Phospholipid free nano-vesicles of Brinzolamide Biopolymer Ocular Insert; design, in vitro and in vivo evaluation

The aim of this work to study the feasibility of using phospholipid free vesicles with positive charge inducer in a slowly dissolving polymer ocular insert to successfully control intraocular pressure (IOP) for an extended period. Brinzolamide (BRNZ) was chosen as a model drug and a full factorial design was assembled to investigate the drug loading effect, ratio of cholesterol to fatty moiety and the type of the fatty moiety used on the vesicle size and entrapment efficiency. Linear regression models were constructed, and optimization of the formulation compositions yielded two formulae with palmitic acid as a negatively charged vesicles and cetrimide positively charged vesicles. Both formulae were studied in term of permeation efficiency through bovine corneal membranes. Positively charged vesicles although it didn't achieve the highest flux and cumulative amount permeated per unit surface area in the experiment time course, it achieved the highest retention of drug inside the corneal tissue, so it was chosen to be incorporated in a slowly dissolving polymer ocular insert. The insert was evaluated in term content, physical evaluation, and release properties. In vivo evaluation of the casted ocular inserts was conducted in male albino rabbits against market eye drop product and IOP readings were collected for 48 hours. The positively charged sterosomes containing BRNZ and formulated in polymer ocular inserts achieved extended control of IOP of the test animals compared to the market product.

Design of transfersomal nanocarriers of nystatin for combating vulvovaginal candidiasis; A different prospective

The objective of this study was to prepare and evaluate Nystatin (NYS) loaded transfersomes to achieve better treatment of vulvovaginal candidiasis. Nystatin transferosomes were formulated utilizing thin film hydration method. A 3² full factorial design was employed to evaluate the effect of different formulation variables. Two independent variables were chosen; the ratio between lecithin surfactant (X₁) was set at three levels (10-40), and the type of surfactants (X₂) was set at three levels (Span 60, Span 85 and Pluronic F-127). The dependent responses were; entrapment efficiency (Y₁: EE %), vesicles size (Y₂: VS) and release rate (Y₃: RR). Design Expert® software was utilized to statistically optimize formulation variables. The vesicles revealed high NYS encapsulation efficiency ranging from 97.35 ± 0.03 to 98.01 ± 0.20% whereas vesicle size ranged from 194.8 ± 20.42 to 400.8 ± 42.09 nm. High negative zeta potential values indicated good stability of the prepared formulations. NYS release from transfersomes was biphasic and the release pattern followed Higuchi's model. The optimized formulation (F7) exhibited spherical morphology under transmission electron microscopy (TEM). In-vitro and in-vivo antifungal efficiency studies revealed that the optimized formula F7 exhibited significant eradication of candida infestation in comparison to free NYS. The results revealed that the developed NYS transfersomes could be a promising drug delivery system to enhance antifungal efficacy of NYS.

Nanofibrous ε-polycaprolactone scaffolds containing Ag-doped magnetite nanoparticles: Physicochemical characterization and biological testing for wound dressing applications in vitro and in vivo

Skin wounds can lead to numerous complications with dangerous health consequences. In this work, magnetite nanoparticles were doped with different concentrations of antimicrobial silver (Ag) ions and incorporated into the electrospun nanofibrous ε-polycaprolactone (PCL) scaffolds. Nanoparticles and scaffolds with various Ag contents were characterized using a range of physicochemical techniques. Ag entered magnetite as cations and preferentially positioned at tetrahedral sites, introducing lattice distortions and topographic irregularities. Amorphization of the structure due to accommodation of Ag expanded the lattice in the bulk and contracted it on the surface, where broadened distribution of Fe–O coordinations was detected. Promoting spin canting and diminishing the double exchange interaction through altered distribution of ferric and ferrous ions, Ag softened the magnetism of magnetite. By making the nanoparticle structure more defective, Ag modified the interface with the polymer and promoted the protrusion of the nanoparticles from the surface of the polymeric nanofibers, thus increasing their roughness and hydrophilicity, with positive repercussions on cell adhesion and growth. Both the viability of human melanocytes and the antibacterial activity against E. coli and S. aureus increased with the concentration of Ag in the magnetite phase of the scaffolds. Skin wound healing rate in rats also increased in direct proportion with the concentration of Ag in the magnetite phase, and no abnormalities in the dermal and epidermal tissues were visible on day 10 in the treatment group. These results imply an excellent potential of these composite nanofibrous scaffolds for use as wound dressings and in other reconstructive skin therapies.

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Electrospun nanofibrous polymeric wound dressings interspersed with magnetite nanoparticles doped with Ag ions were fabricated.

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Detailed physicochemical characterization is provided with aid of diffractometric, spectroscopic and microscopic techniques.

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Both the viability of melanocytes and the antibacterial activity increased with the addition of Ag ions.

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Skin wound healing rate in rats increased to 51 and 92 % on day 10 for dressings without and with Ag, respectively, relative to control.

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Animals treated with Ag-doped dressings displayed no atrophy of sebaceous glands and necrosis of hair follicles of control animals.

Polycaprolactone based electrospun matrices loaded with Ag/hydroxyapatite as wound dressings: Morphology, cell adhesion, and antibacterial activity

The development of a scaffold matrix that can inhibit bacterial infection and promote wound healing simultaneously is an essential demand to improve the health care system. Hydroxyapatite (HAP) doped with different concentrations of silver ions (Ag⁺) were incorporated into electrospun nanofibrous scaffolds of polycaprolactone (PCL) using the electrospinning technique. The formed phase was identified using XRD, while the morphological and roughness behavior were investigated using FESEM. It was shown that scaffolds were configured in randomly distributed nanofibers with diameters around of 0.19-0.40, 0.31-0.54, 1.36, 0.122-0.429 μm for 0.0Ag-HAP@PCL, 0.2Ag-HAP@PCL, 0.6Ag-HAP@PCL, and 0.8Ag-HAP@PCL, respectively. Moreover, the maximum roughness peak height increased significantly from 179 to 284 nm, with the lowest and highest contributions of Ag. The mechanical properties were examined and displayed that the tensile strength increased from 3.11 ± 0.21 MPa to its highest value at 3.57 ± 0.31 MPa for 0.4Ag-HAP@PCL. On the other hand, the cell viability also was enhanced with the addition of Ag and improved from 97.1 ± 4.6% to be around 102.3 ± 3.1% at the highest contribution of Ag. The antibacterial activity was determined, and the highest imbibition zones were achieved at the highest Ag dopant to be 12.5 ± 1.1 mm and 11.4 ± 1.5 mm against E. coli and S. aureus. The in vitro cell proliferation was observed through human fibroblasts cell lone (HFB4) and illustrated that cells were able to grow and spread not only on the fibers' surface but also, they were spreading and adhered through the deep pores.

Brain uptake and accumulation of new levofloxacin-doxycycline combination through the use of solid lipid nanoparticles: Formulation; Optimization and in-vivo evaluation

The objective of this study is to investigate the feasibility of delivery of novel levofloxacin/ doxycycline (LEVO/DOX) combination to the brain by intranasal route to achieve a significant local concentration in the brain and a direct nose-to-brain pathway. Solid lipid nanoparticles (SLN) were selected as a drug carrier and employed Box-Behnken design for optimizing LEVO/DOX-SLN to achieve minimum particle size and maximum apparent entrapment efficiency (EE). SLNs were prepared by hot emulsification and characterized. In vitro release of optimized formulations showed prolonged drug release from the optimized formulation. The results of pharmacokinetic study of the optimized SLN-HPMC gel in plasma and brain revealed significant increase in the brain peak concentration (420, 315 ng/g), the AUC _0-360 min (57130 and 48693.13 ng. min/g) in comparison to intranasal LEVO/DOX free solution with the values of (160, 120) ng/g, (36850, 27637.5 ng⋅min/g) for LEVO and DOX, respectively. The optimized LD-SLN-HPMC gel gave a drug-targeting efficiency (DTE %) of 149.815 and 161.969 for LEVO and DOX, respectively, in comparison to the intravenous route. Moreover, the optimized formulation had a direct transport percentage (DTP %) of 33.285 and 40.236 for LEVO and DOX, respectively, which indicates a significant contribution of direct nose-to-brain pathway in brain drug delivery.

PLGA Nanoparticles as Subconjunctival Injection for Management of Glaucoma

Nanoparticles fabricated from the biodegradable and biocompatible polymer, polylactic-co-glycolic acid (PLGA), could be a promising system for targeting ocular drug delivery. The objective of this work was to investigate the possibility of encapsulating brinzolamide in PLGA nanoparticles in order to be applied as a subconjunctival injection that could represent a starting point for developing new therapeutic strategies against increase in ocular pressure. The brinzolamide-loaded PLGA nanoparticles were fabricated using emulsion-diffusion-evaporation method with varying concentrations of Tween 80 or poloxamer 188 (Plx) in aqueous and organic phases. The nanoparticles were characterized in terms of particle size and size distribution, entrapment efficiency and in-vitro drug release pattern as well as DSC and X-ray analysis. Nanoparticles prepared using Tween 80 in the aqueous phase showed higher encapsulation efficiency and smaller particle size-values compared to those prepared using Plx. Furthermore, the addition of Plx 188 or Brij 97 to the organic phase in the formulation containing Tween 80 in the aqueous phase led to an increase in the particle diameter-values of the obtained nanoparticles. The nanoparticles had the capacity to release the brinzolamide in a biphasic release profile. The nanoparticles were spherical in shape and the drug was entraped in the nanoparticles in an amorphous form. Selected nanoparticles, injected subconjunctivally in normotensive Albino rabbits, were able to reduce the IOP for up to 10 days. Nanoparticles loaded with brinzolamide with lower particle size were able to reduce the IOP for longer period compared to those with higher particle size. Histopathological studies for the anterior cross sections of the rabbits' eyes revealed that the tested nanoparticles were compatible with the ocular tissue. The overall results support that PLGA nanoparticles, applied as subconjunctival injection, can be considered as a promising carrier for ocular brinzolamide delivery with targeting delivery of the drug to the eye tissues.

Brain delivery of olanzapine by intranasal administration of transfersomal vesicles

The aim of this study was to investigate the presence of a possible direct correlation between vesicle elasticity and the amount of drug reaching the brain intranasally. Therefore, transfersomes were developed using phosphatidylcholine (PC) as the lipid matrix and sodium deoxycholate (SDC), Span® 60, Cremophor® EL, Brij® 58, and Brij® 72 as surfactants. The influence of the type of surfactant and PC-to-surfactant ratio on vesicle morphology, size, membrane elasticity, drug entrapment, and in vitro drug release was studied. The prepared transfersomes were mainly spherical in shape, with diameters ranging from 310 to 885 nm. Transfersomes containing SDC and Span 60 with optimum lipid-to-surfactant molar ratio showed suitable diameters (410 and 380 nm, respectively) and deformability indices (17.68 and 20.76 mL/sec, respectively). Values for absolute drug bioavailability in rat plasma for transfersomes containing SDC and those containing Span 60 were 24.75 and 51.35%, whereas AUC(0-360 min) values in rat brain were 22,334.6 and 36,486.3 ng/mL/min, respectively. The present study revealed that the deformability index is a parameter having a direct relation with the amount of the drug delivered to the brain by the nasal route.