Revaprazan-loaded surface-modified solid dispersion: physicochemical characterization and in vivo evaluation

Comparative analysis of novel modified drug delivery systems for improving the oral bioavailability of water-insoluble tadalafil using copovidone, TPGS and hydroxypropyl-β-cyclodextrin

This study aims to develop novel modified drug delivery systems (MDDS) including solid dispersions, solid self-nanoemulsifying drug delivery system (S-SNEDDS) and inclusion compound (IC) of poorly water-soluble tadalafil using various biological macromolecules and compare their ability to improve solubility, dissolution and bioavailability. Ingredients of MDDS were extensively screened using SEM, DSC, and XRD. The MDDS were testified for improved solubilization, dissolution, and bioavailability and were compared with tadalafil powder and commercial product (Cialis tablets 20 mg). All MDDS demonstrated excellent physicochemical properties, improved solubility and dissolution of tadalafil. The sequence of highest solubilization and dissolution was found to be SE-solid dispersion, S-SNEDDS, SA-solid dispersion, and IC. SE-solid dispersion and IC showed spherical morphology and comparatively small particle size. In SA-solid dispersion, the hydrophilic carriers were found attached with the drug surface. Similarly, S-SNEDDS demonstrated the absorbance of L-SNEDDS inside the pores and surface of calcium silicate. All MDDS showed improved oral bioavailability (P < 0.05) in the order of SE-solid dispersion ≥ S-SNEDDS > SA-solid dispersion > commercial product > IC, when compared with tadalafil powder in rats. Thus, the SE-solid dispersion with highest solubility (660-folds) and oral bioavailability (10-folds) of tadalafil may be recommended as the most suitable candidate for the development of oral pharmaceutical products.

Comparison of Solid Self-Nanoemulsifying Systems and Surface-Coated Microspheres: Improving Oral Bioavailability of Niclosamide

Purpose

This study aimed to develop a solid self-nanoemulsifying drug delivery system (SNEDDS) and surface-coated microspheres to improve the oral bioavailability of niclosamide.

Methods

A solubility screening study showed that liquid SNEDDS, prepared using an optimized volume ratio of corn oil, Cremophor RH40, and Tween 80 (20:24:56), formed nanoemulsions with the smallest droplet size. Niclosamide was incorporated into this liquid SNEDDS and spray-dried with calcium silicate to produce solid SNEDDS. Surface-coated microspheres were prepared using sodium alginate and poloxamer 407 and optimized through solubility and dissolution tests. Scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction were used to evaluate the physicochemical properties of the prepared solid SNEDDS, surface-coated microspheres, and the drug alone. The solubility, dissolution, and oral bioavailability were also assessed.

Results

Physicochemical evaluation demonstrated that niclosamide was converted to an amorphous state in the Solid SNEDDS formulation, with enhanced solubility and oral bioavailability. In comparison to niclosamide alone, solid SNEDDS exhibited an increase in drug solubility (approximately 2500-fold vs 158-fold) and oral bioavailability (approximately 10-fold vs 1.65-fold), significantly outperforming surface-coated microspheres.

Conclusion

This solid SNEDDS formulation may be an excellent candidate for niclosamide with improved oral bioavailability for repurposing.

Novel Fimasartan Fluidized Solid Dispersion and Its Tablet: Preparation, Crystallinity, Solubility, Dissolution, and Pharmacokinetics in Beagle Dogs

BACKGROUND AND OBJECTIVES

Fimasartan, an angiotensin II receptor antagonist, exhibits low bioavailability due to its poor solubility; consequently, using solubilization technologies is essential to improve its bioavailability. In this study, novel fimasartan fluidized solid dispersion (FFSD) was developed using a fluid bed granulator to enhance the drug solubility and oral bioavailability.

METHODS

An appropriate FFSD was prepared in 50% ethanol using a fluid bed granulator, and its drug dissolution, morphology, and crystallinity were evaluated in comparison to the powdered drug. Moreover, the dissolution in various pH conditions and pharmacokinetics of the FFSD tablet in beagle dogs were investigated compared to the commercial fimasartan tablet.

RESULTS

Among the hydrophilic polymers tested, hydroxypropyl methylcellulose (HPMC) showed the highest solubility. The FFSD, composed of fimasartan, HPMC, and microcrystalline cellulose at the weight ratio of 20:10:25, gave a granular aggregation of several particles with a smooth surface. The drug in this FFSD existed as an amorphous state, leading to a greatly increased drug dissolution. The FFSD tablet was prepared by compressing a mixture of FFSD, mannitol, croscarmellose sodium, and magnesium stearate at the weight ratio of 55:40:5:1. The FFSD tablet gave significantly higher drug dissolution, plasma concentrations, maximum plasma concentration (Cmax) and area under the whole blood concentration-time curve (AUC) values than did the commercial fimasartan tablet. In the beagle dogs, the FFSD tablet (140.39 ± 27.40 ng·h/ml) had about a 1.7-fold higher AUC than the commercial fimasartan tablet (80.58 ± 22.18 ng·h/ml), indicating an enhancement in the bioavailability.

CONCLUSIONS

This novel FFSD tablet could be a potential oral pharmaceutical product with the improved oral bioavailability of fimasartan.

Modification of microenvironmental pH of nanoparticles for enhanced solubility and oral bioavailability of poorly water-soluble celecoxib

This study aimed to develop a novel pH-modified nanoparticle with improved solubility and oral bioavailability of poorly water-soluble celecoxib by modifying the microenvironmental pH. After assessing the impact of hydrophilic polymers, surfactants and alkaline pH modifiers on the drug solubility, copovidone, sodium lauryl sulfate (SLS) and meglumine were chosen. The optimal formulation of solvent-evaporated, surface-attached and pH-modified nanoparticles composed of celecoxib/copovidone/SLS/meglumine at weight ratios of 1:1:0.2:0, 1:0.375:1.125:0 and 1:1:1:0.2:0.02, respectively, were manufactured using spray drying technique. Their physicochemical characteristics, solubility, dissolution and pharmacokinetics in rats were evaluated compared to the celecoxib powder. The solvent-evaporated and pH-modified nanoparticles converted a crystalline to an amorphous drug, resulting in a spherical shape with a reduced particle size compared to celecoxib powder. However, the surface-attached nanoparticles with insignificant particle size exhibited the unchangeable crystalline drug. All of them gave significantly higher solubility, dissolution, and oral bioavailability than celecoxib powder. Among them, the pH-modified nanoparticles demonstrated the most significant improvement in solubility (approximately 1600-fold) and oral bioavailability (approximately 4-fold) compared to the drug powder owing to the alkaline microenvironment formation effect of meglumine and the conversion to the amorphous drug. Thus, the pH-modified nanoparticle system would be a promising strategy for improving the solubility and oral bioavailability of poorly water-soluble and weakly acidic celecoxib.

A cochleate formulation optimized by D-optimal mixture design enhances oral bioavailability of Revaprazan

A cochleate formulation was developed to enhance the oral bioavailability of revaprazan (RVP). Dimyristoyl phosphatidylcholine (DMPC) liposome containing dicetyl phosphate (DCP) successfully formed a cochleate after treatment with CaCl2, whereas that containing sodium deoxycholate did not. Cochleate was optimised using a D-optimal mixture design with three independent variables-DMPC (X1, 70.58 mol%), cholesterol (X2, 22.54 mol%), and DCP (X3, 6.88 mol%)-and three response variables: encapsulation efficiency (Y1, 76.92%), released amount of free fatty acid at 2 h (Y2, 39.82%), and released amount of RVP at 6 h (Y3, 73.72%). The desirability function was 0.616, showing an excellent agreement between the predicted and experimental values. The cylindrical morphology of the optimised cochleate was visualised, and laurdan spectroscopy confirmed the dehydrated membrane interface, showing an increased generalised polarisation value (approximately 0.5) over small unilamellar vesicle of RVP (RVP-SUV; approximately 0.1). The optimised cochleate showed greater resistance to pancreatic enzyme than RVP-SUV. RVP was released in a controlled manner, achieving approximately 94% release in 12 h. Following oral administration in rats, the optimised cochleate improved the relative bioavailability of RVP by approximately 274%, 255%, and 172% compared to RVP suspension, a physical mixture of RVP and the cochleate, and RVP-SUV, respectively. Thus, the optimised cochleate formulation might be a good candidate for the practical development of RVP.

Sodium alginate-based smart gastro-retentive drug delivery system of revaprazan loaded SLNs; Formulation and characterization

Revaprazan (REV), a novel reversible Proton Pump Inhibitor (PPI) used to treat peptic ulcers, faces challenges in therapeutic efficacy due to its poor dissolution properties and a short half-life. Solid lipid nanoparticles (SLNs) have emerged as a drug delivery system capable of enhancing dissolution and bioavailability of lipid soluble drugs. Here, we report on the development and optimization of a smart gastro-retentive raft system of REV-loaded SLNs (GRS/REV-SLNs) to enhance drug bioavailability and gastric retention. The optimized REV-SLNs had a particle size of 120 nm, a Polydispersity Index (PDI) of 0.313, a zeta potential of -20.7 mV, and efficient drug incorporation of 88 %. Transmission Electron Microscopy (TEM) affirmed the spherical morphology of these REV-SLNs, while Fourier Transform Infrared Spectroscopy (FTIR) revealed no chemical interactions among components. In-vitro assessment of the final GRS/REV-SLNs demonstrated sustained gelation and buoyancy for over 12 h, which would significantly enhance REV retention and its release within the stomach. Further assessments in rats confirmed successful gel transformation within the stomach, resulting in the improved bioavailability of REV. Thus, the development of GRS/REV-SLNs significantly improved the delivery and bioavailability of REV within the stomach, and offers a potentially improved method of treating peptic ulcers.

Rivaroxaban-loaded SLNs with treatment potential of deep vein thrombosis: in-vitro, in-vivo, and toxicity evaluation

OBJECTIVES

Rivaroxaban (RXB), a novel Xa inhibitor having groundbreaking therapeutic potential. However, this drug is associated with few limitations, including its pharmacokinetics related toxicities. Here, we developed RXB-loaded SLNs (RXB-SLNs) to improve its biopharmaceutical profile. Methods: High pressure homogenizer was used to prepare RXB-SLNs, followed by their particle characterization, Transmission electron microscopy (TEM), Dynamic light scattering (DSC), and Powder X-ray diffraction (PXRD) analysis. Beside this, in-vitro, ex-vivo, and in-vivo evaluation, prothrombin time assessment and toxicity was investigated.

RESULTS

RXB-SLNs had their particle size in nano range (99.1 ± 5.50 nm) with excellent morphology and low polydispersity index (0.402 ± 0.02) and suitable zeta potential (-25.9 ± 1.4 mV). The incorporation efficiency was observed around 95.9 ± 3.9%. In-vitro release profiles of the RXB-SLNs exhibited enhanced dissolution (89 ± 9.91%) as compared to pure drug (11 ± 1.43%) after 24 h of the study. PK study demonstrated a seven times enhanced bioavailability of RXB-SLNs when compared with pure drug. Furthermore, RXB-SLNs exhibited an expressive anti-coagulant behavior in human and rat blood plasma. Also, the final formulation exhibited no toxicity after oral administration of the SLNs.

CONCLUSIONS

All together, these studies revealed the capability of the SLNs for carrying the RXB with enhanced therapeutic efficacy and no toxicity, most importantly for the treatment of deep vein thrombosis.

Investigation of the treatment potential of Raloxifene-loaded polymeric nanoparticles in osteoporosis: In-vitro and in-vivo analyses

Osteoporosis (OP), is a systemic bone disorder associated with low bone mass and bone tissue corrosion. Worsening of the disease condition leads to bone delicacy and fracture. Various drugs are available for the treatment of OP, however they have limitations including poor solubility, bioavailability and toxicity. Herein, Raloxifene-loaded polymeric nanoparticles (RLX-PNPs) were developed and investigated for the treatment of OP with possible solutions to the above mentioned problems. RLX-PNPs were prepared by modified ionic gelation method followed by determining their particle properties. FTIR, DSC and PXRD analysis of the RLX-PNPs were performed to check chemical interaction, thermal behavior and crystallinity, respectively. In-vitro release profile of RLX-PNPs was checked in lab setting, whereas its pharmacokinetics was investigated in Sprague-Dawley rats, in-vivo. Finally, the treatment potential of RLX-PNPs was analyzed in OP induced animal model. The optimized PNPs formulation indicated 134.5 nm particle size, +24.4 mV charge and 91.73% % EE. TEM analysis showed spherical and uniform sized particles with no interactions observed in FTIR analysis. In-vitro release of RLX from RLX-PNPs showed more sustained release behavior as compared to RLX-suspension. Moreover, pharmacokinetic investigations showed a significantly enhanced bioavailability of the RLX-PNPs as well as reduced serum levels of alkaline phosphatase and calcium in OP induced rats when compared with RLX-Suspension after oral administration. Findings of this study suggested that the developed RLX-PNPs have the potential to treat OP due to sustained release and improved bioavailability of the incorporated drug.

Enhanced dissolution and bioavailability of revaprazan using self-nanoemulsifying drug delivery system

A self-nanoemulsifying drug delivery system (SNEDDS) was developed to enhance the dissolution and oral bioavailability (BA) of revaprazan (RVP). Various SNEDDSs containing 200 mg of RVP were formulated using Capmul MCM, Tween 80, and Brij L4, and they were characterized according to their size, polydispersity index, and dissolution behavior. Dissolution rates of all SNEDDS formulations significantly (p <0.05) improved with the formation of nanoemulsion with monodispersity. Formulation D resulted in RVP dissolution exceeding 70% at 2 h. Compared to raw RVP, SNEDDS exhibited a 4.8- to 7.4-fold improved effective permeability coefficient (P_eff) throughout the intestine in the in situ single pass intestinal permeability study and a 5.1-fold increased oral BA in the in vivo oral absorption assessment in rats. To evaluate the degree of lymphatic uptake, cycloheximide (CYC), a chylomicron flowing blocker, was pretreated prior to the experiment. This pretreatment barely affected the absorption of raw RVP; however, it greatly influenced the absorption of SNEDDS, resulting in an approximately 40% reduction in both the P_eff value and oral BA representing lymphatic transport. Thus, we suggest that the SNEDDS formulation is a good candidate for improving oral absorption of RVP through enhanced lymphatic uptake.

Novel dapagliflozin di-L-proline cocrystal-loaded tablet: Preparation, physicochemical characterization, and pharmacokinetics in beagle dogs and mini-pigs

Dapagliflozin base and a commercial dapagliflozin propanediol hydrate cocrystal (DPF-PDHC) were highly hygroscopic and thermally unstable. In this study, to address this limitation, we prepared a novel dapagliflozin di-L-proline cocrystal (DPF-LPC) and evaluated its physicochemical characterization compared with DPF-PDHC. After the preparation of the DPF-LPC-loaded tablet, its dissolution, stability and bioequivalence in beagle dogs and mini-pigs were assessed. DPF-LPC was well prepared with a dapagliflozin base and L-proline in a molar ratio of 1:2. Similar to DPF-PDHC, DPF-LPC was highly lipophilic and crystalline in nature. However, these two cocrystals exhibited different melting points and crystalline structures, indicating their different cocrystal forms. Moreover, DPF-LPC exhibited less hygroscopicity and lower water content than DPF-PDHC. The DPF-LPC-loaded tablet composed of DPF-LPC, Comprecel M102, lactose monohydrate, crospovidone, magnesium stearate, and Opadry (coating) at a weight ratio of 15.6:104.4:100.0:8.0:2.0:7.0, was dissolution-equivalent to the commercial tablet. Moreover, it provided lower impurities than the commercial tablet, indicating its better stability. In the two animals, there were no significant differences in the plasma concentrations, AUC, C_max, and T_max values, suggesting that they were bioequivalent. Therefore, the novel DPF-LPC-loaded tablet with excellent stability and bioequivalence may be used as a potential alternative to the commercial DPF-PDHC-loaded tablet.

New potential application of hydroxypropyl-β-cyclodextrin in solid self-nanoemulsifying drug delivery system and solid dispersion

The purpose of this study was to use hydroxypropyl-β-cyclodextrin (HP-β-CD) as a novel carrier in solid SNEDDS and solid dispersions to enhance the solubility and oral bioavailability of poorly water-soluble dexibuprofen. The novel dexibuprofen-loaded solid SNEDDS was composed of dexibuprofen, corn oil, polysorbate 80, Cremophor® EL, and HP-β-CD at a weight ratio of 45/35/50/15/100. This solid SNEDDS spontaneously formed a nano-emulsion with a size of approximately 120 nm. Unlike the conventional solid SNEDDS prepared with colloidal silica as a carrier, this dexibuprofen-loaded solid SNEDDS exhibited a spherical structure. Similar to the dexibuprofen-loaded solid dispersion prepared with HP-β-CD, the transformation of the crystalline drug to an amorphous state with no molecular interactions were observed in the solid SNEDDS. Compared to the solid dispersion and dexibuprofen powder, solid SNEDDS significantly enhanced drug solubility and AUC. Therefore, HP-β-CD is a novel potential carrier in SNEDDS for improving the oral bioavailability of dexibuprofen.

Comparison of Three Different Aqueous Microenvironments for Enhancing Oral Bioavailability of Sildenafil: Solid Self-Nanoemulsifying Drug Delivery System, Amorphous Microspheres and Crystalline Microspheres

Background

The purpose of this study was to screen various drug delivery systems for improving the aqueous solubility and oral bioavailability of sildenafil. Three representative techniques, solid self-nanoemulsifying drug delivery systems (SNEDDS), amorphous microspheres and crystalline microspheres, were compared.

Methods

Both microspheres systems contained sildenafil:Labrasol:PVP at a weight ratio of 1:1:6. The amorphous microspheres were manufactured using ethanol, while crystalline microspheres were generated using distilled water. Liquid SNEDDS was composed of sildenafil:Labrasol:Transcutol HP:Captex 300 in the ratio of 1:70:15:15 (w:w:w:w). The solidification process in SNEDDS was performed using HDK N20 Pharma as a solid carrier.

Results

The amorphous microspheres appeared spherical with significantly decreased particle size compared to the drug powder. The crystalline microspheres exhibited a rough surface with no major particle-size difference compared with sildenafil powder, indicating that the hydrophilic excipients adhered to the sildenafil crystal. Solid SNEDDS presented a smooth surface, assuming that the oily liquid was adsorbed to the porous solid carrier. According to the physicochemical evaluation, the crystalline state maintained in crystalline microspheres, whereas the crystal state changed to amorphous state in other formulations. Amorphous microspheres, crystalline microspheres and solid SNEDDS produced about 79, 55, 82-fold increased solubility, compared to drug powder. Moreover, the prepared formulations provided a higher dissolution rate (%) and plasma concentration than did the drug powder (performance order; solid SNEDDS ≥ amorphous microspheres ≥ crystalline microspheres > drug powder). Among the formulations, solid SNEDDS demonstrated the highest improvement in oral bioavailability (AUC; 1508.78 ± 343.95 h·ng/mL).

Conclusion

Therefore, solid SNEDDS could be recommended as an oral dosage form for enhancing the oral bioavailability of sildenafil.

Development of rebamipide-loaded spray-dried microsphere using distilled water and meglumine: physicochemical characterization and pharmacokinetics in rats

In this study, a novel rebamipide-loaded spray-dried microsphere (RSM) with enhanced drug solubility and oral bioavailability has been developed utilizing meglumine, an alkalizing agent. The influence of carriers on the drug solubility alone, and the solubility and dissolution of the drug in the RSM was investigated. Among the alkalizing agents and hydrophilic polymers tested, meglumine and polyvinyl alcohol (PVA) showed the highest drug solubility and dissolution rate, respectively. Many RSMs were manufactured with various amounts of meglumine and PVA using distilled water, and their drug solubility and dissolution were determined. The physicochemical properties, dissolution and pharmacokinetics of the chosen RSM in rats were assessed compared to the rebamipide powder and commercial tablet. Among the RSMs tested, the one composed of rebamipide, meglumine and PVA at a weight ratio of 3:1.75:6 showed the highest drug solubility and dissolution. This RSM with a smooth spherical form significantly decreased the particle size and modified the amorphous rebamipide. Furthermore, the drug solubility, dissolution, plasma concentrations, AUC and C_max values of RSM were significantly higher than those of drug powder and commercial tablet. Thus, this RSN system developed with distilled water and meglumine is recommended as an oral water-soluble rebamipide-loaded pharmaceutical product.

Developing pH-Modulated Spray Dried Amorphous Solid Dispersion of Candesartan Cilexetil with Enhanced In Vitro and In Vivo Performance

Candesartan cilexetil (CC), a prodrug and highly effective antihypertensive agent, is a poorly soluble (BCS Class II) drug with limited bioavailability. Here, we attempted to improve CC's bioavailability by formulating several CC-loaded amorphous solid dispersions with a hydrophilic carrier (PVPK30) and pH modifier (sodium carbonate) using the spray drying technique. Solubility, in vitro dissolution, and moisture content tests were used for screening the optimized formulation. We identified an optimized formulation of CC/PVPK30/SC, which at the ratio of 1:0.5:1 (w/w/w) exhibited a 30,000-fold increase in solubility and a more than 9-fold enhancement in dissolution compared to pure CC. Solid-state characterization revealed that in pH-modulated CC amorphous solid dispersion (CCSDpM), CC's crystallinity was altered to an amorphous state with the absence of undesirable interactions. Stability studies also showed that the optimized formulation was stable with good drug content and drug release under accelerated conditions of up to 4 weeks and real-time stability conditions of up to 12 weeks. Furthermore, pharmacokinetic parameters, such as AUC and Cmax of candesartan, had a 4.45-fold and 7.42-fold improvement, respectively, in CCSDpM-treated rats compared to those in the CC-treated rats. Thus, these results suggest that CCSDpM is highly effective for increasing oral absorption. The application of these techniques can be a viable strategy to improve a drug's bioavailability.

Effects of different physicochemical characteristics and supersaturation principle of solidified SNEDDS and surface-modified microspheres on the bioavailability of carvedilol

In this study, a solidified self-nanoemulsifying drug delivery system (solidified SNEDDS) and surface-modified microspheres were developed for enhancing the oral bioavailability of carvedilol. Based on the aqueous solubility test, liquid SNEDDS was composed of Peceol™ (oil), Tween® 80 (surfactant), and Labrasol® (co-surfactant) at a weight ratio of 25/50/25, generating the smallest nanoemulsion droplet size. Then, carvedilol was added to liquid SNEDDS and spray-dried with Aerosil® to fabricate the solidified SNEDDS. Surface-modified microspheres were manufactured using copovidone (polymer) and Tween® 80 (surfactant) according to aqueous solubility test results. The proper ratio of copovidone and Tween® 80 was determined based on the solubility and dissolution test. Both prepared formulations and carvedilol powder were compared using four different criteria: physicochemical characteristics, solubility, dissolution, and oral bioavailability. For solidified SNEDDS, carvedilol was encapsulated in liquid SNEDDS and absorbed to the Aerosil® surface, leading to the conversion from a crystalline to an amorphous state. However, the drug maintained its crystal form in the surface-modified microspheres. Round and even-sized particles were attached to the rough surfaces of drug, suggesting that hydrophilic carriers adhered to the hydrophobic drug. All formulations significantly improved drug solubility, dissolution, plasma concentrations, C_max, and AUC compared to carvedilol powder. The parameters were ranked in the following order: solidified SNEDDS > surface-modified microspheres > carvedilol powder. As a result, different solubility-increasing mechanisms provided differences in performance. For carvedilol, the formation of a nano-emulsion in solidified SNEDDS resulted in an efficient supersaturated state, leading to improved solubility (~6.1 fold), dissolution (~1.8 fold), and oral bioavailability (~1.4 fold) that was superior to the hydrophilic microenvironment in surface-modified microspheres.

Development of a Solid Supersaturable Micelle of Revaprazan for Improved Dissolution and Oral Bioavailability Using Box-Behnken Design

PURPOSE

To enhance the oral bioavailability of revaprazan (RVP), a novel solid, supersaturable micelle (SSuM) was developed.

METHODS

Surfactants and solid carriers were screened based on a solubility and a flowability test, respectively. Supersaturating agents, including Poloxamer 407 (P407), were screened. The SSuM was optimized using a Box-Behnken design with three independent variables, including Gelucire 44/14:Brij L4 (G44/BL4; X1) and the amounts of Florite PS-10 (FLO; X2) and Vivapur 105 (VP105; X3), and three response variables, ie, dissolution efficiency at 30 min (Y1), dissolution enhancing capacity (Y2), and Carr's index (Y3). The solid state property was evaluated, and a dissolution test was conducted. RVP, Revanex®, solid micelle (P407-free from the composition of SSuM), and SSuM were orally administrated to rats (RVP 20 mg equivalent/kg) for in vivo pharmacokinetic study.

RESULTS

G44 and BL4 showed great solubility, with a critical micelle concentration range of 119.2-333.0 μg/mL. P407 had an excellent supersaturating effect. FLO and VP105 were selected as solid carriers, with a critical solidifying ratio (g/mL) of 0.30 and 0.91, respectively. With optimized values of X1 (-0.41), X2 (0.31), and X3 (-0.78), RVP (200 mg)-containing SSuM consisting of G44 (253.8 mg), BL4 (106.2 mg), FLO (99.3 mg), VP105 (199.8 mg), and P407 (40 mg) was developed, resulting in Y1 (40.3%), Y2 (0.008), and Y3 (12.3%). RVP existed in an amorphous state in the optimized SSuM, and the SSuM formed a nanosized dispersion in the aqueous phase, with approximately 71.7% dissolution at 2 h. The optimized SSuM improved the relative bioavailability of RVP in rats by approximately 478%, 276%, and 161% compared to raw RVP, Revanex®, and solid micelle, respectively.

CONCLUSION

The optimized SSuM has great potential for the development of solidified formulations of poorly water-soluble drugs with improved oral absorption.

Preparation, Pharmacokinetics, and Antitumor Potential of Miltefosine-Loaded Nanostructured Lipid Carriers

BACKGROUND

The purpose of this study was to investigate the suitability of nanostructured lipid carriers (NLCs) loaded with miltefosine (HePC) as an anticancer drug for the treatment of breast cancer.

METHODS

HePC-NLCs were prepared using a microemulsion technique and then evaluated for particle size, polydispersity index (PDI), incorporation efficiency, in vitro release of entrapped drug, and hemolytic potential. Furthermore, pharmacokinetic, biodistribution, and liver toxicity analyses were performed in Sprague-Dawley rats, and antitumor efficacy was evaluated in Michigan Cancer Foundation-7 (MCF-7) and squamous cell carcinoma-7 (SCC-7) cells in vitro and in tumour-bearing BALB/c mice in vivo. Advanced analyses including survival rate, immunohistopathology, and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assays were performed to evaluate apoptosis in vivo.

RESULTS

The average particle size of the HePC-NLCs was 143 ± 16 nm, with a narrow PDI (0.104 ± 0.002), and the incorporation efficiency was found to be 91 ± 7%. The NLCs released HePC in a sustained manner, and this release was significantly lower than that of free drug. The in vitro hemolytic assay demonstrated a significantly reduced hemolytic potential (~9%) of the NLCs compared to that of the test formulations. The HePC-NLCs demonstrated enhanced pharmacokinetic behaviour over free drug, including extended blood circulation and an abridged clearance rate in rats. Furthermore, the HePC-NLCs exhibited higher cytotoxicity than the free drug in MCF-7 and SCC-7 cells. Moreover, the HePC-NLCs showed significantly enhanced (P < 0.005) antitumor activity compared to that of the control and free drug-treated mouse groups. Tumour cell apoptosis was also confirmed, indicating the antitumor potential of the HePC-NLCs.

CONCLUSION

These findings demonstrate the ability of NLCs as a drug delivery system for enhanced pharmacokinetic, antitumor, and apoptotic effects, most importantly when loaded with HePC.

Potential of solid dispersions to enhance solubility, bioavailability, and therapeutic efficacy of poorly water-soluble drugs: newer formulation techniques, current marketed scenario and patents

In the last few decades, solid dispersion (SD) technology had been studied as an approach to produce an amorphous carrier to enhance the solubility, dissolution rate, and bioavailability of poorly water-soluble drugs. The use of suitable carrier and methodology in the preparation of SDs play a significant role in the biological behavior of the SDs. SDs have been prepared using a variety of pharmaceutically acceptable polymers utilizing various novel technologies. In the recent years, much attention has been paid toward the use of novel carriers and methodologies in exploring novel types of SDs to enhance therapeutic efficacy and bioavailability. The use of novel carriers and methodologies would be very beneficial for formulation scientists to develop some SDs-based formulations for their commercial use and clinical applications. In the present review, current literature of novel methodologies for SD preparation to enhance the dissolution rate, solubility, therapeutic efficacy, and bioavailability of poorly water-soluble drugs has been summarized and analyzed. Further, the current status of SDs, patent status, and future prospects have also been discussed.

Comparative study between high-pressure homogenisation and Shirasu porous glass membrane technique in sildenafil base-loaded solid SNEDDS: Effects on physicochemical properties and in vivo characteristics

The purpose of this study was to compare two types of emulsification techniques in a solid self-nanoemulsifying drug delivery system (SNEDDS); high-pressure homogenisation (HPH) and Shirasu porous glass membrane (SPG). Those two emulsification processes enhanced the solubility, dissolution and oral bioavailability of poorly water-soluble sildenafil base (SB) by producing fine and well-dispersed nanoemulsion droplet. The liquid SNEDDS consisting of Labrasol/Transcutol HP/coconut oil at the weight of 72/18/10, gave the smallest emulsion droplet size among the prepared liquid SNEDDS formulations. Then, the SB-loaded liquid SNEDDS was dissolved in the deionised water and applied to HPH or SPG techniques. Aerosil 200 was suspended as a mesoporous carrier and spray-dried, producing an SB-loaded solid SNEDDS. The emulsion droplet size, solubility and dissolution of each emulsification process were compared to the solid SNEDDS fabricated without any treatment of additional emulsification. Moreover, the physicochemical properties of all formulations were compared. The crystalline state of the drug in all products was converted to the amorphous state. The solid SNEDDS, subjected to HPH technique, provided fine and well-dispersed nanoemulsion. Additionally, it increasingly improved the drug solubility and dissolution as compared to the others, including SB powder, non-treated (NT) and SPG. Furthermore, it gave improved C_max and increased AUC compared to SB powder and SPG, indicating HPH enhanced the oral bioavailability of SB the most. Thus, this solid SNEDDS with HPH would be strongly suggested as an oral SB-loaded pharmaceutical product.

Development of novel tenofovir disoproxil phosphate salt with stability enhancement and bioequivalence to the commercial tenofovir disoproxil fumarate salt in rats and beagle dogs

Tenofovir disoproxil (TD) is very unstable in the solid state under storage conditions. Moreover, tenofovir disoproxil fumarate (TDF), a commercial salt, is chemically unstable in alkaline solution. In this study, a novel tenofovir disoproxil phosphate (TDP), with stability enhancement and bioequivalence to commercial TDF in rats and beagle dogs, has been developed as an alternative. The TDP and its tablets were easily manufactured, and its physicochemical properties, such as morphology, crystallinity, solubility, lipophilicity and stability were investigated and compared to TD and TDF. Its dissolution and pharmacokinetics were investigated in rats and beagle dogs in comparison to TD and TDF. TDP appeared as an irregularly-shaped crystalline powder with a rough surface, like TDF. However, TDP significantly improved the solubility (7.4 ± 1.3 vs. 28.6 ± 1.0 mg/ml), hydrophilicity (Log P, 0.58 ± 0.03 vs. 0.47 ± 0.04), and aqueous stability (drug concentration over 12 h at pH 6.8 84.0 ± 2.0% vs. 88.2 ± 1.5%) of TD compared to TDF. The TDP gave no significant different plasma concentrations, AUC and C_max compared to TDF in rats (AUC, 1242.1 ± 584.9 vs. 825.9 ± 79.5 h·ng/ml; C_max, 154.8 ± 25.4 vs. 210.9 ± 70.3 ng/ml). Moreover, the TDP-loaded tablets were stable for at least six months and provided similar dissolution and bioequivalence to the TDF-loaded commercial product in beagle dogs (AUC, 26,832.7 ± 4093.0 vs. 26,605.3 ± 2530.1 h·ng/ml; C_max, 4364.0 ± 2061.9 vs. 4186.3 ± 2616.5 ng/ml). Therefore, as an alternative salt, the TDP would be a recommendable candidate with stability enhancement and bioequivalence to the commercial TDF.

Spray-Dried Amorphous Solid Dispersions of Atorvastatin Calcium for Improved Supersaturation and Oral Bioavailability

Over the past few decades, the amorphous solid dispersions (ASDs) technique has emerged as a promising strategy to enhance the in vitro/in vivo characteristic of hydrophobic drugs. The low aqueous solubility and poor bioavailability of atorvastatin calcium (ATO), a lipid-lowering drug, present challenges for effective drug delivery. The objective of this work was to improve the aqueous solubility, in vitro dissolution, and oral absorption of ATO with amorphous solid dispersion technique prepared by spray-drying method. The optimized ternary formulation comprising of ATO; hydroxypropyl methylcellulose (HPMC), as a hydrophilic polymer; and sodium lauryl sulfate (SLS), as a surfactant, at a weight ratio of 1/1/0.1, showed significant improvement in aqueous solubility by ~18-fold compared to that of the free drug, and a cumulative release of 94.09% compared to a release of 59.32% of the free drug. Further, physicochemical studies via scanning electron microscopy, differential scanning calorimetry, and powder X-ray diffraction revealed a change from the crystalline state of the free drug to its amorphous state in the ASD. Pharmacokinetic analysis in rats demonstrated 1.68- and 2.39-fold increments in AUC and Cmax, respectively, in the ASD over the free drug. Altogether, hydrophilic carrier-based ASDs prepared by the spray-drying technique represent a promising strategy to improve the biopharmaceutical performance of poorly soluble drugs.