). The optimized formula was further adopted into an alginate-pectin gel matrix to maximize adherence to the skin. The rheology and in-vitro release were studied for the developed nanospanlastics gel. Cytotoxicity and wound healing potential using scratch assay were assessed on human adult dermal fibroblast cells. The optimal piroxicam nanospanlastics formula demonstrated a VS of 124.1 ± 1.3 nm, PDI of 0.21 ± 0.01, and EE% of 97.27±0.21%. About 70.0 ± 0.9% and 57.4 ± 0.1% of piroxicam were released from nanospanlastics dispersion and gel within 24 h, respectively. Nanospanlastics gel of piroxicam flowed in a non-Newtonian pseudoplastic shear thinning pattern. It was also biocompatible with the human dermal fibroblast cells and significantly promoted their migration rate which suggests an auspicious cutaneous wound healing aptitude.

Carboxymethyl cellulose-based rotigotine nanocrystals-loaded hydrogel for increased transdermal delivery with alleviated skin irritation

Transdermal rotigotine (RTG) therapy is prescribed to manage Parkinson's disease (Neupro® patch). However, its use is suffered from application site reactions. Herein, drug nanocrystalline suspension (NS)-loaded hydrogel (NS-HG) employing polysaccharides simultaneously as suspending agent and hydrogel matrix was constructed for transdermal delivery, with alleviated skin irritation. RTG-loaded NS-HG was prepared using a bead-milling technique, employing sodium carboxylmethyl cellulose (Na.CMC) as nano-suspending agent (molecular weight 90,000 g/mol) and hydrogel matrix (700,000 g/mol), respectively. NS-HG was embodied as follows: drug loading: ≤100 mg/mL; shape: rectangular crystalline; crystal size: <286.7 nm; zeta potential: -61 mV; viscosity: <2.16 Pa·s; and dissolution rate: >90 % within 15 min. Nuclear magnetic resonance analysis revealed that the anionic polymers bind to RTG nanocrystals via charge interaction, affording uniform dispersion in the matrix. Rodent transdermal absorption of RTG from NS-HG was comparable to that from microemulsions, and proportional to drug loading. Moreover, NS-HG was skin-friendly; erythema and epidermal swelling were absent after repeated application. Further, NS-HG was chemically stable; >95 % of the drug was preserved up to 4 weeks under long term (25 °C/RH60%), accelerated (40 °C/RH75%), and stress (50 °C) storage conditions. Therefore, this novel cellulose derivative-based nanoformulation presents a promising approach for effective transdermal RTG delivery with improved tolerability.

Evaluation of Emulgel and Nanostructured Lipid Carrier-Based Gel Formulations for Transdermal Administration of Ibuprofen: Characterization, Mechanical Properties, and Ex-Vivo Skin Permeation

In transdermal applications of nonsteroidal anti-inflammatory drugs, the rheological and mechanical properties of the dosage form affect the performance of the drug. The aim of this study to develop emulgel and nanostructured lipid carrier NLC-based gel formulations containing ibuprofen, evaluate their mechanical properties, bioadhesive value and ex-vivo rabbit skin permeability. All formulations showed non-Newtonian pseudoplastic behavior and their viscosity values are suitable for topical application. The particle size of the nanostructured lipid carrier system was found to be 468 ± 21 nm, and the encapsulation efficiency was 95.58 ± 0.41%. According to the index of viscosity, consistency, firmness, and cohesiveness values obtained as a result of the back extrusion study, E2 formulation was found to be more suitable for transdermal application. The firmness and work of shear values of the E2 formulation, which has the highest viscosity value, were also found to be the highest and it was chosen as the most suitable formulation in terms of the spreadability test. The work of bioadhesion values of NLC-based gel and IBU-loaded NLC-based gel were found as 0.226 ± 0.028 and 0.181 ± 0.006 mJ/cm2 respectively. The percentages of IBU that penetrated through rabbit skin from the Ibuactive-Cream and the E2 were 87.4 ± 2.11% and 93.4 ± 2.72% after 24 h, respectively. When the penetration of ibuprofen through the skin was evaluated, it was found that the E2 formulation increased penetration due to its lipid and nanoparticle structure. As a result of these findings, it can be said that the NLC-based gel formulation will increase the therapeutic efficacy and will be a good alternative transdermal formulation.

Nanocomposite Gels Loaded with Flurbiprofen: Characterization and Skin Permeability Assessment in Different Skin Species

Nanocomposite gels consist of nanoparticles dispersed in a gel matrix. The main aim of this work was to develop nanocomposite gels for topical delivery of Flurbiprofen (FB) for humans and farm animals. Nanocomposite gels were prepared stemming from nanoparticles (NPs) freeze-dried with two different cryoprotectants, D-(+)-trehalose (NPs-TRE) and polyethylene glycol 3350 (NPs-PEG), sterilized by gamma (γ) irradiation, and gelled with Sepigel® 305. Nanocomposite gels with FB-NPs-TRE and FB-NPs-PEG were physiochemically characterized in terms of appearance, pH, morphological studies, porosity, swelling, degradation, extensibility, and rheological behavior. The drug release profile and kinetics were assessed, as well as, the ex vivo permeation of FB was assessed in human, porcine and bovine skin. In vivo studies in healthy human volunteers were tested without FB to assess the tolerance of the gels with nanoparticles. Physicochemical studies demonstrated the suitability of the gel formulations. The ex vivo skin permeation capacity of FB-NPs nanocomposite gels with different cryoprotectants allowed us to conclude that these formulations are suitable topical delivery systems for human and veterinary medicine. However, there were statistically significant differences in the permeation of each formulation depending on the skin. Results suggested that FB-NPs-PEG nanocomposite gel was most suitable for human and porcine skin, and the FB-NPs-TRE nanocomposite gel was most suitable for bovine skin.

The Use of Data Mining for Obtaining Deeper Insights into the Fabrication of Prednisolone-Loaded Chitosan Nanoparticles

The present work explores a data mining approach to study the fabrication of prednisolone-loaded chitosan nanoparticles and their properties. Eight PLC formulations were prepared using an automated adaptation of the antisolvent precipitation method. The PLCs were characterized using dynamic light scattering, infrared spectroscopy, and drug release studies. Results showed that that the effective diameter, loading capacity, encapsulation efficiency, zeta potential, and polydispersity of the PLCs were influenced by the concentration and molecular weight of chitosan. The drug release studies showed that PLCs exhibited significant dissolution enhancement compared to pure prednisolone crystals. Principal components analysis and partial least squares regression were applied to the infrared spectra and the DLS data to extract higher-order interactions and correlations between the critical quality attributes and the diameter of the PLCs. Principal components revealed that the spectra clustered according to the type of material, with PLCs forming a separate cluster from the raw materials and the physical mix. PLS was successful in predicting the ED of the PLCs from the FTIR spectra with R2 = 0.98 and RMSE = 27.18. The present work demonstrates that data mining techniques can be useful tools for obtaining deeper insights into the fabrication and properties of PLCs, and for optimizing their quality and performance. It also suggests that FTIR spectroscopy can be a rapid and non-destructive method for predicting the ED of PLCs.

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.

In Vitro and Biological Evaluation of Oral Fast-Disintegrating Films Containing Ranitidine HCl and Syloid® 244FP-Based Ternary Solid Dispersion of Flurbiprofen

Flurbiprofen (FBP), a nonsteroidal anti-inflammatory drug (NSAID), is commonly used to treat the pain of rheumatoid arthritis, but in prolonged use it causes gastric irritation and ulcer. To avoid these adverse events of NSAIDs, the simultaneous administration of H2 receptor antagonists such as ranitidine hydrochloride (RHCl) is obligatory. Here, we developed composite oral fast-disintegrating films (ODFs) containing FBP along with RHCl to provide a gastroprotective effect as well as to enhance the solubility and bioavailability of FBP. The ternary solid dispersion (TSD) of FBP was fabricated with Syloid® 244FP and poloxamer® 188 using the solvent evaporation technique. The synthesized FBP-TSD (coded as TSD) was loaded alone (S1) and in combination with plain RHCl (S2) in the composite ODFs based on hydroxypropyl methyl cellulose E5 (HPMC E5). The synthesized composite ODFs were evaluated by in vitro (thickness, folding endurance, tensile strength, disintegration, SEM, FTIR, XRD and release study) and in vivo (analgesic, anti-inflammatory activity, pro-inflammatory cytokines and gastroprotective assay) studies. The in vitro characterization revealed that TSD preserved its integrity and was effectively loaded in S1 and S2 with optimal compatibility. The films were durable and flexible with a disintegration time ≈15 s. The release profile at pH 6.8 showed that the solid dispersion of FBP improved the drug solubility and release when compared with pure FBP. After in vitro studies, it was observed that the analgesic and anti-inflammatory activity of S2 was higher than that of pure FBP and other synthesized formulations (TSD and S1). Similarly, the level of cytokines (TNF-α and IL-6) was also markedly reduced by S2. Furthermore, a gastroprotective assay confirmed that S2 has a higher safety profile in comparison to pure FBP and other synthesized formulations (TSD and S1). Thus, composite ODF (S2) can effectively enhance the FBP solubility and its therapeutic efficacy, along with its gastroprotective effect.

New Insights into Pharmaceutical Nanocrystals for the Improved Topical Delivery of Therapeutics in Various Skin Disorders

Nanotechnology has provided nanostructure-based delivery of drugs, among which nanocrystals have been investigated and explored for feasible topical drug delivery. Nanocrystals are nano-sized colloidal carriers, considered pure solid particles with a maximum drug load and a very small amount of stabilizer. The size or mean diameter of the nanocrystals is less than 1 μm and has a crystalline character. Prominent synthesis methods include the utilization of microfluidic- driven platforms as well as the milling approach, which is both adaptable and adjustable. Nanocrystals have shown a high capacity for loading drugs, utilization of negligible amounts of excipients, greater chemical stability, lower toxic effects, and ease of scale-up, as well as manufacturing. They have gained interest as drug delivery platforms, and the significantly large surface area of the skin makes it a potential approach for topical therapeutic formulations for different skin disorders including fungal and bacterial infections, psoriasis, wound healing, and skin cancers, etc. This article explores the preparation techniques, applications, and recent patents of nanocrystals for treating various skin conditions.

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.

Nanosuspensions technology as a master key for nature products drug delivery and In vivo fate

The drug nanosuspensions is a universal formulation approach for improved drug delivery of hydrophobic drugs and one the most promising approaches for increasing the biopharmaceutical performance of poorly water-soluble drug substances, especially for nature products. This review aimed to summarize the nanosuspensions preparation approaches and the main technological difficulties encountered in nanosuspensions development, such as guidelines for stabilizers screening, in vivo fate of the intravenously administrated nanosuspensions, and how to realize the intravenously target delivery was reviewed. Furthermore, challenges of nanosuspensions for the nature products delivery also was discussed and commented. Therefore, it hoped to provide reference and assistance for the nanosuspensions production, stabilizers usage, and predictability of in vivo fate and controllability of targeting delivery of the nature products nanosuspensions.

Nanocrystals as an emerging nanocarrier for the management of dermatological diseases

Skin conditions are amongst the most prevalent health issues in the world and come with a heavy economic, social, and psychological burden. Incurable and chronic skin conditions like eczema, psoriasis, fungal infections are linked to major morbidity in the manner of physical pain and a reduction in quality life of patients. Several drugs have difficulties for penetrating the skin due to the barrier mechanism of the skin layers and the incompatible physicochemical characteristics of the drugs. This has led to the introduction of innovative drug delivery methods. Currently, formulations depend on nanocrystals have indeed been researched for topical administration of drugs and have resulted in enhanced skin penetration. This review focuses on skin penetration barriers, modern methods to enhance topical distribution, and the use of nanocrystals to overcome these barriers. By means of mechanisms such as adherence to skin, creation of diffusional corona, targeting of hair follicles, and the generation of a greater concentration gradient throughout the skin, nanocrystals could enhance transport across the skin. Scientists working on product formulations incorporating chemicals that are "challenging-to-deliver" topically may find the most current findings to be of relevance.

Nanotechnology approach for exploring the enhanced bioactivities, biochemical characterisation and phytochemistry of freshly prepared Mentha arvensis L. nanosuspensions

INTRODUCTION

Mentha arvensis L. is the most valuable medicinal plant that possesses anti-inflammatory, hepatoprotective, antimicrobial, and antioxidant properties. There are few studies available in the literature about M. arvensis L nanoparticles, but their nanosuspensions-based information remains unclear and needs further study.

OBJECTIVE

This study was designed to explore the nanotechnology approach for biochemical characterisation, enhanced bioactivities, and photochemistry of freshly prepared M. arvensis L. nanosuspensions.

METHODOLOGY

Nanosuspensions of M. arvensis L. leaves were prepared by following the nanoprecipitation method. In this study, we performed structural and biochemical characterisation through analyses of Fourier-transform infrared (FTIR) spectroscopy, high-performance liquid chromatography (HPLC), phase contrast microscopy and enhanced bioactivities; antioxidant, alpha-amylase inhibition, glycation inhibition and cytotoxicity assays.

RESULTS

FTIR analysis revealed the presence of phenols, amines hydroxyl, carboxylic acid, alkenes, alkenes and alkynes. HPLC analysis revealed the presence of chlorogenic acid, a principal phenolic component. Biofilm inhibition activity revealed that the growth formation of Escherichia coli inhibited up to 62.4% and 53.35% by leaves extract and nanosuspension, respectively. However, the growth of Staphylococcus aureus was not inhibited by nanosuspension and extract. Nanosuspension and extract exhibited 155.92 mg, 108.11 mg gallic acids per 100 g of dry weight total phenolic content and 233.44 mg, 163.933 mg catechin per 100 g of dried weight total flavonoid content in extract and nanosuspension, respectively. Antioxidant activity revealed the scavenging potential of nanosuspensions and extract was 41.01% and 12.07%, respectively. Alpha-amylase inhibiting activity of nanosuspension and extract was 36% and 33%, while, the antiglycation potential of nanosuspension and extract were 41.68% and 35.18%, respectively. Nanosuspensions and extract showed maximum hemolytic activity at 12.91% and 17.18%, respectively.

CONCLUSION

These cost-effective nanoformulations could serve as a platform for therapeutic purposes in controlling the high risk of infectious diseases and designing efficient plant nanosuspensions by discovering novel bioactive compounds in an adequate manner.

Ritonavir nanosuspensions prepared by microfluidization with enhanced solubility and desirable immunological properties

The objective of this study was to develop ritonavir (RTV) nanosuspensions (NSs) by microfluidization method. Particle size (PS) measurements were performed by photon correlation spectroscopy. Amorphous properties of the particles were evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The dissolution studies were conducted in fed state simulated intestinal fluid (FeSSIF) medium. The flow cytometry was utilized to determine the lymphocyte sub-groups and immune response of NSs. RTV NSs were obtained with 400-500 nm PS. The crystal properties of RTV remain unchanged. The solubility of NS was enhanced five times. 57% and 18% of RTV were dissolved in FeSSIF medium for NSs and coarse powder. According to immunological studies, the prepared NSs did not significantly alter the ratio of CD4⁺/CD8⁺. Therefore, NSs may be a beneficial approach for the oral administration of RTV.

Clove Oil Endorsed Transdermal Flux of Dronedarone Hydrochloride Loaded Bilosomal Nanogel: Factorial Design, In vitro Evaluation and Ex vivo Permeation

The goal of this study was to develop a bilosomal gel formulation to enhance transdermal permeability of dronedarone hyrdrochloride (DRN) which suffers from poor oral absorption and limited bioavailability. To overcome this obstacle, bilosomes were successfully prepared using 2³ full-factorial design. Span®40, cholesterol, sodium deoxycholate (bile salt), clove oil (permeability enhancer), and either Tween® 60 or Tween® 80 (edge activator) were used in bilosome preparation by ethanol injection method. In this design, independent variables were X1, edge activator type; X2, edge activator amount (mg); and X3, permeability enhancer concentration (% w/v). Optimal formula (B2) of the highest desirability of (0.776) demonstrated minimum vesicle size (VS) of 312.4 ± 24.42 nm, maximum absolute value of zeta potential (ZP) - 36.17 ± 2.57 mV, maximum entrapment efficiency (EE %) of 80.95 ± 3.01%, maximum deformability Index (DI) of 8.24 ± 1.26 g and maximum drug flux after 12 h (J₁₂) of 21.23 ± 1.54 µg/cm² h upon ex vivo permeation study. After 12 h, 70.29 ± 6.46% of DRN was released from B2. TEM identification of B2 showed spherical shaped nanosized vesicles which were physically stable for 3 months at different temperatures. B2 was incorporated into carboxymethylcellulose gel base for easiness of dermal application. B2 gel demonstrated good physical properties, non-Newtonian psuedoplastic flow, and enhanced release (57.0 ± 8.68% of DRN compared to only 13.3 ± 1.2% released from drug suspension after 12 h) and enhanced skin permeation.

Observation of curcumin-loaded hydroxypropyl methylcellulose (HPMC) oleogels under in vitro lipid digestion and in situ intestinal absorption in rats

Curcumin-loaded nanostructured lipid carriers (Cur-NLCs)-based hydroxypropyl methylcellulose (HPMC) oleogels (Cur-NLCs-HPMC-OGs) were fabricated using a cryogel template. The effect of the HPMC viscosity grade on the oleogel characteristics and in situ intestinal absorption were examined. Highly stable Cur-NLCs were prepared with a mean particle size of 314 nm and polydispersity index of 0.275. Cur-NLCs affected the creamy texture of self-standing Cur-NLCs-HPMC-OGs. The Cur-NLCs were tightly packed as oil droplets in the network of HPMC. However, a high viscosity of HPMC-4000 led to a greater ability to entrap and prevent droplet coalescence compared to a low viscosity of HPMC-400. NLCs promoted the release of free fatty acids during in vitro lipid digestion, whereas HPMC-4000 maintained the strength and durability of oleogels against mechanical and enzymatic breakdown. The in situ loop results revealed higher curcumin absorption by Cur-NLCs-HPMC-OGs than by Cur-HPMC-OGs. HMPC-4000 showed slightly higher curcumin absorption compared to HPMC-400.

Beneath the Skin: A Review of Current Trends and Future Prospects of Transdermal Drug Delivery Systems

The ideal drug delivery system has a bioavailability comparable to parenteral dosage forms but is as convenient and easy to use for the patient as oral solid dosage forms. In recent years, there has been increased interest in transdermal drug delivery (TDD) as a non-invasive delivery approach that is generally regarded as being easy to administer to more vulnerable age groups, such as paediatric and geriatric patients, while avoiding certain bioavailability concerns that arise from oral drug delivery due to poor absorbability and metabolism concerns. However, despite its many merits, TDD remains restricted to a select few drugs. The physiology of the skin poses a barrier against the feasible delivery of many drugs, limiting its applicability to only those drugs that possess physicochemical properties allowing them to be successfully delivered transdermally. Several techniques have been developed to enhance the transdermal permeability of drugs. Both chemical (e.g., thermal and mechanical) and passive (vesicle, nanoparticle, nanoemulsion, solid dispersion, and nanocrystal) techniques have been investigated to enhance the permeability of drug substances across the skin. Furthermore, hybrid approaches combining chemical penetration enhancement technologies with physical technologies are being intensively researched to improve the skin permeation of drug substances. This review aims to summarize recent trends in TDD approaches and discuss the merits and drawbacks of the various chemical, physical, and hybrid approaches currently being investigated for improving drug permeability across the skin.

Nanocrystal-based gel of apremilast ameliorates imiquimod-induced psoriasis by suppressing inflammatory responses

Apremilast is 'difficult-to-deliver' in stratum corneum and viable layers (viable epidermis, dermis) owing to its modest lipophilicity and poor aqueous solubility, respectively. The objective of the present research was to develop apremilast nanocrystal-based gel for enhanced anti-psoriatic efficacy for the treatment of psoriasis. Nanosuspension was generated by wet media milling with a mean particle size of 200 nm. In-vivoefficacy of nanocrystal-based gels was evaluated in the imiquimod-induced psoriatic plaque model. Nanocrystal-based gel (1% and 3% w/w) improved phenotypic, histopathological features of psoriatic skin and attenuated splenic hypertrophy, psoriasis area severity scoring. Enzyme-linked immunosorbent assay was performed to evaluate levels of psoriatic biochemical markers indicating a significant decrease in the concentration of cytokines such as IL-23, IL-17A, IL-6 and TNF-α by nanocrystal-based gels (1% and 3% w/w) over disease induced group. Skin irritation study revealed that nanocrystal-based gel was significantly less irritating than the positive control. These results suggest that nanocrystal-based gel of apremilast can be an effective strategy for the management of psoriasis.

A new nanosuspension prepared with wet milling method for oral delivery of highly variable drug Cyclosporine A: Development, optimization and in vivo evaluation

Cyclosporine A (CsA) is a cyclic polypeptide, that has been widely used for immunosuppression. This study aims to develop nanosuspension for oral administration of CsA using the wet milling (WM) method one of the top-down technologies. The WM method was optimized by studying the effects of critical process parameters for WM on the particle size (PS), particle size distribution (PDI), and zeta potential (ZP) of nanosuspensions using the Design of Experiment (DoE) approach. Nanosuspension was developed using hydroxypropyl methylcellulose (HPMC) and sodium dodecyl sulfate (SDS) and in vitro characterization studies were performed. In vitro dissolution and in vivo pharmacokinetic studies were conducted with biorelevant media (fasted and fed state simulated fluids) and fasted and fed states in rats, respectively. In vivo immunological studies were also performed. PS, PDI, and ZP values for nanosuspension were approximately 600 nm, 0.4, -25 mV, respectively. The solubility of CsA was increased by 4.5-folds by nanosuspensions. Dissolution studies showed that nanosuspension had higher dissolution than the commercial product in the FeSSIF medium. The pharmacokinetic study indicated that AUC_0-24 values of CsA nanosuspension were to be 2.09 and 5.51-fold higher than coarse powder in fasted and fed conditions, respectively. Immunological studies were carried out after oral administration of nanosuspension for 21 days, the ratio of CD4+/CD8+ was found to be more acceptable than the commercial product. These results demonstrated that nanosuspension is a promising approach for increasing the bioavailability and avoiding the food effect on absorption of CsA which one of the highly variable drugs.

Development of cyclosporine A nanosuspension: cytotoxicity and permeability on Caco-2 cell lines

Cyclosporine A is a calcineurin inhibitor and is usually used as an immunosuppressant medication. The main purpose of this study is to develop nanosuspension of polypeptide cyclosporine A by using the wet milling method for oral administration. Cell culture studies were also performed with human intestinal Caco-2 cell lines. Hydroxypropyl methylcellulose and sodium dodecyl sulfate were used as stabilizers in nanosuspension. In vitro characterization studies such as Fourier-transform infrared analysis and morphological imaging with scanning electron microscopy have been carried out with obtained cyclosporine A nanosuspension. The particle size, particle size distribution, and zeta potential values of the nanosuspension were measured approximately 400 nm, 0.4, and -25 mV, respectively. The solubility of cyclosporine A was increased 4.5 times in nanosuspension compared to the coarse cyclosporine A powder. As a result of cytotoxicity studies conducted with different concentrations, it was decided to conduct permeability studies at a dose equivalent to 150 µg/mL cyclosporine A. Permeation studies have shown that the nanosuspension increases cyclosporine A transport by 5 and 1.5 times, respectively, compared to coarse powder and commercial product.

RETRACTED: Transdermal delivery of flurbiprofen from polyoxypropylene-polyoxyethylene block copolymer stabilized reduced graphene oxide to manage pain in spondylitis: In vitro and in vivo studies

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Significant similarities were noticed post-publication between this article and the article that was previously published by an apparently unrelated group of authors: Weifan Li, Guangqi Zhang and Xiaoxia Wei, Journal of Biomaterials Applications 35 (2021) 1034 https://doi.org/10.1177/0885328220988462. Moreover, the authors did not respond to the journal request to comment on these similarities and to provide the raw data, and the Editor-in-Chief decided to retract the article. One of the conditions of submission of a paper for publication is that authors declare explicitly that the paper has not been previously published and is not under consideration for publication elsewhere. As such this article represents an abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

A Recent Update on Drug Delivery Systems for Pain Management

Pain remains a global health challenge affecting approximately 1.5 billion people worldwide. Pain has been an implicit variable in the equation of human life for many centuries considering different types and the magnitude of pain. Therefore, developing an efficacious drug delivery system for pain management remains an open challenge for researchers in the field of medicine. Lack of therapeutic efficacy still persists, despite high throughput studies in the field of pain management. Research scientists have been exploiting different alternatives to curb the adverse side effects of pain medications or attempting a more substantial approach to minimize the prevalence of pain. Various drug delivery systems have been developed such as nanoparticles, microparticles to curb adverse side effects of pain medications or minimize the prevalence of pain. This literature review firstly provides a brief introduction of pain as a sensation and its pharmacological interventions. Second, it highlights the most recent studies in the pharmaceutical field for pain management and serves as a strong base for future developments. Herein, we have classified drug delivery systems based on their sizes such as nano, micro, and macro systems, and for each of the reviewed systems, design, formulation strategies, and drug release performance has been discussed.

Enhanced Dermal Delivery of Flurbiprofen Nanosuspension Based Gel: Development and Ex Vivo Permeation, Pharmacokinetic Evaluations

PURPOSE

The objective of this study was to optimize the Flurbiprofen (FB) nanosuspension (NS) based gel and to investigate the in vitro release, ex vivo permeation, the plasma concentration-time profile and pharmacokinetic parameters.

METHODS

FB-NSs were developed using the wet milling process with the Design of Experiment (DoE) approach. The optimum FB-NS was characterized on the basis of SEM, DSC, XRPD, solubility and permeation studies. The dermal gel was prepared by incorporating FB-NS into HPMC gel. Then the in-vitro release, ex vivo permeation studies were performed, and pharmacokinetic studies were evaluated on rats.

RESULTS

The particle size, polydispersity index and zeta potential values of optimum NS were determined as 237.7 ± 6.8 nm, 0.133 ± 0.030 and - 30.4 ± 0.7 mV, respectively. By means of the surfactant content and nanosized particles of the nanosuspension, the solubility of FB was increased about 7-fold. The percentage permeated amount of FB from FB-NS gel (8.40%) was also found to be higher than the physical mixture (5.25%) and coarse suspension (reference) (2.08%) gels. The pharmacokinetic studies showed that the C_max of FB-NS gel was 2.5 times higher than the reference gel, while AUC_0-24 was 2.96 times higher.

CONCLUSION

FB-NSs were successfully prepared with a wet milling method and optimized with the DoE approach. The optimized FB nanosuspension gel provided better permeation and pharmacokinetic performance compared to FB coarse suspension gel.