Comparison of in vivo pharmacokinetic behaviors of R- and S-flurbiprofen after intravenous injection of flurbiprofen axetil.

Flurbiprofen axetil (FA) is a prodrug of flurbiprofen (FP), and it is hydrolyzed to the active FP by carboxylesterase in plasma after intravenous injection. The pharmacological action of FP is closely related to its chirality, and S-FP shows better analgesic effects than R-FP. Therefore, it is of great significance to compare the in vivo pharmacokinetic behaviors of R-FP and S-FP. In this study, we designed a sensitive high performance liquid chromatography-tandem mass spectrometry method and used CHIRALPAK-IG3 column for chiral separation to quantify the concentrations of R-FP and S-FP in rat plasma. The results show that this method can accurately and effectively analyze the contents of R-FP and S-FP in plasma. In addition, the systemic exposure was approximately 3.09-folds for the S-FP compared with the R-FP following intravenous administration of the FA to rats at a single dose of 4.5 mg/kg. More importantly, the clearance rate of S-FP is significantly smaller than that of R-FP. Therefore, the development of S-FA injectable emulsion for clinical treatment of postoperative pain is very necessary.

Physiologically based pharmacokinetic (PBPK) modeling of flurbiprofen in different CYP2C9 genotypes.

The aim of this study was to establish the physiologically based pharmacokinetic (PBPK) model of flurbiprofen related to CYP2C9 genetic polymorphism and describe the pharmacokinetics of flurbiprofen in different CYP2C9 genotypes. PK-Sim® software was used for the model development and validation. A total of 16 clinical pharmacokinetic data for flurbiprofen in different CYP2C9 genotypes, dose regimens, and age groups were used for the PBPK modeling. Turnover number (kcat) of CYP2C9 values were optimized to capture the observed profiles in different CYP2C9 genotypes. In the simulation, predicted fraction metabolized by CYP2C9, fraction excreted to urine, bioavailability, and volume of distribution were similar to previously reported values. Predicted plasma concentration-time profiles in different CYP2C9 genotypes were visually similar to the observed profiles. Predicted AUCinf in CYP2C9*1/*2, CYP2C9*1/*3, and CYP2C9*3/*3 genotypes were 1.44-, 2.05-, and 3.67-fold higher than the CYP2C9*1/*1 genotype. The ranges of fold errors for AUCinf, Cmax, and t1/2 were 0.84-1.00, 0.61-1.22, and 0.74-0.94 in development and 0.59-0.98, 0.52-0.97, and 0.61-1.52 in validation, respectively, which were within the acceptance criterion. Thus, the PBPK model was successfully established and described the pharmacokinetics of flurbiprofen in different CYP2C9 genotypes, dose regimens, and age groups. The present model could guide the decision-making of tailored drug administration strategy by predicting the pharmacokinetics of flurbiprofen in various clinical scenarios.

N-acetylcysteine functionalized chitosan oligosaccharide-palmitic acid conjugate enhances ophthalmic delivery of flurbiprofen and its mechanisms.

An N-acetylcysteine functionalized chitosan oligosaccharide-palmitic acid conjugate (NAC-COS-PA) with bioadhesive and permeation promoting properties was synthesized to enhance transocular drug delivery. Flurbiprofen (FB) loaded self-assembled NAC-COS-PA nanomicelles (NAC-COS-PA-FB) were prepared and the drug loading was 7.35 ± 0.32%. Human immortalized corneal epithelial (HCE-T) cell cytotoxicity and hen's egg test-chorioallantoic membrane assays confirmed that the conjugate had good biocompatibility. The transportation efficiency of coumarin-6 (C6) loaded nanomicelles in the HCE-T cell monolayer was approximately 1.97 times higher than that of free C6. Decreased intracellular Ca2+ concentration and cell membrane potential, increased cell membrane fluidity, and reversible changes in the F-actin cytoskeleton are presumed to be responsible for the enhanced drug permeation. NAC-COS-PA exhibited strong binding capacity with mucin and rabbit eyeball. In vivo pharmacokinetics indicated that the area under the curve (AUC0-6 h) and the maximum concentration (Cmax) of NAC-COS-PA-FB were approximately 1.92 and 2.44 times that of the FB solution, respectively. NAC-COS-PA-FB demonstrated the best in vivo anti-inflammatory efficacy compared to unfunctionalized nanomicelles (COS-PA-FB) and FB solution. Consequently, NAC-COS-PA appears to be a promising bioadhesive carrier for ophthalmic delivery.

Liver Cirrhosis Affects the Pharmacokinetics of the Six Substrates of the Basel Phenotyping Cocktail Differently.

BACKGROUND: Activities of hepatic cytochrome P450 enzymes (CYPs) are relevant for hepatic clearance of drugs and known to be decreased in patients with liver cirrhosis. Several studies have reported the effect of liver cirrhosis on CYP activity, but the results are partially conflicting and for some CYPs lacking. OBJECTIVE: In this study, we aimed to investigate the CYP activity in patients with liver cirrhosis with different Child stages (A-C) using the Basel phenotyping cocktail approach. METHODS: We assessed the pharmacokinetics of the six compounds and their CYP-specific metabolites of the Basel phenotyping cocktail (CYP1A2: caffeine, CYP2B6: efavirenz, CYP2C9: flurbiprofen, CYP2C19: omeprazole, CYP2D6: metoprolol, CYP3A: midazolam) in patients with liver cirrhosis (n = 16 Child A cirrhosis, n = 15 Child B cirrhosis, n = 5 Child C cirrhosis) and matched control subjects (n = 12). RESULTS: While liver cirrhosis only marginally affected the pharmacokinetics of the low to moderate extraction drugs efavirenz and flurbiprofen, the elimination rate of caffeine was reduced by 51% in patients with Child C cirrhosis. For the moderate to high extraction drugs omeprazole, metoprolol, and midazolam, liver cirrhosis decreased the elimination rate by 75%, 37%, and 60%, respectively, increased exposure, and decreased the apparent systemic clearance (clearance/bioavailability). In patients with Child C cirrhosis, the metabolic ratio (ratio of the area under the plasma concentration-time curve from 0 to 24 h of the metabolite to the parent compound), a marker for CYP activity, decreased by 66%, 47%, 92%, 73%, and 43% for paraxanthine/caffeine (CYP1A2), 8-hydroxyefavirenz/efavirenz (CYP2B6), 5-hydroxyomeprazole/omeprazole (CYP2C19), α-hydroxymetoprolol/metoprolol (CYP2D6), and 1'-hydroxymidazolam/midazolam (CYP3A), respectively. In comparison, the metabolic ratio 4-hydroxyflurbiprofen/flurbiprofen (CYP2C9) remained unchanged. CONCLUSIONS: Liver cirrhosis affects the activity of CYP isoforms differently. This variability must be considered for dose adjustment of drugs in patients with liver cirrhosis. CLINICAL TRIAL REGISTRATION: NCT03337945.

Enhanced Dermal Delivery of Flurbiprofen Nanosuspension Based Gel: Development and Ex Vivo Permeation, Pharmacokinetic Evaluations.

PURPOSE: The objective of this study was to optimize the Flurbiprofen (FB) nanosuspension (NS) based gel and to investigate the in vitro release, ex vivo permeation, the plasma concentration-time profile and pharmacokinetic parameters. METHODS: FB-NSs were developed using the wet milling process with the Design of Experiment (DoE) approach. The optimum FB-NS was characterized on the basis of SEM, DSC, XRPD, solubility and permeation studies. The dermal gel was prepared by incorporating FB-NS into HPMC gel. Then the in-vitro release, ex vivo permeation studies were performed, and pharmacokinetic studies were evaluated on rats. RESULTS: The particle size, polydispersity index and zeta potential values of optimum NS were determined as 237.7 ± 6.8 nm, 0.133 ± 0.030 and - 30.4 ± 0.7 mV, respectively. By means of the surfactant content and nanosized particles of the nanosuspension, the solubility of FB was increased about 7-fold. The percentage permeated amount of FB from FB-NS gel (8.40%) was also found to be higher than the physical mixture (5.25%) and coarse suspension (reference) (2.08%) gels. The pharmacokinetic studies showed that the Cmax of FB-NS gel was 2.5 times higher than the reference gel, while AUC0-24 was 2.96 times higher. CONCLUSION: FB-NSs were successfully prepared with a wet milling method and optimized with the DoE approach. The optimized FB nanosuspension gel provided better permeation and pharmacokinetic performance compared to FB coarse suspension gel.

Napabucasin Drug-Drug Interaction Potential, Safety, Tolerability, and Pharmacokinetics Following Oral Dosing in Healthy Adult Volunteers.

Napabucasin is an orally administered reactive oxygen species generator that is bioactivated by the intracellular antioxidant nicotinamide adenine dinucleotide phosphate:quinone oxidoreductase 1. Napabucasin induces cell death in cancer cells, including cancer stem cells. This phase 1 study (NCT03411122) evaluated napabucasin drug-drug interaction potential for 7 cytochrome P450 (CYP) enzymes and the breast cancer resistance protein transporter/organic anion transporter 3. Healthy volunteers who tolerated napabucasin during period 1 received probe drugs during period 2, and in period 3 received napabucasin (240 mg twice daily; days 1-11) plus a phenotyping cocktail containing omeprazole (CYP2C19), caffeine (CYP1A2), flurbiprofen (CYP2C9), bupropion (CYP2B6), dextromethorphan (CYP2D6), midazolam (CYP3A) (all oral; day 6), intravenous midazolam (day 7), repaglinide (CYP2C8; day 8), and rosuvastatin (breast cancer resistance protein/organic anion transporter 3; day 9). Drug-drug interaction potential was evaluated in 17 of 30 enrolled volunteers. Napabucasin coadministration increased the area under the plasma concentration-time curve from time 0 extrapolated to infinity (geometric mean ratio [90% confidence interval]) of caffeine (124% [109.0%-141.4%]), intravenous midazolam (118% [94.4%-147.3%]), repaglinide (127% [104.7%-153.3%]), and rosuvastatin (213% [42.5%-1068.3%]) and decreased the area under the plasma concentration-time curve from time 0 extrapolated to infinity of dextromethorphan (71% [47.1%-108.3%]), bupropion (79% [64.6%-97.0%]), and hydroxybupropion (45% [15.7%-129.6%]). No serious adverse events/deaths were reported. Generally, napabucasin is not expected to induce/inhibit drug clearance to a clinically meaningful degree.

Effect of deglucuronidation on the results of the Basel phenotyping cocktail.

We investigated the effect of deglucuronidation on the plasma concentration of the constituents of the Basel phenotyping cocktail and on the interpretation of the phenotyping results under basal conditions and after cytochrome P450 (CYP) induction with metamizole. The cocktail containing caffeine (CYP1A2), efavirenz (CYP2B6), flurbiprofen (CYP2C9), omeprazole (CYP2C19), metoprolol (CYP2D6) and midazolam (CYP3A4) was administered to 12 healthy subjects before (basal) and after treatment with metamizole for 1 week. In the basal state, deglucuronidation caused an increase in the plasma concentrations and area under the curve (AUC) of metoprolol, 8'-hydroxyefavirenz, 4'-hydroxyflurbiprofen and 1'-hydroxymidazolam. This effect could be visualized in Bland-Altman plots, where the values for 8'-hydroxyefavirenz, 4'-hydroxyflurbiprofen and 1'-hydroxymidazolam were mostly above the +20% threshold. As a result, the metabolic ratio (MR), calculated as AUCparent drug /AUCmetabolite , decreased with deglucuronidation for CYP2B6, CYP2C9 and CYP3A4 and increased for CYP2D6. Treatment with metamizole, a constitutive androstane receptor-dependent inducer of CYP2B6, CYP2C9, CYP2C19 and CYP3A4, accentuated the effect of deglucuronidation on AUC and MR. The correlation of MRs calculated as the plasma concentration ratio parent drug/metabolite with the MR calculated as the AUC ratio showed that 1 sample obtained between 2 and 6 hours after cocktail ingestion and analysed with and without deglucuronidation is sufficient to obtain reliable phenotyping results. Importantly, CYP2C9 and 3A4 induction would have been missed without deglucuronidation of the plasma samples. In conclusion, deglucuronidation of the plasma samples improves the stability of the phenotyping results of the Basel phenotyping cocktail and is necessary to reliably detect CYP induction.

Sustained-release hot melt extrudates of the weak acid TMP-001: A case study using PBB modelling.

Over the last 30 years, hot melt extrusion has become a leading technology in the manufacture of amorphous drug delivery systems. Mostly applied as an 'enabling formulation' for poorly soluble compounds, application in the design of sustained-release formulations increasingly attracts the attention of the pharmaceutical industry. The drug candidate TMP-001 is currently under evaluation for the early treatment of Multiple Sclerosis. Although this weak acid falls into class II of the Biopharmaceutics Classification System, the compound exhibits high solubility in the upper intestine resulting in high peroral bioavailability. In the present studies, four different formulation prototypes varying in their sustained-release behavior were developed, using L-arginine as a pore-forming agent in concentrations ranging between 0 and 20%. Initially, biorelevant release testing was applied to assess the dissolution behavior of the prototypes. For these formulations, a total drug release of 44.7%, 64.6%, 75%, and 90.5% was achieved in FaSSIF-v2 after 24 h. Two candidates were selected for further characterization considering the crystal structure and the physical stability of the amorphous state of TMP-001 in the formulations together with the release behavior in Level II biorelevant media. Our findings indicate L-arginine as a valuable excipient in the formulation of hot melt extrudates, as its presence led to a considerable stabilization of the amorphous state and favorably impacted the milling process and release behavior of TMP-001. To properly evaluate the proposed formulations and the importance of colonic dissolution and absorption on the overall bioavailability, a physiologically-based biopharmaceutics model was used.

Chiral 4-O-acylterpineol as transdermal permeation enhancers: insights of the enhancement mechanisms of a transdermal enantioselective delivery system for flurbiprofen.

In order to devise more effective penetration enhancers, 4-O-acylterpineol derivatives which were expected to be hydrolyzed into nontoxic metabolites by esterase in the living epidermis, were synthesized from 4-terpineol (4-TER) enantiomers and straight chain fatty acids. Their promoting activities on the SR-flurbiprofen and its enantiomers were tested across full-thickness rabbit skin, as well as to correlate under in vitro and in vivo conditions. The permeation studies indicated that both d-4-O-acylterpineol and l-4-O-acylterpineol had significant enhancing effects, interestingly, d-4-O-aclyterpineol had higher enhancing effects than l-4-O-aclyterpineol with the exception of d-4-methyl-1-(1-methylethyl)-3-cyclohexen-1-yl octadec-9-enoate (d-4-T-dC18). The mechanism of 4-O-acylterpineol facilitating the drug penetration across the skin was confirmed by Attenuated total reflection-Fourier transformed infrared spectroscopy (ATR-FTIR) and molecular simulation. The mechanism of penetration enhancers promoting drug release was explored by the in vitro release experiment. Finally, a relative safety skin irritation of enhancers was also investigated by in vivo histological evaluation. The present research suggested that d-4-O-aclyterpineol and l-4-O-aclyterpineol could significantly promote the penetration of SR-flurbiprofen and its enantiomers both in vitro and in vivo, with the superiorities of high flux and low dermal toxicity.

Fast off-line FPSE-HPLC-PDA determination of six NSAIDs in saliva samples.

A fast off-line FPSE-HPLC-PDA method has been reported that allows simultaneous clean up and determination of six non-steroidal anti-inflammatory drugs (NSAIDs) in saliva samples from healthy volunteers. Particularly, furprofen, indoprofen, ketoprofen, fenbufen, flurbiprofen, and ibuprofen were chromatographically resolved. Benzyl paraben was chosen as the internal standard (BzPB, IS). These target compounds were successfully extracted from human saliva using fabric phase sorptive extraction (FPSE) and then analysed in the liquid chromatographic system by means of a short analytical column (Symmetry C18, 75 × 4.6 mm, 3.5 µm) using acetonitrile (AcN) and phosphate buffer (PBS, 30 mM; pH = 2.5) as the mobile phases. The method, validated through the calculation of all analytical parameters in accordance of International Guidelines, was applied to real saliva sample analysis collected from informed volunteers. The proposed approach that included the use of sol-gel polytetrahydrofuran (sol-gel PTHF) sorbent immobilized on cellulose support and C18 stationary phase used in HPLC, showed high potential as a fast tool for future clinical and forensic applications. The herein reported results encourage potential future application of FPSE in the forensic field. Furthermore, the FPSE membrane was tested in dried saliva spot mode (DSS) in order to check its potential use as a sampling device, also for forensic applications.

Effect of different molecular weight PLGA on flurbiprofen nanoparticles: formulation, characterization, cytotoxicity, and in vivo anti-inflammatory effect by using HET-CAM assay.

Objective: The effect of polymers used in nanoparticle (NP) production on the formulation properties is one of the few studied issues. Therefore, this study aims to formulate flurbiprofen (FLB) loaded NPs with different molecular weight (Mw) poly lactic-co-glycolic acid (PLGA) and investigate the effect of Mw on NP character. One of the most important objectives is to provide a high anti-inflammatory effect with a low dose and the anti-inflammatory efficacy of the selected optimal formulation is to be determined by in vivo hen's egg test on Chorioallantoic Membrane (HET-CAM) analysis that a new, popular and in vivo animal experiment alternative method.Significance: To determine the anti-inflammatory efficacy of the optimum formulation by HET-CAM analysis. To the best of our knowledge, this is the first report on the in vivo anti-inflammatory evaluation of FLB-loaded PLGA NP using the in vivo HET-CAM assay.Methods: Blank and FLB-loaded PLGA NPs were prepared using a nanoprecipitation technique. The cell viability test for all formulation was performed with MTT in the NIH-3T3 mouse embryonic fibroblast cell line. The anti-inflammatory activity of optimum formulation (A6) was examined using the in vivo HET-CAM assay.Results: The particle sizes (PSs) of the FLB-loaded PLGA NPs were between 175 and 198 nm. The encapsulation efficiency (EE%) was a range of 82-93%. In vitro release of NPs showed extended-release up to 144 h. The release kinetics were fitted to the Peppas-Sahlin and Weibull models. The results showed that PS, PDI, EE%, and release rates of NPs were directly related to the Mw of PLGA. There is no statistically significant difference in cell viability study was observed between blank and FLB-loaded PLGA NPs. The in vivo anti-inflammatory activity results indicated that A6 coded formulation was showed significantly good anti-inflammatory potential at low dose.Conclusions: It could be concluded that FLB-loaded NPs seem to be a promising extended-release drug delivery system for oral administration with a low dose and high efficiency.

Development of galangal essential oil-based microemulsion gel for transdermal delivery of flurbiprofen: simultaneous permeability evaluation of flurbiprofen and 1,8-cineole.

Flurbiprofen (FP) is one of the most potent nonsteroidal anti-inflammatory drugs with very low bioavailability of approximately 12% following transdermal administration, compared to that after oral administration. This study aimed to deliver FP as a microemulsion (ME) gel by transdermal administration. Galangal essential oil (GEO) was extracted from Rhizoma Alpiniae Officinarum and identified by GC-MS. The most abundant constituent was determined to be 1,8-cineole (52.06%). Compared to azone, GEO was proved to exert significantly higher (p < .01) penetration enhancement effect and significantly (p < .001) lower skin cell toxicity. The formulation (FP-GEO-ME gel) was prepared using GEO as an oil phase and a penetration enhancer. Compared to that of FP solution, the enhancement ratio (ER) of FP-GEO-ME gel was 4.06. In addition, more than 25% 1,8-cineole permeated through the rat skin. In vivo pharmacokinetic studies revealed that the AUC0-t of FP after transdermal administration of FP-GEO-ME gel was higher by approximately 4.56-fold than that of marketed FP cataplasms. The relative bioavailability of FP and 1,8-cineole after transdermal administration compared to oral administration of FP-GEO-ME were determined to be 96.58% and 85.49%, respectively. FP-GEO-ME gel significantly inhibited carrageenan-induced hind-paw edema and decreased PGE2 levels in rat serum. GEO-ME gel also exhibited significant anti-inflammatory effects at 2 h after the therapy (p < .05). The synergistic effects of FP and GEO were expected for the application of FP-GEO-ME gel. In conclusion, GEO-ME gel may be a promising formulation for transdermal administration of anti-inflammatory hydrophobic drugs, such as FP.

Novel Liposome Aggregate Platform (LAP) system for sustained retention of drugs in the posterior ocular segment following intravitreal injection.

A novel Liposome Aggregate Platform (LAP) system for prolonged retention of drugs in the posterior eye segment after intravitreal injection (IVT) was developed and evaluated. Calcein, FITC-dextran-4000 (FD4) and Flurbiprofen (FLB), were encapsulated in negatively charged liposomes, and mixed with protamine to produce the LAP. The lipid/protamine ratio was fixed, in order to have a convenient aggregation rate permitting IVT injection and also a sustained release of liposome-entrapped molecules (in vitro) from LAP. In vitro release studies confirmed the potential of LAP system consisted of HPC/DPPG/Chol liposomes and protamine (at 1:1 w/w to lipid), to delay calcein, FD4 and FLB release, compared to free liposomes. In vivo studies demonstrated increased vitreous retention of liposomes and LAP for all molecules, compared to the corresponding solutions; however the retention of FD4 is similar for non-aggregated liposomes and LAP, and calcein retention is only slightly increased by LAP compared to liposomes. The later result may be connected with the visible ocular inflammation caused by both dyes; interestingly inflammation was moderately reduced when dyes were entrapped in liposomes and even more when in LAP. No visible inflammation was demonstrated for FLB, and the LAP system significantly increased the retention of FLB in the ocular tissues (compared to non-aggregated liposomes). Taking into account the capability of the novel LAP system to decrease inflammatory reactions towards calcein and FD4, and prolong the retention of FLB in ocular tissues, it is concluded that such systems, after further optimization, may be considered as promising effective and safe approaches for treatment of posterior segment ocular pathologies.

The effect of critical process parameters of the high pressure homogenization technique on the critical quality attributes of flurbiprofen nanosuspensions.

Flurbiprofen (FB) is an effective nonsteroidal anti-inflammatory and BCS class II drug and its poor solubility plays a critical role in limiting its bioavailability. Nanosuspensions can be defined as nanosized colloidal dispersions of drug particles stabilized with stabilizers. The solubility of poor soluble drugs can be increased thanks to their small size and large surface area. The aim of this study is to optimize FB nanosuspensions. The formulations were stabilized with Plantacare 2000® as a surfactant using a combination of High Speed Homogenization (HSH) and High Pressure Homogenization techniques (HPH). We also investigated the effects of the critical process parameters (CPPs) of these techniques (homogenization speed & time for HSH and homogenization pressure & cycle for HPH) on three critical quality attributes of nanosuspensions, being the particle size (PS), polydispersity index (PDI) and zeta potential (ZP). After the optimization of HSH, the macrosuspension was transferred to a high pressure homogenizer. After producing FB nanosuspensions by the HPH technique, seven processes which comprise different homogenization pressures, or combinations and different cycles, were applied. Due to the combination of HSH and HPH techniques and the optimization of CPPs, an optimum formulation for a dermal application was found using a 33 full factorial design with these process parameters, and characterization studies were also performed.

New approaches to tumor therapy with siRNA-decorated and chitosan-modified PLGA nanoparticles.

Objective: In this study, we aimed to develop a candidate modifited polymeric nanoparticle (NP) system that will kill cancer cells by facilitated to apoptosis and also reduce pain. Significance: The primary goal of treatment, especially for metastatic cancers, is to control the growth of the cancer and to alleviate the symptoms. Pain is one of the commonest symptoms of cancer. In cancer treatment, directing cancer cells to death while simultaneously relieving pain will be a new approach. Methods: Chitosan-modified PLGA NPs were prepared using an nanoprecipitation technique. The NPs were loaded with flurbiprofen and decorated with folic acid. STAT3-siRNA was adsorbed to these polymeric NPs using antisense technology. Results: The NPs were small in size (176.9-220.3 nm) with positive zeta potential (+14.1 mV to +27.2 mV). They had high loading capacity and prolonged release properties over 144 hours. Cytotoxicity studies performed with siRNA showed effective electrostatic interaction due to the positively charged NPs. Folic acid facilitated entry into cancer cells and helped to kill them. Conclusion: The formulation we developed is a potential carrier system for both treatment of cancer and prevention of pain, especially for metastatic cancers.

Extended delivery of non-steroidal anti-inflammatory drugs through contact lenses loaded with Vitamin E and cationic surfactants.

The purpose of this study is to extend drug release from ACUVUE Oasys® and ACUVUE TruEye® silicone hydrogel contact lenses by incorporation of vitamin E in conjunction with a cationic surfactant. In ACUVUE Oasys® and ACUVUE TruEye®, the release of ketorolac tromethamine and flurbiprofen sodium is extended from hours to several days for 11% and 21% vitamin E, (weight of vitamin E / weight of dry lens) but with a considerable reduction in the amount of drug released. Cetalkonium chloride and stearylamine increased the drug loading capacity which was otherwise compromised by the addition of vitamin E in the contact lenses. In the case of diclofenac sodium, a sustained release over 150 h for both contact lenses can be achieved. It was found that the release-time-increase factor due to vitamin E has a linear dependence with the octanol-water partition coefficient of the drug in ACUVUE Oasys®. The results in this study show that contact lenses loaded with vitamin E in conjunction with cationic surfactants achieved sustained release of non-steroidal anti-inflammatory drugs (NSAIDs) within the therapeutic window.

Discovery of 4'-OH-flurbiprofen Mannich base derivatives as potential Alzheimer's disease treatment with multiple inhibitory activities.

A series of 4'-OH flurbiprofen Mannich base derivatives were designed, synthesized and evaluated as potential multifunctional agents for the treatment of Alzheimer's disease. The biological screening results indicated that most of these derivatives exhibited good multifunctional activities. Among them, compound 8n demonstrated the best inhibitory effects on self-induced Aß1-42 aggregation (65.03% at 25.0 µM). Moreover, this representative compound also exhibited good antioxidant activity, biometal chelating ability and anti-neuroinflammatory activity in vitro. Furthermore, compound 8n displayed appropriate blood-brain barrier permeability. These multifunctional properties highlight compound 8n as promising candidate for further development of multi-functional drugs against AD.

Anti-inflammatory flurbiprofen nasal powders for nose-to-brain delivery in Alzheimer's disease.

Neuroinflammation occurs in the early stages of Alzheimer's disease (AD). Thus, anti-inflammatory drugs in this asymptomatic initial phase could slow down AD progression, provided they enter the brain. Direct nose-to-brain drug transport occurs along olfactory or trigeminal nerves, bypassing the blood-brain barrier. Nasal administration may enable the drug to access the brain. Here, flurbiprofen powders for nose-to-brain drug transport in early AD-related neuroinflammation were studied. Their target product profile contemplates drug powder deposition in the nasal cavity, prompt dissolution in the mucosal fluid and attainment of saturation concentration to maximise diffusion in the tissue. Aiming to increase drug disposition into brain, poorly soluble flurbiprofen requires the construction of nasal powder microparticles actively deposited in nose for prompt drug release. Two groups of powders were formulated, composed of flurbiprofen acid or flurbiprofen sodium salt. Two spray dryer apparatuses, differing for spray and drying mechanisms, and particle collection, were applied to impact on the characteristics of the microparticulate powders. Flurbiprofen sodium nasal powders disclosed prompt dissolution and fast ex vivo transport across rabbit nasal mucosa, superior to the acid form, in particular when the powder was prepared using the Nano B-90 spray dryer at the lowest drying air temperature.

Validation of an analytical method to quantify the permeation and penetration of flurbiprofen into human pharynx tissue.

The aim of this investigation was to develop receiver and extraction fluids, and subsequently validate an analytical method to quantify the permeation and penetration of flurbiprofen into human pharynx tissue using a Franz diffusion cell. The solubility and stability of flurbiprofen in a suitable receiver fluid, and a suitable extraction method and fluid to recover and quantitate flurbiprofen from human pharynx tissue, were investigated using high-performance liquid chromatography (HPLC). The potential interference of human pharynx tissue in the receiver fluid was also investigated. The HPLC analytical method was successfully validated according to current guidelines. The final receiver fluid demonstrated sufficient solubility and stability, and the extraction method and fluid resulted in >95% recovery of flurbiprofen following exposure to human pharynx tissue. The lower limit of quantitation of flurbiprofen was 0.045 µg/mL in both the receiver and extraction fluids. There was no interference of the human pharynx tissue with the HPLC method. This investigation validated an analytical method for quantitating flurbiprofen, and determined a suitable receiver fluid and extraction method and fluid, which can be used to investigate the permeation and penetration of flurbiprofen through human pharynx tissue using the Franz diffusion cell method.

Study on the drug permeation mechanism from flurbiprofen-loaded glyceryl monooleyl ether-based lyotropic liquid crystalline nanoparticles across the skin: Synchrotron X-ray diffraction and confocal laser scanning microscopy study.

The mechanism underlying the skin permeation of flurbiprofen (FLU)-loaded, glyceryl monooleyl ether-based liquid crystalline nanoparticles (LCNs) with a hexagonal structure was examined by synchrotron X-ray diffraction and confocal laser scanning microscopy (CLSM). Fluorescent-labeled, FLU-loaded LCNs were prepared using coumarin 6 and rhodamine B 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine, triethylammonium salt (Rh-PE), which produce green and red fluorescence, respectively. Application of FLU-loaded LCNs to the hairless mouse stratum corneum (SC) induced expansion of the lattice spacing of the hexagonal structure with FLU release, as confirmed by the changes in the small-angle X-ray diffraction profiles. In addition, the FLU-loaded LCNs completely released FLU near the surface of the SC, which then penetrated the SC. Consequently, the repeat distance of the long periodicity phase was slightly modified. CLSM revealed green fluorescence in the epidermis and hair follicles and red fluorescence in the SC. In conclusion, LCNs adopt several permeation pathways: one is partly via the intercellular matrix and the other is the epidermis via hair follicles.