Cationic Dextran Stearate (Dex-St-GTMAC): Synthesis and Evaluation as Polymeric Micelles for Indomethacin Corneal Penetration.

Background Indomethacin as a non-steroidal anti-inflammatory drug (NSAID) is commonly used to treat some ocular inflammatory disorders. Unfortunately, indomethacin is a drug that is poorly soluble in water; therefore, it has low efficacy. An attractive approach is the targeted delivery of indomethacin to the cornea using cationic dextran stearate as a polymeric micelle drug carrier. Methods A dextran stearate-glycidyl trimethylammonium chloride (Dex-St-GTMAC) copolymer was prepared through the reaction of GTMAC, stearoyl chloride, and dextran. Then, Dex-St-GTMAC was characterized by Fourier transform infrared (FT-IR) spectroscopy and 1H NMR spectroscopy. Dex-St-GTMAC forms micelles in the presence of indomethacin. The prepared polymeric micelles were characterized for size, ζ-potential, drug loading, particle morphology, critical micelle concentration, and encapsulation efficiency. To study the irritation potential of the indomethacin-loaded Dex-St-GTMAC, Het-Cam and Draize tests have been performed. Prepared cationic micelles were subjected to the in vitro drug release and ex vivotrans-corneal permeation test. Results The dialysis method was used for the preparation of indomethacin-loaded micelles (10, 20, and 30%). Measurement of the particle size showed a mean diameter of 122.1 and 150.9 nm for the drug-loaded micelles. Scanning electron microscopy (SEM) images showed that the morphology of the particles is spherical. 10% formulation was chosen as the best formulation due to more surface charge and reasonable drug loading. ζ-potential measurement for the 10% drug-containing micelles showed a value of +39.1 mV. Drug loading efficiency and the encapsulation efficiency for 10% drug-containing micelles were 6.36 and 63.61%, respectively. The results of the Het-Cam and Draize tests indicated that the indomethacin-loaded Dex-St-GTMAC formulation had no toxicity to eye tissues. Based on our results, the prepared micelles (indomethacin-loaded Dex-St-GTMAC) exhibited a sustained drug release pattern compared to the control group. Indomethacin penetration from the micelles to the excised bovine cornea was 1.75-fold greater than the control (indomethacin 0.1% in phosphate-buffered saline (PBS)). Conclusions Data from the ζ-potential, SEM, drug loading capacity, and in vitro drug release studies indicated that cationic dextran stearate polymeric micelles are an appropriate carrier for the efficient penetration of indomethacin into cornea tissues.

Silibinin-loaded nanostructured lipid carriers (NLCs) ameliorated cognitive deficits and oxidative damages in aluminum chloride-induced neurotoxicity in male mice.

Aluminum chloride (AlCl3) and its accumulation in the brain are associated with neurodegenerative disease. Recent investigations have illustrated that silibinin is known to have neuroprotective properties. The present study investigates the neuroprotective effects of silibinin-loaded nanostructured lipid carriers (Sili-NLCs) against AlCl3-induced neurotoxicity in male mice. Sili-NLCs were prepared using the emulsification-solvent evaporation method and subjected to particle size, zeta potential, and entrapment efficiency (% EE) analysis. Mice were treated with AlCl3 (100 mg/kg/day, p.o.) and with the same concentration of silibinin and Sili-NLCs (50,100, and 200 mg/kg/day, p.o.) for 30 days in different groups. After treating animals, behavioral studies were assessed. Also, the brain tissue samples were collected from all mice to evaluate oxidative damage and histological changes. The particle size, polydispersity index, zeta potential, and entrapment efficiency (% EE) of prepared Sili-NLCs found 239.7 ± 4.04 nm, 0.082 ± 0.003, - 16.33 ± 0.15 mV, and 72.65 ± 2.03 %, respectively. Brain uptake studies showed that Sili-NLCs had a 5.7-fold greater uptake in the mice brain than the free drug. The AlCl3 caused significant cognitive impairment and increased the level of lipid peroxidation accompanied by decreasing antioxidant enzyme activity in the brain tissue. These findings correlated well with the histopathological experiments. Furthermore, treatment with Sili-NLCs significantly improved the AlCl3-induced cognitive impairment, neurochemical anomalies, and histopathological changes. Given these results, silibinin, when delivered using NLCs, is potentially more effective than free silibinin in decreasing AlCl3- induced neurotoxicity.

Novel naltrexone hydrochloride nanovaccine based on chitosan nanoparticles promotes induction of Th1 and Th17 immune responses resulting in protection against Toxoplasma gondii tachyzoites in a mouse model.

This study was aimed to encapsulate and construct the Toxoplasma gondii surface antigen (SAG1) and naltrexone hydrochloride (NLT-HCL) as an adjuvant within chitosan nanoparticles (CS-NPs) to develop efficacious vaccine against T. gondii. Seven groups of BALB/c mice were immunized with SAG1, chitosan (CS), NLT-SAG1, CS-SAG1, CS-SAG1-NLT, CS-NLT and PBS. The efficiency of each approach was detected in vivo mouse immunization. Moreover, the immuno-induction effect of SAG1 recombinant protein and CS-NPs-based NLT-HCL as an adjuvant in a vaccine delivery was evaluated. Experimentally, Th1/Th17 biased cellular and humoral immune responses were activated in the mice immunized with CS-SAG1-NLT nanoparticles that were accompanied by considerable increased production of IFN-γ, IL-17, IL-12, IL-4, IFN-γ/IL-4 ratio, IgG, IgG2a. This group of mice also showed significantly increased survival time post-challenging. The successful encapsulated SAG1 recombinant protein and NLT-HCL, as an adjuvant, within CS-NPs can induce immune responses against toxoplasmosis. We could incorporate NLT-HCL adjuvant into the CS-NPs based delivery systems, which makes CS-NPs attractive as a colloidal carrier system for NLT-HCL as secondary adjuvant. This new approach or the simultaneous use of CS and NLT demonstrated that the co-administration of CS-NPs and NLT-HCL induce production of IL-17 cytokine. This approach can be used for vaccination purposes, in which Th17 and Th1 cellular immune are considered the key of the successful immune response.

Effects of progesterone nanoparticles on the sperm capacitation and acrosome reaction in asthenozoospermia men.

Low motility is one of the causes of male infertility. In this study, the effects of progesterone solid lipid nanoparticles (SLNs) on sperm capacitation, acrosome reaction, oxidative stress and expression of SPACA1 and MAPK way genes were investigated. Progesterone SLNs were synthesized using the solvent emulsification evaporation method. Twenty asthenozoospermia samples were selected, and sperm and acrosome membrane integrity, acrosome reaction, sperm motility, viability, total antioxidant capacity (TAC), total oxidative status tests and PKA, PTK, P38MAPK and SPACA1 gene expressions were assessed. The synthesized nanoparticles were prepared with the size (187.6 nm), PDI (0.184), EE (85.82%), LP (3.43%) and ZP (-23.5mV). Progesterone SLNs increased sperm and acrosome membrane integrity and TAC (p < .05). Also, the expression of P38MAPK, PKA, PTK, and SPACA1 genes in this group showed a significant increase (p < .001). Progesterone SLNs increased acrosome reaction, sperm capacitation and TAC. Also, it increased the expression of PTK PKA, SPACA1 and P38MAPK genes.

Besifloxacin-loaded ocular nanoemulsions: design, formulation and efficacy evaluation.

The purpose of this study was to develop and evaluate nanoemulsions (NEs) containing besifloxacin for ocular drug delivery. Pseudo ternary phase diagrams were constructed using Triacetin (oil), Cremophor® RH 40 (surfactant), and Transcutol®P (co-surfactant) to identify NE regions. Six formulations were developed by low-energy emulsification method and then evaluated for size, refractive index, pH, osmolality, viscosity, and drug release. After accelerated physical stability and bovine conrneal permeation studies, NE2 was chosen as optimized formulation forantimicrobial efficacy, and hen's egg test-chorioallantoic membrane (HET-CAM) tests. The particle size of optimum NE was 14 nm with a narrow size distribution. Moreover, other physicochemical characterizations were in the acceptable range for ocular administration. Besifloxacin-loaded NEs demonstrated sustained release pattern and 1.7-fold higher permeation compared with the control suspension in the ex vivo transcorneal permeation study. HET-CAM test indicated no irritation, and HL% revealed no damage to the tissue, so the optimum NE is well tolerated by the eye. In vitro antimicrobial evaluation, showed comparative efficacy of lower drug-loaded NE (0.2%) versus 0.6% besifloxacin suspension (equal concentration to commercial besifloxacin eye drop). In conclusion, besifloxacin-loaded NEs could be considered as a suitable alternative to the marketed suspension for treating bacterial eyeinfections.

Development of the Binary and Ternary Atorvastatin Solid Dispersions: In Vitro and In Vivo Investigations.

The object of this study was to prepare binary and ternary solid dispersions of atorvastatin (ATR) by the melting method using PEGs and poloxamer 188 (P188) as the carriers, singly and in combination with each other. Dissolution behavior, solubility studies, X-ray diffractometry, differential scanning calorimetry, and Fourier transform infrared spectroscopy were studied. Furthermore, antihyperlipidemic activities of formulations were compared to each other by serum lipid analyses in hyperlipidemic rats. Based on the results, the highest dissolution efficiency (DE30 = 83%) was obtained by binary systems consisted of ATR and P188. Also, no additional improvement was observed in dissolution properties of ternary solid dispersion formulations. Solubility studies showed enhancement of ATR phase solubility in water and a buffer solution containing P188 or PEG 10000. Furthermore, saturated solubility of ATR in the buffer solution improved more than twofold in the optimized ternary dispersion system. No crystalline changes occurred in PEG-based formulations; meanwhile, partial amorphization happened in the ATR-P188 combination. Finally, the in vivo study in hyperlipidemic rats exhibited a rapid decrease in the lipid profile of all formulations compared to ATR (after 7 days). Moreover, reduction of serum triglycerides and total cholesterol on the 14th day in the ATR group (p value < 0.01) was less than solid dispersion or physical mixing preparations (p value < 0.001). These findings proved the appropriate influence of using PEG and P188 in solid dispersion systems for the improvement of the therapeutic efficiency of ATR.

Studying the ophthalmic toxicity potential of developed ketoconazole loaded nanoemulsion in situ gel formulation for ophthalmic administration.

Ocular fungal infections are one of the essential reasons for vision loss, especially in developing countries for tropical regions. Ketoconazole (KZ), a broad-spectrum antifungal drug, is a lipophilic compound and practically insoluble in water. Since topical ophthalmic drug delivery confronts low bioavailability, an in situ gel formulation is designed to improve the residence time and consequently the bioavailability. Safety of the developed formulation as a carrier for ophthalmic drug delivery was measured using three different methods: MTT assay for measuring cell viability in which the human retinal pigmentation epithelial cells (RPE) were used, HET-CAM as a borderline method between in vivo and in vitro techniques for investigating the irritation potential of the chosen formulation which was done by adding formulation directly on the CAM surface and visually monitoring the vessels in terms of irritation reactions, and finally the modified Draize test for evaluating tolerability of the selected formulation on eyes. According to our results from the MTT test, cell viability for KZ-NE in situ gel formulation at 0.1% concentration was acceptable. The results obtained from the HET-CAM investigation didn't show any sign of vessel injury on the CAM surface for prepared formulation. Additionally, during 24 hours, the developed formulation was tolerable by rabbit eyes. Regarding our results, KZ-NE in situ gel formulation was non-irritant and non-toxic and can be well-tolerated and presented as an applicable vehicle for ophthalmic delivery of the anti-fungal drug.

Development of Perphenazine-Loaded Solid Lipid Nanoparticles: Statistical Optimization and Cytotoxicity Studies.

OBJECTIVE: Perphenazine (PPZ), as a typical antipsychotic medical substance, has the same effectiveness compared to atypical antipsychotic medications for the treatment of schizophrenia. Despite the lipophilic essence, PPZ encounters limited bioavailability caused by the first-pass metabolism following oral administration. In the present study, PPZ-containing solid lipid nanoparticles (PPZ-SLNs) were prepared and optimized based on different factors, including lipid and surfactant amount, to develop appropriate and safe novel oral dosage forms of PPZ. METHODS: The solvent emulsification-evaporation method was utilized to form SLNs by using soybean lecithin, glycerol monostearate (GMS), and Tween 80. Statistical optimization was done by the Box-Behnken design method to achieve formulation with optimized particle size, entrapment efficiency, and zeta potential. Also, transmission electron microscopy, in vitro release behavior, differential scanning calorimetry (DSC), and powder X-ray diffractometry (P-XRD) studies and cytotoxicity studies were assessed. RESULTS: Optimization exhibited the significant effect of various excipients on SLN characteristics. Our finding indicated that the mean particle size, zeta potential, and entrapment efficiency of optimized PPZ-SLN were, respectively, 104 ± 3.92 nm, -28 ± 2.28 mV, and 83% ± 1.29. Drug release of PPZ-SLN was observed to be greater than 90% for 48 h that emphasized a sustained-release pattern. The DSC and P-XRD studies revealed the amorphous state of PPZ-SLN. FTIR spectra showed no incompatibility between the drug and the lipid. Performing cytotoxicity studies indicated no significant cytotoxicity on HT-29 cell culture. CONCLUSION: Our study suggests that PPZ-SLNs can make a promising vehicle for a suitable therapy of schizophrenia for the oral drug delivery system.

Acyclovir-Loaded Nanoemulsions: Preparation, Characterization and Irritancy Studies for Ophthalmic Delivery.

Objective: The main goal of the present work was to develop and evaluate nanoemulsions (NEs) containing acyclovir (ACV) for ophthalmic drug delivery.Method: Firstly, component screening was performed by determining ACV solubility in various oils, surfactants, and co-surfactants. Different NE formulations were developed based on pseudo-ternary phase diagrams, and physicochemical assets were evaluated. Selected formulations were subjected to the drug release efficacy, stability studies, and ex-vivo trans-corneal permeation test. The safety of NEs was investigated by the modified Draize test and hen's egg test-chorioallantoic membrane (HET-CAM).Results: Based on the solubility studies, Tween 20, Triacetin, and Tramsectol®P were chosen to prepare NE formulations. Developed NEs showed desirable physiochemical properties, including a droplet size of less than 15 nm. Selected formulations (F1 and F2) exhibited a sustained drug release pattern compared to the control group (P < .001). ACV penetration from F1 and F2 to the excised bovine cornea was 2.85 and 2.9-fold more than the control, respectively. Furthermore, HET-CAM and modified Draize test confirmed that F1 and F2 were safe for ocular administration.Conclusion: Present investigation revealed that ACV-loaded NEs could be effective, and safe platform for ophthalmic delivery of ACV.

Preparation, characterization, and in vivo evaluation of perphenazine-loaded nanostructured lipid carriers for oral bioavailability improvement.

OBJECTIVE: The main scope of the present investigation was to improve the bioavailability of perphenazine (PPZ) by incorporating it into the nanostructured lipid carriers (NLCs). SIGNIFICANCE: As a result of lipophilic nature and poor aqueous solubility, as well as extensive hepatic metabolism, PPZ has low systemic bioavailability via the oral route. NLCs have shown potentials to surmount the oral delivery drawbacks of poorly water-soluble drugs. METHODS: The PPZ-NLCs were prepared by the emulsification-solvent evaporation method and subjected for particle size, zeta potential, and entrapment efficiency (EE) analysis. The optimized NLCs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and powder X-ray diffractometry (PXRD). Besides, in vitro release behavior, storage stability, and pharmacokinetic studies followed by a single-dose oral administration in rats were performed. RESULTS: Optimized PPZ-NLCs showed a particle size of less than 180 nm with appropriate EE of more than 95%. Microscopic images captured with SEM and TEM exhibited that NLCs were approximately spherical in shape. DSC and PXRD analysis confirmed reduced crystallinity of PPZ after incorporation in NLCs. FTIR spectra demonstrated no chemical interactions between PPZ and NLC components. In vitro release studies confirmed the extended-release properties of NLC formulations. PPZ-NLCs exhibited good stability at 4 °C within three months. The oral bioavailability of NLC-6 and NLC-12 was enhanced about 3.12- and 2.49-fold, respectively, compared to the plain drug suspension. CONCLUSION: NLC can be designated as an effective nanocarrier for oral delivery of PPZ.

Pharmacokinetics and brain distribution studies of perphenazine-loaded solid lipid nanoparticles.

BACKGROUND: Perphenazine (PPZ) is a typical antipsychotic that is mainly administrated for the treatment of schizophrenia. Due to its highly lipophilic nature and extensive hepatic first-pass metabolism, its oral bioavailability is low (40%). OBJECTIVE: The novel nanocarriers like solid lipid nanoparticles (SLN) have been reported to be highly effective for improving the therapeutic effect of drugs. Therefore the main scope of the present investigation was the evaluation of in vivo characteristics of PPZ-SLN in terms of pharmacokinetic parameters and brain distribution. METHODS: The PPZ-SLN was prepared by the solvent-emulsification and evaporation method. The storage stability of PPZ-SLN and empty SLN powders was studied for 3 months. In vivo pharmacokinetic studies and brain distribution evaluations were performed following a single oral dose administration of PPZ and PPZ-SLN suspensions on male Wistar rats. An HPLC method was established and validated for the quantitative determination of PPZ in plasma and brain samples. RESULTS: The storage stability studies revealed the good storage stability of the both PPZ-SLN and empty SLN at 4 °C. Compared to PPZ suspension, the relative bioavailability and the brain distribution of PPZ-SLN were increased up to 2-fold and 16-fold, respectively. Mean residence time (MRT) and half-life (t1/2) of PPZ-SLN were significantly (p value < 0.01) increased in both plasma and brain homogenate compared to PPZ suspension. CONCLUSION: The significant improvement in the pharmacokinetic properties of PPZ following one oral dose indicates that SLN is a promising drug delivery system for PPZ and shows a high potential for successful brain delivery of this antipsychotic.

Investigating the ocular toxicity potential and therapeutic efficiency of in situ gel nanoemulsion formulations of brinzolamide.

Glaucoma is an ocular disease i.e. more common in older adults with elevated intraocular pressure and a serious threat to vision if it is not controlled. Due to the limitations regarding the conventional form of brinzolamide (Azopt®), two optimum formulations of in situ gel nanoemulsion were developed. To ensure the safety and efficacy of developed formulations for ocular drug delivery, the current study was designed. MTT assay was carried out on the human retinal pigmentation epithelial cells. To investigate the irritation potential of the chosen formulations, hen's egg test-chorioallantoic membrane as a borderline test between in vivo and in vitro methods has been done. The modified Draize method was utilized to evaluate eye tolerance against the selected formulations. Intraocular pressure was measured by applying the prepared formulations to the eyes of normotensive albino rabbits in order to assess the therapeutic efficacy. Based on MTT test, cell viability for NE-2 at 0.1% and NE-1 at 0.1 and 0.5% concentrations was acceptable. The results of the hen's egg test-chorioallantoic membrane test indicated no sign of vessel injury on the chorioallantoic membrane surface for both formulations. Also, during 24 h, both formulations were well-tolerated by rabbit eyes. The pharmacodynamics effects of formulations had no difference or were even higher than that of suspension in case of adding lower concentration (0.5%) of brinzolamide to the formulations. With regard to the results of the mentioned methods, our advanced formulations were effective, safe, and well-tolerated, thus can be introduced as an appropriate vehicle for ocular delivery of brinzolamide.

Brinzolamide-loaded nanoemulsions: ex vivo transcorneal permeation, cell viability and ocular irritation tests.

The aim of this study was to investigate the corneal penetration of brinzolamide (BZ) nanoemulsions (NEs) and evaluate their in vitro and ex vivo irritancy potential. Twelve BZ NEs were prepared by the spontaneous emulsification method and ex vivo permeability studies were conducted using excised bovine corneas fixed onto Franz diffusion cells. To confirm the safety of the formulations for ophthalmic use, preparations were examined for potential ocular irritancy using a cell viability assay on retinal cells, the Hen's Egg Test-Chorio-Allantoic Membrane (HET-CAM) and the bovine corneal opacity-permeability (BCOP) test. Seven BZ NEs exhibited superior penetration across isolated bovine cornea compared to the marketed BZ suspension. The half maximal inhibitory concentration (IC50) values of various surfactants and oils determined using the sulforhodamine B cell viability assay on retinal cells showed that Transcutol P, Cremophor RH40 and Triacetin were the least toxic excipients and may be safely used in the eye at various concentrations. HET-CAM and BCOP tests revealed that NE6B and NE4C did not result in any irritation and were thus considered safe for ocular use. Our finding suggests that optimized NEs can be a safe and effective vehicle for ocular delivery of BZ.

Formulation Development and Evaluation of the Therapeutic Efficacy of Brinzolamide Containing Nanoemulsions.

Brinzolamide (BZ) is an intraocular pressure reducing agent with low bioavailability. The purpose of the present study was to overcome this issue by development of BZ containing nanoemulsions (NEs) as an ocular drug delivery system with desirable therapeutic efficacy. Brinzolamide NEs were prepared by the spontaneous emulsification method. Based on initial release studies, twelve formulations with the slowest release characteristics were subjected to further physicochemical investigations such as particle size, polydispersity index, pH, refractive index, osmolality and viscosity. The therapeutic efficacy of these formulations was assessed by measuring the intraocular pressure after instillation of the prepared NEs in normotensive albino rabbit eyes. Nanoemulsions with suitable physicochemical properties exhibited high formulation stability under different conditions. more over biological evaluations indicated that using lower drug concentrations in NE formulations (0.4%) had a similar or even better pharmacodynamic effect compared to the commercial suspension with a higher drug concentration (1%). Our findings suggest that NEs could be effectively used as carriers for enhancing the bioavailability of topically applied ophthalmic drugs.

The effect of PEG molecular weights on dissolution behavior of simvastatin in solid dispersions.

The purpose of the present study was to investigate the effect of polyethylene glycol (PEG) molecular weights (6000, 12000 and 20000) as solid dispersion (SD) carriers on the dissolution behavior of simvastatin. SDs with various drug : carrier ratios were prepared by solvent method and evaluated for dissolution rate. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), infrared spectroscopy and solubility studies were also performed on the optimum SD formulation. Samples prepared with all three types of PEG showed improved drug dissolution compared to intact drug and corresponding physical mixtures. Meanwhile, the best result was obtained by PEG 12000 with drug : carrier ratio of 1:7 which showed a 3-fold increase in dissolution rate compared to the intact drug. Based on DSC and XRD, no crystalline change occurred during the sample preparation. Solubility studies revealed that increasing the PEG molecular weight resulted in higher phase solubility of drug. In addition, saturated solubility of the optimum SD was significantly higher than that of intact drug and the related physical mixture (24.83, 8.74 and 8.88 µg/mL, respectively) that could be due to the decreased particle size and aggregation. The results confirmed the influence of PEG molecular weight on drug dissolution rate from solid dispersion systems.