Effect of renal function on the pharmacokinetics of LCZ696 (sacubitril/valsartan), an angiotensin receptor neprilysin inhibitor.

Purpose: LCZ696 (sacubitril/valsartan), an angiotensin receptor neprilysin inhibitor, is indicated for chronic heart failure (HF) and reduced ejection fraction (HFrEF) to reduce the risk of cardiovascular death and hospitalization for HF. Following oral administration, LCZ696 provides systemic exposure to valsartan and sacubitril (a prodrug), and its metabolite sacubitrilat (the active neprilysin inhibitor, formerly named as LBQ657), which is eliminated primarily via renal route. Since renal dysfunction is a common comorbidity in patients with HF, two open-label studies assessing the effect of mild, moderate, and severe renal impairment were conducted.

Evaluation of food effect on the oral bioavailability of pradigastat, a diacylglycerol acyltransferase 1 inhibitor.

Pradigastat, a diacylglycerol acyltransferase 1 inhibitor, is being developed for the treatment of familial chylomicronemia syndrome. The results of two studies that evaluated the effect of food on the oral bioavailability of pradigastat using randomized, open-label, parallel group designs in healthy subjects (n=24/treatment/study) are presented. In study 1, a single dose of 20 mg pradigastat was administered under the fasted condition or with a high-fat meal.

Probenecid treatment enhances retinal and brain delivery of N-4-benzoylaminophenylsulfonylglycine: an anionic aldose reductase inhibitor.

Anion efflux transporters are expected to minimize target tissue delivery of N-[4-(benzoylaminophenyl)sulfonyl]glycine (BAPSG), a novel carboxylic acid aldose reductase inhibitor, which exists as a monocarboxylate anion at physiological conditions. Therefore, the objective of this study was to determine whether BAPSG delivery to various eye tissues including the retina and the brain can be enhanced by probenecid, a competitive inhibitor of anion transporters. To determine the influence of probenecid on eye and brain distribution of BAPSG, probenecid was administered intraperitoneally (120 mg/kg body weight; i.

Fluocinolone inhibits VEGF expression via glucocorticoid receptor in human retinal pigment epithelial (ARPE-19) cells and TNF-alpha-induced angiogenesis in chick chorioallantoic membrane (CAM).

Purpose: The purpose of this study was to determine whether fluocinolone inhibits vascular endothelial growth factor (VEGF) expression in a retinal pigment epithelial cell line (ARPE-19) and TNF-alpha-induced angiogenesis in chick chorioallantoic membrane (CAM) assay.

Methods: The dose-dependent effect of fluocinolone (0.0001-1 microM) on VEGF secretion, VEGF mRNA expression, and cytotoxicity was determined in confluent monolayers of ARPE-19 cells using ELISA, RT-PCR, and MTT assay, respectively.

Evaluation of the potential for steady-state pharmacokinetic interaction between vildagliptin and simvastatin in healthy subjects.

Background: Vildagliptin is an orally active, potent and selective inhibitor of dipeptidyl peptidase IV (DPP-4), the enzyme responsible for the degradation of incretin hormones. By enhancing prandial levels of incretin hormones, vildagliptin improves glycemic control in type 2 diabetes. Co-administration of vildagliptin and simva statin, an HMG-CoA-reductase inhibitor may be required to treat patients with diabetes and dyslipidemia.

Effect of clopidogrel on the steady-state pharmacokinetics of fluvastatin.

This study assessed the effects of clopidogrel, a CYP 2C9 inhibitor, on fluvastatin pharmacokinetics in healthy volunteers. The effects of combined clopidogrel-fluvastatin treatment on platelet function were also determined. Subjects received 80 mg fluvastatin (extended-release formulation) alone on days 1 through 9, 80 mg fluvastatin and 300 mg clopidogrel (loading dose) on day 10, and 80 mg fluvastatin and 75 mg clopidogrel (maintenance dose) on days 11 through 19.

Single periocular injection of celecoxib-PLGA microparticles inhibits diabetes-induced elevations in retinal PGE2, VEGF, and vascular leakage.

Purpose: To determine whether celecoxib inhibits VEGF secretion from ARPE-19 cells and to investigate further the safety and effectiveness of periocular celecoxib-poly (lactide-co-glycolide; PLGA) microparticles in inhibiting elevations in retinal PGE(2), VEGF, and blood-tissue barrier leakage at the end of 60 days in a streptozotocin diabetic rat model.

Methods: VEGF mRNA and protein expression in ARPE-19 cells was evaluated in the presence of 0 to 10 microM celecoxib, and cytotoxicity of celecoxib on ARPE-19 and RF6A cells was evaluated over a 0- to 100-microM concentration range. Celecoxib-PLGA microparticles were prepared by a modified solvent evaporation technique, sterilized by 25 kGy of gamma-irradiation, and characterized for size, zeta potential, drug loading, and in vitro release.

Intratracheal budesonide-poly(lactide-co-glycolide) microparticles reduce oxidative stress, VEGF expression, and vascular leakage in a benzo(a)pyrene-fed mouse model.

The purpose of this study was to determine whether intratracheally instilled polymeric budesonide microparticles could sustain lung budesonide levels for one week and inhibit early biochemical changes associated with benzo(a)pyrene (B[a]P) feeding in a mouse model for lung tumours. Polymeric microparticles of budesonide-poly (DL-lactide-co-glycolide) (PLGA 50:50) were prepared using a solvent evaporation technique and characterized for their size, morphology, encapsulation efficiency, and in-vitro release. The microparticles were administered intratracheally (i.

Subconjunctivally administered celecoxib-PLGA microparticles sustain retinal drug levels and alleviate diabetes-induced oxidative stress in a rat model.

We have previously reported that repeated oral doses of celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, reduced diabetes-induced retinal vascular endothelial growth factor (VEGF) expression [Ayalasomayajula, S.P., Kompella, U.

Retinal delivery of celecoxib is several-fold higher following subconjunctival administration compared to systemic administration.

Purpose: We have previously demonstrated that celecoxib, a selective COX-2 inhibitor, reaches the retina following repeated oral administrations and inhibits diabetes-induced vascular endothelial growth factor (VEGF) mRNA expression and vascular leakage in a rat model. The aim of this study was to quantify the relative retinal bioavailability of celecoxib from the subconjunctival route compared to a systemic route.

Methods: The plasma and ocular tissue distribution of celecoxib was determined in male Sprague-Dawley rats following subconjunctival and intraperitoneal administrations of drug suspension at a dose of 3 mg/rat.

Inhibition of cyclooxygenase-2, but not cyclooxygenase-1, reduces prostaglandin E2 secretion from diabetic rat retinas.

Up-regulation of cyclooxygenase-2 occurs in retinal cells during the early onset of diabetic retinopathy. Under these conditions, prostaglandin production is elevated, which in turn leads to an increased expression of vascular endothelial growth factor (VEGF)--a growth factor implicated in vascular leakage and neovascularization. In this ex vivo study, we tested whether cyclooxygenase-1 or cyclooxygenase-2 is responsible for diabetes-induced secretion of prostaglandin E2 from isolated rat retinas.

Systemic and ocular pharmacokinetics of N-4-benzoylaminophenylsulfonylglycine (BAPSG), a novel aldose reductase inhibitor.

To better develop N-[4-(benzoylamino)phenylsulfonyl]glycine (BAPSG), a potent and selective aldose reductase inhibitor capable of delaying the progression of ocular diabetic complications, the objective of this study was to assess its pharmacokinetics. The plasma pharmacokinetics of BASPG was assessed in male Sprague-Dawley rats following intravenous, intraperitoneal and oral routes of administration and its distribution to various tissues including those of the eye was studied following intraperitoneal administration. In addition, rat plasma protein binding of BAPSG was studied using ultracentrifugation method and its ocular tissue disposition was assessed following topical administration in rabbits.

Nanoparticle formulation enhances the delivery and activity of a vascular endothelial growth factor antisense oligonucleotide in human retinal pigment epithelial cells.

The objective of this study was to investigate the delivery and activity of a vascular endothelial growth factor (VEGF) antisense oligonucleotide in a human retinal pigment epithelial cell line (ARPE-19) using a biodegradable nanoparticulate delivery system. A 19-mer antisense phosphorothioate oligonucleotide (PS-ODN) complementary to bases 6-24 relative to the translational start site of the VEGF mRNA, a sense PS-ODN and a mismatch PS-ODN were examined for the inhibition of secretion and mRNA expression of VEGF using an enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction, respectively. Nanoparticles of the antisense oligonucleotides were formulated using a poly(lactide-co-glycolide) (50:50) copolymer using a double emulsion solvent evaporation method.

Subconjunctival nano- and microparticles sustain retinal delivery of budesonide, a corticosteroid capable of inhibiting VEGF expression.

Purpose: The purpose of this study was to determine whether budesonide inhibits expression of vascular endothelial growth factor (VEGF) in a retinal pigment epithelial cell line (ARPE-19) and to determine whether subconjunctivally administered budesonide nano- and microparticles sustain retinal drug levels.

Methods: The effect of budesonide (100 pM to 10 microM) on VEGF secretion, expression of VEGF mRNA, and cytotoxicity were determined in ARPE-19 cells by ELISA, RT-PCR, and a cell-viability assay, respectively. To determine the involvement of glucocorticoid receptor in the observed effects of budesonide, secretion and mRNA expression studies were also performed in the presence of a glucocorticoid receptor antagonist (RU486).

Celecoxib, a selective cyclooxygenase-2 inhibitor, inhibits retinal vascular endothelial growth factor expression and vascular leakage in a streptozotocin-induced diabetic rat model.

Overexpression of vascular endothelial growth factor (VEGF) is implicated in the development of vascular leakage and retinal neovascularization in diabetic subjects. The objective of this study was to determine whether celecoxib, a selective cyclooxygenase-2 enzyme inhibitor, reaches ocular tissues following oral administration and inhibits the retinal VEGF expression and vascular leakage in a streptozotocin-induced diabetic rat model. After administering a single intraperitoneal injection of streptozotocin (60 mg/kg) to Sprague-Dawley rats and ensuring the induction of diabetes at the end of 24 h, celecoxib was administered b.

Induction of vascular endothelial growth factor by 4-hydroxynonenal and its prevention by glutathione precursors in retinal pigment epithelial cells.

Although 4-hydroxynonenal, a highly reactive lipid peroxidation product, is implicated in several age-related disorders such as Alzheimer's and Parkinson's diseases, its role in age-related macular degeneration is not known. The purpose of this study was to determine whether 4-hydroxynonenal increases vascular endothelial growth factor (VEGF) expression in human retinal pigment epithelial cells (ARPE-19), a source of VEGF in choroidal neovascularization observed in age-related macular degeneration. In addition, it was the purpose of this study to assess whether glutathione (GSH) and GSH precursors can inhibit the effects of 4-hydroxynonenal.

A biodegradable injectable implant sustains systemic and ocular delivery of an aldose reductase inhibitor and ameliorates biochemical changes in a galactose-fed rat model for diabetic complications.

Purpose: To fabricate and characterize in vitro and in vivo performance of a sustained release biodegradable implant for N-4-(benzoylaminophenylsulfonyl glycine) (BAPSG), a novel aldose reductase inhibitor.

Methods: The ability of BAPSG to inhibit aldose reductase activity and glucose-induced vascular endothelial growth factor (VEGF) expression was assessed in a retinal pigment epithelial cell line (ARPE-19). A poly (DL-lactic-co-glycolic acid) implant containing 50% w/w BAPSG was fabricated and characterized for drug loading, in vitro drug release, and the thermal behavior of the drug and the polymer.