Case study: cremophor EL-based liquid formulations as simple substitutes for amorphous solid dispersions in early preclinical in vivo studies

OBJECTIVES

The objective of the present case study was to increase the exposure of the poorly soluble crystalline compound A.

METHODS

Mice received 10 mg/kg of crystalline compound A formulated in eight different cosolvent, oil, and cyclodextrin mixtures.

KEY FINDINGS

In all cases, AUC0-24h and maximum blood/plasma concentration (Cmax) were in the range of 6-16 µM × h and <1.4 µm, respectively, with a bioavailability below 18%. When 6% cremophor (CrEL) was added to three selected vehicles, AUC0-24h and Cmax increased ~5-10 times. The obtained pharmacokinetic profile of the most improved formulation using CrEL was possible to superimpose on the one obtained after administration of a CrEL-free amorphous solid dispersion (ASD, HPMC-AS:drug, 80:20) suspension of compound A.

CONCLUSIONS

It is crucial to find an optimal screen vehicle as early as possible for a poorly water-soluble lead series and then avoid time and resource-consuming vehicle testing of multiple compounds in vivo. An ASD approach is more suited for clinical development when more time and resources are allocated to the project. In this case study, some preclinical formulations were used to maximize exposure but also as preindicators for ASDs later in the development chain.

Nose-to-brain delivery of sorafenib-loaded lipid-based poloxamer-carrageenan nanoemulgel: Formulation and therapeutic investigation in glioblastoma-induced orthotopic rat model

Glioblastoma multiforme (GBM) has a poor clinical prognosis, where conventional treatment offers therapeutic limitations. Therefore, the current study introduces a first-of-its-kind sorafenib (SOR) nanoemulsion (SNE) loaded with poloxamer-carrageenan nanoemulgel (SPCNEG), a novel dual-functional and natural polymer-based payload system for effective intranasal chemotherapeutic administration. The nanoformulation was developed using carrageenan (a natural gelling agent), poloxamer (a mucoadhesive agent), glyceryl caprate as lipid, and Cremophor EL:PEG 400 blend as surfactant system. The improved biopharmaceutical attributes of developed formulations were confirmed from the release experiments, revealing augmentation in drug release from SNE (84.56 ± 3.78 %) and SPCNEG (68.62 ± 4.11 %) up to 3.41- and 8.12-fold compared to plain SOR. The ex vivo experiments showed a similar enhancement in drug permeation. Moreover, the SNE also showed superior performance on glioma cell lines, as indicated by lower IC50 (2.23 μg/mL) than plain SOR (16.61 μg/mL). The pharmacokinetic study revealed a 2.52- and 3.24-fold increase in SNE and SPCNEG brain concentration, respectively, compared to Soranib®. Additionally, a high correlation was also observed between in vitro drug release and in vivo absorption at prespecified time intervals for developed formulations. In conclusion, the current research promising and non-invasive alternative to existing interventions for enhanced brain targeting potential.

Glucuronidation of orally administered drugs and the value of nanocarriers in strategies for its overcome

The gastrointestinal tract (GIT) plays a pivotal role in the absorption of orally administered drugs, with the small intestine serving as the primary site due to its extensive surface area and specialized cell types, including enterocytes and M cells. After oral administration, drugs are generally transported via the portal vein to the liver, where they undergo first-pass metabolism. This process involves various enzymatic reactions, including glucuronidation, facilitated by uridine diphosphate-glucuronosyltransferase (UGT), a major phase 2 reaction in mammalian metabolism. UGTs conjugate glucuronic acid to a wide array of endogenous and exogenous substrates, enhancing their solubility and excretion, but significantly affecting the bioavailability and therapeutic efficacy of drugs. UGT enzymes are ubiquitously distributed across tissues, prominently in the liver, but also in the GIT, kidneys, brain, and other organs where they play crucial roles in xenobiotic metabolism. Species-specific differences in UGT expression and activity impact the selection of animal models for pharmacological studies. Various experimental models - ranging from computational simulations (in silico) to laboratory experiments (in vitro) and animal studies (in vivo) - are employed throughout drug discovery and development to evaluate drug metabolism, including UGT activity. Effective strategies to counter pre-systemic metabolism are critical for improving drug bioavailability. This review explores several approaches including prodrugs, co-administration of specific molecules or use of inhibiting excipients in formulations. Strategies incorporating these excipients in nanoformulations demonstrate notable increases in drug absorption and bioavailability. This review highlights the importance of targeted delivery systems and excipient selection in overcoming metabolic barriers, aiming to optimize drug efficacy and patient outcomes.

Alopecia Management Potential of Rosemary-Based Nanoemulgel Loaded with Metformin: Approach Combining Active Essential Oil and Repurposed Drug

Introduction

Androgenetic alopecia (AGA) is a multifactorial and age-related dermatological disease that affects both males and females, usually at older ages. Traditional hair repair drugs exemplified by minoxidil have limitations such as skin irritation and hypertrichosis. Thus, attention has been shifted to the use of repurposing drugs. Metformin is an anti-diabetic drug, that can promote hair follicle regeneration via upregulation of the hair-inductive capability. Hence, the current study aims to fabricate a safe and effective nanoemulsion to improve metformin efficacy in targeting AGA.

Methods

Rosemary oil was selected as the oily phase due to its ability to increase blood flow and hair growth. Rosemary-based nanoemulsions were statistically optimized by Box-Behnken experimental design, loaded with metformin, and incorporated into a hydrogel to form a nanoemulgel. Metformin-loaded nanoemulsions were assessed for their diametric size, uniformity, zeta potential, and metformin characteristics within the formulated nanosystem. The nanoemulgel was then evaluated in terms of its pH, percentage drug content, and in-vitro release performance. In-vivo study assessed the nanoemulgel's ability to augment hair growth in rats.

Results

The experimental design displayed that using 50%w/w, 20%w/w, and 10%w/w of Cremophor®, Labrafil®, and deionized water, respectively, resulted in nanoemulsion formulation with the smallest globule size (125.01 ± 0.534 nm), unimodal size distribution (PDI=0.103), negative surface charge (-19.9 ± 2.01 mV) with a spherical morphological structure. Rosemary-based nanoemulgel displayed acceptable physicochemical characterizations namely; a neutral pH value of 6.7±0.15, high drug content (92.9± 2.3%), and controlled metformin in-vitro release. Besides, the formulated nanoemulgel significantly increased the number of hair follicles in the animal model compared with other controls and tested groups.

Conclusion

The designed nanoemulgel is a promising approach for treating androgenic alopecia.

Preparation, In-vitro, Ex-vivo, and Pharmacokinetic Study of Lasmiditan as Intranasal Nanoemulsion-based In Situ Gel

BACKGROUND

Lasmiditan (LAS) is a recently developed antimigraine drug and was approved in October, 2019 for the treatment of acute migraines; however, it suffers from low oral bioavailability, which is around 40%.

OBJECTIVES

This study aimed to improve the LAS bioavailability via formulation as nanoemulsionbased in situ gel (NEIG) given intranasally and then compare the traditional aqueous-LASsuspension (AQS) with the two successful intranasal prepared formulations (NEIG 2 and NEIG 5) in order to determine its relative bioavailability (F-relative) via using rabbits.

METHODS

Two successfully prepared nanoemulsion (NE) formulas, a and b, were selected for the incorporation of different percentages of pH-sensitive in situ gelling polymer (Carbopol 934) to prepare NEIGs 1, 2, 3, 4, 5, and 6. The pH, gelation capacity, gel strength, and viscosity were predicted for the prepared NEIGs. The release (in vitro) and the nasal permeation (ex vivo) were determined for NEIG 2 and 5, and then both were subjected to pharmacokinetics in vivo studies. Eighteen male rabbits weighing 2.0 to 2.5 kg were employed in the parallel design study. The body surface area (BSA) normalization method was applied for LAS dose calculation. Serial blood samples were taken out and subjected to drug analysis using the HPLC method previously developed and validated by Kumar et al. Primary pharmacokinetics parameters, including maximum drug concentration in plasma (Cmax), time to reach C-max (T-max), and area under the concentration-time curve from time zero to affinity (AUCt0-∞) were calculated. Both NE (a and b), together with NEIG (2 and 5) formulas, were subjected to the stability study. Finally, a nasal ciliotoxicity study was carried out to evaluate the nasal toxicity of developed NEIGs 2 and 5.

RESULTS

The results showed that NEIGs 2 and 5 could be selected as the optimized NEIGs as both achieved 100% permeation within 20 min and then released within 25 and 35 min, respectively, thus achieving 3.3 folds with higher permeation percentages as compared to the AQS. Both NEIGs 2 and 5 exerted comparable release and permeation values as the corresponding NE a and b with more residence time in order to overcome the normal nasal physiological clearance. The values of C-max, Tmax, and AUC0- ∞ for NEIG 2 and NEIG 5 were 8066 ± 242 ng/ml, 0.75 ± 0.05 h, 19616.86 ± 589 ng. h/ml, and 7975.67 ± 239 ng/ml, 1.0 ± 0.05 h, 17912.36 ± 537 ng. h/ml, respectively, compared to the traditional AQS, which is equal to 4181.09 ± 125 ng/ml, 2 ± 0.2 h, and 8852.27 ± 266 ng. h/ml, respectively. It was discovered that NEIGs 2 and 5 had better intranasal delivery of LAS and could significantly (p < 0.05) achieve a higher value of permeability coefficient (3.3 folds) and 2.5 folds improvement in bioavailability when compared to AQS. The NE a, NE b, NEIG2, and NEIG5 formulations showed good stability at various temperatures. According to the nasal ciliotoxicity study, the nasal mucosal membrane, which was treated with NEIG 5, showed irritation with a bit of damage. However, damage was not observed when it was treated with NEIG 2, indicating the biocompatibility of the last one to be selected as the optimum formula.

CONCLUSION

NEIG 2 and NEIG 5 are promising new intranasal formulas with a faster onset of action and greater bioavailability than the oral dosage form (AQS). Finally, the selected optimum gold formula that will be ready for further clinical study is NEIG 2.

Antifungal Activity of Piperine-based Nanoemulsion Against Candida spp. via In Vitro Broth Microdilution Assay

Candidemia leaves a trail of approximately 750,000 cases yearly, with a morbidity rate of up to 30%. While Candida albicans still ranks as the most predominantly isolated Candida species, C. glabrata comes in second, with a death rate of 40-50%. Although infections by Candida spp are commonly treated with azoles, the side effects and rise in resistance against it has significantly limited its clinical usage. The current study aims to address the insolubility of piperine and provide an alternative treatment to Candida infection by formulating a stable piperine-loaded O/W nanoemulsion, comprised of Cremophor RH40, Transcutol HP and Capryol 90 as surfactant, co-surfactant, and oil, respectively. Characterization with zetasizer showed the droplet size, polydispersity (PDI) and zetapotential value of the nanoemulsion to be 24.37 nm, 0.453 and -21.10 mV, respectively, with no observable physical changes such as phase separation from thermostability tests. FTIR peaks confirms presence of piperine within the nanoemulsion and TEM imaging visualized the droplet shape and further confirms the droplet size range of 20-24 nm. The MIC90 value of the piperine-loaded nanoemulsion determined with in vitro broth microdilution assay was approximately 20-50% lower than that of the pure piperine in DMSO, at a range of 0.8-2.0 mg/mL across all Candida spp. tested. Overall, the study showed that piperine can be formulated into a stable nanoemulsion, which significantly enhances its antifungal activity compared to piperine in DMSO.

Therapeutic potential of limonene-based syringic acid nanoemulsion: Enhanced ex-vivo cutaneous deposition and clinical anti-psoriatic efficacy

Nanoemulsions have carved their position in topical delivery owing to their peculiar features of forming a uniform film on the skin and conquering stratum corneum barrier and hence fostering dermal penetration and retention. The present work developed syringic acid nanoemulsion (SA-NE) by spontaneous emulsification as an anti-psoriatic remedy via the dermal route. SA-NE were prepared with either lauroglycol90, limonene or their combination (oil phase) and tween80 (surfactant) with variable concentrations. The physicochemical characteristics of SA-NE were assessed together with Ex-vivo skin deposition and dermal toxicity. The effectiveness of optimal formula in psoriatic animal model and psoriatic patients was investigated using PASI scoring and dermoscope examination. Results showed that, SA-NE containing mixture of lauroglycol 90, limonene and 10 % tween80 (F5), was selected as the optimal formula presenting stable nanoemulsion for 2-month period, showing droplet size of 177.6 ± 13.23 nm, polydispersity index of 0.16 ± 0.06, zeta potential of -21.23 ± 0.41 mV. High SA% in different skin strata and no dermal irritation was noticed with limonene-based SA-NE also it showed high in-vitro anti- inflammatory potential compared to the blank and control formulations. A preclinical study demonstrated that limonene-based SA-NE is effective in alleviating psoriasis-like skin lesions against imiquimod-induced psoriasis in rats. Clinically, promising anti-psoriatic potential was asserted as all patients receiving F5 experienced better clinical improvement and response to therapy, achieving ≥ 50 % reduction in PASI scores versus only 35 % responders in the Dermovate® cream group. Collectively, the practical feasibility of limonene-based SA-NE topical delivery can boost curative functionality in the treatment of psoriatic lesions.

Effect of Cremophor RH40, Hydroxypropyl Methylcellulose, and Mixing Speed on Physicochemical Properties of Films Containing Nanostructured Lipid Carriers Loaded with Furosemide Using the Box-Behnken Design

This study aimed to examine the characteristics of H-K4M hydroxypropyl methylcellulose (HPMC) films containing nanostructured lipid carriers (NLCs) loaded with furosemide. A hot homogenization technique and an ultrasonic probe were used to prepare and reduce the size of the NLCs. Films were made using the casting technique. This study used a Box-Behnken design to evaluate the influence of three key independent variables, specifically H-K4M concentration (X1), surfactant Cremophor RH40 concentration (X2), and mixing speed (X3), on the physicochemical properties of furosemide-loaded NLCs and films. The furosemide-loaded NLCs had a particle size ranging from 54.67 to 99.13 nm, and a polydispersity index (PDI) ranging from 0.246 to 0.670. All formulations exhibited a negative zeta potential, ranging from -7.05 to -5.61 mV. The prepared films had thicknesses and weights ranging from 0.1240 to 0.2034 mm and 0.0283 to 0.0450 g, respectively. The drug content was over 85%. Film surface wettability was assessed based on the contact angle, ranging from 32.27 to 68.94°. Film tensile strength varied from 1.38 to 7.77 MPa, and their elongation at break varied from 124.19 to 170.72%. The ATR-FTIR analysis confirmed the complete incorporation of the drug in the film matrix. Therefore, the appropriate selection of values for key parameters in the synthesis of HPMC films containing drug-loaded NLCs is important in the effective development of films for medical applications.

Microemulsions based on Acer truncatum seed oil and its fatty acids: fabrication, rheological property, and stability

AIMS

To construct the microemulsion delivery system (ME) loading ATSO and NA and study their physicochemical characteristics to enhance their stability and water solubility.

METHODS

By plotting ternary phase diagrams, the composition and proportions of the MEs were determined. The physicochemical characteristics and stability of MEs were evaluated by mean diameter, polydispersity index (PDI), pH, electrical conductivity, transmission electron microscopy (TEM), rheological behaviour measurement, and phase inversion temperature (PIT).

RESULTS

The MEs was composed with EL-40 as a surfactant and specifically with the addition of ethanol as a cosurfactant in NA-loaded ME. The mean diameters of ATSO-loaded ME and NA-loaded ME were 39.65 ± 0.24 nm and 32.90 ± 2.65 nm, and PDI were 0.49 ± 0.01 and 0.28 ± 0.14, respectively. The TEM confirmed the spherical and smooth morphology of MEs. The rheological results indicated that MEs are dilatant fluids with the advantages of low viscosity, high fluidity, and tolerance to temperature fluctuations. The mean diameter and PDI of MEs showed no significant change after storage at 25 °C for 28 days and centrifugation.

CONCLUSION

The prepared microemulsions could expand the application prospects of ATSO and NA products in cosmetics, medicine, foods and other fields.

Isotretinoin self-nano-emulsifying drug delivery system: Preparation, optimization and antibacterial evaluation

Purpose

Isotretinoin (ITN) is a poorly water-soluble drug. The objective of this study was to design a successful liquid self-nanoemulsifying drug delivery system (L-SNEDDS) for ITN to improve its solubility, dissolution rate, and antibacterial activity.

Methods

According to solubility and emulsification studies, castor oil, Cremophor EL, and Transcutol HP were selected as system excipients. A pseudo ternary phase diagram was constructed to reveal the self-emulsification area. The developed SNEDDS were visually assessed, and the droplet size was measured. In vitro release studies and stability studies were conducted. The antimicrobial effectiveness against multiple bacterial strains, including Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and different accessory gene regulator (Agr) variants were investigated for the optimum ITN-loaded SNEDDS formulation.

Results

Characterization studies showed emulsion homogeneity and stability (%T 95.40-99.20, A graded) with low droplet sizes (31.87 ± 1.23 nm-115.47 ± 0.36 nm). It was found that the developed ITN-SNEDDS provided significantly a higher release rate (>96 % in 1 h) as compared to the raw drug (<10 % in 1 h). The in vitro antimicrobial activities of pure ITN and ITN-loaded SNEDDS demonstrated a remarkable inhibitory effect on bacterial growth with statistically significant findings (p < 0.0001) for all tested strains when treated with ITN-SNEDDS as compared to the raw drug.

Conclusion

These outcomes suggested that SNEDDS could be a potential approach for improving solubility, dissolution rates, and antibacterial activity of ITN.

Quality by design approach-based fabrication and evaluation of self-nanoemulsifying drug delivery system for improved delivery of venetoclax

Breast cancer is reported as one of the most prevalent non-cutaneous malignancies in women. Venetoclax (VEN) is an approved BCl-2 inhibitor for the treatment of chronic myeloid leukemia with very limited oral bioavailability and exhibits an enormous impact on breast cancer. In the current investigation, venetoclax-loaded self-nanoemulsifying drug delivery systems (VEN-SNEDDS) were designed and fabricated to improve the aqueous solubility, permeability, and anticancer efficacy of VEN. Various surface-active parameters of the reconstituted SNEDDS were determined to scrutinize the performance of the selected surfactant mixture. Central composite design (CCD) was used to optimize the VEN-SNEDDS. The globule size of reconstituted VEN-SNEDDS was 71.3 ± 2.8 nm with a polydispersity index of 0.113 ± 0.01. VEN-SNEDDS displayed approximately 3-4 fold, 6-7 fold, and 5-6 fold reduced IC50 as compared to free VEN in MDA-MB-231, MCF-7, and T47 D cells, respectively. VEN-SNEDDS showed greater cellular uptake, apoptosis, reactive oxygen species generation, and higher BAX/BCL2 ratio with decreased caspase 3 and 8 and BCL-2 levels in the MDA-MB-231 cells compared to pure VEN. VEN-SNEDDS exhibited approximately fivefold enhancement in Cmax and an improved oral bioavailability compared to VEN suspension in in vivo pharmacokinetic studies.

Fluconazole-Loaded Ibuprofen In Situ Gel-Based Oral Spray for Oropharyngeal Candidiasis Treatment

Oral candidiasis is a fungal infection affecting the oral mucous membrane, and this research specifically addresses on a localized treatment through fluconazole-loaded ibuprofen in situ gel-based oral spray. The low solubility of ibuprofen is advantageous for forming a gel when exposed to an aqueous phase. The 1% w/w fluconazole-loaded in situ gel oral sprays were developed utilizing various concentrations of ibuprofen in N-methyl pyrrolidone. The prepared solutions underwent evaluation for viscosity, surface tension, contact angle, water tolerance, gel formation, interface interaction, drug permeation, and antimicrobial studies. The higher amount of ibuprofen reduced the surface tension and retarded solvent exchange. The use of 50% ibuprofen as a gelling agent demonstrated prolonged drug permeation for up to 24 h. The incorporation of Cremophor EL in the formulations resulted in increased drug permeation and exhibited effective inhibition against Candida albicans, Candida krusei, Candida lusitaniae, and Candida tropicalis. While the Cremophor EL-loaded formulation did not exhibit enhanced antifungal effects on agar media, its ability to facilitate the permeation of fluconazole and ibuprofen suggested potential efficacy in countering Candida invasion in the oral mucosa. Moreover, these formulations demonstrated significant thermal inhibition of protein denaturation in egg albumin, indicating anti-inflammatory properties. Consequently, the fluconazole-loaded ibuprofen in situ gel-based oral spray presents itself as a promising dosage form for oropharyngeal candidiasis treatment.

Lomustine's nanoemulsion as nose-to-brain drug delivery system for CNS tumor treatment

Nose-to-brain delivery allows the direct targeting of drug molecules bypassing the Blood Brain Barrier and systemic effect. Nanoemulsion is one of the novel strategies to deliver drug in this route due to its simplicity in manufacturing, long-term stability, and strong solubilization property for drug. The anticancer drug lomustine had poor oral bioavailability in addition to its serious side effect, therefore, developing more effective drug delivery with direct targeting towards the brain through intra-nasal administration applying nanoemulsion technology is a promising alternative. The work involved lomustine solubility screening in oils, surfactants and cosurfactants as well as emulsifier ratio (Smix) nanoemulsion area was identified using pseudo-ternary phase diagrams. Eighteen nanoemulsion formulas were produced for optimization, then characterized for droplet size, polydispersity index, zeta potential, entrapment efficiency, conductivity, transmittance, dilution, visual transparency, physical stability and in vitro release. The optimum NE formula showed droplet size, zeta potential, polydispersity index, entrapment efficiency, %transmittance, conductivity of 31.31 nm, -30.65 mV, 0.159, 98.12%, 99.08%, and 951 us/cm, respectively. The best formula released 100% lomustine within 15 min which is a promising potential drug delivery system that may deliver the drug quickly and directly to the brain as a safe and effective alternative to oral delivery.

Nanoemulsion Loaded with Clotrimazole Based on Rapeseed Oil for Potential Vaginal Application-Development, Initial Assessment, and Pilot Release Studies

Vaginal candidiasis (VC) is an emerging global hardly treated health issue affecting millions of women worldwide. In this study, the nanoemulsion consisting of clotrimazole (CLT), rapeseed oil, Pluronic F-68, Span 80, PEG 200, and lactic acid was prepared using high-speed and high-pressure homogenization. Yielded formulations were characterized by an average droplet size of 52-56 nm, homogenous size distribution by volume, and a polydispersity index (PDI) < 0.2. The osmolality of nanoemulsions (NEs) fulfilled the recommendations of the WHO advisory note. NEs were stable throughout 28 weeks of storage. The stationary and dynamic (USP apparatus IV) pilot study of the changes of free CLT over time for NEs, as well as market cream and CLT suspension as references, were conducted. Test results of the changes in the amount of free CLT released from the encapsulated form were not coherent; in the stationary method, NEs yielded up to 27% of the released CLT dose within 5 h, while in the USP apparatus IV method, NEs released up to 10% of the CLT dose. NEs are promising carriers for vaginal drug delivery in the treatment of VC; however, further development of the final dosage form and harmonized release or dissolution testing protocols are needed.

A Full Factorial Design to Optimize Aminexil Nano Lipid Formulation to Improve Skin Permeation and Efficacy Against Alopecia

Aminexil (AMX) is considered to be one of the most widely used hair growth promoters. Nanostructured lipid carriers (NLC) are employed to increase the permeation of both lipophilic and hydrophilic drugs. Aminexil nanostructured lipid carrier (NLC) designed by pre-emulsion/ultrasonication method was utilized for alopecia treatment. For selecting optimum excipients, a solubility study was executed in liquid lipids, solid lipids, surfactants, and co-surfactants. A 2³ full factorial design was utilized for NLC optimization. Characterization of the developed formulas was performed. The penetration of the optimized formula across cuticle tissues was studied using confocal laser scanning microscopy (CLSM). AMX showed high solubility in glyceryl monostearate (GMS) and stearic acid, 28.87 ± 2.17 and 58.06 ± 2.227 mg/g, respectively. The results of physicochemical characterization showed that formula A7 was the optimized one. It is composed of GMS (solid lipid), oleic acid:garlic oil (1:1 v/v) (liquid lipid), and a surfactant/co-surfactant mixture (Cremophor EL/Transcutol HP). The particle size (PS) was 238.0 ± 2.13 nm, entrapment efficiency (EE) 100.535 ± 6.73%, and zeta potential (ZP) - 29.3 ± 0.93 mv. Ex vivo permeation study demonstrates the potential of AMX-NLC (formula A7) as a delivery system for AMX. The CLSM highly proved AMX-loaded NLC penetration through the skin. The histological study clearly demonstrated that AMX-loaded NLC promoted hair growth more effectively than the market product in chemotherapy-induced alopecia rats. The acquired findings revealed that targeting of AMX-loaded NLC into hair follicles was improved.

A QbD Approach to Design and to Optimize the Self-Emulsifying Resveratrol-Phospholipid Complex to Enhance Drug Bioavailability through Lymphatic Transport

Objectives: Despite having profound therapeutic value, the clinical application of resveratrol is restrained due to its <1% bioavailability, arising from the extensive fast-pass effect along with enterohepatic recirculation. This study aimed to develop a self-emulsifying formulation capable of increasing the bioavailability of resveratrol via lymphatic transport. Methods: The resveratrol−phospholipid complex (RPC) was formed by the solvent evaporation method and characterized by FTIR, DSC, and XRD analyses. The RPC-loaded self-emulsifying drug delivery system (SEDDS) was designed, developed, and optimized using the QbD approach with an emphasis on resveratrol transport through the intestinal lymphatic pathway. The in vivo pharmacokinetic study was investigated in male Wister Albino rats. Results: The FTIR, DSC, and XRD analyses confirmed the RPC formation. The obtained design space provided robustness of prediction within the 95% prediction interval to meet the CQA specifications. An optimal formulation (desirability value of 7.24) provided Grade-A self-emulsion and exhibited a 48-fold bioavailability enhancement compared to the pure resveratrol. The cycloheximide-induced chylomicron flow blocking approach demonstrated that 91.14% of the systemically available resveratrol was transported through the intestinal lymphatic route. Conclusions: This study suggests that an optimal self-emulsifying formulation can significantly increase the bioavailability of resveratrol through lymphatic transport to achieve the desired pharmacological effects.

Selective Targeting and Eradication of Various Human Non-Small Cell Lung Cancer Cell Lines Using Self-Assembled Aptamer-Decorated Nanoparticles

The leading cause of cancer mortality remains lung cancer (LC), of which non-small cell lung cancer (NSCLC) is the predominant type. Chemotherapy achieves only low response rates while inflicting serious untoward toxicity. Herein, we studied the binding and internalization of S15-aptamer (S15-APT)-decorated polyethylene glycol-polycaprolactone (PEG-PCL) nanoparticles (NPs) by various human NSCLC cell lines. All the NSCLC cell lines were targeted by S15-APT-decorated NPs. Confocal microscopy revealed variable levels of NP binding and uptake amongst these NSCLC cell lines, decreasing in the following order: Adenocarcinoma (AC) A549 cells > H2228 (AC) > H1299 (large cell carcinoma) > H522 (AC) > H1975 (AC). Flow cytometry analysis showed a consistent variation between these NSCLC cell lines in the internalization of S15-APT-decorated quantum dots. We obtained a temperature-dependent NP uptake, characteristic of active internalization. Furthermore, cytotoxicity assays with APT-NPs entrapping paclitaxel, revealed that A549 cells had the lowest IC50 value of 0.03 µM PTX (determined previously), whereas H2228, H1299, H522 and H1975 exhibited higher IC50 values of 0.38 µM, 0.92 µM, 2.31 µM and 2.59 µM, respectively (determined herein). Cytotoxicity was correlated with the binding and internalization of APT-NPs in the various NSCLC cells, suggesting variable expression of the putative S15 target receptor. These findings support the development of APT-targeted NPs in precision nanomedicine for individual NSCLC patient treatment.

A Cosmeceutical Topical Water-in-Oil Nanoemulsion of Natural Bioactives: Design of Experiment, in vitro Characterization, and in vivo Skin Performance Against UVB Irradiation-Induced Skin Damages

Introduction

Damage to human skin occurs either chronologically or through repetitive exposure to ultraviolet (UV) radiation, where collagen photodegradation leads to the formation of wrinkles and skin imperfections. Consequently, cosmeceutical products containing natural bioactives to restore or regenerate collagen have gained a remarkable attention as an ameliorative remedy.

Methods

This study aimed to develop and optimize collagen-loaded water-in-oil nanoemulsion (W/O NE) through a D-optimal mixture design to achieve an ideal multifunctional nanosystem containing active constituents. Vit E was included as a constituent of the formulation for its antioxidant properties to minimize the destructive impact of UV radiation. The formulated systems were characterized in terms of their globule size, optical clarity, and viscosity. An optimized system was selected and evaluated for its physical stability, in vitro wound healing properties, and in vivo permeation and protection against UV radiation. In addition, the effect of collagen-loaded NE was compared to Vit C-loaded NE and collagen-/Vit C-loaded NEs mixture as Vit C is known to enhance collagen production within the skin.

Results

The optimized NE was formulated with 25% oils (Vit E: safflower oil, 1:3), 54.635% surfactant/cosurfactant (Span 80: Kolliphor EL: Arlasolve, 1:1:1), and 20.365% water. The optimized NE loaded with either collagen or Vit C exhibited a skin-friendly appearance with boosted permeability, and improved cell viability and wound healing properties on fibroblast cell lines. Moreover, the in vivo study and histopathological investigations confirmed the efficacy of the developed system to protect the skin against UV damage. The results revealed that the effect of collagen-/Vit C-loaded NEs mixture was more pronounced, as both drugs reduced the skin damage to an extent that it was free from any detectable alterations.

Conclusion

NE formulated using Vit E and containing collagen and/or Vit C could be a promising ameliorative remedy for skin protection against UVB irradiation.

Topical non-aqueous nanoemulsion of Alpinia galanga extract for effective treatment in psoriasis: in vitro and in vivo evaluation

Non-aqueous nanoemulsion (NANE) of Alpinia galanga extract (AGE) was prepared using Palmester 3595 (MCT oil) as oil phase, Cremophor RH 40-Transcutol P® as surfactant-co-surfactant (S_mix), and glycerin as non-aqueous polar continuous phase. The composition was optimized by applying three-level, four factor Box-Behnken design (BBD). The mean droplet size and zeta potential of the optimized AGE NANE was found to be 60.81 ± 18.88 nm and -7.99 ± 4.14 mV, respectively. The ex vivo permeation studies of AGE NANE and AGE per se on porcine skin reported flux of 125.58 ± 8.36 µg/cm² h^-1 and 12.02 ± 1.64 µg/cm²h^-1, respectively. Therefore, the enhancement ratio has shown 10-folds increase in the flux for AGE NANE when compared to extract per se. Later, confocal laser scanning microcopy confirmed that AGE NANE were able to penetrate into skin's stratum by trans-follicular transport mechanism. The stability studies of AGE NANE confirmed its stability at 30 ± 2℃ /75 ± 5 % RH and 5 ± 3℃. The efficacy of AGE NANE was evaluated in vivo on imiquimod (IMQ) induced mouse model. The mice treated with low and high doses of AGE NANE (groups VI and VII) showed significant (p<0.05) amelioration of psoriasis. Results of histopathology indicated reduction in psoriasis area severity index in AGE NANE treated mice (group VI and group VII).

Reduced the Food Effect and Enhanced the Oral Bioavailability of Ivacaftor by Self-Nanoemulsifying Drug Delivery System (SNEDDS) Using a New Oil Phase

Purpose

The purpose of this work was to develop an ivacaftor self-nanoemulsion drug delivery system (IVA-SNEDDS) using the newly developed double headed miscellaneous lipid (DHML) as oil phase to reduce the food effect and inter-individual absorption variability of IVA.

Methods

The lipids with the greatest solubility to IVA were selected as the oil phase of IVA-SNEDDS by saturation solubility method. Then, among different surfactants and co-surfactants, those with good emulsifying ability for the selected oil phase were selected, and the proportion of surfactant and co-surfactant was further selected by pseudo-ternary phase diagram. The prepared IVA-SNEDDS were screened and evaluated in vitro and in beagle dogs.

Results

The optimized IVA-SNEDDS formulation consisting of DHML, Tween 80, and Transcutol HP with the weight ratio of 2:2:1 was physically stable and it was easy to disperse in water, pH 1.2 hydrochloric acid and pH 6.8 phosphate buffer solution, and generated a fine homogeneous nanoemulsion, with mean globule size less than 75 nm regardless of dilution ratio. In vitro drug release studies showed that the drug in IVA-SNEDDS could be completely released in a short time, while the drug release in IVA-suspension was less than 1% at 60 min. In vivo, using IVA-suspension (Fed) as a reference, the relative oral bioavailability of IVA-suspension (Fasted), IVA-SNEDDS (Fasted), and IVA-SNEDDS (Fed) were 23.35%, 153.63%, and 149.89%, respectively. This showed that IVA-SNEDDS could eliminate the positive food effect, improve the oral bioavailability, and reduce the IVA absorption difference between individuals.

Conclusion

As the oil phase of SNEDDS, DHML can significantly improve the drug solubility and drug loading of IVA-SNEDDS. Moreover, DHML was easily emulsified and can effectively form a nanoemulsion in vivo and in vitro. The prepared IVA-SNEDDS can reduce the inter-individual absorption variability of IVA, eliminate its food effect and improve its oral bioavailability.

Augmented experimental design for bioavailability enhancement: a robust formulation of abiraterone acetate

Abiraterone acetate (ABRTA) is clinically beneficial in management of metastatic castration-resistant prostate cancer (PC-3). With highlighted low solubility and permeability, orally hampered treatment of ABRTA necessitate high dose to achieve therapeutic efficacy. To triumph these challenges, we aimed to develop intestinal lymphatic transport facilitating lipid-based delivery to enhance bioavailability. ABRTA-containing self-nano emulsified drug delivery (ABRTA-SNEDDS) was statistically optimized by D-optimal design using design expert. Optimized formulation was characterized for particle size, thermodynamic stability, in vitro release, in vivo bioavailability, intestinal lymphatic transport, in vitro cytotoxic effect, anti-metastatic activity, and apoptosis study. Moreover, hemolysis and histopathology studies have been performed to assess pre-clinical safety. Nano-sized particles and successful saturated drug loading were obtained for optimized formulation. In vitro release upto 98.61 ± 3.20% reveal effective release of formulation at intestinal pH 6.8. ABRTA-SNEDDS formulation shows enhanced in vivo exposure of Abiraterone (2.5-fold) than ABRTA suspension in Sprague-Dawley rats. In vitro efficacy in PC-3 cell line indicates 3.69-fold higher therapeutic potential of nano drug delivery system. Hemolysis and histopathology study indicates no significant toxicities to red blood cells and tissues, respectively. Apparently, an opportunistic strategy to increasing bioavailability of ABRTA via intestinal lymphatic transport will create a viable platform in rapidly evolving chemotherapy. Enhanced translational utility of delivery was also supported through in vitro therapeutic efficacy and safety assessments. HighlightsAbiraterone acetate is a prostate cancer drug, impeded with low bioavailability.ABRTA loaded in self nano emulsifying drug delivery enhanced its bioavailability.Intestinal lymphatic transport played role in enhanced bioavailability of ABRTA.ABRTA-SNEDDS enhanced in vitro cytotoxic activity of ABRTA.ABRTA-SNEDDS found safe in preclinical safety evaluations.

Preparation of eugenol nanoemulsions for antibacterial activities

Eugenol is a versatile plant essential oil, but its high volatility and low water solubility greatly limit its application. Accordingly, this study prepared eugenol nanoemulsions by a high-speed shearing technique. Through visual inspection and a series of characterizations, including dynamic light scattering, and confocal laser scanning microscopy, the optimized formula was determined to be 5% (w/w) oil phase (eugenol) and 8% (w/w) surfactant (Tween-80), and the optimized shearing time was 5 min. The optimized nanoemulsion had good stability, small droplets (85 nm), and uniform distribution. At a concentration of 0.02 mg μL-1, the nanoemulsion showed strong inhibition against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Scanning electron microscopy (SEM) images showed severe deformation and membrane rupture of both bacteria treated by the nanoemulsion. This result was further confirmed by the leakage of proteins in both bacteria after treatment. The results of reactive oxygen species (ROS) and malondialdehyde (MDA) measurements indicated that the increased levels of ROS in both bacteria treated by the nanoemulsion triggered lipid peroxidation, thus increasing the MDA levels, ultimately causing changes in cell membrane permeability and disruption of the membrane structure. In addition, the nanoemulsion had a small effect on the proliferation and apoptosis of hepatocytes (L02) and lung cells (BEAS-2B), indicating its good biocompatibility. In this study, we developed a novel eugenol nanoemulsion with high stability and good biological activity, which may provide a promising and effective method for wound treatment in the healthcare area.

Non-ionic Surfactants as a P-Glycoprotein(P-gp) Efflux Inhibitor for Optimal Drug Delivery-A Concise Outlook

Significant research efforts have been devoted to unraveling the mystery of P-glycoprotein(P-gp) in drug delivery applications. The efflux membrane transporter P-gp is widely distributed in the body and accountable for restricting drug absorption and bioavailability. For these reasons, it is the primary cause of developing multidrug resistance (MDR) in most drug delivery applications. Therefore, P-gp inhibitors must be explored to address MDR and the low bioavailability of therapeutic substrates. Several experimental models in kinetics and dynamic studies identified the sensitivity of drug molecules and excipients as a P-gp inhibitor. In this review, we aimed to emphasize nonionic surface-active agents for effective reversal of P-gp inhibition. As it is inert, non-toxic, noncharged, and quickly reaching the cytosolic lipid membrane (the point of contact with P-gp efflux protein) enables it to be more efficient as P-gp inhibitors. Moreover, nonionic surfactant improves drug absorption and bioavailability through the various mechanism, involving (i) association of drug with surfactant improves solubilization, facilitating its cell penetration and absorption; (ii) weakening the lateral membrane packing density, facilitating the passive drug influx; and (iii) inhibition of the ATP binding cassette of transporter P-glycoprotein. The application of nonionic surfactant as P-gp inhibitors is well established and supported by various experiments. Altogether, herein, we have primarily focused on various nonionic surfactants and their development strategies to conquer the MDR-causing effects of P-gp efflux protein in drug delivery. Graphical Abstract.

Lipid-based nano-formulation platform for eplerenone oral delivery as a potential treatment of chronic central serous chorioretinopathy: in-vitro optimization and ex-vivo assessment

PURPOSE

Eplerenone (EPL) is a selective mineralocorticoid receptor antagonist used for treatment of chronic central serous chorioretinopathy which characterized by accumulation of subretinal fluid causing a localized area of retinal detachment. unfortunately, EPL suffers from poor oral bioavailability due to poor aqueous solubility in addition to high hepatic first pass metabolism.

METHOD

Aiming to improve its oral bioavailability, EPL-loaded nanostructured lipid carriers (NLCs) were prepared by the emulsification solvent evaporation method and in-vitro evaluated for particle size (PS), polydispersity index (PDI), zeta potential (ZP), and entrapment efficiency (EE%). A D-optimal design was used for study the effect of liquid lipid to solid lipid ratio, surfactant type and percentage on PS, PDI, EE%, and for data optimization. The optimized EPL-loaded NLCs system was further evaluated using in-vitro drug release and ex-vivo permeation studies through rabbit intestine in comparison to EPL aqueous suspension. The physicochemical properties of the drug in the optimized system were further examined using FT-IR and X-ray diffraction studies.

RESULTS

The resultant NLCs showed small PS (100.85-346.60 nm), homogenous distribution (0.173-0.624), negatively charged particles (ZP -20.20 to -36.75 mV), in addition to EE% (34.31-70.64%). The optimized EPL-loaded NLCs system with a desirability value of 0.905 was suggested through the Design expert® software, containing liquid to solid lipid ratio (2:1) in presence of 0.43%w/v Pluronic® F127 as a surfactant. The optimized EPL-loaded NLCs system showed a PS of 134 nm and PDI of 0.31, in addition to high EE% (76 ± 6.56%w/w), and ZP (-32.37 mV). The ex-vivo permeation study showed two-fold higher drug permeation through rabbit intestine compared to that from the aqueous drug suspension after 24 h, confirming the ability of optimized EPL-loaded NLCs system as successful oral targeting delivery carrier.

CONCLUSION

Our results pave the way for a new oral nanotherapeutic approach toward CSCR treatment. In-vivo study is currently under investigation.

Development and Evaluations of Transdermally Delivered Luteolin Loaded Cationic Nanoemulsion: In Vitro and Ex Vivo Evaluations

Introduction: Luteolin (LUT) is natural flavonoid with multiple therapeutic potentials and is explored for transdermal delivery using a nanocarrier system. LUT loaded cationic nanoemulsions (CNE1–CNE9) using bergamot oil (BO) were developed, optimized, and characterized in terms of in vitro and ex vivo parameters for improved permeation. Materials and methods: The solubility study of LUT was carried out in selected excipients, namely BO, cremophor EL (CEL as surfactant), labrasol (LAB), and oleylamine (OA as cationic charge inducer). Formulations were characterized with globular size, polydispersity index (PDI), zeta potential, pH, and thermodynamic stability studies. The optimized formulation (CNE4) was selected for comparative investigations (% transmittance as %T, morphology, chemical compatibility, drug content, in vitro % drug release, ex vivo skin permeation, and drug deposition, DD) against ANE4 (anionic nanoemulsion for comparison) and drug suspension (DS). Results: Formulations such as CNE1–CNE9 and ANE4 (except CNE6 and CNE8) were found to be stable. The optimized CNE4 based on the lowest value of globular size (112 nm), minimum PDI (0.15), and optimum zeta potential (+26 mV) was selected for comparative assessment against ANE4 and DS. The %T values of CNE1–CNE9 were found to be ˃95% and CEL content slightly improved the %T value. The spherical CNE4 was compatible with excipients and showed % total drug content in the range of 97.9–99.7%. In vitro drug release values from CNE4 and ANE4 were significantly higher than DS. Moreover, permeation flux (138.82 ± 8.4 µg/cm²·h), enhancement ratio (8.23), and DD (10.98%) were remarkably higher than DS. Thus, ex vivo parameters were relatively high as compared to DS which may be attributed to nanonization, surfactant-mediated reversible changes in skin lipid matrix, and electrostatic interaction of nanoglobules with the cellular surface. Conclusion: Transdermal delivery of LUT can be a suitable alternative to oral drug delivery for augmented skin permeation and drug deposition.

Enhanced Bioavailability of AC1497, a Novel Anticancer Drug Candidate, via a Self-Nanoemulsifying Drug Delivery System

AC1497 is an effective dual inhibitor of malate dehydrogenase 1 and 2 targeting cancer metabolism. However, its poor aqueous solubility results in low bioavailability, limiting its clinical development. This study was conducted to develop an effective self-nanoemulsifying drug delivery system (SNEDDS) of AC1497 to improve its oral absorption. Based on the solubility of AC1497 in various oils, surfactants, and cosurfactants, Capryol 90, Kolliphor RH40, and Transcutol HP were selected as the components of SNEDDS. After testing various weight ratios of Capryol 90 (20–30%), Kolliphor RH40 (35–70%), and Transcutol HP (10–35%), SNEDDS-F4 containing 20% Capryol 90, 45% Kolliphor RH40, and 35% Transcutol HP was identified as an optimal SNEDDS with a narrow size distribution (17.8 ± 0.36 nm) and high encapsulation efficiency (93.6 ± 2.28%). Drug release from SNEDDS-F4 was rapid, with approximately 80% of AC1497 release in 10 min while the dissolution of the drug powder was minimal (<2%). Furthermore, SNEDDS-F4 significantly improved the oral absorption of AC1497 in rats. The maximum plasma concentration and area under the plasma concentration–time curve of AC1497 were, respectively 6.82- and 3.14-fold higher for SNEDDS-F4 than for the drug powder. In conclusion, SNEDDS-F4 with Capryol 90, Kolliphor RH40, and Transcutol HP (20:45:35, w/w) effectively improves the solubility and oral absorption of AC1497.

Ocular microemulsion of brinzolamide: Formulation, physicochemical characterization, and in vitro irritation studies based on EpiOcular™ eye irritation assay

In recent years, the hydrophobic active substances have led researchers to develop new formulations to enhance bioavailability and dissolution rate; brinzolamide, a lipophilic drug belongs to carbonic anhydrase inhibitors, which cause reduction of intraocular pressure in patients suffering from glaucoma. Currently, the marketed product of brinzolamide is in the form of ocular drops; nonetheless, the conventional drops provide decreased therapeutic efficacy owing to their low bioavailability and pulsed drug release. Thus, the development of novel ocular formulations such as topical microemulsions is of high importance. In this work, the preparation of new microemulsions containing brinzolamide (0.2, 0.5 and 1% w/w) and comprised from isopropyl myristate, tween 80 and span 20 and Cremophor EL was performed. The obtained microemulsions were further characterized for their physicochemical properties. In addition, Fourier Transformed-Infrared spectroscopy was used touate the compatibility of active ingredients and components. In vitro release studies along with kinetic modeling were performed using the dialysis membrane method in simulated tear fluid. Bioadhesion studies were performed using Texture analysis. Finally, in vitro ocular irritation based on EpiOcular™ Eye Irritation Test and cytocompatibility studies was performed to examine any possible harm on ocular cells and predict in vivo safety profile.

Emulsion-Based Multicompartment Vaginal Drug Carriers: From Nanoemulsions to Nanoemulgels

In order to overcome the limitations associated with vaginal administration of drugs, e.g., the short contact time of the drug form with the mucosa or continuous carrier wash-out, the development of new carriers for gynecological use is necessary. Furthermore, high individual anatomical and physiological variability resulting in unsatisfactory therapeutic efficacy of lipophilic active substances requires application of multicompartment drug delivery systems. This manuscript provides an up-to-date comprehensive review of the literature on emulsion-based vaginal dosage forms (EVDF) including macroemulsions, microemulsions, nanoemulsions, multiple emulsions and self-emulsifying drug delivery systems. The first part of the paper discusses (i) the influence of anatomical-physiological conditions on therapeutic efficacy of drug forms after local and systemic administration, (ii) characterization of EVDF components and the manufacturing techniques of these dosage forms and (iii) methods used to evaluate the physicochemical and pharmaceutical properties of emulsion-based vaginal dosage forms. The second part of the paper presents (iv) the results of biological and in vivo studies as well as (v) clinical evaluation of EVDF safety and therapeutic efficacy across different indications.

Development and evaluation of surfactant-based elastic vesicular system for transdermal delivery of Cilostazole: ex-vivo permeation and histopathological evaluation studies

Cilostazole (CLZ) is an anti-platelet drug that suffers from extensive first pass-metabolism and gastrointestinal side effects. This study aimed to prepare spanlastics for enhancing the transdermal delivery of CLZ to avoid its oral problems. CLZ-loaded spanlastic dispersions were prepared by ethanol injection technique according to a 4¹3¹2¹ full factorial design to investigate the effect of formulation variables on entrapment efficiency (EE%), particle size (PS), zeta potential (ZP), and the percent of drug released after 2 and 24 h (Q2 and 24 h). Spanlastic-loaded gel of the optimized formula was prepared using hydroxypropyl methylcellulose (HPMC K4M). The optimum formula (F13), constitutes of Span60 and CremophoreRH40 at a weight ratio of 80:20 and distilled water for hydration, had the highest desirability value of (0.841) and exhibited the highest EE% of (69.29 ± 0.29%), PS of (452.7 ± 5.94 nm), ZP of (-32.6 ± 0.4 mV), Q 2 h of (33.28 ± 1.45%) and Q24h of (82.37 ± 1.37. F13 was subjected to ex-vivo permeation study and showed a cumulative amount permeated after 48 h(Q_48h) equal to (750.71 ± 3 μg/cm²) in comparison to the drug suspension which showed Q_48h equal to (190.20 ± 6.3 μg/cm²). Also, F13 showed an increase in the drug flux of (17.84 μg/cm².h) and enhancement ratio(ER) of (5.71 ± 0.1) in comparison to the drug suspension that showed drug flux of (3.12 ± 0.0 μg/cm².h). Spanlastics-loaded gel was subjected to an in-vitro release study compared to(F13) spanlastic dispersion and showed a more sustained release effect. In addition, histopathological studies showed no sign of skin alteration confirming safe delivery through the skin. CLZ showed promising results with high potential to be delivered transdermally.

Studies on Surfactants, Cosurfactants, and Oils for Prospective Use in Formulation of Ketorolac Tromethamine Ophthalmic Nanoemulsions

Nanoemulsions (NE) are isotropic, dispersions of oil, water, surfactant(s) and cosurfactant(s). A range of components (11 surfactants, nine cosurfactants, and five oils) were investigated as potential excipients for preparation of ketorolac tromethamine (KT) ocular nanoemulsion. Diol cosurfactants were investigated for the effect of their carbon chain length and dielectric constant (DEC), Log P, and HLB on saturation solubility of KT. Hen's Egg Test-ChorioAllantoic Membrane (HET-CAM) assay was used to evaluate conjunctival irritation of selected excipients. Of the investigated surfactants, Tween 60 achieved the highest KT solubility (9.89 ± 0.17 mg/mL), followed by Cremophor RH 40 (9.00 ± 0.21 mg/mL); amongst cosurfactants of interest ethylene glycol yielded the highest KT solubility (36.84 ± 0.40 mg/mL), followed by propylene glycol (26.23 ± 0.82 mg/mL). The solubility of KT in cosurfactants was affected by four molecular descriptors: carbon chain length, DEC, log P and HLB. KT solubility was directly proportional to DEC and the HLB yet, inversely proportional to carbon chain length and log P. All surfactants, except Labrasol ALF, were non-irritant. The majority of cosurfactants were slightly irritant, butylene glycol was a moderate irritant, pentylene and hexylene glycols were strong irritants. These findings will inform experiments aimed at developing NE formulations for ocular administration of KT.

Development of Self-Nanoemulsifying Drug Delivery Systems Containing 4-Allylpyrocatechol for Treatment of Oral Infections Caused by Candida albicans

Clinical use of 4-Allylpyrocatechol (APC), a potential antifungal agent from Piper betle, is limited because of its low water solubility. The current study explores the development of the self-nanoemulsifying drug delivery system (SNEDDS) containing APC (APC-SNEDDS) to enhance APC solubility. Results demonstrated that excipient type and concentration played an important role in the solubility of APC in the obtained SNEEDS. SNEDDS, comprising 20% Miglyol 812N, 30% Maisine 35-1, 40% Kolliphor RH40, and 10% absolute ethanol, provided the highest loading capacity and significantly increased water solubility of APC. Oil-in-water nanoemulsions (NE) with droplet sizes of less than 40 nm and a narrow size distribution were obtained after dispersing this APC-SNEDDS in water. The droplets had a negative zeta potential between -10 and -20 mV. The release kinetics of APC from APC-SNEDDS followed the Higuchi model. The NE containing 1.6 mg APC/mL had effective activity against Candida albicans with dose-dependent killing kinetics and was nontoxic to normal cells. The antifungal potential was similar to that of 1 mg nystatin/mL. These findings suggest that APC-SNEDDS are a useful system to enhance the apparent water solubility of APC and are a promising system for clinical treatment of oral infection caused by C. albicans.

Synthesis and Technology of Nanoemulsion-Based Pesticide Formulation

Declines in crop yield due to pests and diseases require the development of safe, green and eco-friendly pesticide formulations. A major problem faced by the agricultural industry is the use of conventional agrochemicals that contribute broad-spectrum effects towards the environment and organisms. As a result of this issue, researchers are currently developing various pesticide formulations using different nanotechnology approaches. The progress and opportunities in developing nanoemulsions as carriers for plant protection or nanodelivery systems for agrochemicals in agricultural practice have been the subject of intense research. New unique chemical and biologic properties have resulted in a promising pesticide nanoformulations for crop protection. These innovations-particularly the nanoemulsion-based agrochemicals-are capable of enhancing the solubility of active ingredients, improving agrochemical bioavailability, and improving stability and wettability properties during the application, thus resulting in better efficacy for pest control and treatment. All of these-together with various preparation methods towards a greener and environmentally friendly agrochemicals-are also discussed and summarized in this review.

Self-Nanoemulsifying Drug Delivery Systems for Enhancing Solubility, Permeability, and Bioavailability of Sesamin

Sesamin (SSM) is a water-insoluble compound that is easily eliminated by liver metabolism. To improve the solubility and bioavailability of SSM, this study developed and characterized a self-nanoemulsifying drug delivery system (SNEDDS) for the oral delivery of SSM and conducted pharmacokinetic assessments. Oil and surfactant materials suitable for SNEDDS preparation were selected on the basis of their saturation solubility at 37 ± 0.5 °C. The mixing ratios of excipients were determined on the basis of their dispersibility, transmittance (%), droplet sizes, and polydispersity index. An SNEDDS (F10) formulation comprising glyceryl trioctanoate, polyoxyethylene castor oil, and Tween 20 at a ratio of 10:10:80 (w/w/w) was the optimal formulation. This formulation maintained over 90% of its contents in different storage environments for 12 weeks. After the self-emulsification of SNEDDS, the SSM dispersed droplet size was 66.4 ± 31.4 nm, intestinal permeability increased by more than three-fold, relative bioavailability increased by approximately 12.9-fold, and absolute bioavailability increased from 0.3% to 4.4%. Accordingly, the developed SNEDDS formulation can preserve SSM's solubility, permeability, and bioavailability. Therefore, this SNEDDS formulation has great potential for the oral administration of SSM, which can enhance its pharmacological application value.

Triamcinolone Acetonide-Loaded PEGylated Microemulsion for the Posterior Segment of Eye

Present work investigates the possibility of a polyethyleneglycolylated (PEGylated) microemulsion (ME) to deliver drug to the posterior segment of eye. Triamcinolone acetonide (TA), a widely used drug in intraocular diseases, was selected as the model drug. Based on solubility and emulsification capacity, components of microemulsion were selected and optimum formulation was obtained using a pseudoternary phase diagram. The optimized ratio of Capmul MCM C8 (oil): AccononMC8-2 (surfactant): Transcutol (cosurfactant): deionized water was 5:35.5:4.5:55. This was further PEGylated using 1,2-distearoylphosphatylethanolamine-polyethyleneglycol 2000 (DSPE-PEG 2000). This PEGylated ME loaded with TA was characterized and evaluated in vitro, ex vivo, and in vivo for topical ocular use. The developed PEGylated ME loaded with TA was homogenous, stable, and nonirritable to eye and had the ability to reach the posterior segment of eye on topical instillation.

Topical Delivery of Coenzyme Q10-Loaded Microemulsion for Skin Regeneration

The aim of this study was to develop a coenzyme Q10 (CoQ10) microemulsion system with improved solubility, penetration, and wound healing efficacy. Based on the pseudo-ternary diagram, microemulsions containing isopropyl myristate (IPM), Cremophor EL^®, and Transcutol^® HP were selected and confirmed to be nanosized (<20 nm) and thermodynamically stable based on the dilution and thermodynamic stability tests. The CoQ10-loaded microemulsion with a surfactant/co-surfactant (S/CoS) ratio of 2:1 (w/w %) demonstrated a higher permeation efficacy compared to microemulsions with S/CoS ratio of 3:1 or 4:1 (w/w %). Additionally, the CoQ10-loaded microemulsion with an S/CoS ratio of 2:1 demonstrated a relatively rapid wound healing effect in keratinocytes and fibroblasts. Overall, these data suggest that a microemulsion based on IPM, Cremophor EL^®, and Transcutol^® HP could be an effective vehicle for the topical administration of CoQ10 and could be utilized for the application of other therapeutic agents that have difficulty in penetrating the skin.

PEGylated microemulsion for dexamethasone delivery to posterior segment of eye

Dexamethasone (Dex) is one of the most commonly used anti-vascular endothelial growth factor (anti-VEGF) drugs being used in ocular diseases whether it is associated with anterior segment or posterior segment. For diseases of posterior segment of eye, Dex is delivered as intravitreal implant but the route used for the same is very invasive and poses several hazards on long term use. Thus, topical formulation with ability to outreach retina from ocular surface was intended. Thus, polyethylene glycolylated (PEGylated) microemulsion (ME) was attempted as it can cross the membranous barrier of eye (cornea, conjunctiva, and sclera) and remain afloat in fluidic barrier (aqueous humor, choroid, etc.) as well. Present investigation involved development of Dex-loaded PEGylated ME which was stable, non-toxic to ocular surface, capable to cross cornea and enhanced residence as well as availability of loaded drug in retina. The developed PEGylated ME had physicochemical properties like size (15.98 ± 3.05 nm), polydispersity index (0.25 ± 0.04), zeta potential (-0.04 ± 0.47 mV), percentage transmittance (99.84 ± 1.17%), and drug content (99.32 ± 3.21%). It showed sustained Dex release in in vitro conditions. It also displayed efficiency in enhancing retention of drugs in retina in in vivo pharmacokinetic study on Sprague-Dawley rats. PEGylated ME can retain the drug in retina of rats longer than simple eye drop solution via topical ocular route.

Cremophor EL Nano-Emulsion Monomerizes Chlorophyll a in Water Medium

In this paper, the application of a non-ionic detergent Cremophor EL for monomerization of chlorophyll a in an aqueous medium is studied. The spectrophotometric properties of chlorophyll a encapsulated into the Cremophor EL nano-emulsion system were characterized by electronic absorption, steady-state and time-resolved fluorescence as well as circular dichroism spectroscopy. The results have shown that chlorophyll a dissolves more efficiently in the aqueous medium containing low-level Cremophor (5 wt%) than at an ethanolic solution even in the concentration of 10⁻⁴ M. The molecular organization of the chlorophyll a in the Cremophor EL nano-micelles was also investigated by means of Raman spectroscopy. The spectral changes in the frequency of the C=O stretching group were used to distinguish the aggregation state of chlorophyll. It was revealed that chlorophyll a exists dominantly in the monomeric form in the Cremophor EL aqueous solution. The promising aspect of the use of Cremophor EL nano-emulsion as a delivery system is to maintain stable chlorophyll monomer in an aqueous medium. It would open the potential for a new, practical application of chlorophyll a in medicine, as a dietary supplement or studies on molecular organization of chlorophyll a in the well-defined artificial system.

Takes Two to Tango: Choreography of the Coadsorption of CTAB and Hexanol at the Oil-Water Interface

Mixed surfactant systems at the oil-water interface play a vital role in applications ranging widely from drug delivery to oil-spill remediation. Synergistic mixtures are superior emulsifiers and more effective at modifying surface tension than either component alone. Mixtures of surfactants with dissimilar polar head groups are of particular interest because of the additional degree of control they offer. The interplay of hydrophobic and electrostatic effects in these systems is not well understood, in part because of the difficulty in examining their behavior at the buried oil-water interface where they reside. Here, surface-specific vibrational sum frequency spectroscopy is utilized in combination with surface tensiometry and computational methods to probe the cooperative molecular interactions between a cationic surfactant cetyltrimethylammonium bromide (CTAB) and a nonionic alcohol (1-hexanol) that induce the two initially reluctant surfactants to coadsorb synergistically at the interface. A careful deuteration study of CTAB reveals that hexanol cooperates with CTAB such that both molecules preferentially orient at the interface for sufficiently large enough concentrations of hexanol. This work's methodology is unique and serves as a guide for future explorations of macroscopic properties in these complex systems. Results from this work also provide valuable insights into how interfacial ordering impacts surface tensiometry measurements for nonionic surfactants.