Formulation and Characterization of Eplerenone Nanoemulsion Liquisolids, An Oral Delivery System with Higher Release Rate and Improved Bioavailability

Oral bioavailability enhancement of doxazosin mesylate: Nanosuspension versus self-nanoemulsifying drug delivery systems

Background and purpose

Doxazosin mesylate (DOX) is an antihypertensive drug that possesses poor water solubility and, hence, poor release properties. Both nanosuspensions and self-nanoemulsifying drug delivery systems (SNEDDS) are becoming nanotechnology techniques for the enhancement of water solubility of different drugs.

Experimental approach

The study's goal was to identify the best drug delivery system able to enhance the release and antihypertensive effect of DOX by comparing the physical characteristics such as particle size, zeta potential, entrapment efficiency, release rate, and main arterial blood pressure of DOX-loaded nanosuspensions and SNEDDS in liquid and solid form.

Key results

DOX nanosuspension preparation had a particle size of 385±13 nm, poly-dispersity index of 0.049±3, zeta potential of 50 ± 4 mV and drug release after 20 min (91±0.43 %). Liquid SNEDDS had a droplet size of 224±15 nm, poly-dispersity index of (0.470±0.01), zeta potential of -5±0.10 mV and DR20min of 93±4 %. Solid SEDDS showed particle size of 79±14 nm, poly-dispersity index of 1±0.00, a zeta potential of -18 ±0.26 mv and DR20min of 100 ±2.72 %.

Conclusion

Finally, in terms of the mean arterial blood pressure lowering, solid SNEDDS performed better effect than both liquid SNEDDS and nanosuspension (P >0.05).

Current challenges ahead in preparation, characterization, and pharmaceutical applications of nanoemulsions

Nanoemulsions (NEs) are emulsions with particle size of less than around 100 nm. Reviewing the literature, several reports are available on NEs, including preparation, characterization, and applications of them. This review aims to brief challenges that researchers or formulators may encounter when working with NEs. For instance, when selecting NE components and identifying their concentrations, stability and safety of the preparation should be evaluated. When preparing an NE, issues over scale-up of the preparation as well as possible effects of the preparation process on the active ingredient need to be considered. When characterizing the NEs, the two major concerns are accuracy of the method and accessibility of the characterizing instrument. Also a highly efficient NE for clinical use to deliver the active ingredient to the target tissue with maximum safety profile is commonly sought. Throughout the review we also have tried to suggest approaches to overcome the challenges. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Targeted cross-linker delivery for the in situ mapping of protein conformations and interactions in mitochondria

Current methods for intracellular protein analysis mostly require the separation of specific organelles or changes to the intracellular environment. However, the functions of proteins are determined by their native microenvironment as they usually form complexes with ions, nucleic acids, and other proteins. Here, we show a method for in situ cross-linking and analysis of mitochondrial proteins in living cells. By using the poly(lactic-co-glycolic acid) (PLGA) nanoparticles functionalized with dimethyldioctadecylammonium bromide (DDAB) to deliver protein cross-linkers into mitochondria, we subsequently analyze the cross-linked proteins using mass spectrometry. With this method, we identify a total of 74 pairs of protein-protein interactions that do not exist in the STRING database. Interestingly, our data on mitochondrial respiratory chain proteins ( ~ 94%) are also consistent with the experimental or predicted structural analysis of these proteins. Thus, we provide a promising technology platform for in situ defining protein analysis in cellular organelles under their native microenvironment.

Improvement of dissolution profile of eplerenone with solidified self-emulsifying drug delivery systems (S-SEDDS)

BACKGROUND

Eplerenone is a member of antihypertensives used individually or in combination with other medicines. Eplerenone exhibits poor solubility and is considered a class II drug.

OBJECTIVE

Increasing the solubility of eplerenone by using both liquid and solid self-emulsifying drug delivery system as an alternative to its marketed tablet product.

METHODS

Solubility studies of eplerenone were done with different oils, surfactants, and co-surfactants to determine which one has the highest solubility for eplerenone and determine the preference in the formulations of liquid self-emulsifying drug delivery system. The solidification process was carried out with the adsorption to solid carrier method. Optimal ratios of components were specified with pseudo-ternary phase diagram technique. Self-emulsifying drug delivery system formulations were characterized in terms of chemical interaction, droplet size/distribution, crystallization behaviors, and rheological evaluation. In vitro drug release studies were conducted and compared to pure drug and marketed product.

RESULTS

The solubility screening results showed high solubility of EPL in triacetin (11.99 mg/mL) as oil, Kolliphor®EL (≈ 2.65 mg/mL), and Tween^®80 (≈ 1.91 mg/mL) as surfactant and polyethylene glycol 200 (PEG200) (≈ 8.50 mg/mL), dimethyl sulfoxide (≈ 7.57 mg/mL), Transcutol^®P (≈ 6.03 mg/mL) as co-surfactant, respectively. Rheology studies revealed that liquid self-emulsifying drug delivery formulations exhibited non-Newtonian pseudoplastic flow.

CONCLUSION

Solid self-emulsifying drug delivery systems prepared with Aerosil and Neusilin have shown tremendous improvement in terms of eplerenone dissolution by releasing the entire dose with boosted effect within 5 and 30 minutes respectively compared to the marketed product and pure eplerenone (p < 0.05).

Codelivery of Phytochemicals with Conventional Anticancer Drugs in Form of Nanocarriers

Anticancer drugs in monotherapy are ineffective to treat various kinds of cancer due to the heterogeneous nature of cancer. Moreover, available anticancer drugs possessed various hurdles, such as drug resistance, insensitivity of cancer cells to drugs, adverse effects and patient inconveniences. Hence, plant-based phytochemicals could be a better substitute for conventional chemotherapy for treatment of cancer due to various properties: lesser adverse effects, action via multiple pathways, economical, etc. Various preclinical studies have demonstrated that a combination of phytochemicals with conventional anticancer drugs is more efficacious than phytochemicals individually to treat cancer because plant-derived compounds have lower anticancer efficacy than conventional anticancer drugs. Moreover, phytochemicals suffer from poor aqueous solubility and reduced bioavailability, which must be resolved for efficacious treatment of cancer. Therefore, nanotechnology-based novel carriers are employed for codelivery of phytochemicals and conventional anticancer drugs for better treatment of cancer. These novel carriers include nanoemulsion, nanosuspension, nanostructured lipid carriers, solid lipid nanoparticles, polymeric nanoparticles, polymeric micelles, dendrimers, metallic nanoparticles, carbon nanotubes that provide various benefits of improved solubility, reduced adverse effects, higher efficacy, reduced dose, improved dosing frequency, reduced drug resistance, improved bioavailability and higher patient compliance. This review summarizes various phytochemicals employed in treatment of cancer, combination therapy of phytochemicals with anticancer drugs and various nanotechnology-based carriers to deliver the combination therapy in treatment of cancer.

Application of Machine-Learning Algorithms for Better Understanding the Properties of Liquisolid Systems Prepared with Three Mesoporous Silica Based Carriers

The processing of liquisolid systems (LSS), which are considered a promising approach to improving the oral bioavailability of poorly soluble drugs, has proven challenging due to the relatively high amount of liquid phase incorporated within them. The objective of this study was to apply machine-learning tools to better understand the effects of formulation factors and/or tableting process parameters on the flowability and compaction properties of LSS with silica-based mesoporous excipients as carriers. In addition, the results of the flowability testing and dynamic compaction analysis of liquisolid admixtures were used to build data sets and develop predictive multivariate models. In the regression analysis, six different algorithms were used to model the relationship between tensile strength (TS), the target variable, and eight other input variables. The AdaBoost algorithm provided the best-fit model for predicting TS (coefficient of determination = 0.94), with ejection stress (ES), compaction pressure, and carrier type being the parameters that influenced its performance the most. The same algorithm was best for classification (precision = 0.90), depending on the type of carrier used, with detachment stress, ES, and TS as variables affecting the performance of the model. Furthermore, the formulations with Neusilin® US2 were able to maintain good flowability and satisfactory values of TS despite having a higher liquid load compared to the other two carriers.

Biphasic dissolution combined with modified cylinder method-A new promising method for dissolution test in drug-loaded nanoemulsions

Dissolution testing is important in assessing the in vitro drug release performance for oral administration dosage forms. However, currently, a simple and efficient in vitro test to investigate critical factors that may impact the drug release and bioavailability at the development stage of a drug-loaded nanoemulsion (NE) is lacking. Thus, in this study, we developed a new combined biphasic and modified cylinder (BP + MC) method to evaluate the dissolution profile of NEs. Flubendazole (FLZ), a Biopharmaceutical Classification System (BCS) Class II drug, offers a new prospective for drug repositioning for treating lung cancer and cryptococcal meningitis. We compared the drug release profiles of three different FLZ formulations (micronized as a suspension, loaded in NE, and solubilized in oil) by using three different methods (dialysis bag, modified cylinder method, and a new BP + MC method). The results showed potential higher drug release of FLZ from the suspension compared to FLZ-loaded NE at pH 1.2, and higher drug release from FLZ-loaded NE compared to other forms in octanol phase. These results correlate well with the in vivo test performed in mice carried out in our previous works. Furthermore, the partition mechanism of the drug released from the NE is discussed in-depth in this article, as well as the advantage of drug-loaded NEs over other preparations in creating supersaturable conditions. Based on the results, we provide new insights into how dissolution methods for a poorly water-solubility drug can be designed. Therefore, we present this new combined BP + MC method as a potential new discriminative dissolution test for future studies when developing drug-loaded NE and comparing with other dosage forms.

Development of eplerenone nano sono-crystals using factorial design: enhanced solubility and dissolution rate via anti solvent crystallization technique

OBJECTIVE

The purpose of this work was to improve EP solubility by using a sono-crystalization approach to reduce particle size and hence, increase the dissolution rate. Significance Eplerenone (EP) is an antagonist of the aldosterone receptor and is used for the treatment of hypertension and chronic heart failure. EP was classed as biopharmaceutical classification (BCS) class II because of its poor solubility and high permeability, which retards dissolution rate and drug absorption, and decreases bioavailability.

METHODS

Three-factors and two-level (2³) multifactorial design have been employed to study the effect of independent variables which are drug concentration; (X1), stabilizer type (X2), and stabilizer concentration (X3) on responses; saturated solubility of EP in distilled water (Y1), saturated solubility in acidic media pH 1.2 (Y2), particle size (Y3), and polydispersity index, PDI (Y4). Also, they were characterized by Fourier transformed infrared spectroscopy (FTIR), Powder X-ray diffraction (PXRD), Differential scanning calorimetry (DSC), and yield percentage. The optimum formula was further subjected to an in-vitro release study.

RESULTS

The optimized formulation showed a saturated solubility of EP as 1.29, and 1.86 (mg/ml) in distilled water and acidic media (pH 1.2) respectively. Also, the particle size of 133 nm, and PDI of 0.824 with a small percentage of the difference between the observed and predicted values. Ninety-one percent of EP was released within 10 min., and it was completely released within 45 min. with a significantly higher release rate compared to raw drug.

CONCLUSION

This work resulted in a satisfactory enhancement of solubility and dissolution rate which, is suitable for further in-vivo analysis.

An overview on liquisolid technique: its development and applications

With its simplicity and cost-effectiveness, the liquisolid technique offers solutions for numerous formulation problems. Among these are dissolution enhancement and sustaining drug release, and the liquisolid technique dealt with both approaches. This review focuses on the latest advances in the technique. It discusses modified additives for use as carrier materials, which secure the required large surface area for enclosing liquids. The review also covers the modern liquipellet technique derived from the extrusion/palletization technique. Also, the liquiground term is introduced, combining the advantages of co-grinding with the liquisolid concept. Furthermore, several grades of Eudragits, and hydrophilic retarding polymers are mentioned to explain modes of sustaining drug release. This review sums up the liquisolid technique development and its applications recently achieved.

Nanostructured Lipid Carrier-Based Codelivery of Raloxifene and Naringin: Formulation, Optimization, In Vitro, Ex Vivo, In Vivo Assessment, and Acute Toxicity Studies

This work aimed to develop dual drug-loaded nanostructured lipid carriers of raloxifene and naringin (RLX/NRG NLCs) for breast cancer. RLX/NRG NLCs were prepared using Compritol 888 ATO and oleic acid using a hot homogenization-sonication method and optimized using central composite design (CCD). The optimized RLX/NRG NLCs were characterized and evaluated using multiple technological means. The optimized RLX/NRG NLCs exhibited a particle size of 137.12 nm, polydispersity index (PDI) of 0.266, zeta potential (ZP) of 25.9 mV, and entrapment efficiency (EE) of 91.05% (raloxifene) and 85.07% (naringin), respectively. In vitro release (81 ± 2.2% from RLX/NRG NLCs and 31 ± 1.9% from the RLX/NRG suspension for RLX and 93 ± 1.5% from RLX/NRG NLCs and 38 ± 2.01% from the RLX/NRG suspension for NRG within 24 h). Concurrently, an ex vivo permeation study exhibited nearly 2.3 and 2.1-fold improvement in the permeability profiles of RLX and NRG from RLX/NRG NLCs vis-à-vis the RLX/NRG suspension. The depth of permeation was proved with CLSM images which revealed significant permeation of the drug from the RLX/NRG NLCs formulation, 3.5-fold across the intestine, as compared with the RLX/NRG suspension. An in vitro DPPH antioxidant study displayed a better antioxidant potential of RLX/NRG in comparison to RLX and NRG alone due to the synergistic antioxidant effect of RLX and NRG. An acute toxicity study in Wistar rats showed the safety profile of the prepared nanoformulations and their excipients. Our findings shed new light on how poorly soluble and poorly permeable medicines can be codelivered using NLCs in an oral nanoformulation to improve their medicinal performance.

A Revolutionary Blueprint for Mitigation of Hypertension via Nanoemulsion

Hypertension is one of the most important causes of mortality, affecting the health status of the patient. At the same time, hypertension causes a huge health and economic burden on the whole world. The incidence and prevalence of hypertension are rising even among young people in both urban as well as rural communities. Although various conventional therapeutic moieties are available for the management of hypertension, they have serious flaws such as hepatic metabolism, reduced dose frequency, poor aqueous solubility, reduced bioavailability, and increased adverse effects, making the drug therapy ineffective. Therefore, it is required to design a novel drug delivery system having the capability to solve the constraints associated with conventional treatment of hypertension. Nanotechnology is a new way of using and manipulating the matter at the molecular level, whose functional organization is measured in nanometers. The applications of nanotechnology in the field of medicine provide an alternative and novel direction for the treatment of cardiovascular diseases and show excellent performance in the field of targeted drug therapy. Various nanotechnologies based drug delivery systems, such as solid lipid nanoparticles, nanosuspension, nanoemulsion, liposome, self-emulsifying systems, and polymeric nanoparticles, are available. Among them, nanoemulsion has provided a niche to supplement currently available therapeutic choices due to numerous benefits like stability, ease of preparation, enhanced drug absorption, reduced hepatic metabolism, increased dose frequency, enhanced bioavailability, and encapsulation of hydrophilic as well as hydrophobic drugs. This present review provides an in-depth idea about progression in treatment of hypertension, constraints for antihypertensive drug therapy, need of nanoemulsions to overcome these constraints, comparative analysis of nanoemulsions over other nanostructure drug delivery systems, pharmacodynamics studies of nanoemulsions for treatment of hypertension, recent patents for drug-loaded nanoemulsions meant for hypertension, and marketed formulations of nanoemulsions for hypertension.

Eplerenone repurposing in management of chorioretinopathy: Mechanism, nanomedicine-based delivery applications and future trends

Chronic central serous chorioretinopathy (CSCR) is an ocular threatening disease, a common cause of central vision loss, affecting the posterior pole of the eye. Eplerenone (EPL) is a selective mineralocorticoid receptor antagonist that used primarily to treat hypertension. Recently, it has shown many benefits in modifying the physio-pathological processes occurring upon stimulation of renin-angiotensin aldosterone system at the ocular level. In CSCR treatment, several clinical studies and case reports prove the efficacy and safety of EPL. However, some setbacks for such studies as a relatively small number of participants and short follow-up periods. This review article is intended to describe theories about the nature and classification of CSCR and recapitulate EPL therapeutic benefits as selective mineralocorticoid receptor antagonist in the treatment of CSCR. Furthermore, a literature survey on clinical studies discussing the results of use of EPL in treatment of CSCR. In addition, EPL therapeutic formulations that were developed up to date, and the future potential delivery systems will be suggested.

Liquisolid systems: Evaluation of the influence of formulation variables on the optimum liquid load

Liquisolid systems represent an emerging approach in the preparation of solid dosage forms with liquid lipophilic drug or poorly water-soluble drug solution/suspension in suitable liquid vehicle. This study addresses the lack of data regarding the compaction behavior of liquisolid systems, with the aim to investigate the influence of liquid load, carrier to coating ratio, carrier type (microcrystalline cellulose vs. spray dried calcium hydrogen phosphate, anhydrous (Fujicalin®)) on flowability and compaction properties of liquisolid systems and to determine the optimum liquid loads. Liquisolid admixtures with Fujicalin® showed notably better flowability than those with microcrystalline cellulose. An increase in carrier to coating ratio led to enhanced flowability of the admixtures. Compacts with Fujicalin® had good mechanical properties up to 24.7% liquid, while those with microcrystalline cellulose had acceptable mechanical strength up to 16.2% liquid. Liquisolid systems with Fujicalin® showed similar tabletability profiles as those with microcrystalline cellulose, despite having higher liquid content. The ejection stress values indicated that the addition of lubricant might be needed in the case of liquisolid systems with Fujicalin®. Superior properties of Fujicalin® as a carrier for liquisolid tablets were revealed, and dynamic compaction analysis was found to be a valuable tool for the assessment of compaction behavior of liquisolid systems.

Liquisolid systems as a novel approach in formulation and manufacturing of solid dosage forms: Challenges and perspectives

Liquisolid systems are a novel, promising platform for the production of solid dosage forms with a high liquid content, i.e. dispersion of the drug in a suitable, hydrophilic, non-volatile liquid vehicle or liquid drug. This technology requires conventional, but highly porous excipients (carrier and coating material in the appropriate ratio) able to absorb/adsorb liquid medication, resulting in both good flowability and acceptable compression properties. This approach has shown great potential to improve the dissolution rate and bioavailability of poorly soluble drugs, and has been recognized as a good alternative to common, more complex and expensive techniques. A variety of applications of this simple technique have been investigated recently, including the preparation of: modified release tablets, orally disintegrating tablets, solid dosage forms with liquid herbal extracts, etc. This emerging technology has numerous advantages, and the most important are: simplicity, cost-effectiveness, applicability in large scale production and environmental friendliness. However, it is accompanied by certain challenges as well, such as limited applicability in the case of highly dosed drugs. This article aims to give a comprehensive overview of recent progress regarding the potential applications of this technology, as well as to give an insight into the new liquisolid-based techniques intending to further support its commercial applicability.

Eplerenone nanocrystals engineered by controlled crystallization for enhanced oral bioavailability

Poor aqueous solubility of eplerenone (EPL) is a major obstacle to achieve sufficient bioavailability after oral administration. In this study, we aimed to develop and evaluate eplerenone nanocrystals (EPL-NCs) for solubility and dissolution enhancement. D-optimal combined mixture process using Design-Expert software was employed to generate different combinations for optimization. EPL-NCs were prepared by a bottom-up, controlled crystallization technique during freeze-drying. The optimized EPL-NCs were evaluated for their size, morphology, thermal behavior, crystalline structure, saturation solubility, dissolution profile, in vivo pharmacokinetics, and acute toxicity. The optimized EPL-NCs showed mean particle size of 46.8 nm. Scanning electron microscopy revealed the formation of elongated parallelepiped shaped NCs. DSC and PXRD analysis confirmed the crystalline structure and the absence of any polymorphic transition in EPL-NCs. Furthermore, EPL-NCs demonstrated a 17-fold prompt increase in the saturation solubility of EPL (8.96 vs. 155.85 µg/mL). The dissolution rate was also significantly higher as indicated by ∼95% dissolution from EPL-NCs in 10 min compared to only 29% from EPL powder. EPL-NCs improved the oral bioavailability as indicated by higher AUC, C_max, and lower T_max than EPL powder. Acute oral toxicity study showed that EPL-NCs do not pose any toxicity concern to the blood and vital organs. Consequently, NCs prepared by controlled crystallization technique present a promising strategy to improve solubility profile, dissolution velocity and bioavailability of poorly water-soluble drugs.

Nanoemulsion and Solid Nanoemulsion for Improving Oral Delivery of a Breast Cancer Drug: Formulation, Evaluation, and a Comparison Study

Letrozole (LZ) is an aromatase inhibitor, which inhibits the formation of estrogens from androgens. Nanoemulsion is a liquid emulsion formulation utilized to increase solubility, bioavailability, and drug delivery to cancer cells. This study aims to improve LZ oral delivery through formulating solid nanoemulsion (SNE). Peppermint oil, tween 80, and transcutol P were used as an oil, surfactant, and co-surfactant, respectively. The optimized nanoemulsion (NE-3) was then incorporated into solid polyethylene glycol (PEG) to formulate (SNE). The optimized (NE-3), SNE-2, and the available marketed tablet have been compared. The optimized (NE-3) was selected according to specific parameters of optimum small nano-size 80 nm, PDI of 0.181, the zeta potential of-98.2, high transmittance (99.78%), optimum pH (5.6), a high percent of LZ content (99.03 ± 1.90), the relatively low viscosity of 60.2 mPa.s, and a rapid release of LZ within 30 min. NE-3 was selected to be formulated as SNE. LZ's best release rate was 80% in 5 min with a content homogeneity of 99.85 ± 0.04 for SNE-2. Zero-order kinetics is determined to have the greatest R² values. Field emission scanning electron microscopy (FE-SEM) detected that SNE-2 was (36.75-96.64 nm) with a spherical form and no adhesion or aggregation. FT-IR showed no significant variations in position and shape of the absorption peaks between the pure drug and optimal formulation diagrams. This novel nanoemulsion technology aids in improving the solubility of poorly water-soluble drugs, particularly the SNE delivery method, which has a higher in-vitro release rate and expiration date of LZ than others.

Hesperidin-loaded nanoemulsions improve cytotoxicity, induce apoptosis, and downregulate miR-21 and miR-155 expression in MCF-7

Hesperidin, a ubiquitous plant-based flavanone, was encapsulated into nanoemulsions (HP-NEM) using a spontaneous emulsification method to improve its solubility and enhance bioavailability and efficacy in breast cancer treatment using MCF-7 cell lines. The cytotoxic and apoptotic effects of HP-NEM against MCF-7 and its impact on oncomiRs, microRNA-21, and microRNA-155 expression were also assessed. The optimised HP-NEM displayed a spherical shape with 305 ± 40.8 nm, 0.308 ± 0.04, and -11.6 ± 3.30 mV and 93 ± 0.45% for particle size, polydispersity index (PDI), zeta-potential (ζ), and encapsulation efficiency, respectively. Cytotoxicity studies using MTT assay showed selective toxicity of the HP-NEM against MCF-7 without affecting normal cells (HEK 293). Treatment with the HP-NEM induced cell death through apoptosis, cell cycle arrest in the G2/M phase, and downregulated miR-21 and miR-155 expression in MCF-7. This study supports the use of HP-NEM as a potential therapeutic agent in breast cancer treatment.

Sesame Oil-Based Nanostructured Lipid Carriers of Nicergoline, Intranasal Delivery System for Brain Targeting of Synergistic Cerebrovascular Protection

Nicergoline (NIC) is a semisynthetic ergot alkaloid derivative applied for treatment of dementia and other cerebrovascular disorders. The efficacy of sesame oil to slow and reverse the symptoms of neurodegenerative cognitive disorders has been proven. This work aimed to formulate and optimize sesame oil-based NIC-nanostructured lipid carriers (NIC–NLCs) for intranasal (IN) delivery with expected synergistic and augmented neuroprotective properties. The NIC–NLC were prepared using sesame oil as a liquid lipid. A three-level, three-factor Box–Behnken design was applied to statistically optimize the effect of sesame oil (%) of the total lipid, surfactant concentration, and sonication time on particle size, zeta potential, and entrapment efficacy as responses. Solid-state characterization, release profile, and ex vivo nasal permeation in comparison to NIC solution (NIC–SOL) was studied. In vivo bioavailability from optimized NIC–NLC and NIC–SOL following IN and IV administration was evaluated and compared. The optimized NIC–NLC formula showed an average particle size of 111.18 nm, zeta potential of −15.4 mV, 95.11% entrapment efficacy (%), and 4.6% loading capacity. The NIC–NLC formula showed a biphasic, extended-release profile (72% after 48 h). Permeation of the NIC–NLC formula showed a 2.3 enhancement ratio. Bioavailability studies showed a 1.67 and 4.57 fold increase in plasma and brain following IN administration. The results also indicated efficient direct nose-to-brain targeting properties with the brain-targeting efficiency (BTE%) and direct transport percentage (DTP%) of 187.3% and 56.6%, respectively, after IN administration. Thus, sesame oil-based NIC–NLC can be considered as a promising IN delivery system for direct and efficient brain targeting with improved bioavailability and expected augmented neuroprotective action for the treatment of dementia.

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.

Abdulbaqi I, Seok Ming T, Siok Yee C, A. Wahab H, Asif SM, Darwis Y. Liquid and Solid Self-Emulsifying Drug Delivery Systems (SEDDs) as Carriers for the Oral Delivery of Azithromycin: Optimization, In Vitro Characterization and Stability Assessment

Azithromycin (AZM) is a macrolide antibiotic used for the treatment of various bacterial infections. The drug is known to have low oral bioavailability (37%) which may be attributed to its relatively high molecular weight, low solubility, dissolution rate, and incomplete intestinal absorption. To overcome these drawbacks, liquid (L) and solid (S) self-emulsifying drug delivery systems (SEDDs) of AZM were developed and optimized. Eight different pseudo-ternary diagrams were constructed based on the drug solubility and the emulsification studies in various SEDDs excipients at different surfactant to co-surfactant (Smix) ratios. Droplet size (DS) < 150 nm, dispersity (Đ) ≤ 0.7, and transmittance (T)% > 85 in three diluents of distilled water (DW), 0.1 mM HCl, and simulated intestinal fluids (SIF) were considered as the selection criteria. The final formulations of L-SEDDs (L-F1(H)), and S-SEDDs (S-F1(H)) were able to meet the selection requirements. Both formulations were proven to be cytocompatible and able to open up the cellular epithelial tight junctions (TJ). The drug dissolution studies showed that after 5 min > 90% and 52.22% of the AZM was released from liquid and solid SEDDs formulations in DW, respectively, compared to 11.27% of the pure AZM, suggesting the developed SEDDs may enhance the oral delivery of the drug. The formulations were stable at refrigerator storage conditions.

Nanoemulsion Stabilized by Safe Surfactin from Bacillus Subtilis as a Multifunctional, Custom-Designed Smart Delivery System

The developing field of bio-nanotechnology aims to advance colloidal research via the introduction of multifunctional nanoparticles to augment the dermal effectiveness of active substances. Self-emulsifying drug delivery systems (SEDDS)-isotropic mixtures of oils, surfactants, solvents and co-solvents or surfactants-are attracting interest in the cosmeceutical field. As part of this study, SEDDS systems containing vitamin C or vitamin E and curcumin were developed, whereby the bioavailability of the active compounds increased by enhancing their permeability to deeper layers of the skin. A composition consisting of 50% surfactin from Bacillus subtilis, 30% Transcutol and 20% oil phase was designed to encapsulate the active substances, i.e., vitamin C or vitamin E and curcumin, contained in the oil phase. The developed carriers were characterized by average particle sizes of 69-183 nm. The formulations with the vitamins were found to be physically and chemically stable for 6 months. Transdermal tests were carried out, showing that the carriers enable the transport of active substances deep into the skin, stopping at the dermis border. The formulations with vitamin C and vitamin E reduced the discoloration, the vascular lesions, and the depth of the wrinkles on the tested skin, which can be useful in cosmetics in the treatment of problem skin, including capillary and sensitive skin.

An Investigation into the Influence of Process Parameters and Formulation Variables on Compaction Properties of Liquisolid Systems

Liquisolid technology, as a promising approach for bioavailability enhancement, has received increasing attention in recent years. However, literature reports addressing the challenges for its industrial application, particularly those related to compaction behavior of liquisolid systems, are scarce. The aim of this study was to investigate the influence of process parameters and formulation variables on the flowability, wetting, and compaction properties of the liquisolid systems prepared in a fluid bed processor. The experiments with microcrystalline cellulose, as a carrier, were performed according to 2³ full factorial design. The effects of liquid content, spray air pressure, and liquid feed rate on the properties of liquisolid systems were investigated. Liquisolid admixtures with microcrystalline cellulose were compared with those prepared with novel carriers, Fujicalin^® and Neusilin^® US2. "Out-die" Heckel, modified Walker, and Kuentz-Leuenberger models were used to analyze the compressibility of liquisolid admixtures. The results obtained showed that an increase in liquid content (in the range of 10 to 15%) led to a decrease in flowability of liquisolid admixtures with microcrystalline cellulose, as well as more pronounced influence of spraying conditions. On the other hand, higher liquid content led to higher compressibility. Fujicalin^® and Neusilin^® US2 liquisolid admixtures were found to have superior flowability and compressibility in comparison with those with microcrystalline cellulose, despite the considerably higher liquid load (50-55% liquid content in Neusilin^® US2 compacts). Acceptable compactibility of the investigated liquisolid systems was observed. The fluid bed processor was shown to be suitable equipment for production of liquisolid systems, but with careful adjustment of process parameters.