Development and optimization of solid lipid nanoparticles of amikacin by central composite design

Solid lipid nanoparticles (SLNs) have been studied as a drug-delivery system for the controlling of drug release. These colloidal systems have many important advantages, such as biocompatibility, good tolerability, and ease of scale-up. In the preparation of SLNs, many factors are involved in the characteristics of the particles, such as particle size, drug loading, and zeta potential. In this study, fractional factorial design was applied to examine which variables affect the physicochemical properties of amikacin SLNs. Study was continued by a statistical central composite design (CCD) to minimize particle size and maximize drug-loading efficiency of particles. The results showed that three quantitative factors, including the amount of lipid phase, ratio of drug to lipid, and volume of aqueous phase, were the most important variables on studied responses. The best predicted model for particle size was the quadratic model, and for drug-loading efficiency, was the linear model without any significant lack of fit. Optimum condition was achieved when the ratio of drug to lipid was set at 0.5, the amount of lipid phase at 314?mg, and the volume of aqueous phase at 229?mL. The optimized particle size was 149?±?4?nm and the drug-loading efficiency 88?±?5%. Polydispersity index was less than 0.3. The prepared particles had spherical shape, and the drug release from nanoparticles continued for 144 hours (6 days) without significant burst effect.     

Formulation and optimization of solid lipid nanoparticles of buspirone HCl for enhancement of its oral bioavailability

Solid lipid nanoparticles (SLNs) of buspirone HCl as a water-soluble drug were prepared by emulsification-evaporation, followed by the sonification method. A preliminary screening of the most effective parameters on the production of nanoparticles by a Taguchi L₈ orthogonal array showed that the lipid type, surfactant percentage, speed of homogenizer, and acetone:dichloromethane (DCM) ratio had a significant effect on particle size. In the next step, the lipid was fixed on cetyl alcohol, surfactant on Tween 20, lecithin:lipid weight ratio on 20:70, sonication time on 30 seconds, and the other effective, independent factors aforementioned were studied each at three levels by a three-factor, three-level Box-Behnken design. The percentage of drug entrapment, mean particle-size diameter, and zeta potential were studied as the responses. Contour plots were constructed to further elucidate the relationship between the independent and dependent variables. A pharmacokinetic study was conducted in male Wistar rats after oral administration of 15?mg.kg^?1 buspirone in the form of free drug or SLNs. The optimized SLNs had aq particle size of 345.7?nm, loading efficiency of 32.8%, and zeta potential of ?6.8?mV. Buspirone released about 90% during 4.5?hours in vitro. It was found that the relative bioavailability of the drug in SLNs was significantly increased, compared to that of the drug solution.     

Enhancement of oral bioavailability of pentoxifylline by solid lipid nanoparticles

Pentoxifylline (PTX) is a highly water-soluble, hemorheologic drug that undergoes first-pass effect with 20% bioavailability. The solid lipid nanoparticles (SLNs) of PTX were prepared to enhance its oral bioavailability by homogenization, followed by the sonification method. Seven different variables, each at two levels, were studied: lipid type, surfactant type and concentration, speed of homogenizer, acetone:dichloromethane (DCM) ratio, lecithin:lipid ratio, and sonication time. The mean particle size and size distribution, drug entrapment efficiency (EE%), zeta potential, and drug release of the SLNs were investigated. A pharmacokinetic study was conducted in male Wistar rats after oral administration of 10?mg kg^?1 PTX in the form of free drug or SLNs. The z-average particle size, zeta potential, and EE% of the SLNs were at least 250?nm, ?30.2 mV, and 70%, respectively. Among the studied factors, the lipid type, surfactant type, and percentage had a significant effect on the particle size. Zeta potential was more affected by lipid type, acetone:DCM ratio, and sonication time. Speed of homogenizer and acetone:DCM ratio had a significant effect on the EE%. The optimized SLN was prepared by 80?mg of cetyl alcohol, 10?mg of lecithin, acetone:DCM ratio (1:2), 30-second sonication, 3% Tween 20, and a mixing rate of 800?rpm. In vitro drug release lasted for about 5 hours. It was found that the relative bioavailability of PTX in SLNs was significantly increased, compared to that of the PTX solution. SLNs offer a promising approach to improve the oral bioavailability of PTX that is affected by a high first-pass effect.     

Preparation and Optimization of Meropenem-Loaded Solid Lipid Nanoparticles: <Emphasis Type="Italic">In Vitro</Emphasis> Evaluation and Molecular Modeling

Encapsulation of antibiotics into nanocarriers has the potential to overcome resistance and disadvantages associated with conventional dosage forms as well as increase half-life of an antibiotic. Encapsulation of meropenem (MRPN) into solid lipid nanoparticles (SLNs) remains unexplored among the limited work reported on nanoformulation incorporating MRPN. The study aimed to use an experimental design, to optimize MRPN-loaded SLNs, and to undertake in vitro and in silico evaluations. A Box-Behnken design (BBD) was used to optimize manufacturing conditions of glycerol monostearate (GMS) SLNs loaded with MRPN. The SLNs were prepared using hot homogenization and ultrasonication method. Optimized MRPN-SLNs showed particle size, zeta potential, and entrapment efficiency of 112.61?±?0.66 nm, ?20.43?±?0.99 mV, and 89.94?±?1.26%, respectively. The morphology of the SLNs revealed nearly spherical shaped particles. Differential scanning calorimetry and X-ray diffraction analysis showed that meropenem was present in amorphous form in the SLNs. Controlled in vitro MRPN release from SLNs was achieved and followed the Korsmeyer-Peppas model (R ²?=?0.9679). Prolonged in vitro antibacterial activity against Escherichia coli was also observed. The molecular modeling showed that both hydrophobic interactions and hydrogen bonding led to a stable MRPN-GMS complex formation, which was confirmed by its low heat of formation (?5536.13 kcal/mol). This stable complex could have contributed to the controlled release of MRPN from the SLNs and subsequent sustained antibacterial activity.     

Preparation,characterization and cytotoxic evaluation of bovine serum albumin nanoparticles encapsulating 5-methylmellein: A secondary metabolite isolated from Xylaria psidii

In this study, 5-methylmellein (5-MM) loaded bovine serum albumin nanoparticles (BSA NPs) were developed using desolvation technique. The developed nanoparticles were characterized for their mean particle size, polydispersity, zeta potential, loading efficiency, X-ray diffractometry (XRD), differential scanning calorimetry (DSC) and release profile. The developed nanoparticles were spherical in shape under transmission electron microscopy (TEM) and atomic force microscopy (AFM). The developed 5-MM loaded BSA NPs demonstrated a mean particle size with a diameter of 154.95?±?4.44?nm. The results from XRD and DSC studies demonstrated that the crystal state of the 5-MM was converted to an amorphous state in polymeric matrix. The encapsulation and loading efficiency was found to be 73.26?±?4.48% and 7.09?±?0.43%. The in vitro cytotoxicity in human prostate cancer cell line (PC-3), human colon cancer cells (HCT-116) and human breast adenocarcinoma cell line (MCF-7) cells demonstrated enhanced cytotoxicity of 5-MM BSA NPs as compared to native 5-MM after 72-h treatment. The enhancement in cytotoxicity of 5-MM BSA NPs was also supported by increase in cellular apoptosis, mitochondrial membrane potential loss and generation of high reactive oxygen species (ROS). In conclusion, these findings collectively indicated that BSA nanoparticles may serve as promising drug delivery system for improving the efficacy of 5-methylmellein.     

Progesterone-loaded nanosized transethosomes for vaginal permeation enhancement: formulation,statistical optimization,and clinical evaluation in anovulatory polycystic ovary syndrome

Bio-identical progesterone (PRG) is an exogenous female steroidal hormone which is used for treatment of polycystic ovary syndrome (PCOS). However, it suffers from poor bioavailability due to hepatic metabolism and poor solubility. The target of this work was to evaluate and statistically optimize PRG-loaded nanovesicle transethosomes (NVTEs) based in mucoadhesive gel for transvaginal delivery of PRG as potential luteal-phase support. A 2⁴ full factorial design was used to explore the effect of phosphatidylcholine (PC), Tween 80, cetyltrimethyl ammonium bromide and ethanol concentration on particle size, entrapment efficiency (EE%), % in vitro PRG release after 24?h and transvaginal flux. PRG-loaded NVTEs were prepared by injection sonication method. The results revealed that the mean particle sizes ranged from 133.3?±?3.42 to 349.5?±?1.24?nm, zeta potential ranged from –23.5?±?3.84 to +74.6?±?4.97?mV, EE% ranged from 87.93?±?3.58 to 97.05?±?2.61%, % PRG release ranged from 50.9?±?2.75 to 90.69?±?2.07 and transvaginal flux ranged from 0.274?±?0.03 to 0.531?±?0.04?mg/cm²/h. The optimized formulation was subjected to transmission electron microscope for morphological examination and then incorporated in the mucoadhesive vaginal gel using Carbopol 974, hydroxyl propyl methylcellulose and sodium alginate. The optimized formulation was clinically studied in anovulatory PCOS and showed a significant increase in the serum PRG, endometrial thickness, echogenicity degree and the pregnancy rate. Briefly, PRG-loaded NVTEs vaginal gel might be a promising formulation for luteal phase support and increase pregnancy rate in anovulatory PCOS.     

Development of Lipid-Based Nanoparticles for Enhancing the Oral Bioavailability of Paclitaxel

The current research work investigates the potential of solid lipid nanoparticles (SLNs) in improving the oral bioavailability of paclitaxel. Paclitaxel-loaded SLNs (PTX-SLNs) were prepared by modified solvent injection method using stearylamine as lipid, soya lecithin and poloxamer 188 as emulsifiers. SLNs were characterized in terms of surface morphology, size and size distribution, surface chemistry and encapsulation efficiency. Pharmacokinetics and bioavailability studies were conducted in male Swiss albino mice after oral administration of PTX-SLNs. SLNs exhibited spherical shape with smooth surface as analyzed by transmission electron microscopy (TEM). The mean particle size of SLNs was 96 ± 4.4 nm with a low polydispersity index of 0.162 ± 0.04 and zeta potential of 39.1 ± 0.8 mV. The drug entrapment efficiency was found to be 75.42 ± 1.5% with a loading capacity of 31.5 ± 2.1% (w/w). Paclitaxel showed a slow and sustained in vitro release profile and followed Higuchi kinetic equations. After oral administration of the PTX-SLNs, drug exposure in plasma and tissues was ten- and twofold higher, respectively, when compared with free paclitaxel solution. PTX-SLNs produced a high mean C _max (10,274 ng/ml) compared with that of free paclitaxel solution (3,087 ng/ml). The absorbed drug was found to be distributed in liver, lungs, kidneys, spleen, and brain. The results suggested that PTX-SLNs dispersed in an aqueous environment are promising novel formulations that enhanced the oral bioavailability of hydrophobic drugs, like paclitaxel and were quite safe for oral delivery of paclitaxel as observed by in vivo toxicity studies.     

PEGylated liposomes of anastrozole for long-term treatment of breast cancer: in vitro and in vivo evaluation

The aim of present study was to develop conventional and PEGylated (long circulating), liposomes containing anastrozole (ANS) for effective treatment of breast cancer. ANS is a third-generation non-steroidal aromatase inhibitor of the triazole class used for the treatment of advanced and late-stage breast cancer in post-menopausal women. Under such disease conditions the median duration of therapy should be prolonged until tumor regression ends (>31 months). Liposomes were prepared by the thin film hydration method by using ANS and various lipids such as soyaphosphatidyl choline, cholesterol and methoxy polyethylene glycol distearoyl ethanolamine in different concentration ratios and evaluated for physical characteristics, in vitro drug release and stability. Optimized formulations of liposome were studied for in vitro cytotoxic activity against the BT-549 and MCF-7 cell lines and in vivo behavior in Wistar rats. Preformulation studies, both Fourier transform infrared study and differential scanning calorimetry analysis showed no interaction between the drug and the excipients used in the formulations. The optimized formulations AL-07 and AL-09 liposomes showed encapsulation efficiencies in the range 65.12?±?1.05% to 69.85?±?3.2% with desired mean particle size distribution of 101.1?±?5.9 and 120.2?±?2.8?nm and zeta potentials of ?43.7?±?4.7 and ?62.9?±?3.5 mV. All the optimized formulations followed Higuchi-matrix release kinetics and when plotted in accordance with the Korsemeyer–Peppas method, the n-value 0.5?n?in vitro cytotoxicity studies (p?(0–∞) values when compared to pure drug (p?相似文献   

Enhancement of lomefloxacin Hcl ocular efficacy via niosomal encapsulation: in vitro characterization and in vivo evaluation

The aim of this study is to develop and evaluate niosomal dispersions loaded with the hydrophilic drug; lomefloxacin Hcl (LXN) for the management of ocular bacterial conjunctivitis. LXN-loaded niosomes were prepared by the thin film hydration method following a full factorial formulation design. Two independent variables were evaluated: the type of surfactant (X1) and the surfactant:cholesterol ratio (X2). The dependent variables comprised entrapment efficiency (EE%: Y1), particle size (PS: Y2) and zeta potential (ZP: Y3). The optimum formulation, N-LXN14 (Tw60: CH, 1:1), was spherical in shape and exhibited EE% of 68.41?±?0.07, PS of 176.0?±?0.98 and ZP of -40.70?±?2.20 with a sustained release profile over 8?hours following the Higuchi model. N-LXN14 proved good physicochemical stability under refrigeration up to 3 months. Ocular irritancy test showed no signs of ocular toxicity, confirming the safety and suitability for ocular application. Microbiological evaluation of the antibacterial effect of N-LXN14 was conducted using the susceptibility test and through the induction of topical conjunctivitis by Staphylococcus aureus (S. aureus) followed by topical therapy. Susceptibility test manifested significantly higher percent inhibition of S. aureus and higher AUC_0–12?h of N-LXN14 (604.59?±?0.05) compared to the commercial product (126.25?±?0.049). Both clinical observation and colony count of the infected eyes after eight days of treatment demonstrated significant improvement in therapeutic response. The infected eyes were completely healed with eradication of S. aureus. In conclusion, the results showed that LXN niosomal dispersions may serve as a promising superior ocular delivery system in the treatment of bacterial conjunctivitis.     

Dextrose modified bilosomes for peroral delivery: improved therapeutic potential and stability of silymarin in diethylnitrosamine-induced hepatic carcinoma in rats

Abstract

Hepatic carcinoma (HC) is one of the most prevalent cancers, ranked as the second most common cause of cancer-related deaths worldwide. Silymarin (SYL) has been reported for its anticarcinogenic activity against various types of cancer such as prostate, breast, ovary, colon, lung, bladder and liver. Due to poor solubility and low bioavailability SYL lacks satisfactory therapeutic value thus designing a suitable and effective delivery system of SYL can led to improved therapeutic potential. The present study was aimed to develop SYL-loaded dextrose (DEX) modified bilosomes for targeted delivery to HC cells. The DEX-modified bilosomes were prepared through thin-film hydration method and optimized employing Box Behnken design. The bilosomes were evaluated for percent entrapment, drug loading, in vitro release and cytotoxicity on Hep-G2 cells. The optimized DEX-SYL-BL exhibited a particle size of 219.3?±?2.99?nm, percent entrapment of 62.32?±?4.23%, drug loading of 34.56?±?1.23% and 84.96?±?2.76% drug release respectively over a period of 24?hr. The stability of bilosomes was ascertained in simulated gastric and intestinal fluids. Cytotoxicity studies revealed greater performance of DEX-SYL-BL in terms of reduced viability in Hep-G2 cell lines when compared with pure SYL and SYL-BL. Further DEX-modified bilosomes were evaluated in vivo for their therapeutic efficacy in DEN-induced (Diethylnitrosamine) hepatic carcinoma in animal model. The DEX-SYL-BL displayed higher therapeutic potential as revealed from enhanced survival and reduced tumour burden in animals. DEX-SYL-BL also displayed significant restoration of altered oxidative markers and SGOT, SGPT levels towards normal value when compared with pure SYL.     

Optimization of methazolamide-loaded solid lipid nanoparticles for ophthalmic delivery using Box–Behnken design

The purpose of the present study was to optimize methazolamide (MTZ)-loaded solid lipid nanoparticles (SLNs) which were used as topical eye drops by evaluating the relationship between design factors and experimental data. A three factor, three-level Box–Behnken design (BBD) was used for the optimization procedure, choosing the amount of GMS, the amount of phospholipid, the concentration of surfactant as the independent variables. The chosen dependent variables were entrapment efficiency, dosage loading, and particle size. The generated polynomial equations and response surface plots were used to relate the dependent and independent variables. The optimal nanoparticles were formulated with 100?mg GMS, 150?mg phospholipid, and 1% Tween80 and PEG 400 (1:1, w/v). A new formulation was prepared according to these levels. The observed responses were close to the predicted values of the optimized formulation. The particle size was 197.8?±?4.9?nm. The polydispersity index of particle size was 0.239?±?0.01 and the zeta potential was 32.7?±?2.6?mV. The entrapment efficiency and dosage loading were about 68.39% and 2.49%, respectively. Fourier transform infrared spectroscopy (FT-IR) study indicated that the drug was entrapped in nanoparticles. The optimized formulation showed a sustained release followed the Peppas model. MTZ-SLNs showed significant prolonged decreasing intraocular pressure effect comparing with MTZ solution in vivo pharmacodynamics studies. The results of acute eye irritation study indicated that MTZ-SLNs and AZOPT both had no eye irritation. Furthermore, the MTZ-SLNs were suitable to be stored at low temperature (4?°C).     

Cellulose Buccoadhesive Film Bearing Glimepiride: Physicomechanical Characterization and Biophysics of Buccoadhesion

The present study aimed to develop buccoadhesive film of glimepiride with unique combination of polymers and to investigate its effect(s) on physicomechanical parameters, drug-release, and permeation of films. Drug-polymer interaction was examined by FTIR and DSC analysis. Films were prepared by solvent casting technique and characterized for film strength (320?±?8.5 g, 28.98?±?2.00 mJ), buccoadhesive strength (28.8?±?1.37 g, 3.04?±?0.32 mJ), and tensile strength (260?±?6.88 g, 18.00?±?0.44 mJ) by new instrumental techniques. Increase in polymer concentration augmented zeta potential of polymeric matrix-mucin mixture and exhibited strong buccoadhesion (electrical theory). Buccoadhesion was also influenced by particle size (adsorption theory) and swelling (wetting theory). Erosion behavior of films was observed in swelling and SEM studies. Film GM4 exhibited 98?±?2% in vitro drug release and 85?±?8% ex vivo drug permeation in 12 h with controlled diffusion mechanism. Films were compatible with oral probiotic microorganisms. Stability studies revealed no significant (P?<?0.05) variation in physicomechanical characteristics.     

Mannosylated liposomes bearing Amphotericin B for effective management of visceral Leishmaniasis

The cationic and mannosylated liposomes were prepared using the cast film method and compared for their antileishmaniasis activity. The surface of the Amphotericin B (Amp B)-bearing cationic multilamellar liposomes was covalently coupled with p-aminophenyl-α-D-mannoside using glutaraldehyde as a coupling agent, which was confirmed by agglutination of the vesicles with concanavalin A. The prepared liposomes were characterized for shape, size, percent drug entrapment, vesicle count, zeta potential, and in vitro drug release. Vesicle sizes of cationic and mannosylated liposomes were found to be 2.32?±?0.23 and 2.69?±?0.13?µm, respectively. Zeta potential of cationic liposomes was higher (30.38?±?0.3 mV), as compared to mannosylated liposomes (17.7?±?0.8 mV). Percentage drug release from cationic and mannose-coupled liposomes was found to be 45.7%?±?3.1 and 41.9%?±?2.8, respectively, after 24 hours. The in vivo antileishmanial activity was performed on Leishmania donovani–infected golden hamster, and results revealed that Amp B solution was reduced by 42.5?±?1.8% in the parasite load, whereas the placebo cationic liposomes and drug-containing cationic liposomes showed a reduced parasite load (i.e., 28.1?±?1.5 and 61.2?±?3.2%, respectively). The mannose-coupled liposomes showed a maximum reduction in parasite load (i.e., 78.8?±?3.9%). The biodistribution study clearly showed the higher uptake of mannosylated liposomes in the liver and spleen and hence the active targeting to the reticular endothelial system, which, in turn, would provide a direct attack of the drug to the site where the pathogen resides, rendering the other organs free and safe from the toxic manifestations of the drug.     

<Emphasis Type="Italic">In Vitro</Emphasis> Anti-inflammatory and Antimicrobial Activities of Azithromycin After Loaded in Chitosan- and Tween 20-Based Oil-in-Water Macroemulsion for Acne Management

The objectives of the current investigation are (1) to prepare and characterize (particle size, surface charge (potential zeta), surface morphology by transmission electron microscopy, drug content, and drug release) the azithromycin (AZM, 100 mg)-loaded oil-in-water (o/w) macroemulsion, (2) to assess the toxicity of macroemulsion with or without AZM using RBC lysis test in comparison with AZM in phosphate buffer solution of pH 7.4, (3) to compare the in vitro antimicrobial activity (in Escherichia coli using zone inhibition assay) of AZM-loaded macroemulsion with its aqueous solution, and (4) to assess the in vitro anti-inflammatory effect (using egg albumin denaturation bioassay) of the AZM-loaded macroemulsion in comparison with diclofenac sodium in phosphate buffer solution of pH 7.4. The AZM-loaded macroemulsion possessed the dispersed oil droplets with a mean diameter value of 52.40?±?1.55 μm. A reversal in the zeta potential value from negative (?2.16?±?0.75 mV) to positive (+6.52?±?0.96 mV) was noticed when AZM was added into the macroemulsion. At a 1:5 dilution ratio, 2.06?±?0.03 mg of drug was released from macroemulsion followed by 1.01?±?0.01 and 0.25?±?0.08 mg, respectively, for 1:10 and 1:40 dilution ratios. Antimicrobial activity maintenance and significant reduction of RBC lysis property were noticed for AZM after loaded in the macroemulsion. However, an increment in the absorbance values for emulsion-treated samples in comparison to the control samples was noticed in the anti-inflammatory test. This speculates the potential of the AZM-loaded emulsion to manage inflammatory conditions produced at Acne vulgaris.     

Topical delivery and in vivo antileishmanial activity of paromomycin-loaded liposomes for treatment of cutaneous leishmaniasis

The present study aimed to evaluate the potential of liposomes loaded with paromomycin (PA), an aminoglycoside antibiotic associated with poor skin penetration, for the topical treatment of cutaneous leishmaniasis (CL). Fluid liposomes were prepared and characterized for particle size, zeta potential, and drug entrapment. Permeation studies were performed with two in vitro models: intact and stripped skin. The antileishmanial activity of free and liposomal PA was evaluated in BALB/c mice infected by Leishmania (L.) major. Drug entrapment ranged from 10 to 14%, and the type of vesicle had little influence on this parameter. Particle size and polydispersity index of the vesicles composed by phosphatidylcholine (PC) and PC/cholesterol (Chol) ranged from of 516 to 362?nm and 0.7 to 0.4, respectively. PA permeation across intact skin was low, regardless of the formulation tested, while drug penetration into skin (percent of the applied dose) from PC (7.2?±?0.2%) and PC/Chol (4.8?±?0.2%) liposomes was higher than solution (1.9?±?0.1%). PA-loaded liposomes enhanced in vitro drug permeation across stripped skin and improved the in vivo antileishmanial activity in experimentally infected mice. Our findings suggest that the liposomes represent a promising alternative for the topical treatment of CL using PA.     

Enhanced Solubility and Bioavailability of Naringenin via Liposomal Nanoformulation: Preparation and <Emphasis Type="Italic">In Vitro</Emphasis> and <Emphasis Type="Italic">In Vivo</Emphasis> Evaluations

This study was aimed at preparing orally administered naringenin-loaded liposome for pharmacokinetic and tissue distribution studies in animal models. The liposomal system, consisting of phospholipid, cholesterol, sodium cholate, and isopropyl myristate, was prepared using the thin-film hydration method. Physicochemical characterization of naringenin-loaded liposome such as particle size, zeta potential, and encapsulation efficiency produced 70.53?±?1.71 nm, ?37.4?±?7.3 mV, and 72.2?±?0.8%, respectively. The in vitro release profile of naringenin from the formulation in three different media (HCl solution, pH 1.2; acetate buffer solution, pH 4.5; phosphate buffer solution, pH 6.8) was significantly higher than the free drug. The in vivo studies also revealed an increase in AUC of the naringenin-loaded liposome from 16648.48 to 223754.0 ng·mL^?1 h as compared with the free naringenin. Thus, approximately 13.44-fold increase in relative bioavailability was observed in mice after oral administration. The tissue distribution further showed that the formulation was very predominant in the liver. These findings therefore indicated that the liposomal formulation significantly improved the solubility and oral bioavailability of naringenin, thus leading to wider clinical applications.     

Solid lipid nanoparticles for transdermal delivery of avanafil: optimization,formulation, in-vitro and ex-vivo studies

Context: Avanafil (AVA) is used in the treatment of erectile dysfunction, but is reported for its poor aqueous solubility. Solid lipid nanoparticles (SLNs) are lipid carriers that can greatly enhance drug solubility and bioavailability.

Objective: This work was aimed to formulate and optimize AVA SLNs with subsequent loading into hydrogel films for AVA transdermal delivery.

Materials and methods: AVA SLNs were prepared utilizing homogenization followed by ultra-sonication technique. The prepared SLNs were characterized for particle size, charge, surface morphology and drug content. The optimized SLNs formulation was incorporated into transdermal films prepared using HPMC and chitosan. Hydrogel films were evaluated for ex-vivo rat skin permeation using automated Franz diffusion cells. The permeation parameters and the release mechanism were evaluated. The transdermal permeation of the prepared AVA SLNs through the skin layers was studied using confocal laser scanning microscope.

Results: Lipid concentration and % of oil in lipid had a pronounced effect on particle size while, entrapment efficiency was significantly affected by lipid concentration and % of cholesterol. The optimized AVA SLNs showed particle size and entrapment efficiency of 86?nm and 85.01%, respectively. TEM images revealed spherecity of the particles. High permeation parameters were observed from HPMC films loaded with AVA SLNs. The release data were in favor of Higuchi diffusion model. The prepared AVA SLNs were able to penetrate deeper in skin layers.

Conclusion: HPMC transdermal film-loaded AVA SLNs is an effective and alternative to per-oral drug administration.     

Preparation and Enhanced Oral Bioavailability of Cryptotanshinone-Loaded Solid Lipid Nanoparticles

In this study, solid lipid nanoparticles (SLNs) were successfully prepared by an ultrasonic and high-pressure homogenization method to improve the oral bioavailability of the poorly water-soluble drug cryptotanshinone (CTS). The particle size and distribution, drug loading capacity, drug entrapment efficiency, zeta potential, and long-term physical stability of the SLNs were characterized in detail. A pharmacokinetic study was conducted in rats after oral administration of CTS in different SLNs, and it was found that the relative bioavailability of CTS in the SLNs was significantly increased compared with that of a CTS-suspension. The incorporation of CTS in SLNs also markedly changes the metabolism behavior of CTS to tanshinone IIA. These results indicate that CTS absorption is enhanced significantly by employing SLN formulations, and SLNs represent a powerful approach for improving the oral absorption of poorly soluble drugs.     

Fabrication of Nanosuspension Directly Loaded Fast-Dissolving Films for Enhanced Oral Bioavailability of Olmesartan Medoxomil: <Emphasis Type="Italic">In Vitro</Emphasis> Characterization and Pharmacokinetic Evaluation in Healthy Human Volunteers

Olmesartan medoxomil (OM) is an antihypertensive drug with poor water solubility and low oral bioavailability (28.6%). Accordingly, this study aimed to formulate and evaluate OM nanosuspension incorporated into oral fast-dissolving films (FDFs) for bioavailability enhancement. OM nanosuspension was prepared by antisolvent-precipitation-ultrasonication method and characterized regarding particle size (122.67?±?5.03 nm), span value (1.40?±?0.51), and zeta potential (??46.56?±?1.20 mV). Transmission electron microscopy (TEM) of the nanosuspension showed spherical non-aggregating nanoparticles. The nanosuspension was then directly loaded into FDFs by solvent casting technique. A full factorial design (2²?×?3¹) was implemented for optimization of the FDFs using Design-Expert® software. Physical and mechanical characteristics in addition to dissolution profiles of the FDFs were investigated. The optimum formula (FDF1) showed 0.43?±?0.02 kg/mm² tensile strength, 20.50?±?2.12 s disintegration time, and 87.53?±?2.50 and 95.99?±?0.25% OM dissolved after 6 and 10 min, respectively. Accelerated and long-term shelf stability studies confirmed the stability of FDF1. More than 75% OM was dissolved within 10 min from FDF1 compared with 9.80 and 47.80% for films prepared using coarse drug powder and market tablet, respectively. Relative bioavailability of FDF1 compared to market tablet was assessed in healthy human volunteers. The C_max value increased significantly from 66.62?±?14.95 to 179.28?±?23.96 ng/mL for market tablet and FDF1, respectively. Similarly, the AUC_0–72 value significantly increased from 498.36?±?217.46 to 1083.67?±?246.32 ng h/mL for market tablet and FDF1, respectively. Relative bioavailability of FDF1 was 209.28%. The highlighted results verified the effectiveness of OM nanosuspension-loaded FDFs in improving OM bioavailability.     

Enhancing the Therapeutic Efficacy of Tamoxifen Citrate Loaded Span-Based Nano-Vesicles on Human Breast Adenocarcinoma Cells

Serious adverse effects and low selectivity to cancer cells are the main obstacles of long term therapy with Tamoxifen (Tmx). This study aimed to develop Tmx-loaded span-based nano-vesicles for delivery to malignant tissues with maximum efficacy. The effect of three variables on vesicle size (Y₁), zeta potential (Y₂), entrapment efficiency (Y₃) and the cumulative percent release after 24 h (Y₄) were optimized using Box-Behnken design. The optimized formula was prepared and tested for its stability in different storage conditions. The observed values for the optimized formula were 310.2 nm, ??42.09 mV, 75.45 and 71.70% for Y₁, Y₂, Y₃, and Y₄, respectively. The examination using electron microscopy confirmed the formation of rounded vesicles with distinctive bilayer structure. Moreover, the cytotoxic activity of the optimized formula on both breast cancer cells (MCF-7) and normal cells (BHK) showed enhanced selectivity (9.4 folds) on cancerous cells with IC₅₀ values 4.7?±?1.5 and 44.3?±?1.3 μg/ml on cancer and normal cells, respectively. While, free Tmx exhibited lower selectivity (2.5 folds) than optimized nano-vesicles on cancer cells with IC₅₀ values of 9.0?±?1.1 μg/ml and 22.5?±?5.3 μg/ml on MCF-7 and BHK cells, respectively. The promising prepared vesicular system, with greater efficacy and selectivity, provides a marvelous tool to overcome breast cancer treatment challenges.