Difluprednate-Hydroxypropyl-ß-Cyclodextrin-Based Ophthalmic Solution for Improved Delivery in a Porcine Eye Model.

Purpose: Difluprednate (DFP) is an approved corticosteroid, available as an ophthalmic emulsion (Durezol®), used to treat pain and inflammation of the eye following ocular surgeries. This study utilized hydroxypropyl-ß-cyclodextrin (HPBCD)-based DFP ophthalmic solution for improved ocular delivery. Methods: The DFP-HPBCD complex formation was studied in the liquid and solid states. Phase solubility, molecular docking studies, differential scanning calorimetry, and Fourier transform infrared spectroscopy suggested inclusion complexation of DFP and HPBCD. Results: DFP-HPBCD-based eye drops (solution) provided 16 and 26 times higher transcorneal permeation when compared to the suspension (no HPBCD, control) and Durezol, respectively (P < 0.001). In addition, ocular drug distribution studies conducted in continuously perfused whole porcine eyes showed DFP permeated into all of the ocular tissues in significantly higher amounts than Durezol. Conclusions: The solution-based eye drops in this study is iso-osmotic, safe, and more permeable in porcine eyes compared to Durezol.

Difluprednate versus Prednisolone Acetate after Cataract Surgery: a Systematic Review and Meta-Analysis.

OBJECTIVE: Topical steroids are the cornerstone in controlling the inflammation after cataract surgery. Prednisolone acetate and difluprednate are the two main products for this purpose. However, it is unclear which one should be used in terms of effectiveness and safety. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Medline via PubMed, Cochrane Central Register of Controlled Trials, Web of science and clinicaltrials.gov were searched through 10 January 2018, and updated on 20 July 2019, in addition to researching the references' lists of the relevant articles. ELIGIBILITY CRITERIA: Randomised-controlled trials (RCTs) comparing difluprednate and prednisolone acetate regardless of the dosing regimen used. DATA EXTRACTION AND SYNTHESIS: Two independent authors assessed the included RCTs regarding the risk of bias using the Cochrane tool. Relevant data were extracted, and meta-analysis was conducted using a random-effects model. The Grading of Recommendations Assessment, Development, and Evaluation approach was used to appraise the evidence quality. RESULTS: We included six RCTs with 883 patients: 441 received difluprednate and 442 received prednisolone acetate. The evidence quality was graded as moderate for corneal oedema and intraocular pressure and low for anterior chamber (AC) clearance. After small incision cataract surgery, difluprednate was superior in clearing AC cells at 1 week (OR=2.5, p>0.00001) and at 2 weeks (OR=2.5, p=0.04), as well as clearing the AC flare at 2 weeks (OR=6.7, p=0.04). After phacoemulsification, difluprednate was superior in terms of corneal clarity at 1 day (OR=2.6, p=0.02) and 1 week after surgery (OR=1.96, p=0.0007). No statistically significant difference was detected between both agents at 1 month in effectiveness. Also, both agents were safe, evaluated by the ocular hypertension (OR=1.23, p=0.8). CONCLUSION: With low-to-moderate certainty, difluprednate and prednisolone acetate are safe agents for controlling the inflammation after cataract surgery. Difluprednate showed significant superiority in terms of AC cells and AC flare at 2 weeks postoperatively.

Effect of 0.05% Difluprednate Ophthalmic Emulsion on Proinflammatory Cytokine Levels After Retinal Laser Photocoagulation in Rabbits.

PURPOSE: We aimed to evaluate the effect of the topical application of a strong corticosteroid, difluprednate, on the levels of inflammatory and angiogenic cytokine in the vitreous and aqueous humor after laser photocoagulation. METHODS: Pigmented rabbits were treated with retinal laser photocoagulation and divided into 4 groups, namely control (no additional treatment), topical application of difluprednate 0.05%, betamethasone sodium phosphate 0.1%, and sub-Tenon injection of triamcinolone acetonide (STTA). Samples of vitreous and aqueous humor were collected on posttreatment days 0, 1, 7, and 14. The levels of intraocular vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1), and monocyte chemotactic protein-1 (MCP-1) were measured using an immunoassay. Intraocular pressure (IOP) was monitored in each group. RESULTS: VEGF, IL-6, ICAM-1, and MCP-1 were significantly elevated on day 1 and were reduced in both the vitreous and aqueous humor following topical application of difluprednate and STTA. Topical betamethasone reduced their levels in the aqueous humor but not in the vitreous. A significant increase of IOP induced by difluprednate returned to control levels after withdrawal of administration. CONCLUSION: Although the elevation of IOP was an expected, manageable side effect, topical application of difluprednate was more effective than STTA and betamethasone for reducing inflammatory cytokine levels after laser treatment.

Expression of inflammatory and structural matrix genes in synovial fluid following intra-articular administration of isoflupredone acetate to exercised horses.

BACKGROUND: Intra-articular use of corticosteroids is commonplace in performance horses. Isoflupredone acetate (IPA) is one of four Food and Drug Administration approved corticosteroids for intra-articular use in horses. The lack of published reports describing the efficacy and duration of effects of this drug warrant further study. OBJECTIVES: To assess the effects of intra-articular administration of IPA on the expression of selected anti- and pro-inflammatory and structural matrix genes following intra-articular administration to exercised Thoroughbred horses and to correlate these effects with drug concentrations. STUDY DESIGN: Block design in vivo experiment. METHODS: Twelve exercised horses received either a single intra-articular administration of 8 mg of IPA or 0.9% saline solution. Synovial fluid samples were collected prior to and up to 42 days post drug administration from the treated joints. Microarray and qRT-PCR analysis were used to assess changes in expression levels of various inflammatory and structural genes post drug administration. RESULTS: On microarray analysis, 855, 23,358 and 26,411 genes had a measurable fold change (increase or decrease in expression levels) when comparing baseline samples to 24 h, baseline samples to day 7 and 24 h samples to day 7, respectively. Of the genes selected for further study by qRT-PCR analysis, expression of ANXA-1 (lipocortin) was significantly increased and IL23A and MMP1 and MMP9 significantly decreased following IPA administration. Expression levels of collagen genes were not significantly different from baseline. MAIN LIMITATIONS: Limitations include the use of a noninflammatory model as results may differ in the presence of an acute inflammatory insult and the inability to measure protein concentrations of inflammatory mediators due to limited synovial fluid sample volume. CONCLUSIONS: Expression relative to baseline, for both inflammatory and matrix genes for up to 42 days post IPA administration, suggests a prolonged effect relative to detection time in both plasma and synovial fluid.

Antimicrobial activity of different filling pastes for deciduous tooth treatment.

Guedes-Pinto paste is the filling material most employed in Brazil for endodontic treatment of deciduous teeth; however, the Rifocort® ointment has been removed. Thus, the aim of this study was to investigate the antimicrobial potential of filling pastes, by proposing three new pharmacological associations to replace Rifocort® ointment with drugs of already established antimicrobial power: Nebacetin® ointment, 2% Chlorhexidine Gluconate gel, and Maxitrol® ointment. A paste composed of Iodoform, Rifocort® ointment and Camphorated Paramonochlorophenol (CPC) was employed as the gold standard (G1). The other associations were: Iodoform, Nebacetin® ointment and CPC (G2); Iodoform, 2% Chlorhexidine Digluconate gel and CPC (G3); Iodoform, Maxitrol® ointment and CPC (G4). The associations were tested for Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans), Streptococcus oralis (S. oralis), Enterococcus faecalis (E. faecalis), Escherichia coli (E. coli), and Bacillus subtilis (B. subtilis), using the methods of dilution on solid medium - orifice agar - and broth dilution. The results were tested using statistical analysis ANOVA and Kruskal-Wallis. They showed that all the pastes had a bacteriostatic effect on all the microorganisms, without any statistically significant difference, compared with G1. S. aureus was statistically significant (multiple comparison test of Tukey), insofar as G2 and G3 presented the worst and the best performance, respectively. All associations were bactericidal for E. coli, S. aureus, S. mutans and S. oralis. Only G3 and G4 were bactericidal for E. faecalis, whereas no product was bactericidal for B. subtilis. Thus, the tested pastes have antimicrobial potential and have proved acceptable for endodontic treatment of primary teeth.

Antimicrobial activity of different filling pastes for deciduous tooth treatment

Guedes-Pinto paste is the filling material most employed in Brazil for endodontic treatment of deciduous teeth; however, the Rifocort® ointment has been removed. Thus, the aim of this study was to investigate the antimicrobial potential of filling pastes, by proposing three new pharmacological associations to replace Rifocort® ointment with drugs of already established antimicrobial power: Nebacetin® ointment, 2% Chlorhexidine Gluconate gel, and Maxitrol® ointment. A paste composed of Iodoform, Rifocort® ointment and Camphorated Paramonochlorophenol (CPC) was employed as the gold standard (G1). The other associations were: Iodoform, Nebacetin® ointment and CPC (G2); Iodoform, 2% Chlorhexidine Digluconate gel and CPC (G3); Iodoform, Maxitrol® ointment and CPC (G4). The associations were tested for Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans), Streptococcus oralis (S. oralis), Enterococcus faecalis (E. faecalis), Escherichia coli (E. coli), and Bacillus subtilis (B. subtilis), using the methods of dilution on solid medium – orifice agar – and broth dilution. The results were tested using statistical analysis ANOVA and Kruskal-Wallis. They showed that all the pastes had a bacteriostatic effect on all the microorganisms, without any statistically significant difference, compared with G1. S. aureus was statistically significant (multiple comparison test of Tukey), insofar as G2 and G3 presented the worst and the best performance, respectively. All associations were bactericidal for E. coli, S. aureus, S. mutans and S. oralis. Only G3 and G4 were bactericidal for E. faecalis, whereas no product was bactericidal for B. subtilis. Thus, the tested pastes have antimicrobial potential and have proved acceptable for endodontic treatment of primary teeth.

Difluprednate for inflammatory eye disorders.

Uveitis is the third leading cause of preventable blindness in the U.S. Topical administration of corticosteroids remains the mainstay in the management of acute autoimmune anterior uveitis. Difluprednate 0.05% ophthalmic emulsion is a potent new topical corticosteroid that exhibits enhanced penetration, better bioavailability, rapid local metabolism and strong efficacy, with a low incidence of adverse effects. In June 2008, difluprednate ophthalmic emulsion 0.05% gained FDA approval in the U.S. for the treatment of postoperative ocular inflammation and pain. Recently, a multicenter, randomized clinical trial showed difluprednate to be noninferior to prednisolone acetate 1% dosed twice as often, the current standard of care for the acute management of endogenous uveitis in the U.S. Furthermore, difluprednate proved to have a comparable safety profile. Here, we review difluprednate pharmacokinetics, ocular indications, animal studies, as well as the results of the clinical trials conducted to date in the U.S.

Evaluation of exogenous glucocorticoid injection on preweaning growth performance of neonatal pigs under commercial conditions.

Three commercial trials were conducted to evaluate the use of dexamethasone (Dex) and/ or isoflupredone (Predef) in improving preweaning growth performance of neonatal pigs. The objectives of the commercial trials were threefold: 1) to evaluate Predef in comparison with Dex; 2) to address the sexual dimorphic growth response observed in a previous commercial trial; and 3) to determine whether there is any benefit of providing Dex treatment to pigs being fed supplemental milk. In Exp. 1, 276 pigs (Triumph 4 x PIC Camborough 22) were assigned according to birth weight and sex to three treatments. Treatments included saline (Control), Dex (2 mg/kg BW i.m. injection of Dex), or Predef (2 mg/kg BW i.m. injection of Predef 2X) within 24 h after birth. A treatment effect was observed for BW at weaning (P < 0.001), with pigs injected with Predef being 0.51 kg lighter than Control and Dex-treated pigs. The lower BW of Predef-treated pigs at weaning were a result of a lower ADG (P < 0.001) during the preweaning period compared with Control and Dex pigs. In Exp. 2, 703 pigs (Triumph 4 x PIC Camborough 22) were assigned according to birth weight and sex to three treatments. Treatments included either an i.m. injection of saline (Control), Dexl (1 mg/kg BW of Dex), or Dex2 (2 mg/kg BW of Dex) within 24 h after birth. No treatment effects were observed for BW at weaning (P = 0.24) or ADG (P = 0.19). In Exp. 3, 342 pigs (Genetiporc) were assigned according to birth weight and sex to two treatments. Treatments included either an i.m. injection of saline or Dex (2 mg/kg BW) within 24 h after birth. All pigs were provided supplemental milk from the time of treatment until weaning age. No treatment effects were observed for BW at weaning (P = 0.13) or ADG (P = 0.11). The negative response to Predef was similar to the growth-suppressive effects observed by others using chronic glucocorticoid treatment. In contrast to our previous findings, Dex did not improve preweaning growth performance regardless of dose or supplemental milk.

Pharmacodynamics of isoflupredone acetate in an endotoxin-induced mastitis model.

The effect of intravenous administration of the steroidal drug isoflupredone acetate on lactating dairy cows with mastitis induced using gram-negative bacterial endotoxin was investigated. Cows were randomly assigned to one of four treatment groups: untreated controls, isoflupredone acetate only, mastitis only, and mastitis plus isoflupredone acetate. Isoflupredone acetate was given to treated groups at a dose of 20 mg intravenously, once. Mastitic cows receiving treatment were given isoflupredone acetate after the development of clinical signs. When compared with untreated mastitic controls, cows with endotoxin-induced mastitis treated with isoflupredone acetate did not exhibit measurable differences in heart rate, rectal temperature, rumen motility, or changes in mammary gland surface area in the 14 h following the administration of intramammary endotoxin. Healthy cows treated with isoflupredone acetate had a higher heart rate over the 14 h after drug administration than did untreated healthy controls. When compared with untreated mastitic controls, cows treated with isoflupredone acetate did not exhibit statistically significant differences in milk production following endotoxin-induced mastitis.

Novel fluorinated antiinflammatory steroid with reduced side effects: methyl 9 alpha-fluoroprednisolone-16-carboxylate.

In an effort to test the hypothesis that 9 alpha-fluorination of a steroidal antedrug would enhance receptor binding affinity and local antiinflammatory activity, without concomitantly increasing adverse systemic effects, a fluorinated analog, 10, of methyl 11 beta, 21-dihydroxy- 3,20-dioxo-1,4-pregnadiene-16 alpha-carboxylate (DP16CM, 1) was synthesized and evaluated. In the acute rat croton oil-induced ear edema bioassay, 10 was found to be twice as potent as 1. This increase in topical potency was consistent with enhanced binding affinity of 10, relative to 1. The IC50 values for displacement of [3H]dexamethasone from glucocorticoid receptors of rat hepatoma tissue culture cells were 0.16, 1.2, and 0.03 microM for 10, 1, and prednisolone, respectively. Following multiple topical ID50 applications of predniosolone, 1, and its new fluorinated analog, 10, in the rat subacute croton oil-induced ear edema bioassay, only prednisolone exhibited significant untoward effects, such as reduction in relative thymus and adrenal weights, plasma corticosterone levels, and normal body weight gain. Thus, while fluroination of 1 enhanced its topical potency, there was not a concomitant increase in untoward systemic effects. This lack of adverse systemic effects is ostensibly due to the presence of the metabolically labile 16-carboxylate ester moiety.

Allergic rhinitis model with Brown Norway rat and evaluation of antiallergic drugs.

An animal disease model of allergic rhinitis was developed with Brown Norway (BN) rat, a high immunoglobulin E responder strain. BN rats were immunized with ovalbumin (OA) and made to suffer from allergic rhinitis. The severity of allergic rhinitis was assessed by determining the extent of the three kinds of markers, Evan's blue, histamine and N-acetyl-beta-D-glucosaminidase, released into the nasal perfusate following the OA challenge to the nasal cavity of OA-sensitized BN rats. This experimental system was appreciated by antiallergic drugs; chlorpheniramine maleate inhibited the release of Evan's blue and elevated that of histamine, but did not affect the N-acetyl-beta-D-glucosaminidase level. Halopredone acetate inhibited the releases of all the three markers. The estimation of the released markers using allergic rhinitis brought about in BN rats was found to be a useful experimental system for evaluating the effect of drugs on allergic rhinitis.

Structure-activity relationships for blood pressure effects of prednisolone in sheep.

This study investigated the effect of 5 day infusions of 6 alpha and 9 alpha-fluoro and 16 alpha, 17 alpha-acetal analogues of prednisolone on blood pressure in conscious sheep. In vivo mineralocorticoid (MC) and glucocorticoid (GC) activities of these steroids were also measured. Prednisolone (100 mg/d) produced a small increase in mean arterial pressure associated with increased fasting plasma [glucose] and polyuria, but had no MC activity. 9 alpha-fluoro substitution greatly enhanced both the pressor and MC activity of prednisolone. The effect of 9 alpha-fluoro substitution on pressor activity was not affected by beta-methylation at C-16 (betamethasone), but was attenuated by either alpha-hydroxylation or alpha-methylation at C-16 (triamcinolone and dexamethasone, respectively). The effect of 9 alpha-fluoro substitution on MC activity as determined by urinary Na excretion was not altered by a methyl group at C-16 in either alpha or beta configuration but the MC activity was attenuated by an alpha-hydroxyl group at C-16. In contrast, 6 alpha-fluoro substitution had little influence on pressor, MC and GC activities. 16 alpha, 17 alpha-acetonide and 16 alpha, 17 alpha-butylidenedioxy substitution increased the pressor activity of parent compounds, but had no influence on either GC or MC activity. This study demonstrates a dissociation between the pressor effects and the MC and GC activities associated with steroid administration and provides further evidence to support the concept of 'hypertensinogenic' class of steroid activity which can be distinguished from their MC and GC activity.

Steroid antagonism of the hypertensinogenic activity of adrenocortical steroids.

Previous studies in sheep have provided evidence for a separate "hypertensinogenic" class of adrenocortical steroid activity which is not simply related to their classical mineralocorticoid (MC) and/or glucocorticoid (GC) actions. This study investigated the structure-activity relationships of the effects of structural analogues of prednisolone on mean arterial pressure (MAP), and MC and GC actions in sheep. Infusions of these synthetic GC at 0.6 and 24 mg/day produced variable pressor effects which were dissociated from their MC and GC actions. In other experiments, the minimum adrenocortical steroid requirement to reproduce the onset of ACTH-dependent hypertension was determined. Infusion of cortisol, aldosterone, 17 alpha-hydroxy progesterone and 17 alpha,20 alpha-dihydroxy-4-pregnene-3-one was found to be sufficient to reproduce the hypertensive response to ACTH administration in sheep. A subsequent experiment showed that substitution of cortisol by the more potent synthetic GC, prednisolone had no effect on MAP. Therefore, cortisol appears to exert an essential action in ACTH hypertension which is not dependent on its GC activity. Other studies have found that prednisolone (100 mg/day) antagonized 9 alpha-fluoro-prednisolone (0.6 mg/day) induced hypertension but not its MC effects. The effect of progesterone (500 mg/day) and the progesterone analogues, norethisterone, medroxy-progesterone and 16 alpha-methyl progesterone on ACTH (5 micrograms/kg per day) hypertension was investigated. Progesterone completely blocked the hypertension and MC effects of ACTH infusion, while medroxy-progesterone partially blocked the increase in MAP. These data support our concept of a "hypertensinogenic" class of steroid activity.

[Peri- and postnatal study on halopredone acetate in rats].

A peri- and postnatal study of halopredone acetate (THS-201), a synthetic corticosteroid, was carried out using Jcl: Wistar rats. Pregnant rats were treated subcutaneously in doses of 0.05, 0.4, 3.2 and 25.6 mg/kg/day, from day 17 of gestation to day 21 after delivery. All pregnant rats were allowed to litter naturally, and the postnatal development of offsprings was observed. The results obtained from the present study were as follows. No influences of THS-201 administration were observed on gestation, delivery and lactation of dams. THS-201 administration did not have any influences on viability and development, various functions such as reflex response, learning and reproductive performance of F1 generation, and further on development of F2 generation. Therefore, it was concluded that the non-effect dose of THS-201 for the reproduction of dams and development of F1 generation was 25.6 mg/kg/day.

[Fertility study on halopredone acetate in rats].

A fertility study of halopredone acetate (THS-201), a synthetic corticosteroid, was carried out using Jcl: Wistar rats. Male rats were treated subcutaneously for 63 days before mating and throughout mating, and female rats were treated subcutaneously for 14 days before mating and until day 7 of gestation, in doses of 0.04, 0.2, 1.0 and 5.0 mg/kg/day. Male and female rats in the same dose were mated. All of the pregnant rats were killed on day 20 of gestation and their fetuses were examined morphologically. The results obtained from the present study were as follows. A decrease in body weight gain was observed in male rats of 1.0 and 5.0 mg/kg groups, compared to the vehicle control group. In female rats of 5.0 mg/kg group, a decrease in body weight gain during gestation period was observed. However, no influences attributable to THS 201 administration were observed on the fertility and fetal development. These results indicated that the non-effect dose of THS-201 for the fertility of rats and fetal development was 5.0 mg/kg/day.

[Effect of difluprednate on adrenocortical and gonadal function].

The effects of difluprednate on the deposition of liver glycogen, the inhibition of adrenocortical function, the estrogenic, progestational and androgenic activities, and the excretion of electrolytes were investigated by comparing them with those of fluocinonide. The following results were obtained: 1) the deposition of liver glycogen was remarkably increased by subcutaneous administration of these two glucocorticoids, and in the dose of 0.1 mg/kg, the effect of difluprednate (35.1-fold the control value) was larger than that of fluocinonide (19.4-fold the control value) in mice. 2) the administration of difluprednate and fluocinonide greatly induced the decrease in the corticosterone concentration in the rat serum and adrenal gland (0.1 and 1 mg/kg, s.c.). 3) the estrogenic, progestational and androgenic activities were not recognized by administration of difluprednate in rats. 4) the two glucocorticoids induced an increase in the electrolytes excretion (especially K+) and the urine volume. 5) by the repeated injection of difluprednate (1.0 mg/kg) and fluocinonide (0.1 mg/kg), decrease of the body weight was observed in all of the experimental animals. In these experiments, it was recognized that the glucocortical action of difluprednate was similar or more potent in comparison with the action of fluocinonide and that the systemic effects of fluocinonide such as body weight loss was larger than that of difluprednate.

The influence of sex on fetal rabbit lung maturation and on the response to glucocorticoid.

Female premature rabbit fetuses had more stable lungs than male premature rabbit fetuses. In both male and female rabbit fetuses, deflation stability increased to a similar extent after administration of glucocorticoid, but the resultant male lungs were significantly less stable. The lungs of female fetuses treated with steroid had greater histologic maturity than those of male fetuses, with a higher proportion of air space and thinner airspace after completion of pressure-volume studies. These results indicate that sex differences must be considered in studies of lung maturation.