Yosra S.R. Elnaggar

Self-nanoemulsifying drug delivery systems of tamoxifen citrate: Design and optimization

Tamoxifen citrate is an antiestrogen for peroral breast cancer treatment. The drug delivery encounters problems of poor water solubility and vulnerability to enzymatic degradation in both intestine and liver. In the current study, tamoxifen citrate self-nanoemulsifying drug delivery systems (SNEDDS) were prepared in an attempt to circumvent such obstacles. Preliminary screening was carried out to select proper ingredient combinations. All surfactants screened were recognized for their bioactive aspects. Ternary phase diagrams were then constructed and an optimum system was designated. Three tamoxifen SNEDDS were then compared for optimization. The systems were assessed for robustness to dilution, globule size, cloud point, surface morphology and drug release. An optimum system composed of tamoxifen citrate (1.6%), Maisine 35-1 (16.4%), Caproyl 90 (32.8%), Cremophor RH40 (32.8%) and propylene glycol (16.4%) was selected. The system was robust to different dilution volumes and types. It possessed a mean globule size of 150 nm and a cloud point of 80 degrees C. Transmission electron microscopy demonstrated spherical particle morphology. The drug release from the selected formulation was significantly higher than other SNEDDS and drug suspension, as well. Realizing drug incorporation into an optimized nano-sized SNEDD system that encompasses a bioactive surfactant, our results proposed that the prepared system could be promising to improve oral efficacy of the tamoxifen citrate.

Lecithin-based nanostructured gels for skin delivery: An update on state of art and recent applications

Conventional carriers for skin delivery encounter obstacles of drug leakage, scanty permeation and low entrapment efficiency. Phospholipid nanogels have recently been recognized as prominent delivery systems to circumvent such obstacles and impart easier application. The current review provides an overview on different types of lecithin nanostructured gels, with particular emphasis on liposomal versus microemulsion gelled systems. Liposomal gels investigated encompassed classic liposomal hydrogel, modified liposomal gels (e.g. Transferosomal, Ethosomal, Pro-liposomal and Phytosomal gels), Microgel in liposomes (M-i-L) and Vesicular phospholipid gel (VPG). Microemulsion gelled systems encompassed Lecithin microemulsion-based organogels (LMBGs), Pluronic lecithin organogels (PLOs) and Lecithin-stabilized microemulsion-based hydrogels. All systems were reviewed regarding matrix composition, state of art, characterization and updated applications. Different classes of lecithin nanogels exhibited crucial impact on transdermal delivery regarding drug permeation, drug loading and stability aspects. Future perspectives of this theme issue are discussed based on current laboratory studies.

Novel curcumin-loaded gel-core hyaluosomes with promising burn-wound healing potential: Development, in-vitro appraisal and in-vivo studies

Despite its effectiveness, curcumin (Curc) dermal delivery is handicapped by hydrophobicity, high metabolism and poor skin permeation. In this work, the potential of novel self-assembled nanogels, namely gel-core hyaluosome (GC-HS) to enhance Curc delivery to wound sites, enhance healing rate and decrease scar formation was evaluated. Curc-GC-HS were prepared using film hydration technique and evaluated regarding size, zeta potential (ZP), entrapment efficiency (% EE), and in vitro release. Structure elucidation was performed using light, polarizing and transmission electron microscopy (TEM). In-vivo burn-wound healing potential, skin deposition ability and histological study were evaluated using female Sprague Dawley rats. Curc-GC-HS were compared to conventional transfersomal gel (Curc-T-Pl gel), and other conventional gels. Curc-GC-HS showed nanosize (202.7 ± 0.66 nm), negative ZP (-33 ± 2.6 mV) and % EE (96.44 ± 1.29%). TEM revealed discrete vesicles with characteristic bilayer structure. Polarizing microscopy proposed liquid crystalline consistency. Burn-wound healing study showed that Curc-GC-HS was the only system exhibiting marked improvement at day 7 of treatment. At 11th day, Curc-GC-HS treated wounds showed almost normal skin with no scar confirmed by histological analysis. Curc-GC-HS showed five folds higher skin deposition compared to conventional Curc-T-Pl gel. To conclude, novel gel-core hyaluosomes elaborated are promising nanogels able to increase Curc skin penetration and dermal localization while protecting it against degradation. Future perspective encompasses assessing potential of novel nanocarrier for skin cancer therapy.

Development of novel polymer-stabilized diosmin nanosuspensions: In vitro appraisal and ex vivo permeation

Scanty solubility and permeability of diosmin (DSN) are perpetrators for its poor oral absorption and high inter-subject variation. This article investigated the potential of novel DSN nanosuspensions to improve drug delivery characteristics. Bottom-up nanoprecipitation technique has been employed for nanosuspension development. Variables optimized encompassed polymeric stabilizer type, DSN: stabilizer ratio, excess stabilizer removal, spray drying, and mannitol incorporation. In vitro characterization included particle size (PS), infrared spectroscopy (IR), differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM), and dissolution profile. Ex vivo permeation was assessed in rats using non-everted sac technique and HPLC. Optimal DSN nanosuspension (DSN:hydroxypropylmethyl cellulose HPMC 2:1) was prepared with acid base neutralization technique. The formula exhibited the lowest PS (336 nm) with 99.9% drug loading and enhanced reconstitution properties after mannitol incorporation. SEM and TEM revealed discrete, oval drug nanocrystals with higher surface coverage with HPMC compared to MC. DSN nanosuspension demonstrated a significant enhancement in DSN dissolution (100% dissolved) compared to crude drug (51%). Permeation studies revealed 89% DSN permeated from the nanosuspension after 120 min compared to non-detected amounts from drug suspension. Conclusively, novel DSN nanosuspension could successful improve its dissolution and permeation characteristics with promising consequences of better drug delivery.

Intranasal Piperine‐Loaded Chitosan Nanoparticles as Brain‐Targeted Therapy in Alzheimer's Disease: Optimization, Biological Efficacy, and Potential Toxicity

Piperine (PIP) is a phytopharmaceutical with reported neuroprotective potential in Alzheimers disease (AD). Oral PIP delivery suffers from its hydrophobicity and pre-systemic metabolism. In this article, mono-disperse intranasal chitosan nanoparticles (CS-NPs) were elaborated for brain targeting of PIP. Formula optimization was based on particle size (PS), zeta potential (ZP), polydispersity index (PDI), % entrapment efficiency (% EE), release studies, and transmission electron microscopy. AD was induced in 48 male Wistar rats on which full behavioral and biochemical testing was conducted. Brain toxicity was assessed based on Caspase-3 assay for apoptosis and tumor necrosis factor for inflammation. Spherical NPs with optimum % EE (81.70), PS (248.50 nm), PDI (0.24), and ZP (+56.30 mV) were elaborated. PIP-NPs could significantly improve cognitive functions as efficient as standard drug (donpezil injection) with additional advantages of dual mechanism (Ach esterase inhibition and antioxidant effect). CS-NPs could significantly alleviate PIP nasal irritation and showed no brain toxicity. This work was the first to report additional mechanism of PIP in AD via anti-apoptosis and anti-inflammatory effects. To conclude, mucoadhesive CS-NPs were successfully tailored for effective, safe, and non-invasive PIP delivery with 20-folds decrease in oral dose, opening a gate for a future with lower AD morbidity.Piperine (PIP) is a phytopharmaceutical with reported neuroprotective potential in Alzheimers disease (AD). Oral PIP delivery suffers from its hydrophobicity and pre-systemic metabolism. In this article, mono-disperse intranasal chitosan nanoparticles (CS-NPs) were elaborated for brain targeting of PIP. Formula optimization was based on particle size (PS), zeta potential (ZP), polydispersity index (PDI), % entrapment efficiency (% EE), release studies, and transmission electron microscopy. AD was induced in 48 male Wistar rats on which full behavioral and biochemical testing was conducted. Brain toxicity was assessed based on Caspase-3 assay for apoptosis and tumor necrosis factor for inflammation. Spherical NPs with optimum % EE (81.70), PS (248.50nm), PDI (0.24), and ZP (+56.30mV) were elaborated. PIP-NPs could significantly improve cognitive functions as efficient as standard drug (donpezil injection) with additional advantages of dual mechanism (Ach esterase inhibition and antioxidant effect). CS-NPs could significantly alleviate PIP nasal irritation and showed no brain toxicity. This work was the first to report additional mechanism of PIP in AD via anti-apoptosis and anti-inflammatory effects. To conclude, mucoadhesive CS-NPs were successfully tailored for effective, safe, and non-invasive PIP delivery with 20-folds decrease in oral dose, opening a gate for a future with lower AD morbidity.

Novel piperine-loaded Tween-integrated monoolein cubosomes as brain-targeted oral nanomedicine in Alzheimer's disease: pharmaceutical, biological, and toxicological studies.

Alzheimer’s disease (AD) is one of the most patient devastating central nervous system diseases with no curative therapy. An effective oral therapy with brain-targeting potential is required that is hampered by blood–brain barrier. Piperine (PIP) is a natural alkaloid with memory enhancing potentials. Oral PIP delivery suffers from its hydrophobicity and first-pass metabolism. In this study, novel Tween-modified monoolein cubosomes (T-cubs) were elaborated as bioactive nanocarriers for brain-targeted oral delivery of PIP. Seven liquid crystalline nanoparticles (cubosomes) were prepared testing different bioactive surfactants (Tween 80, poloxamer, and Cremophor). Full in vitro characterization was carried out based on particle size, zeta potential, polydispersity index, entrapment efficiency, and in vitro release. Morphological examination and structure elucidation were performed using transmission and polarizing microscopes. Sporadic dementia of Alzheimer’s type was induced in 42 male Wistar rats on which full behavioral and biochemical testing was conducted. Brain toxicity was assessed based on Caspase-3 assay for apoptosis and tumor necrosis factor-α for inflammation. Liver and kidney toxicity studies were conducted as well. Among others, T-cubs exhibited optimum particle size (167.00±10.49 nm), polydispersity index (0.18±0.01), and zeta potential (−34.60±0.47 mv) with high entrapment efficiency (86.67%±0.62%). Cubs could significantly sustain PIP in vitro release. In vivo studies revealed T-cubs potential to significantly enhance PIP cognitive effect and even restore cognitive function to the normal level. Superiority of T-cubs over others suggested brain-targeting effect of Tween. Toxicological studies contended safety of cubs on kidney, liver, and even brain. T-cubs exhibited potential anti-inflammatory and anti-apoptotic activity of loaded PIP, indicating potential to stop AD progression that was first suggested in this article. Novel oral nanoparticles elaborated possess promising in vitro and in vivo characteristics with high safety for effective chronic treatment of AD.

Sildenafil citrate nanoemulsion vs. self-nanoemulsifying delivery systems: rational development and transdermal permeation

Sildenafil citrate (SC) is the first choice drug for erectile dysfunction. Nevertheless, drug oral delivery is hampered by some obstacles including first pass metabolism, numerous side effects, relatively short duration and long onset of action. Furthermore, drug delivery formulation and transdermal application of SC is challenged by its amphoteric nature, low oil and water solubility, pH-dependent characteristics and poor membrane permeability. In this paper, relevance of nanomedicine to improve SC characteristics and transdermal permeation was assessed. SC-loaded self-nanoemulsifying drug delivery system (SNEDDS) and nanoemulsions have been developed and appraised. Both nanocarriers encompassed the bioactive excipient, Cremophor RH40® as a surfactant. The nanocarriers encompassed an oil blend of Caproyl 90® and Maisine 35-1® and propylene glycol as a co-surfactant. Nanocarrier assessment was based on solubility studies, robustness to dilution, globule size analysis, cloud point measurement, transmission electron microscopy and in-vitro dialysis. Transdermal permeation study of nanocarriers and drug suspensions via human skin was performed using modified Franz diffusion assembly. SC-SNEDD system was robust to dilution in different media and folds of dilution, maintaining its nano-metric range. SC-nanoemulsion exhibited spherical shaped globules 70 nm in size. Cloud points of all dispersions formed were higher enough than 37°C. In-vitro release from both nanocarriers was significantly higher than drug suspension. Nanoemulsion elaborated could significantly enhance transdermal permeation of SC with higher initial permeation and prolonged release. Paradoxically, SC-SNEDDS exhibited scanty transdermal permeation that could be attributed to low water content of stratum corneum. Nanoemulsion and SNEDDS elaborated exhibited promising in-vitro characteristics for oral sildenafil citrate delivery whereas nanoemulsion elaborated was promising for SC transdermal permeation, as well.

Rationale employment of cell culture versus conventional techniques in pharmaceutical appraisal of nanocarriers

Nanomedicines are enjoying a widespread popularity realizing their intriguing potential to solve drug delivery obstacles. Assessment of major quality attributes of nanocarriers is a crucial process for approving their therapeutic outcomes. Disparate assessment methods that recently encompassed cell line technique were employed . Routinely, a cell line model was viewed as an excellent platform for gene and vaccine deliveries. However, its application in pharmaceutical assessment of nanocarriers was not so far overviewed. This review provides a meticulous look at cell culture implementations in evaluation of major quality attributes of nanocarriers, including oral permeability, cytotoxicity and efficiency of tumor targeting. Among others, cell culture technique strikes the right balance between predictability and throughput. It could circumvent drawbacks of in-vivo and in-vitro techniques while gathering privileges of both. Imperative pharmaceutical considerations demanded for proper application of this technique were emphasized. Furthermore, challenges encountered in assessment of versatile nanocarriers were highlighted with proposed solutions. Finally, future research perspectives in this theme issue were suggested.

Self-emulsifying phospholipid pre-concentrates (SEPPs) for improved oral delivery of the anti-cancer genistein: Development, appraisal and ex-vivo intestinal permeation.

Genistein (GEN), a potent anticancer agent, suffers from scanty oral bioavailability due to poor solubility and extensive metabolism. This work endeavored to enhance GEN solubility and intestinal permeability via fabrication of self-emulsifying phospholipid pre-concentrates (SEPPs) using some bioactive surfactants. Moreover, the potential of surfactant-free SEPP to address GEN obstacles was investigated. SEPPs were prepared from Phosal(®) 53MCT, oil/phosphatidylcholine mixture, alone or with only 30% of different surfactant/co-surfactant mixture (S/CO). In-vitro characterization encompassed globule size analysis, zeta potential (ZP), transmission electron microscopy, and in-vitro release. Ex-vivo intestinal permeation study was performed using non-everted rat intestinal sac technique. Upon aqueous dilution, SEPPs were easily dispersed with spherical globules within a nano-range size (from 165±15 to 425±20nm) and adequate negative ZP (>-30mV). SEPPs demonstrated a significant enhancement in GEN release compared to drug suspension without superior effect due to added S/CO. Permeation study revealed that at least 12.13% free GEN was permeated after 120min from SEPPs compared to only 3.7% from drug suspension. Among different SEPPs, SEPP containing 30% Tween 80/Transcutol HP mixture showed the highest GEN permeation (18.54%). Conclusively, SEPP might be a promising nanocarrier that enhances GEN bioavailability via improving dissolution and inhibition of pre-systemic clearance.

Novel cremochylomicrons for improved oral bioavailability of the antineoplastic phytomedicine berberine chloride: Optimization and pharmacokinetics

Berberine chloride (BER) is an antineoplastic phytomedicine that combat non-Hodgkin lymphoma. BER suffers from low oral bioavailability due to p-glycoprotein efflux and first-pass metabolism. Lymphatic drug targeting recently gained a profound attention due to circumventing hepatic first-pass metabolism and targeting lymph diseases. Therefore, novel BER-loaded cremochylomicrons were elaborated to mitigate BER drawbacks and enhance its lymphatic targeting and bioavailability. Optimized cremochylomicron was prepared with 2.5%w/v Cremophor El and 12.5% w/w berberine content. Promising in vitro characteristics (particle size = 175.6 nm and entrapment efficiency = 95.5%) were obtained. Lyophilized system showed high colloidal stability over 6 months. In addition in vivo pharmacokinetics study demonstrated significant enhancement (>2fold) in the rate and extent of absorption in cremochylomicron over free BER. Moreover, cremochylomicrons demonstrated in significant increase in mean residence time and volume of distribution with decreased intestinal drug clearance as a result of efflux inhibition. In another avenue, a significant reduction in BER absorption (43%) in presence of cycloheximide inhibitor was obtained confirming the lymphatic targeting ability of cremochylomicrons. In conclusion, berberine-loaded cremochylomicron could be considered as a promising nanoplatform for targeting lymphatic system and improving BER oral bioavailability with lower dose and side effects.