Influence of Surface-Modification via PEGylation or Chitosanization of Lipidic Nanocarriers on In Vivo Pharmacokinetic/Pharmacodynamic Profiles of Apixaban.

Nanostructured lipid carriers (NLCs) have been proven to significantly improve the bioavailability and efficacy of many drugs; however, they still have many limitations. These limitations could hinder their potential for enhancing the bioavailability of poorly water-soluble drugs and, therefore, require further amendments. From this perspective, we have investigated how the chitosanization and PEGylation of NLCs affected their ability to function as a delivery system for apixaban (APX). These surface modifications could enhance the ability of NLCs to improve the bioavailability and pharmacodynamic activity of the loaded drug. In vitro and in vivo studies were carried out to examine APX-loaded NLCs, chitosan-modified NLCs, and PEGylated NLCs. The three nanoarchitectures displayed a Higuchi-diffusion release pattern in vitro, in addition to having their vesicular outline proven via electron microscopy. PEGylated and chitosanized NLCs retained good stability over 3 months, versus the nonPEGylated and nonchitosanized NLCs. Interestingly, APX-loaded chitosan-modified NLCs displayed better stability than the APX-loaded PEGylated NLCs, in terms of mean vesicle size after 90 days. On the other hand, the absorption profile of APX (AUC0-inf) in rats pretreated with APX-loaded PEGylated NLCs (108.59 µg·mL-1·h-1) was significantly higher than the AUC0-inf of APX in rats pretreated with APX-loaded chitosan-modified NLCs (93.397 µg·mL-1·h-1), and both were also significantly higher than AUC0-inf of APX-Loaded NLCs (55.435 µg·mL-1·h-1). Chitosan-coated NLCs enhanced APX anticoagulant activity with increased prothrombin time and activated partial thromboplastin time by 1.6- and 1.55-folds, respectively, compared to unmodified NLCs, and by 1.23- and 1.37-folds, respectively, compared to PEGylated NLCs. The PEGylation and chitosanization of NLCs enhanced the bioavailability and anticoagulant activity of APX over the nonmodified NLCs; this highlighted the importance of both approaches.

Atorvastatin-loaded pro-nanolipospheres with ameliorated oral bioavailability and antidyslipidemic activity.

Despite significant advances in oral drug delivery technologies, many drugs are prone to limited oral bioavailability due to biological barriers that hinder drug absorption. Pro-nanolipospheres (PNL) are a form of delivery system that can potentiate the oral bioavailability of poorly water-soluble drugs through a variety of processes, including increased drug solubility and protecting them from degradation by intestinal or hepatic first-pass metabolism. In this study, pro-nanolipospheres were employed as a delivery vehicle for improving the oral bioavailability of the lipophilic statin, atorvastatin (ATR). Various ATR-loaded PNL formulations, composed of various pharmaceutical ingredients, were prepared by the pre-concentrate method and characterized by determining particle size, surface charge, and encapsulation efficiency. An optimized formula (ATR-PT PNL) showing the smallest particle size, highest zeta potential, and highest encapsulation efficiency was selected for further in vivo investigations. The in vivo pharmacodynamic experiments demonstrated that the optimized ATR-PT PNL formulation exerted a potent hypolipidemic effect in a Poloxamer® 407-induced hyper-lipidaemia rat model by restoring normal cholesterol and triglyceride serum levels along with alleviating serum levels of LDL while elevating serum HDL levels, compared to pure drug suspensions and marketed ATR (Lipitor®). Most importantly, oral administration of the optimized ATR-PT PNL formulation showed a dramatic increase in ATR oral bioavailability, as evinced by a 1.7- and 3.6-fold rise in systemic bioavailability when compared with oral commercial ATR suspensions (Lipitor®) and pure drug suspension, respectively. Collectively, pro-nanolipospheres might represent a promising delivery vehicle for enhancing the oral bioavailability of poorly water-soluble drugs.

Preparation and Characterization of a Novel Mucoadhesive Carvedilol Nanosponge: A Promising Platform for Buccal Anti-Hypertensive Delivery.

Carvedilol (CRV) is a non-selective third generation beta-blocker used to treat hypertension, congestive heart failure and angina pectoris. Oral administration of CRV showed poor bioavailability (25%), which might be ascribed to its extensive first-pass metabolism. Buccal delivery is known to boost drugs bioavailability. The aim of this study is to investigate the efficacy of bilosomes-based mucoadhesive carvedilol nanosponge for enhancing the oral bioavailability of CRV. The bilosomes were prepared, optimized and characterized for particle size, surface morphology, encapsulation efficiency and ex-vivo permeation studies. Then, the optimized formula was incorporated into a carboxymethyl cellulose/hydroxypropyl cellulose (CMC/HPC) composite mixture to obtain buccal nanosponge enriched with CRV bilosomes. The optimized bilosome formula (BLS9), showing minimum vesicle size, maximum entrapment, and highest cumulative in vitro release, exhibited a spherical shape with 217.2 nm in diameter, 87.13% entrapment efficiency, and sustained drug release for up to 24 h. In addition, ex-vivo drug permeation across sheep buccal mucosa revealed enhanced drug permeation with bilosomal formulations, compared to aqueous drug suspension. Consecutively, BLS9 was incorporated in a CMC/HPC gel and lyophilized for 24 h to obtain bilosomal nanosponge to enhance CRV buccal delivery. Morphological analysis of the prepared nanosponge revealed improved swelling with a porosity of 67.58%. The in vivo assessment of rats indicated that CRV-loaded nanosponge efficiently enhanced systolic/diastolic blood pressure, decreased elevated oxidative stress, improved lipid profile and exhibited a potent cardio-protective effect. Collectively, bilosomal nanosponge might represent a plausible nanovehicle for buccal delivery of CRV for effective management of hypertension.

Tailoring Apixaban in Nanostructured Lipid Carrier Enhancing Its Oral Bioavailability and Anticoagulant Activity.

Apixaban (Apx), an oral anticoagulant drug, is a direct factor Xa inhibitor for the prophylaxis against venous thromboembolism. Apx has limited oral bioavailability and poor water solubility. The goal of this study was to improve the formulation of an Apx-loaded nanostructured lipid carrier (NLC) to increase its bioavailability and effectiveness. As solid lipid, liquid lipid, hydrophilic, and lipophilic stabilizers, stearic acid, oleic acid, Tween 80, and lecithin were used, respectively. Utilizing Box-Behnken design, the effects of three factors on NLC particle size (Y1), zeta potential (Y2), and entrapment efficiency percent (Y3) were examined and optimized. The optimized formula was prepared, characterized, morphologically studied, and pharmacokinetically and pharmacodynamically assessed. The observed responses of the optimized Apx formula were 315.2 nm, -43.4 mV, and 89.84% for Y1, Y2, and Y3, respectively. Electron microscopy revealed the homogenous spherical shape of the NLC particles. The in vivo pharmacokinetic study conducted in male Wistar rats displayed an increase in AUC and Cmax by 8 and 2.67 folds, respectively, compared to oral Apx suspension. Moreover, the half-life was increased by 1.94 folds, and clearance was diminished by about 8 folds, which makes the NLC formula a promising sustained release system. Interestingly, the pharmacodynamic results displayed the superior effect of the optimized formula over the drug suspension with prolongation in the cuticle bleeding time. Moreover, both prothrombin time and activated partial thromboplastin time are significantly increased. So, incorporating Apx in an NLC formula significantly enhanced its oral bioavailability and pharmacodynamic activity.

Fluticasone propionate-loaded solid lipid nanoparticles with augmented anti-inflammatory activity: optimisation, characterisation and pharmacodynamic evaluation on rats.

This work aimed to elaborate an optimised fluticasone propionate (FP)-loaded solid lipid nanoparticles (SLNs) to enhance FP effectiveness for topical inflammatory remediation. The influences of drug amount, lipid, and surfactant ratios, on drug release pattern and stability were investigated utilising Box-Behnken design. Elaboration, characterisation, and pharmacodynamic evaluation in comparison with the marketed formulation (Cutivate® cream, 0.05%w/w FP), were conducted for the optimised SLNs. The optimised SLNs with a size of 248.3 ± 1.89 nm (PDI = 0.275) and -32.4 ± 2.85 mV zeta potential were evidenced good stability physiognomies. The optimised SLNs pre-treated rats exhibited non-significant difference in paw volume from that of the control group and showed a significant reduction in both PGE2 and TNF-α levels by 51.5 and 61%, respectively, in comparison with the Carrageenan group. The optimised FP-loaded SLNs maximised the efficacy of FP towards inflammation alleviation that increase its potential as efficient implement in inflammatory skin diseases remediation.

Impact of the mucoadhesive lyophilized wafer loaded with novel carvedilol nano-spanlastics on biochemical markers in the heart of spontaneously hypertensive rat models.

The purpose of this investigation was to encapsulate carvedilol, a model beta-blocker antihypertensive into nano-spanlastics, followed by incorporation into 1% CMC wafer to afford a mucoadhesive buccal drug delivery system, targeting to sidestep the first-pass metabolism, improving the drug absorption and pharmacological effect, achieving non-invasive buccal delivery for treating hypertension. Carvedilol-loaded nano-spanlastics were rendered by ethanol injection technique, using 23 factorial design. The effect of formulation variables was investigated on nano-spanlastic characteristics. The optimal nano-spanlastic formulation (S2; containing 20% Brij 97) exhibited particle size (239.8 ± 5 nm), entrapment efficiency (98. 16 ± 1.44%), deformability index (8.74 ± 0.42 g), and the flux after 24 h (Jmax) (22.5 ± 0.25 (µg/cm2/h) with enhancement ratio 2.87 as well as excellent stability after storage. Permeation study verified the preeminence of the S2 formula. A confocal laser scanning microscope showed deep penetration of S2 through sheep buccal mucosa formula compared to rhodamine B solution. S2-based wafer showed acceptable characters (pH, swelling, drug content, residence time, and release rate). In vivo studies (pharmacodynamic study and biochemical evaluation) showed considerable improvement in blood pressure, the profile of the lipid, oxidant stress biomarkers, and cardiac markers. Histopathological studies revealed the superiority of S2 wafer in the protection of heart tissues over Carvid®. The results achieved indicate that nano-spanlastic-based wafer offers a promising improving trans-buccal carvedilol delivery system. Graphical abstract.

Influence of formulation variables on miconazole nitrate-loaded lipid based nanocarrier for topical delivery.

The purpose of this study was to develop miconazole nitrate (MN) based solid lipid nano-carrier formulae for topical delivery to enhance its antifungal effectiveness. Miconazole nitrate loaded Solid lipid nanoparticles (MN-SLNs) were formulated using a high shear homogenization technique characterized by particle size, polydispersity index (PI), trapping efficiency (EE percent), drug loading (DL percent) and zeta potential (ZP) characteristics. Furthermore, the optimized formulae were investigated for in-vitro release, ex-vivo study, skin toxicity test, and antifungal activity. With a particle size range of 244.2 ± 27.2 nm to 493.6 ± 35.3 nm, the selected MN-SLNs were spherical shaped. A high EE product percentage ranging from 79.38 ± 2.35 percent to 95.92 ± 6.12 percent and Zeta potential ZP values ranging from-21.6 ± 7.05 mV to-31.4 ± 6.84 mV suggesting strong stability was achieved. A controlled release of MN from the SLNs up to 48 h was shown in-vitro release study. The ex-vivo study showed that the selected MN-SLN (F4) mixture exhibited higher MN flux in the skin than a 1% MN solution. Moreover, selected MN-SLN (F4) has demonstrated a higher zone of inhibition against Candida albicans than a simple drug solution. MN-SLN (F4) had the lowest toxicity value for the skin. Besides, the MN-SLNs (F4) substantially reported antifungal activity with the least histopathological improvements compared to MN-solution utilizing immune-suppressing albino rats with induced candidiasis fungal infection. It can be fulfilled that SLNs can be acquired as a promising carrier for topical delivery of poorly soluble MN.

Development of Betamethasone Dipropionate-Loaded Nanostructured Lipid Carriers for Topical and Transdermal Delivery.

INTRODUCTION: Betamethasone dipropionate is a highly effective corticosteroid anti-inflammatory. However, the main drawback of its topical use is the limited skin penetration into deeper skin layers. Also, its systemic use has shown many side effects. OBJECTIVE: The goal of this research was to formulate betamethasone dipropionate in nanostructured lipid carriers (NLC) formulae that contain oleic acid to aid its penetration to deeper skin layers and to aid absorption to local regions upon topical application. METHODS: NLC formulae were prepared by high shear homogenization then sonication. Formulae were characterized for their particle size, size distribution, electric potential, occlusion factor, entrapment efficiency, drug loading, transmission electron microscopy, in vitro drug release, and ex vivo skin penetration. Compatibility of ingredients with drug was tested using differential scanning calorimetry. Formulae were shown to have appropriate characteristics. NLC formulae were superior to traditional topical formulation in drug release. RESULTS: Upon testing ex vivo skin penetration, betamethasone dipropionate prepared in NLC formulae was shown to penetrate more efficiently into skin layers than when formulated as a traditional cream. NLC formulation that contained higher percentage of oleic acid showed higher penetration and higher amount of drug to pass through skin. CONCLUSION: In general, NLC with lower oleic acid percentage was shown to deliver betamethasone dipropionate more efficiently into deeper skin layers while that of a higher oleic acid percentage was shown to deliver the drug more efficiently into deeper skin layers and through the skin, transdermally.

Factors affecting liposomes particle size prepared by ethanol injection method.

Ethanol injection is one of the techniques frequently used to produce liposomes which favors both simplicity and safety. In this process, an ethanolic solution of lipids is rapidly injected into an aqueous medium through a needle, dispersing the phospholipids throughout the medium and promoting the vesicle formation. Being a critical parameter that determines the fate of liposome and its distribution, we studied different factors affecting the particle size of liposomes including different phospholipid (Phosal® 53 MCT) and cholesterol concentrations and the use of different types of non-ionic surfactants at fixed Phosal® 53 MCT concentration of 50 mg per formulation. Both Phosal® 53 MCT and cholesterol concentration had direct effect on liposomes particle size. Non-ionic surfactants produced liposomes of smaller particle size when compared to conventional liposomes formed using Phosal® 53 MCT 300 mg per formulation only, whereas this effect was diminished when higher Phosal® 53 MCT to cholesterol ratios were used that obviously increased liposomes size. Smaller liposomes sizes were obtained upon using non-ionic surfactants of lower hydrophilic/hydrophobic balance (HLB) as both Tween 80 and Cremophor RH 40 produced liposomes of smaller particle size compared to Poloxamer 407. The smallest liposomes particle size was successfully obtained in the formulation comprising 300 mg Phosal® MCT, 150 mg cholesterol and 50 mg Tween 80.

Novel Solid Self-Nanoemulsifying Drug Delivery System (S-SNEDDS) for Oral Delivery of Olmesartan Medoxomil: Design, Formulation, Pharmacokinetic and Bioavailability Evaluation.

The main purpose of this study was to develop a solid self-nanoemulsifying drug delivery system (S-SNEDDS) of Olmesartan (OLM) for enhancement of its solubility and dissolution rate. In this study, liquid SNEDDS containing Olmesartan was formulated and further developed into a solid form by the spray drying technique using Aerosil 200 as a solid carrier. Based on the preliminary screening of different unloaded SNEDDS formulae, eight formulae of OLM loaded SNEEDS were prepared using Capryol 90, Cremophor RH40 and Transcutol HP as oil, surfactant and cosurfactant, respectively. Results showed that the mean droplet size of all reconstituted SNEDDS was found to be in the nanometric range (14.91-22.97 nm) with optimum PDI values (0.036-0.241). All formulae also showed rapid emulsification time (15.46 ± 1.34-24.17 ± 1.47 s), good optical clarity (98.33% ± 0.16%-99.87% ± 0.31%) and high drug loading efficiency (96.41% ± 1.20%-99.65% ± 1.11%). TEM analysis revealed the formation of spherical and homogeneous droplets with a size smaller than 50 nm. In vitro release of OLM from SNEDDS formulae showed that more than 90% of OLM released in approximately 90 min. Optimized SNEDDS formulae were selected to be developed into S-SNEDDS using the spray drying technique. The prepared S-SNEDDS formulae were evaluated for flow properties, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), reconstitution properties, drug content and in vitro dissolution study. It was found that S-SNEDDS formulae showed good flow properties and high drug content. Reconstitution properties of S-SNEDDS showed spontaneous self-nanoemulsification and no sign of phase separation. DSC thermograms revealed that OLM was in solubilized form and FTIR supported these findings. SEM photographs showed smooth uniform surface of S-SNEDDS with less aggregation. Results of the in vitro drug release showed that there was great enhancement in the dissolution rate of OLM. To clarify the possible improvement in pharmacokinetic behavior of OLM S-SNEDDS, plasma concentration-time curve profiles of OLM after the oral administration of optimized S-SNEDDS formula (F3) were compared to marketed product and pure drug in suspension. At all time points, it was observed that OLM plasma concentrations in rats treated with S-SNEDDS were significantly higher than those treated with the drug in suspension and marketed product.

Effect of Antiadherents on the Physical and Drug Release Properties of Acrylic Polymeric Films.

Antiadherents are used to decrease tackiness of a polymer coating during both processing and subsequent storage. Despite being a common excipient in coating formulae, antiadherents may affect mechanical properties of the coating film as well as drug release from film-coated tablets, but how could addition of antiadherents affect these properties and to what extent and is there a relation between the physical characteristics of the tablet coat and the drug release mechanisms? The aim of this study was to evaluate physical characteristics of films containing different amounts of the antiadherents talc, glyceryl monostearate, and PlasACRYL(TM) T20. Eudragit RL30D and Eudragit RS30D as sustained release polymers and Eudragit FS30D as a delayed release material were used. Polymer films were characterized by tensile testing, differential scanning calorimetry (DSC), microscopic examination, and water content as calculated from loss on drying. The effect of antiadherents on in vitro drug release for the model acetylsalicylic acid tablets coated with Eudragit FS30D was also determined. Increasing talc concentration was found to decrease the ability of the polymer films to resist mechanical stress. In contrast, glyceryl monostearate (GMS) and PlasACRYL produced more elastic films. Talc at concentrations higher than 25% caused negative effects, which make 25% concentration recommended to be used with acrylic polymers. All antiadherents delayed the drug release at all coating levels; hence, different tailoring of drug release may be achieved by adjusting antiadherent concentration with coating level.

Nanostructured lipid carriers (NLCs) versus solid lipid nanoparticles (SLNs) for topical delivery of meloxicam.

OBJECTIVE: The aim of this study was to develop nanostructured lipid carriers (NLCs) as well as solid lipid nanoparticles (SLNs) and evaluate their potential in the topical delivery of meloxicam (MLX). MATERIALS AND METHODS: The effect of various compositional variations on their physicochemical properties was investigated. Furthermore, MLX-loaded lipid nanoparticles-based hydrogels were formulated and the gels were evaluated as vehicles for topical application. RESULTS AND DISCUSSION: The results showed that NLC and SLN dispersions had spherical shapes with an average size between 215 and 430 nm. High entrapment efficiency was obtained ranging from 61.94 to 90.38% with negatively charged zeta potential in the range of -19.1 to -25.7 mV. The release profiles of all formulations exhibited sustained release characteristics over 48 h and the release rates increased as the amount of liquid lipid in lipid core increased. Finally, Precirol NLC with 50% Miglyol® 812 and its corresponding SLN were incorporated in hydrogels. The gels showed adequate pH, non-Newtonian flow with shear-thinning behavior and controlled release profiles. The biological evaluation revealed that MLX-loaded NLC gel showed more pronounced effect compared to MLX-loaded SLN gel. CONCLUSION: It can be concluded that lipid nanoparticles represent promising particulate carriers for topical application.

Effects of glycerides on the intestinal absorption of cyclosporine a using the in-situ mesenteric vein cannulated rat model.

The purpose of this study was to evaluate and compare the effect of glycerides with different fatty acid distributions (e.g. Arlacel 186, Capmul GMO and Captex 350) on Cyclosporine absorption in rat ileum segment using the modified single-pass intestinal perfusion with mesenteric vein cannulation. Drug concentration in the perfusate and blood plasma was analyzed by HPLC; and permeability coefficients were calculated from drug appearance in blood (P(blood)) and disappearance from perfusate (P(lumen)). Particle size was measured using Malvern Zetasaizer 1000HSA. Rheologic properties were measured using Brookfield viscometer. The results show that the average particle sizes after dilution (100 folds) of formulae containing Arlacel 186, Capmul GMO and Captex 350 and containing 0.8 mM CsA were 260+/-35.8, 130+/-11.4 and 37.5+/-6.0 nm, respectively. The polydispersity index was 0.6, 0.7 and 0.108 for formulations with Arlacel 186, Capmul GMO and Captex 350, respectively. CsA permeability coefficients (P(blood)) calculated from drug appearance in the blood in presence of Arlacel 186, Capmul GMO and Captex 350 were 0.3x10(-6), 1.0x10(-6) and 1.7x10(-6) cm2/sec, respectively. Phenol red was used as a water marker to determine net water absorption and secretion. Its constant concentration suggested that formulation did not alter intestinal water flux. From the results we can conclude that degree of glyceride esterification has a potential impact on the average particle size distribution and polydispersity of the formed micelles on dilution, which on turn contribute to the interaction between membrane and drug.

Tablet formulation containing meloxicam and beta-cyclodextrin: mechanical characterization and bioavailability evaluation.

The purpose of this research was to evaluate beta-cyclodextrin (beta-CD) as a vehicle, either singly or in blends with lactose (spray-dried or monohydrate), for preparing a meloxicam tablet. Aqueous solubility of meloxicam in presence of beta-CD was investigated. The tablets were prepared by direct compression and wet granulation techniques. The powder blends and the granules were evaluated for angle of repose, bulk density, compressibility index, total porosity, and drug content. The tablets were subjected to thickness, diameter, weight variation test, drug content, hardness, friability, disintegration time, and in vitro dissolution studies. The effect of beta-CD on the bioavailability of meloxicam was also investigated in human volunteers using a balanced 2-way crossover study. Phase-solubility studies indicated an A(L)-type diagram with inclusion complex of 1:1 molar ratio. The powder blends and granules of all formulations showed satisfactory flow properties, compressibility, and drug content. All tablet formulations prepared by direct compression or wet granulation showed acceptable mechanical properties. The dissolution rate of meloxicam was significantly enhanced by inclusion of beta-CD in the formulations up to 30%. The mean pharmacokinetic parameters (C(max), K(e), and area under the curve [AUC](0-infinity)) were significantly increased in presence of beta-CD. These results suggest that beta-CD would facilitate the preparation of meloxicam tablets with acceptable mechanical properties using the direct compression technique as there is no important difference between tablets prepared by direct compression and those prepared by wet granulation. Also, beta-CD is particularly useful for improving the oral bioavailablity of meloxicam.