Controlling the Evolution of Selective Vancomycin Resistance through Successful Ophthalmic Eye-Drop Preparation of Vancomycin-Loaded Nanoliposomes Using the Active-Loading Method.

Vancomycin is the front-line defense and drug of choice for the most serious and life-threatening methicillin-resistant Staphylococcus aureus (MRSA) infections. However, poor vancomycin therapeutic practice limits its use, and there is a consequent rise of the threat of vancomycin resistance by complete loss of its antibacterial activity. Nanovesicles as a drug-delivery platform, with their featured capabilities of targeted delivery and cell penetration, are a promising strategy to resolve the shortcomings of vancomycin therapy. However, vancomycin's physicochemical properties challenge its effective loading. In this study, we used the ammonium sulfate gradient method to enhance vancomycin loading into liposomes. Depending on the pH difference between the extraliposomal vancomycin-Tris buffer solution (pH 9) and the intraliposomal ammonium sulfate solution (pH 5-6), vancomycin was actively and successfully loaded into liposomes (up to 65% entrapment efficiency), while the liposomal size was maintained at 155 nm. Vancomycin-loaded nanoliposomes effectively enhanced the bactericidal effect of vancomycin; the minimum inhibitory concentration (MIC) value for MRSA decreased 4.6-fold. Furthermore, they effectively inhibited and killed heteroresistant vancomycin-intermediate S.aureous (h-VISA) with an MIC of 0.338 µg mL-1. Moreover, MRSA could not develop resistance against vancomycin that was loaded into and delivered by liposomes. Vancomycin-loaded nanoliposomes could be a feasible solution for enhancing vancomycin's therapeutic use and controlling the emerging vancomycin resistance.

Syringeable atorvastatin loaded eugenol enriched PEGylated cubosomes in-situ gel for the intra-pocket treatment of periodontitis: statistical optimization and clinical assessment.

Atorvastatin calcium (ATV) is a well-known anti-hyperlipidemic drug currently being recognized for possessing an anti-inflammatory effect. Introducing it as a novel remedy for periodontitis treatment necessitates developing a syringeable modified delivery system capable of targeting inflammation within the periodontal pockets. Thus, a 33 Box-Behnken design was used to generate eugenol enriched PEGylated cubosomes. Based on the desirability function, the optimized formulation (OEEPC) was selected exhibiting a solubilization efficiency (SE%) of 97.71 ± 0.49%, particle size (PS) of 135.20 ± 1.11 nm, polydispersity index (PDI) of 0.09 ± 0.006, zeta potential (ZP) of -28.30 ± 1.84 mV and showing a sustained drug release over 12 h. It displayed a cubic structure under the transmission electron microscope, furthermore, it was stable upon storage for up to 30 days. Hence, it was loaded into an optimum syringeable in-situ gel (ISG) which displayed the desired periodontal gelation temperature (34 ± 0.70 °C) and an adequate gelation time (46 ± 2.82 sec), it also released approximately 75% of the drug within 72 h. Clinical evaluation of the ISG showed a promising percentage reduction of about 58.33% in probing depth, 90% in the bleeding index, 81.81% in the plaque index, and 70.21% in gingival levels of transforming growth factor-ß1. This proved that the formulated syringeable intra-pocket delivery system of ATV is an efficient candidate for diminishing inflammation in periodontitis.

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.

Atorvastatin-loaded emulsomes foam as a topical antifungal formulation.

Dermal fungal infection faces many challenges, especially for immunocompromised patients. Recently, the repositioning of atorvastatin (ATO) as a promising anti-mycoses therapy is used to overcome some issues of conventional therapeutic agents such as microbial resistance. The goal of this study was to develop a suitable formula for dermal fungal infection. Wherefore, ATO was entrapped into emulsomes and then incorporated in a foam system for topical convenient application. The D-optimal design was used for the optimization of ATO-emulsome and foam to achieve suitable responses. Regarding emulsomes, cholesterol weight and sonication time were independent variables that impact emulsome size, polydispersity index, surface charge, and entrapment efficiency. The optimum formula showed a size of 359.4 ± 8.97 nm, PDI of 0.4752 ± 0.012, a zeta potential of -21.27 ± 0.53 mV, and a drug entrapment of 95 ± 2.38%. Transmission electron microscope and Fourier-transform infrared spectroscopy (FT-IR) proved the assembly of ATO-emulsome. Foam composition was optimized to achieve good expansion, stability, and viscosity using a surfactant triple mixture and hydroxypropyl methylcellulose. The selected ATO-emulsome foam which consisted of 1% HPMC, 1.249% SDS, and 4% pluronic showed prolonged drug release. Efficient permeation through skin layers was asserted by using a confocal laser scanning microscope. Moreover, the homogenous distribution of the foam bubbles upholds stability and conserves the system from rapid collapse. The antifungal activity was confirmed by an in-vitro and in-vivo microbiology study beside in-vivo biocompatibility. In conclusion, ATO-emulsome and incorporation in foam have demonstrated good antifungal activity which presented a unique aspect for potential clinical applications.

Repurposing of atorvastatin emulsomes as a topical antifungal agent.

Cutaneous fungal infection therapy confronts several issues concerning skin permeation in addition to drug resistance and adverse effects of conventional drugs. The repurposing strategy is supposed to overcome some of those therapeutic obstacles. Recently, atorvastatin (ATO) revealed antifungal activity. ATO is an antihyperlipidemic drug with pH-dependent solubility, which limits skin permeation. This study aims to improve ATO antifungal activity by encapsulation in an emulsomes (EMLs) system, which seeks to ameliorate skin penetration. Therefore, multiple factors were investigated according to the One-Factor-at-a-Time (OFAT) design to achieve the optimum formula with targeted characteristics. Minimizing particle-size and polydispersity-index, besides elevating zeta-potential (ZP) and entrapment-efficiency were the desirable responses during assessing 11 factors. The selected ATO-EMLs formula (E21) recorded 250.5 nm in particle size, polydispersity index of 0.4, ZP of -25.93 mV, and 83.12% of drug entrapped. Morphological study of E21 revealed spherical core-shell vesicles in nanosize. DSC, XRD, and FTIR were conducted to discover the physicochemical properties and confirm emulsomes formation. Optimized ATO-EMLs slowed drug release rate as only 75% of ATO was released after 72 h. Stability study recommended storage between 2 and 8 °C. The in vivo permeation study remarked a homogeneous penetration of EMLs in different skin layers. The in vivo skin irritation test revealed limited histopathological changes. The in vitro and in vivo microbiological studies demonstrated a good antifungal activity of ATO-EMLs. ATO-EMLs system improved antifungal activity as the MIC values reduced from 650 µg/mL for free ATO to 550 µg/mL for ATO-EMLs. These findings may shed light on ATO as an antifungal drug and nanosystems as a tool to support drug repurposing.

Development, Characterization, and in-vivo Pharmacokinetic Study of Lamotrigine Solid Self-Nanoemulsifying Drug Delivery System.

PURPOSE: This study aimed to prepare solid self-nanoemulsified drug delivery system (S-SNEDDS) of lamotrigine (LMG) for enhancing its dissolution and oral bioavailability (BA). METHODS: Nineteen liquid SNEDDS were prepared (R1-R19) using D-optimal design with different ratios of oil, surfactant (S), and cosurfactant (Cos). The formulations were characterized regarding robustness to dilution, droplet size, thermodynamic stability testing, self-emulsification time, in-vitro release in 0.1 N HCl and phosphate buffer (PB; pH 6.8). Design Expert® 11 software was used to select the optimum formulations. Eight S-SNEDDS were prepared (S1-S8) using 23 factorial design, and characterized by differential scanning calorimetry (DSC), powder x-ray diffraction (PXRD), and scanning electron microscopy (SEM). The optimum formulation was chosen regarding in-vitro drug released in 0.1 N HCl and PB, compared to pure LMG and commercial tablet (Lamictal®). The BA of LMG from the optimized S-SNEDDS formulation was evaluated in rabbits compared to pure LMG and Lamictal®. RESULTS: The optimized S-SNEDDS was S2, consisting of R9 adsorbed on Aeroperl® 300 in a ratio of 1:1, with the best results regarding in-vitro drug released in 0.1 N HCl at 15 min (100%) compared to pure LMG (73.40%) and Lamictal® (79.43%), and in-vitro drug released in PB at 45 min (100%) compared to pure LMG (30.46%) and Lamictal® (92.08%). DSC, PXRD, and SEM indicated that LMG was molecularly dispersed within the solid nano-system. The BA of S2 was increased 2.03 and 1.605 folds compared to pure LMG, and Lamictal®, respectively. CONCLUSION: S2 is a promising S-SNEDDS formulation. It can be a potential carrier for improving dissolution, and BA of LMG.

Optimization of nutraceutical coenzyme Q10 nanoemulsion with improved skin permeability and anti-wrinkle efficiency.

Coenzyme Q10 (CoQ10) is an insoluble, poorly permeable antioxidant with great biological value which acts as anti-aging and anti-wrinkle agent. To improve its permeability through topical application, the current study aimed at formulating oil/water (o/w) nanoemulsion (NE) as an efficient vehicle for delivering (CoQ10) through the skin barriers. The solubility of (CoQ10) was tested for various oils, surfactants (S), and co-surfactants (CoS). The NE region was determined by constructing pseudoternary phase diagrams. NE formulae containing 1, 2, and 3% w/w drug have been subjected to thermodynamic stability test. The formulae that passed thermodynamic stability tests were characterized by physical properties as pH, viscosity, refractive index, droplet size, zeta-potential, TEM, electroconductivity, in vitro release, and ex vivo permeation. The formula 'F2' containing 10% w/w isopropyl myristate (oil phase), 60% w/w of Tween 80: Transcutol HP mixture (S/CoSmix) at ratio 2:1, 30% w/w water and 2% w/w drug was evaluated for its anti-wrinkle efficiency using an animal model. The 'F2' formula showed 11.76 ± 1.1 nm droplet size, 1.4260 ± 0.0016 refractive index, 0.228 PDI, -14.7 ± 1.23 mv zeta potential, 7.06 ± 0.051 pH, 199.05 ± 0.35 cp viscosity, and the highest percentage of drug release in the selected dissolution media. About 47.21% of the drug was released in phosphate buffer 7.4 containing 5% w/v Labrasol and 5% w/v isopropyl alcohol through 24 h. It also showed the highest drug flux (Jss = 3.164 µg/cm2/h), enhancement ratio (Er = 8.32), and permeability coefficient (Kp = 22.14 × 10-4 cm2/h). CoQ10 NE reduced the skin wrinkles and gave the skin smooth appearance. Our investigation suggests the potential use of NE as a vehicle for enhancing solubility and permeability of CoQ10 and thus improving its anti-wrinkle efficiency.

Laminated sponges as challenging solid hydrophilic matrices for the buccal delivery of carvedilol microemulsion systems: Development and proof of concept via mucoadhesion and pharmacokinetic assessments in healthy human volunteers.

Carvedilol (CVD) suffers from low absolute bioavailability (25%) due to its limited aqueous solubility and hepatic first-pass metabolism. Hydroxypropyl methylcellulose (HPMC) laminated buccal sponges loaded with CVD microemulsions (CVD-ME) were exploited to surmount such limitations. Six pseudoternary-phase diagrams were constructed using Capmul® MCM C8/Capmul® PG8, Tween® 80, propylene glycol and water. Six CVD-ME systems (0.625% w/v) were incorporated into HPMC core sponges backed with Ethocel® layers. The sponges were preliminary evaluated via FT-IR, DSC and XRD. The surface pH, morphology and in vitro drug release studies were evaluated. In vivo mucoadhesion and absorption studies of the best achieved laminated sponges (F4) were assessed in healthy volunteers. CVD-ME systems displayed nano-spherical clear droplets. The sponges showed interconnecting porous matrices through which CVD was dispersed in amorphous state. No intermolecular interaction was detected between CVD and HPMC. The surface pH values were almost neutral. The sponges loaded with CVD-ME systems showed more sustained-release profiles than those loaded with CVD-powder. Compared to Dilatrend® tablets, the significantly (P<0.05) higher bioavailability (1.5 folds), delayed Tmax and prolonged MRT(0-∞) unraveled the dual-potential of F4 sponges for water-insoluble drugs, like CVD, in improving drug oral bioavailability and in controlling drug release kinetics via buccal mucosa.

Transdermal delivery of vancomycin hydrochloride using combination of nano-ethosomes and iontophoresis: in vitro and in vivo study.

This study aimed to evaluate transdermal delivery of vancomycin hydrochloride using the combination of ethosomes as an encapsulating vesicle and iontophoresis. Ethosomes were prepared and evaluated in terms of electrochemical stability. Cathodal iontophoresis of negatively charged ethosomes and anodal iontophoresis of free drug solution and positively charged vesicles were conducted. The effect of current mode, density, concentration of drug and ionic strength was studied. In vivo study was performed by inducing mediastinitis in Sprague-Dawley rats using methicillin-resistant Staphylococcus aureus as infected pathogen, the mean bacterial count was compared between groups of rats, one of the treated groups received drug intramuscularly while the other group received vancomycin using iontophoretic delivery of optimized ethosomal formula. Ethosomes showed efficient electrochemical stability, cathodal iontophoresis of negatively charged vesicle (F2) showed maximum transdermal flux (550 µg/cm(2)/h) compared to free drug solution and other ethosomal formulae, transdermal flux was reduced by altering current mode from continuous to ON/OFF mode, reducing current density and by using normal saline as drug solvent; on the other hand, flux was potentiated by increasing drug concentration from 25 to 75 mg/ml. In vivo study revealed that there was a significant difference in terms of bacterial count between untreated and treated groups, while there was no statistically significant difference between the I.M. vancomycin treatment and treatment conducted by iontophoretic delivery of vancomycin encapsulated in ethosomal formula. Combination between ethosomes and iontophoresis had succeeded in delivering vancomycin transdermally.

Mucoadhesive nanoparticles as carrier systems for prolonged ocular delivery of gatifloxacin/prednisolone bitherapy.

A fluoroquinolone/glucocorticoid combination for the treatment of bacterial keratitis in the form of mucoadhesive nanoparticle suspensions was developed to prolong the release and improve patient compliance. Gatifloxacin/prednisolone loaded nanoparticles were prepared using Eudragit RS 100 and RL 100 and coated with the bioadhesive polymer, hyaluronic acid. FT-IR and DSC studies revealed no interaction between gatifloxacin and prednisolone. The effects of the drug:polymer ratio (D:P) and the RS/RL ratio were studied. The obtained nanoparticles were distinct and spherical with a solid dense structure. They have average particle size range of 315.2 to 973.65 nm. Increasing the D:P ratio significantly lowered the entrapment efficiency for both drugs (p < 0.05). The nanoparticle suspensions revealed significantly prolonged drug release comparing to the free drugs (p < 0.05) with no burst effect. Increasing the polymer concentration and the Eudragit RS ratio significantly decreased the release efficiency values. Gatifloxacin showed anomalous release (n = 0.4943) from 1:1 D:P ratio nanoparticle suspension and Fickian diffusion mechanism (n < 0.45) from formulas prepared at higher D:P ratios. Gatifloxacin showed better bioavailability and sustained action in aqueous humor and corneal tissue from the nanoparticles compared to the commercial eye drops. The resulting nanoparticle suspension is promising in reducing dose frequency and improving patient compliance.