An Albumin-Enriched Nanocomplex Achieves Systemic Delivery of Clopidogrel Bisulfate to Ameliorate Renal Ischemia Reperfusion Injury in Rats.

Herein, an albumin-enriched nanocomplex was developed for the solubilization and intravascular administration of clopidogrel bisulfate (CLP). In particular, CLP nanoparticles (HS-CLP-NPs) were synthesized via an improved nab-technology method using Solutol HS-15, and bovine serum albumin (BSA) was further enriched on the nanoparticle surface forming a protein corona (BH-CLP-NPs). BH-CLP-NPs displayed an average size of 163.4 ± 10.5 nm, a zeta potential of 1.85 ± 0.03 mV, an encapsulation efficiency of 99.9%, and a drug loading capacity of 32.9%. The cumulative release of CLP from BH-CLP-NPs reached about 60% within 168 h. The pharmacokinetic study on the CLP metabolite indicated that the BSA-enriched nanoparticle showed greater in vivo exposure. Pharmacodynamic studies in the renal ischemia/reperfusion injury rat model further demonstrated the renal protective effect of systemically administered BH-CLP-NPs against acute kidney injury with significantly downregulated blood urea nitrogen and creatinine levels. Overall, the albumin-enriched nanocomplexes offer a neat and efficient strategy for the development of poorly water-soluble drugs to achieve intravascular administration.

Effect of Different Absorption Enhancers on the Nasal Absorption of Nalmefene Hydrochloride.

The purpose of this work is to explore the effects of novel absorption enhancers on the nasal absorption of nalmefene hydrochloride (NMF). First, the influence of absorption enhancers with different concentrations and types and drug concentrations on the nasal absorption of NMF was investigated in vivo in rats. The absorption enhancers studied include n-dodecyl-ß-D-maltoside (DDM), hydroxypropyl-ß-cyclodextrin (HP-ß-CD), and polyethylene glycol (15)-hydroxy Stearate (Solutol®HS15). At the same time, the in situ toad palate model and rat nasal mucosa model were used to assess the cilia toxicity. The results showed that all the absorption enhancers investigated significantly promote the nasal absorption of NMF, but with different degrees and trends. Among them, the 0.5% (w/v) DDM had the strongest enhancement effect, followed by 0.5% (w/v) Solutol®HS15, 0.25% (w/v) DDM, 0.25% (w/v) Solutol®HS15, 0.1% (w/v) Solutol®HS15, 0.1% (w/v) DDM, and 0.25% (w/v) HP-ß-CD, with absolute bioavailability of 76.49%, 72.14%, 71.00%, 69.46%, 60.41%, 59.42%, and 55.18%, respectively. All absorption enhancers exhibited good safety profiles in nasal ciliary toxicity tests. From the perspective of enhancing effect and safety, we considered DDM to be a promising nasal absorption enhancer. And in addition to DDM, Solutol®HS15 can also promote intranasal absorption of NMF, which will provide another option for the development of nalmefene hydrochloride nasal spray.

Self-Assembled Micelles Improve the Oral Bioavailability of Dihydromyricetin and Anti-Acute Alcoholism Activity.

Dihydromyricetin (DMY) is highly effective in counteracting acute alcohol intoxication. However, its poor aqueous solubility and permeability lead to the low oral bioavailability and limit its clinic application. The aim of this work is to use Solutol®HS15 (HS 15) as surfactant to develop novel micelle to enhance the oral bioavailability of DMY by improving its solubility and permeability. The DMY-loaded Solutol®HS15 micelles (DMY-Ms) were prepared by the thin-film hydration method. The particle size of DMY-Ms was 13.97 ± 0.82 nm with an acceptable polydispersity index of 0.197 ± 0.015. Upon entrapped in micelles, the solubility of DMY in water was increased more than 25-fold. The DMY-Ms had better sustained release property than that of pure DMY. In single-pass intestinal perfusion models, the absorption rate constant (Ka) and permeability coefficient (Papp) of DMY-Ms were 5.5-fold and 3.0-fold than that of pure DMY, respectively. The relative bioavailability of the DMY-Ms (AUC0-∞) was 205% compared with that of pure DMY (AUC0-∞), indicating potential for clinical application. After administering DMY-Ms, there was much lower blood alcohol level and shorter duration of the loss of righting relax (LORR) in drunk animals compared with that treated by pure DMY. In addition, the oral administration of DMY-Ms greatly reduced oxidative stress, and significantly defended liver and gastric mucosa from alcoholic damages in mice with alcohol-induced tissue injury. Taken together, HS 15-based micelle system greatly improves the bioavailability of DMY and represents a promising strategy for the management of acute alcoholism. Graphical abstract.

Thymoquinone-Loaded Soluplus®-Solutol® HS15 Mixed Micelles: Preparation, In Vitro Characterization, and Effect on the SH-SY5Y Cell Migration.

Thymoquinone (TQ) is the main active ingredient of Nigella sativa essential oil, with remarkable anti-neoplastic activities with anti-invasive and anti-migratory abilities on a variety of cancer cell lines. However, its poor water solubility, high instability in aqueous solution and pharmacokinetic drawbacks limits its use in therapy. Soluplus® and Solutol® HS15 were employed as amphiphilic polymers for developing polymeric micelles (SSM). Chemical and physical characterization studies of micelles are reported, in terms of size, homogeneity, zeta potential, critical micelle concentration (CMC), cloud point, encapsulation efficiency (EE%), load capacity (DL), in vitro release, and stability. This study reports for the first time the anti-migratory activity of TQ and TQ loaded in SSM (TQ-SSM) in the SH-SY5Y human neuroblastoma cell line. The inhibitory effect was assessed by the wound-healing assay and compared with that of the unformulated TQ. The optimal TQ-SSM were provided with small size (56.71 ± 1.41 nm) and spherical shape at ratio of 1:4 (Soluplus:Solutol HS15), thus increasing the solubility of about 10-fold in water. The entrapment efficiency and drug loading were 92.4 ± 1.6% and 4.68 ± 0.12, respectively, and the colloidal dispersion are stable during storage for a period of 40 days. The TQ-SSM were also lyophilized to obtain a more workable product and with increased stability. In vitro release study indicated a prolonged release of TQ. In conclusion, the formulation of TQ into SSM allows a bio-enhancement of TQ anti-migration activity, suggesting that TQ-SSM is a better candidate than unformulated TQ to inhibit human SH-SY5Y neuroblastoma cell migration.

A Novel Gel-Forming Solution Based on PEG-DSPE/Solutol HS 15 Mixed Micelles and Gellan Gum for Ophthalmic Delivery of Curcumin.

Curcumin (Cur) is a naturally hydrophobic polyphenol with potential pharmacological properties. However, the poor aqueous solubility and low bioavailability of curcumin limits its ocular administration. Thus, the aim of this study was to prepare a mixed micelle in situ gelling system of curcumin (Cur-MM-ISG) for ophthalmic drug delivery. The curcumin mixed micelles (Cur-MMs) were prepared via the solvent evaporation method, after which they were incorporated into gellan gum gels. Characterization tests showed that Cur-MMs were small in size and spherical in shape, with a low critical micelle concentration. Compared with free curcumin, Cur-MMs improved the solubility and stability of curcumin significantly. The ex vivo penetration study revealed that Cur-MMs could penetrate the rabbit cornea more efficiently than the free curcumin. After dispersing the micelles in the gellan gum solution at a ratio of 1:1 (v/v), a transparent Cur-MM-ISG with the characteristics of a pseudoplastic fluid was formed. No obvious irritations were observed in the rabbit eyes after ocular instillation of Cur-MM-ISG. Moreover, Cur-MM-ISG showed a longer retention time on the corneal surface when compared to Cur-MMs using the fluorescein sodium labeling method. These findings indicate that biocompatible Cur-MM-ISG has great potential in ophthalmic drug therapy.

The role of organic anion-transporting polypeptides and formulation in the clearance and distribution of a novel Nav 1.7 channel blocker.

PF-06456384 is an extremely potent and selective blocker of the Nav 1.7 sodium channel designed as a potential intravenous (i.v.) analgesic targeting high potency and rapid clearance to minimize the potential for residual effects following the end of infusion. In our previous experience targeting oral molecules, the requirement to obtain potent, Nav 1.7 selective molecules led to a focus on acidic, amphipilic compounds cleared primarily by organic anion-transporting polypeptide mediated hepatic uptake and subsequent biliary excretion. However, the physicochemical properties of the i.v. lead matter were substantially different, moving from acidic, amphiphilic chemical space to zwitterions as well as substantially increasing molecular weight. This report describes the continued relevance of organic anion-transporting polypeptide driven hepatic uptake in this physicochemical space and highlights an apparent impact of the formulation excipient Solutol on the clearance and distribution of PF-06456384.

Preparation and evaluation of curcumin-loaded self-assembled micelles.

OBJECTIVE: Curcumin being used to treat various chronic diseases while its poor bioavailability issue limited its wide clinical application as a therapeutic agent. The aim of this work was to prepare curcumin-loaded self-assembled micelles using soluplus and solutol®HS15 (SSCMs) to enhance curcumin's solubility and thus oral bioavailability. METHODS: Optimum formulation was investigated and the optimized ratio of drugs and excipients was obtained and the SSCMs were prepared via ethanol solvent evaporation method. The optimal SSCMs were characterized by transmission electron microscopy, drug content analysis including loading efficiency (LE%) and entrapment efficiency (EE%), and the cumulative amount of curcumin released from the micelles were all calculated using HPLC method. The in vitro cytotoxicity and the permeability of SSCMs were measured by Caco-2 cell monolayers and the oral bioavailability was evaluated by SD rats. KEY FINDINGS: The solubility of curcumin in self-assembled micelles was dramatically increased by 4200 times as compared to free curcumin. Caco-2 cells transport experiment exhibited that while soluplus and solutol®HS15 were self-assembled into micelles, it could not only promote the permeability of curcumin across membrane for better absorption, but also could restrain the curcumin pumped outside due to the role of P-gp efflux mechanism of soluplus and solutol®HS15. Furthermore, the prepared SSCMs formulation was almost nontoxic and had safety performance on Caco-2 cells model. Moreover, curcumin's oral bioavailability of SSCMs formulation in SD rats had doubled than that of free curcumin. CONCLUSIONS: The prepared SSCMs were characterized by PS, PDI, LE%, EE% data analysis. After the soluplus and solutol®HS15 were self assembled into micelles, both the solubility and membrane permeability of curcumin were evaluated to have been enhanced, as well as the effect of efflux pump of curcumin was inhibited, hence to promote oral absorption and generate an increased bioavailability.

Preparation and Optimization Lipid Nanocapsules to Enhance the Antitumor Efficacy of Cisplatin in Hepatocellular Carcinoma HepG2 Cells.

This work aimed to develop and optimize several lipid nanocapsule formulations (LNCs) to encapsulate cisplatin (CDDP) for treatment of hepatocellular carcinoma. By comparing the effect of oil/surfactant ratio, lecithin content, and oil/surfactant type on LNC characteristics, two LNCs were selected as optimal formulations: HS15-LNC (Solutol HS 15/MCT/lecithin, 54.5:42.5:3%, w/w) and EL-LNC (Cremophor EL/MCT/lecithin, 54.5:42.5:3%, w/w). Both LNCs could effectively encapsulate CDDP with the encapsulation efficiency of 73.48 and 78.84%. In vitro release study showed that both LNCs could sustain the release CDDP. Moreover, cellular uptake study showed that C6-labeled LNCs could be effectively internalized by HepG2 cells. Cellular cytotoxicity study revealed that both LNCs showed negligible cellular toxicity when their concentrations were below 313 µg/mL. Importantly, CDDP-loaded LNCs exhibited much stronger cell killing potency than free CDDP, with the IC50 values decreased from 17.93 to 3.53 and 5.16 µM after 72-h incubation. In addition, flow cytometric analysis showed that the percentage of apoptotic cells was significantly increased after treatment with LNCs. Therefore, the prepared LNC formulations exhibited promising anti-hepatocarcinoma effect, which could be beneficial to hepatocellular carcinoma therapy.

Capmul MCM/Solutol HS15-Based Microemulsion for Enhanced Oral Bioavailability of Rebamipide.

Rebamipide (RBP) is a potent anti-ulcer and anti-oxidative agent, which is a BCS class IV drug with a low oral bioavailability of less than 10%. Thus, the systemic absorption of RBP into the blood circulation is an essential prerequisite for exerting its pharmacological activities after oral dosing. Herein, we report on microemulsion (ME) systems for the enhancement of oral RBP bioavailability. In this study, MEs consisting of Capmul MCM (oil), Solutol HS15 (surfactant), and ethanol (co-surfactant) were prepared by the construction of pseudo-ternary phase diagram. The RBP-loaded MEs had spherical nano-sized droplets with narrow size distribution and neutral zeta potential. Moreover, the prepared MEs significantly enhanced the dissolution and oral bioavailability of RBP with no discernible intestinal toxicity. These results suggest that the present ME system could be further developed as an alternative oral formulation for RBP.

Development of cyclosporine A microemulsion for parenteral delivery.

The goal of this study was to develop a parenteral microemulsion formulation of cyclosporine A (CyA). The CyA solubility in caprylic capric triglyceride (GTCC), ethyl oleate and soybean oil were determined. The pseudo-ternary diagrams of oil (GTCC), surfactant (Solutol® HS-15), cosurfactants (ethanol/polyethylene glycol 400 [PEG 400] mixture) and water were constructed to identify boundaries for microemulsion existence. The CyA was added at 3, 6 and 9% w/w to the optimal microemulsion composition. Microemulsion particle size, solution viscosity and conductivity were examined. The microemulsion stability and haemolytic potential were examined after dilution in 5% dextrose solution for injection to 1 mg/mL CyA. Microemulsion stability was examined after a three-month storage at 4 and 25 °C. The GTCC was selected as an oil phase for CyA microemulsion based on solubility results. The optimum CyA microemulsion formulation consisted of 2.5% CyA, 9% GTCC, 24% Solutol® HS 15, 8% PEG 400, 4% ethanol and 52.5% water based on weight percent. The average particle sizes of the optimized blank and drug-loaded microemulsions were 68.7 nm and 71.6 nm, respectively and remained unchanged upon 25-fold dextrose dilution. The results of microemulsion physical and CyA chemical were confirmed by a three-month stability study at 4 and 25 °C. In vitro haemolysis studies indicated that CyA microemulsions were well tolerated by erythrocytes. The novel microemulsion formulation of CyA was developed that is suitable for parenteral administration. This new formulation could potentially have less vehicle-associated side effects that current commercial formulation of CyA based on Cremophor® EL and ethanol solution.

Enhanced brain distribution of Ginsenoside F1 via intranasal administration in combination with absorption enhancers.

Ginsenoside F1 (GF1) is a potential drug candidate for the treatment of Alzheimer's disease. Nevertheless, its low oral bioavailability and poor solubility limit clinical application. By utilizing either a direct or indirect approach, intranasal administration is a non-invasive drug delivery method that can deliver drugs to the brain rapidly. But large molecule drug delivered to the brain through intranasal administration may be insufficient to reach required concentration for therapeutic effect. In this study, using GF1 as a model drug, the feasibility of intranasal administration in combination with absorption enhancers to increase brain distribution of GF1 was explored. First of all, the appropriate absorption enhancers were screened by in situ nasal perfusion study. GF1-HP-ß-CD inclusion complex was prepared and characterized. Thereafter, in vivo absorption of GF1 after intranasal or intravenous administration of its inclusion complex with/without absorption enhancers was investigated, and safety of the formulations was evaluated. The results showed that 2% Solutol HS 15 was a superior absorption enhancer. HP-ß-CD inclusion complex improved GF1 solubility by 150 fold. Following intranasal delivery, the absolute bioavailability of inclusion complex was 46%, with drug brain targeting index (DTI) 247% and nose-to-brain direct transport percentage (DTP) 58%. Upon further addition of 2% Solutol HS 15, the absolute bioavailability was increased to 75%, with DTI 315% and DTP 66%. Both nasal cilia movement and biochemical substances (total protein and lactate dehydrogenase) leaching studies demonstrated 2% Solutol HS 15 was safe to the nasal mucosa. In conclusion, intranasal administration combining with safe absorption enhancers is an effective strategy to enhance drug distribution in the brain, showing promise for treating disorders related to the central nervous system.

Effects of Solutol (Kolliphor) and cremophor in polyethylene glycol 400 vehicle formulations in Sprague-Dawley rats and beagle dogs.

When conventional vehicles (eg, methylcellulose and water) impart inadequate physical, chemical, and/or biological properties for proper toxicological assessment of test article formulations, nonconventional vehicles may be considered. Often toxicity data for nonconventional vehicle formulations are limited. Studies were conducted to collect toxicity data from a rodent and a non-rodent species given 2 nonconventional vehicles, Solutol HS15/polyethylene glycol (PEG) 400 and Cremophor RH40/PEG 400, with differing formulations and dose volumes (10 mL/kg for rats; 2 or 5 mL/kg for dogs). In rats, both vehicles caused increase in kidney weights (males only) and decrease in thymic weights (males only) without concurrent microscopic findings; altered urine electrolytes, minimally decreased serum electrolytes (males only), and increased serum total cholesterol (females only) were also present. The Cremophor formulation was also associated with increased serum urea (males only) and urine phosphorus: creatinine. For rats given the Solutol formulation, both genders had decreased urine glucose parameters and males had increased urine volume. In dogs, loose/watery feces and emesis were present given either vehicle, and mucus-cell hyperplasia of the ileum was present given the Solutol formulation. Increased red blood cell mass and decreased urine volume in dogs given 30% Solutol/70% PEG 400 (5 mL/kg/d) were likely due to subclinical dehydration and hemoconcentration. For the Cremophor formulations, dose volume-dependent increased incidence of minimal subepithelial gastric hemorrhage was noted in dogs, and dogs given 5 mL/kg/d showed increased serum urea nitrogen. Overall, regardless of the formulation or dose volume, neither vehicle produced overt toxicity in either species, but the Solutol formulation produced fewer effects in rats. Generally, lower dose volumes minimized the severity and/or incidence of findings.

Enhanced delivery of the phototherapeutic nanoparticles via hepatocyte overload.

Phototherapeutic nanoparticles (NPs) were prepared with methylene blue (MB), indocyanine green (ICG), and Solutol through self-assembly. Generation of reactive oxygen species and elevation of temperature were observed that verify the photodynamic/photothermal effects of the NPs. Morphology and size distribution of the NPs were examined by transmittance electron microscopy and dynamic light scattering. The biodistribution of the NPs and their antitumor efficacy were examined using tumor-bearing mice to understand the phototherapeutic effect of the NPs on tumors. To enhance targetability with enhanced therapeutic efficacy, empty NPs (Solutol nanoparticles without MB and ICG) at different concentrations were injected along with the phototherapeutic NPs. Enhanced delivery of the phototherapeutic NPs at the tumor site was examined based on hepatocyte overload.

Physicochemical Characterization and Pharmacological Evaluation of Novel Propofol Micelles with Low-Lipid and Low-Free Propofol.

We developed safe and stable mixed polymeric micelles with low lipids and free propofol for intravenous administration, to overcome the biological barrier of the reticuloendothelial system (RES), reduce pain upon injection, and complications of marketed propofol formulation. The propofol-mixed micelles were composed of distearoyl-phosphatidylethanolamine-methoxy-poly (ethylene glycol 2000) (DSPE mPEG2k) and Solutol HS 15 and were optimized using Box Behnken design (BBD). The optimized formulation was evaluated for globule size, zeta potential, loading content, encapsulation efficiency, pain on injection, histological evaluation, hemolysis test, in vivo anesthetic action, and pharmacokinetics, in comparison to the commercialized emulsion Diprivan. The optimized micelle formulation displayed homogenous particle sizes, and the free drug concentration in the micelles was 60.9% lower than that of Diprivan. The paw-lick study demonstrated that propofol-mixed micelles significantly reduced pain symptoms. The anesthetic action of the mixed micelles were similar with the Diprivan. Therefore, we conclude that the novel propofol-mixed micelle reduces injection-site pain and the risk of hyperlipidemia due to the low content of free propofol and low-lipid constituent. It may be a more promising clinical alternative for anesthetic.

Increased antitumor efficacy of ginsenoside Rh2 via mixed micelles: in vivo and in vitro evaluation.

The aim of this work is to apply Solutol® HS15 and TPGS to prepare self-assembled micelles loading with ginsenoside Rh2 to increase the solubility of ginsenoside Rh2, hence, improving the antitumor efficacy. Ginsenoside Rh2-mixed micelles (Rh2-M) were prepared by thin film dispersion method. The optimal Rh2-M was characterized by particle size, morphology, and drug encapsulation efficiency. The enhancement of in vivo anti-tumor efficacy of Rh2-M was evaluated by nude mice bearing tumor model. The solubility of Rh2 in self-assembled micelles was increased approximately 150-folds compared to free Rh2. In vitro results demonstrated that the particle size of Rh2-M is 74.72 ± 2.63 nm(PDI = 0.147 ± 0.15), and the morphology of Rh2-M is spherical or spheroid, and the EE% and LE% are 95.27 ± 1.26% and 7.68 ± 1.34%, respectively. The results of in vitro cell uptake and in vivo imaging showed that Rh2-M could not only increase the cell uptake of drugs, but also transport drug to tumor sites, prolonging the retention time. In vitro cytotoxicity and in vivo antitumor results showed that the anti-tumor effect of Rh2 can be effectively improved by Rh2-M. Therefore, Solutol® HS15 and TPGS could be used to entrapping Rh2 into micelles, enhancing solubility and antitumor efficacy.

Combined administration of PTX and S-HM-3 in TPGS/Solutol micelle system for oncotarget therapy.

BACKGROUND: S-HM-3 is a tumor angiogenesis inhibitor with short half-life (25 min). In this present, TPGS/Solutol polymeric micelles was prepared to load together insoluble paclitaxel (PTX) and soluble S-HM-3, expecting to together deliver them to the tumor site with long-circulating, targeting function and combating multi-drug resistance (MDR). MATERIALS AND METHODS: PTX and S-HM-3 loaded TPGS/Solutol micelles (PHTSm) were prepared by the method of thin-film evaporation, and characterized by dynamic light scattering, transmission electron microscope (TEM), atomic force microscopy (AFM) and releasing properties. The anticancer effect of the polymeric micelles system was evaluated and confirmed by experiments of in vitro cell uptake study, in vivo pharmacokinetics, and pharmacodynamics studies. RESULTS: Micelles exhibited smooth spherical morphology with 20~30 nm and low critical micelle concentration (CMC) value of 0.000124 mg/mL. Only about 30% of PTX were slowly released from micelles at 48h, which can beneficial to the long circulation in blood. The results of in vitro cell assay proved that S-HM-3 could be easier to get into MDA-MB-231 cell, and its angiogenesis inhibition ability was also enhanced after integrating into micelles. In particular, the results of in vivo studies showed that the half-life of S-HM-3 and PTX was significantly prolonged 25.27 and 5.54 folds, and their AUC0-∞ was enhanced 129.78 and 15.65 times, respectively. Meanwhile 83.05% tumor inhibition rate of PHTSm was achieved compared with 59.99% of PTX. CONCLUSIONS: TPGS and Solutol micelles hold promising potential to resolve the conundrum of combined therapy of cytotoxic drug and angiogenesis inhibitor with different physicochemical property and anticancer mechanism in clinical use.

Enhancing the oral bioavailability of baicalein via Solutol® HS15 and Poloxamer 188 mixed micelles system.

OBJECTIVES: To increase the solubility of baicalein (BAI) by preparing BAI-micelles (BAI-M) with Solutol HS15 (HS15) and Poloxamer 188 (F68), thereby improving its oral bioavailability. METHODS: Baicalein micelles were prepared with HS15 and F68 by thin-film dispersion method and optimized by central composite design (CCD) approach. Physicochemical, in vitro release, Caco-2 cell transport and pharmacokinetic studies of BAI-M were performed. KEY FINDINGS: The optimal formulation showed spherical shape by characterization of the transmission electron microscope with average small size (23.14 ± 1.46 nm) and high entrapment efficiency (92.78±0.98%) and drug loading (6.45±1.54%). The in vitro release study of BAI-M showed a significantly sustained release pattern compared with free BAI. Caco-2 cell transport study demonstrated that high permeability of BAI was achieved after loading it into micelles. Meanwhile, pharmacokinetics study of BAI-M showed a 3.02-fold increase in relative oral bioavailability compared with free BAI. CONCLUSIONS: Based on our findings, we concluded that HS15 can be used as a carrier in this drug delivery system that includes F68, and BAI-M has great potential in improving solubility and oral bioavailability.

Novel bicephalous heterolipid based self-microemulsifying drug delivery system for solubility and bioavailability enhancement of efavirenz.

There is an increasing demand for new lipidic biocompatible and safe materials for self-microemulsifying drug delivery system (SMEDDS). The present work reports the synthesis, characterization, oral mucosal irritation study, and application of novel erucic acid ester of G0-PETIM dendron based bicephalous heterolipid (BHL) as an oil phase in SMEDDS using Efavirenz (EFA), a BCS class II drug with poor water solubility and poor bioavailability. Studies were conducted to optimize EFA SMEDDS using different ratios of the BHL as oil phase and surfactant: co-surfactant weight ratios (Km). At Km (1.5), the microemulsion was spontaneously formed in water with mean globule size of 22.78 ±â€¯0.25 nm and polydispersity index (PDI) of 0.23 ±â€¯0.031 with high drug loading efficiency of 80.35 ±â€¯3.1%. Standard stability tests were performed on EFA SMEDDS and the results indicated it to be highly stable. The in vitro dissolution profile of EFA SMEDDS showed >95% of the drug release within an hour and expectedly substantial enhancement in in vivo bioavailability was observed; almost 6-fold increase in bioavailability with parameters Cmax 5.2 µg/mL, Tmax 3 h, and AUC(0-∞) 23.48 µg/h/mL respectively as compared the plain suspension of the drug. In conclusion, the BHL can be used effectively as an oil phase in SMEDDS to enhance solubility and bioavailability of BCS Class II drugs. Further, it holds, in general, a great promise as a new excipient for solubility and bioavailability enhancements.

Soluplus micelles for acyclovir ocular delivery: Formulation and cornea and sclera permeability.

Nearly 20% of people affected by the herpes simplex virus (HSV) suffer from vision problems. The virus can infect all layers of the cornea or cause inflammatory diseases of the sclera. The aim of this work was to test whether encapsulation of acyclovir in Soluplus or Solutol polymeric micelles increases its solubility, corneal permeability and sclera penetration. The aqueous solubility of acyclovir is known to be low, and therefore approaches that increase both its solubility and ability to penetrate through the eye may favor the efficacy of the treatments. Copolymer dispersions (covering wide range of concentrations) were prepared in water and PBS 7.4 and characterized regarding size and Z-potential (close to zero). Solutol micelles increased their size when the drug was incorporated (135 vs. 19 nm), while Soluplus micelles showed little difference (137 nm). Only Soluplus micelles significantly enhanced acyclovir solubility and withstood dilution stability tests. Soluplus (12-20%) formulations showed a progressive increase in viscoelasticity as temperature rose, which may allow for easy dropping onto the eye and subsequent retention in the gel form. Drug permeability through bovine cornea and sclera was investigated in detail. Although similar permeability coefficients were recorded for the drug when applied as the free drug in solution or formulated in Soluplus micelles, the micelle formulation significantly shortened the permeation lag time through the cornea. Moreover, Soluplus micelles were advantageous compared to the drug solution in terms of greater amount of acyclovir accumulated in both cornea and sclera, and higher steady state flux. If compared with cornea, the amounts of drug permeated through the sclera were approx. 10 times greater, which opens the possibility of drug delivery to the posterior eye segment.

Improved oral bioavailability of magnolol by using a binary mixed micelle system.

The aim of this study was to prepare two novel magnolol (MO)-loaded binary mixed micelles (MO-M) using biocompatible copolymers of Soluplus (SOL) and Solutol® HS15 (HS15), SOL and d-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS), to improve magnolol's poor solubility and its oral bioavailability. The organic solvent evaporation method was used to obtain two MO-M by optimization; one was prepared by using SOL and HS15 (MO-H), and the other was prepared by using SOL and TPGS (MO-T). The entrapment efficiency (EE%) and drug loading (DL%) of MO-T were 94.61 ± 0.91% and 4.03 ± 0.19%, respectively, and the MO-H has higher EE% and DL% (98.37 ± 1.23%, 4.12 ± 0.16%). TEM results showed that the morphology of MO-M was homogeneous and was spherical in shape. The dilution stability of MO-M did not undergo significant changes. Permeability of MO-M across a Caco-2 cell monolayer was enhanced in Caco-2 cell transport models. The pharmacokinetics study showed that the relative oral bioavailability of MO-T and MO-H increased by 2.39- and 2.98-fold, respectively, compared to that of raw MO. This indicated that MO-H and MO-T could promote absorption of MO in the gastrointestinal tract. Collectively, the mixed micelles demonstrated greater efficacy as a drug delivery system. The development of these novel mixed micelles is valuable for resolving the poor solubility and bioavailability of drugs.