Investigating superiority of novel bilosomes over niosomes in the transdermal delivery of diacerein: in vitro characterization, ex vivo permeation and in vivo skin deposition study.

Skin is considered the most accessible organ of the body because of its underlying capillary network. However, stratum corneum (SC), the upper most layer of skin, represents major diffusional barrier for most drugs. Hence, the use of edge activators (EAs) in designing novel elastic vesicles is hypothesized to impart their lipid bilayer with ultra-flexibility to trespass SC by high self-optimizing deformability. To confirm this hypothesis, this work aimed at developing novel bilosomes by modulating conventional niosomal composition using different bile salts as EAs and investigating their superiority over niosomes for transdermal delivery of diacerein (DCN), as model drug. Bilosomes were prepared by thin film hydration (TFH) technique according to full 31.22 factorial design to select the optimal formulation using Design-Expert® software. The optimal bilosomes (B6) showed nanosized vesicles (301.65 ± 17.32 nm) and 100.00 ± 0.00 % entrapment efficiency. Ex vivo permeation studies and in vivo evaluation revealed that B6 exhibited superior permeation and drug retention capacity compared to the conventional niosomal formulation and drug suspension. Furthermore, B6 was subjected to in vivo histopathological study using male Wistar rats which ensured its safety for topical application. Overall, the results confirmed the hypothesized superiority of bilosomes over niosomes for enhancing DCN flux across the skin.

Comparison of nanomilling and coprecipitation on the enhancement of in vitro dissolution rate of poorly water-soluble model drug aripiprazole.

The aim of this study was to evaluate the effect of coprecipitation and nanomilling on the crystallinity of a model drug, aripiprazole and evaluate the in vitro dissolution rate (IDR). Aripiprazole compositions were prepared by physical mixing, coprecipitation and nanomilling using hydroxypropylcellulose (HPC), polyvinylpyrrolidone (PVP) K17 and pluronic F127. The particle size, solubility, IDR and drug crystallinity were studied. Aripiprazole pluronic compositions were compressed into tablets and dissolution rate was evaluated. The particle size of nanomilled compositions was significantly smaller than that of the other compositions. The saturation solubility of aripiprazole from nanoparticle (NP) and coprecipitate (CP) from PVP and Pluronic was comparable, however, NP of HPC containing composition showed higher solubility when compared to its CP compositions. The crystallinity of aripiprazole decreased from physical mixtures to coprecipitates and further in NPs. The increased aripiprazole IDR was due to decreased crystallinity from coprecipitate compositions and disruption of crystallinity from nanomilled compositions. Aripiprazole tablets prepared from nanomilled powder dissolved >75% within 10 min compared with 17% and 20% for tablets prepared from physical mixture and coprecipitate powders, respectively. The increase in IDR due to nanomilling was more significant than coprecipitation and NPs retained the IDR after compression into tablets.

Effect of fixed aqueous layer thickness of polymeric stabilizers on zeta potential and stability of aripiprazole nanosuspensions.

The aim of this study was to evaluate the effect of the thickness of adsorbed polymer layer (also known as Fixed Aqueous Layer Thickness, FALT) of polymeric stabilizers on zeta potential and stability of nanoparticles in a suspension. Aripiprazole, a poorly water soluble drug was used as a model drug to evaluate rationale for increased FALT and to understand the effect of hydrophilicity and hydrophobicity of polymeric stabilizers on FALT of aripiprazole nanosuspensions. The nanosuspensions were prepared by media milling and Pluronic F68, Pluronic F127, Hydroxypropyl methylcellulose (HPMC) and Hydroxypropyl cellulose (HPC) were used as polymeric stabilizers. The particle size (immediately after preparation and after 1 week of storage at 25°C) and zeta potential of aripiprazole nanosuspensions were determined. For Pluronics, FALT was determined theoretically whereas for HPMC and HPC it was calculated as Debye Huckel parameter from the zeta potential dependence on the ionic strength. An increase in FALT resulted in reduced zeta potential. With an increase in FALT of polymers used, the stability of nanosuspensions showed improvement. Furthermore, a linear correlation was shown to exist between the FALT and length of hydrophilic chains in Pluronics.

Norfloxacin loaded nano-cubosomes for enhanced management of otitis externa: In vitro and in vivo evaluation.

The research's goal is to design and formulate nano-structured cubosomes loaded with norfloxacin (NFX)formanagement of otitis externa. In this study, glyceryl monooleate (GMO) as lipid phase, Cremophor EL as surfactant and either Pluronic F108 or Pluronic F127 as stabilizer were the used ingredients. The nano-cubosomal formulation "CUB 1" (its dispersed phase is composed of GMO (95%), Cremophor EL (2.5%) and Pluronic F108 (2.5%)) was the best achieved one. It had small particles size (216.75 ± 2.47 nm), good polydispersity index (0.339 ± 0.012) and acceptable zeta potential (-41.2 ± 2.262 mV). Images obtained after transmission electron microscopy examination ensured nearly cubic shape of formed nanoparticles with excellent dispersibility. Moreover, micrographs of rabbit ear skin specimens examined by confocal laser microscopy ensured good permeation capability of nano-structured cubosomes.In addition, in vivoskin deposition results revealed that higher amount of NFX was deposited in the rabbit ear skin throughout the study period (10 h) compared to drug suspension. Additionally, histopathological results proved that NFX loaded cubosomes can be safely applied topically on ear skin without any signs of inflammation nor skin irritation. Accordingly, these results anticipated the nano-structured cubosomal capabilities as a favorable nano-carrier for dermal NFX delivery to external ear skin for enhancing the management of otitis externa.

Fabrication of levofloxacin polyethylene glycol decorated nanoliposomes for enhanced management of acute otitis media: Statistical optimization, trans-tympanic permeation and in vivo evaluation.

Acute otitis media (AOM), an infection in the middle ear, is usually treated through systemic administration of antibiotics because the stratum corneum of the intact tympanic-membrane (TM) possesses low permeability that holds against the ototopical antibiotics use. Therefore, the objective of this work was to encapsulate levofloxacin (LFX) into polyethylene glycol 400 (PEG 400) decorated nanoliposomes (PNLs) as an approach for drug delivery through the intact tympanic-membrane. LFX loaded-PNLs were primed by ethanol injection technique. A 23 full factorial design, using Design-Expert® software, was developed to optimize formulation variables. Particle size, polydispersity index, zeta potential and entrapment efficiency percent of the formulae were determined. The optimal formulation (F7, prepared using 30:1 phospholipid to drug weight ratio, 30 mg cholesterol and 125 mg PEG 400) exhibited improved ex vivo trans-tympanic permeation compared to nanoliposomes lacking PEG 400 and drug solution. In addition, F7 showed greater extent of in vivo deposition of LFX in the intact TM compared to drug solution. Furthermore, in vivo histopathological examination proved the tolerability of the PNLs after ototopical application. Overall, the obtained results revealed that PNLs could be promising for LFX delivery through intact TM providing means for the ototopical drug application for treatment of acute middle ear infections.

Use of transethosomes for enhancing the transdermal delivery of olmesartan medoxomil: in vitro, ex vivo, and in vivo evaluation.

INTRODUCTION AND AIM: Olmesartan medoxomil (OLM) is an antihypertensive drug with low oral bioavailability due to extensive first-pass metabolism. This study aimed to prepare transetho somes (TEs) for enhancing the transdermal delivery of OLM to avoid its oral problems. METHODS: TE formulae were prepared utilizing 51.31 full factorial design using various surfactants (SAAs) and different phospholipid-to-SAA ratios. The formulae were characterized regarding their entrapment efficiency percentage (EE%), particle size (PS), polydispersity index (PDI), zeta potential (ZP), and the amount of drug released after 6 hours (Q6h). Design Expert® software was employed to select the optimum formula. RESULTS: The optimum formula (TE14) had an EE% of 58.50%±1.30%, PS of 222.60±2.50 nm, PDI of 0.11±0.06, ZP of -20.80±0.30 mV, and Q6h of 67.40%±0.20%. In addition, TE14 was compared to transferosomes (TFs) in terms of elasticity and was found to show higher deformability index. Further, evaluation of ex vivo permeation using both rat and shed snake skin showed higher permeability of TE14 compared to TFs and OLM suspension. Confocal laser scanning microscopy confirmed the capability of the fluorolabeled TE14 to penetrate deep within the skin, while the histopathological study confirmed its safety. TE14 successfully maintained normal blood pressure values of rats up to 24 hours. Moreover, TE14 showed superiority in dermatokinetic study when compared with drug suspension. CONCLUSION: Taken together, the obtained results confirmed the potential of employing TEs as a successful carrier for the transdermal delivery of OLM.

Tailoring of PEGylated bilosomes for promoting the transdermal delivery of olmesartan medoxomil: in-vitro characterization, ex-vivo permeation and in-vivo assessment.

INTRODUCTION: The intention of this work was to load olmesartan medoxomil (OLM), a sparsely water soluble antihypertensive bioactive with low oral bioavailability (26%), into PEGylated bilosomes (PBs) for augmenting its transdermal delivery. PBs contain PEGylated single chain edge activator besides the components of traditional bilosomes (Span 60, cholesterol and bile salts). The PEG gives further resilience to vesicle membrane and is speculated to augment both permeability and bioavailability of OLM. METHODS: A 24 factorial experiment was constructed to inspect the impact of diverse variables on vesicles' features and sort out the optimal formula adopting Design Expert® software utilizing thin film hydration technique. Vesicles' evaluation was done by finding out entrapment efficiency percent (EE%), particle size (PS), polydispersity index (PDI), zeta potential (ZP) and amount of drug released after 6 hrs (Q6h). The optimal formula was selected and characterized for further investigations. RESULTS: The optimal formula (PB15) showed spherical vesicles with EE% of 72.49±0.38%, PS of 559.30±10.70 nm, PDI of 0.57±0.15, ZP of -38.35±0.65 mV and Q6h of 59.60±0.24%. PB15 showed higher deformability index (28.39±5.71 g) compared to traditional bilosomes (5.88±0.90 g) and transethosomes (14.94±0.63 g). Further, PB15 showed superior skin permeation from rat's skin relative to the drug suspension. Moreover, confocal laser scanning microscopy examination revealed efficient penetration of the fluoro-labeled PB15 through skin. Histopathological study ensured the safety of PB15. In addition, in-vivo skin deposition studies showed higher OLM deposition in rat's skin from PB15 compared to transethosomes and OLM suspension. Furthermore, pharmacodynamic and pharmacokinetic studies performed using male Wistar rats and male Albino rabbits, respectively, showed the superiority of PB15 over oral tablets. PB15 was found to have significantly higher AUC0-48 and AUC0-∞ relative to the oral tablets. As well, the relative bioavailability of PB15 was found to be 235.04%. CONCLUSION: Overall, the obtained results confirmed the creditable effect of PB15 for transdermal delivery.

Fabrication of novel elastosomes for boosting the transdermal delivery of diacerein: statistical optimization, ex-vivo permeation, in-vivo skin deposition and pharmacokinetic assessment compared to oral formulation.

Diacerein (DCN) is a hydrophobic osteoarthritis (OA) drug with short half-life and low oral bioavailability. Furthermore, DCN oral administration is associated with diarrhea which represents obstacle against its oral use. Hence, this article aimed at developing elastosomes (edge activator (EA)-based vesicular nanocarriers) as a novel transdermal system for delivering DCN efficiently and avoiding its oral problems. For achieving this goal, elastosomes were prepared according to 41.21 full factorial design using different EAs in varying amounts. The prepared formulae were characterized regarding their entrapment efficiency percentage (EE%), particle size (PS), polydispersity index (PDI), zeta potential (ZP) and deformability index (DI). Desirability function was employed using Design-Expert® software to select the optimal elastosomes (E1) which showed EE% of 96.25 ± 2.19%, PS of 506.35 ± 44.61 nm, PDI of 0.46 ± 0.09, ZP of -38.65 ± 0.91 mV, and DI of 12.74 ± 2.63 g. In addition, E1 was compared to DCN-loaded bilosomes and both vesicles exhibited superior skin permeation potential and retention capacity compared to drug suspension. In-vivo histopathological study was performed which ensured the safety of E1 for topical application. Furthermore, the pharmacokinetic study conducted in albino rabbits demonstrated that there was no significant difference in the rate and extent of DCN absorption from topically applied E1 compared to oral suspension. Multiple level C in-vitro in-vivo correlation showed good correlation between in-vitro release and in-vivo drug performance for E1 and DCN oral suspension. Overall, results confirmed the admirable potential of E1 to be utilized as novel carrier for transdermal delivery of DCN and bypassing its oral side effects.

Design and development of microemulsion systems of a new antineoplaston A10 analog for enhanced intravenous antitumor activity: In vitro characterization, molecular docking, 125I-radiolabeling and in vivo biodistribution studies.

A10, (3-phenylacetylamino-2,6-piperidinedione), is a natural peptide with broad antineoplastic activity. Recently, in vitro antitumor effect of a new A10 analog [3-(4-methoxybenzoylamino)-2,6-piperidinedione] (MPD) has been verified. However, poor aqueous solubility represents an obstacle towards intravenous formulation of MPD and impedes successful in vivo antitumor activity. To surmount such limitation, MPD microemulsion (MPDME) was developed. A 3122 full factorial design using Design-Expert® software was adopted to study the influence of different parameters and select the optimum formulation (MPDME1). Transmission electron microscopy (TEM) displayed spherical droplets of MPDME1. The cytotoxicity of MPDME1 in Michigan Cancer Foundation 7 (MCF-7) breast cancer cell line exceeded that of MPD solution (MPDS) and tamoxifen. Compatibility with injectable diluents, in vitro hemolytic studies and in vivo histopathological examination confirmed the safety of parenteral application of MPDME1. Molecular docking results showed almost same binding affinity of A10, MPD and 125I-MPD with histone deacetylase 8 (HDAC8) receptor. Accordingly, radioiodination of MPDME1 and MPDS was done via direct electrophilic substitution reaction. Biodistribution of 125I-MPDME1 and 125I-MPDS in normal and tumor (ascites and solid) bearing mice showed high accumulation of 125I-MPDME1 in tumor tissues. Overall, the results proved that MPDME represents promising parenteral delivery system capable of improving antineoplastic activity of MPD.

Improved Targeting and Tumor Retention of a Newly Synthesized Antineoplaston A10 Derivative by Intratumoral Administration: Molecular Docking, Technetium 99m Radiolabeling, and In Vivo Biodistribution Studies.

BACKGROUND: Recently, the direct intratumoral (i.t.) injection of anticancer agents has been investigated. A newly synthesized Antineoplaston A10 analog 3-(4-methoxybenzoylamino)-2,6-piperidinedione (MPD) showed an antitumor activity in human breast cancer cell line. Unfortunately, MPD suffered from poor water solubility. MATERIALS AND METHODS: Pseudoternary phase diagram of oil (isopropyl myristate), surfactant (Tween 80), cosurfactant (ethanol), and water was plotted. MPD microemulsion (MPDME) was developed and characterized for particle size (PS), polydispersity index (PDI), zeta potential (ZP), and morphology (transmission electron microscopy). MPDME and MPD solution (MPDS) were radiolabeled with technetium 99m (99mTc) using stannous chloride dihydrate (SnCl2.2H2O). Molecular docking of MPD and 99mTc-MPD was performed to study the interaction with DNA. RESULTS: The impacts of intravenous (i.v.) and i.t. injections of 99mTc-MPDME and 99mTc-MPDS on biodistribution were studied. The developed MPDME showed spherical droplets with mean PS (74.00 ± 5.69 nm), PDI (0.25 ± 0.03), and ZP (33.90 ± 0.90 mV). Labeling yield of 99mTc-MPDME and 99mTc-MPDS was 97.00% ± 0.60% and 92.02% ± 0.45%, respectively. MPD and 99mTc-MPD showed almost same binding affinity with DNA binding site. Biodistribution results showed that i.t. injection of 99mTc-MPDME significantly enhanced tumor retention compared to i.v. route. CONCLUSIONS: Herein, the authors concluded that microemulsion could be used as i.t. injectable delivery vehicle to improve targeting and tumor retention of MPD.

Fabrication of novel ultradeformable bilosomes for enhanced ocular delivery of terconazole: In vitro characterization, ex vivo permeation and in vivo safety assessment.

The objective of this work was to encapsulate terconazole (TCZ), a water insoluble antifungal drug, into novel ultradeformable bilosomes (UBs) for achieving enhanced ocular delivery. In addition to the constituents of the conventional bilosomes; namely, Span 60, cholesterol, and the bile salts, UBs contain an edge activator which imparts extra elasticity to the vesicles and consequently hypothesized to result in improved corneal permeation. In this study, TCZ loaded UBs were prepared utilizing ethanol injection method according to 23 full factorial design. The investigation of the influence of different formulation variables on UBs properties and selection of the optimum formulation was done using Design-Expert® software. The selected UBs formulation (UB1; containing 10mg bile salt and 5mg Cremophor EL as an edge activator) showed nanosized spherical vesicles (273.15±2.90nm) and high entrapment efficiency percent (95.47±2.57%). Results also revealed that the optimum UBs formulation exhibited superior ex vivo drug flux through rabbit cornea when compared with conventional bilosomes, niosomes, and drug suspension. Furthermore, in vivo ocular tolerance and histopathological studies conducted using male albino rabbits proved the safety of the fabricated UBs after topical ocular application. Overall, the obtained results confirmed that UBs could be promising for ocular drug delivery.

Design and optimization of topical methotrexate loaded niosomes for enhanced management of psoriasis: application of Box-Behnken design, in-vitro evaluation and in-vivo skin deposition study.

Psoriasis, a skin disorder characterized by impaired epidermal differentiation, is regularly treated by systemic methotrexate (MTX), an effective cytotoxic drug but with numerous side effects. The aim of this work was to design topical MTX loaded niosomes for management of psoriasis to avoid systemic toxicity. To achieve this goal, MTX niosomes were prepared by thin film hydration technique. A Box-Behnken (BB) design, using Design-Expert(®) software, was employed to statistically optimize formulation variables. Three independent variables were evaluated: MTX concentration in hydration medium (X1), total weight of niosomal components (X2) and surfactant: cholesterol ratio (X3). The encapsulation efficiency percent (Y1: EE%) and particle size (Y2: PS) were selected as dependent variables. The optimal formulation (F12) displayed spherical morphology under transmission electron microscopy (TEM), optimum particle size of 1375.00 nm and high EE% of 78.66%. In-vivo skin deposition study showed that the highest value of percentage drug deposited (22.45%) and AUC0-10 (1.15 mg.h/cm(2)) of MTX from niosomes were significantly greater than that of drug solution (13.87% and 0.49 mg.h/cm(2), respectively). Moreover, in-vivo histopathological studies confirmed safety of topically applied niosomes. Concisely, the results showed that targeted MTX delivery might be achieved using topically applied niosomes for enhanced treatment of psoriasis.

Investigating the potential of employing bilosomes as a novel vesicular carrier for transdermal delivery of tenoxicam.

Bilosomes represent an evolving vesicular carrier that have been explored for oral vaccines delivery based on its ability to resist enzymes and bile salts in the gastrointestinal tract (GIT). Bilosomes vesicles are formed of bilayer membrane of non-ionic surfactant molecules encompassing bile salts. Although, bilosomes have not been proposed for transdermal drug delivery, this carrier seems to have promising potential in this regard. Accordingly, the aim of this investigation was to assess the capability and safety of utilizing bilosomes for transdermal delivery of tenoxicam (TX) as a model drug. A 3(1)2(2) full factorial design was adopted to study the effects of different formulation parameters on bilosomes properties and select the optimal formulation using Design-Expert(®) software. The selected formulation displayed nano-sized spherical vesicles (242.5 ± 6.43nm) with reasonable entrapment efficiency percent (68.33 ± 2.33%). Confocal laser scanning microscopy confirmed the capability of the flourolabeled bilosomes to penetrate deep within the skin. Both, ex vivo permeation and in vivo skin deposition studies confirmed the superiority of bilosomes over drug solution in delivering TX transdermally. In addition, in vivo histopathological study proved the safety of topically applied bilosomes. In summary, the highlighted results confirmed that bilosomes can be further adopted for delivering drugs transdermally.

Preparation, optimization, and in vitro simulated inhalation delivery of carvedilol nanoparticles loaded on a coarse carrier intended for pulmonary administration.

Carvedilol (CAR) is a potent antihypertensive drug but has poor oral bioavailability (24%). A nanosuspension suitable for pulmonary delivery to enhance bioavailability and bypass first-pass metabolism of CAR could be advantageous. Accordingly, the aim of this work was to prepare CAR nanosuspensions and to use artificial neural networks associated with genetic algorithm to model and optimize the formulations. The optimized nanosuspension was lyophilized to obtain dry powder suitable for inhalation. However, respirable particles must have a diameter of 1-5 µm in order to deposit in the lungs. Hence, mannitol was used during lyophilization for cryoprotection and to act as a coarse carrier for nanoparticles in order to deliver them into their desired destination. The bottom-up technique was adopted for nanosuspension formulation using Pluronic stabilizers (F127, F68, and P123) combined with sodium deoxycholate at 1:1 weight ratio, at three levels with two drug loads and two aqueous to organic phase volume ratios. The drug crystallinity was studied using differential scanning calorimetry and powder X-ray diffractometry. The in vitro emitted doses of CAR were evaluated using a dry powder inhaler sampling apparatus and the aerodynamic characteristics were evaluated using an Andersen MKII cascade impactor. The artificial neural networks results showed that Pluronic F127 was the optimum stabilizer based on the desired particle size, polydispersity index, and zeta potential. Results of differential scanning calorimetry combined with powder X-ray diffractometry showed that CAR crystallinity was observed in the lyophilized nanosuspension. The aerodynamic characteristics of the optimized lyophilized nanosuspension demonstrated significantly higher percentage of total emitted dose (89.70%) and smaller mass median aerodynamic diameter (2.80 µm) compared with coarse drug powder (73.60% and 4.20 µm, respectively). In summary, the above strategy confirmed the applicability of formulating CAR in the form of nanoparticles loaded on a coarse carrier suitable for inhalation delivery.

Instantaneous enteric nano-encapsulation of omeprazole: pharmaceutical and pharmacological evaluation.

Recently, great attention has been paid to nanocapsules. The interest of these structures is due to their promising applications as drug delivery systems. The objective of this study was to develop novel enteric coating technique based on instantaneous encapsulation of the acid-labile drug, omeprazole in innovative enteric nanocapsules. Omeprazole enteric nanocapsules were formulated by varying the type and amount of the enteric polymer. The particle size (PS), polydispersity index (PDI), zeta potential (ZP) and encapsulation efficiency (EE) values of the prepared enteric nanocapsules were determined. A full 2(1)×3(1) factorial design was used for planning and analysis of the experimental trials to select the optimized formulation. The highest desirability value was 0.7463 for formula E3 (containing 200mg hydroxypropyl methylcellulose phthalate (HPMCP)). The stability of omeprazole was reflected by the absence of the exothermal peak when the drug was encapsulated as detected by differential scanning calorimetry (DSC) thermograms. In vitro drug release study confirmed the USP specifications required to meet the key formulation characteristics of gastro-resistance. In vivo pharmacological assessment showed that the optimized nanocapsules were able to protect rat stomach against ulcer formation compared to the aqueous suspension of the drug which showed less significant protection.