Preparation of technetium-99m labeled ibuprofen by direct route and technetium-99m tricarbonyl route: a comparison of in vivo behaviors.

In the current study, ibuprofen (ibu) which is a non-steroidal anti-inflammatory drug (NSAID) was radiolabeled with 99mTc using two different methods: stannous chloride method (direct route) and technetium-99m tricarbonyl [99mTc(CO)3]+ route. Thus, it's aimed to investigate the radiolabeling potential of ibu for inflammation detection and to monitor if there is any difference in in vivo distribution depending on the radiolabeling route. Quality control studies of both radiolabeled ibu were performed by radiochromatographic methods (Thin Layer Liquid Radio Chromatography and High Performance Liquid Radio Chromatography). Radiolabeling yields of 99mTc-ibu and 99mTc(CO)3-ibu were determined as 99.05 ± 0.83% and 91.79 ± 3.30% (n = 5), respectively. Experimental lipophilicities of both radiolabeled ibu were determined. The biological behavior of both radiolabeled ibu was investigated in healthy Albino Wistar male rats by in vivo biodistribution studies. It was seen that both radiolabeled ibuprofen showed renal excretion while organ uptakes of 99mTc-ibu and 99mTc(CO)3-ibu differ against time.

A New Application Route of Nitrofurantoin: Preparation and Characterization of Novel Transdermal Formulations.

OBJECTIVES: Nitrofurantoin is widely used in the prophylaxis of urinary-tract infections. The aim of this study was to develop and characterize innovative transdermal formulations of nitrofurantoin, to increase the patient compliance and decrease the adverse effects such as nausea and vomiting which limit the drug use in long-term. METHODS: Nitrofurantoin loaded microemulsion, gel (hydrogel, lipogel and DMSO gel) and film formulations were prepared and characterized via several parameters. Ex-vivo drug permeation studies were performed to determine the amount of drug permeated through the rat skin. In in-vivo studies, in order to detect nitrofurantoin in urine, the selected formulations were applied to male Wistar rats transdermally. Also, skin irritation tests (transepidermal water loss and erythema) were performed. RESULTS: All nitrofurantoin loaded formulations were prepared successfully and were stable at +4°C for 3 months. 13%, 16%, 32.5%, 36.5% and 39% of drugs permeated through the rat skin in the 168th hour for hydrogel, lipogel, film, microemulsion and DMSO gel, respectively. Only with film and DMSO gel formulations, nitrofurantoin was detected in urine. Transepidermal water loss was increased compared to basal level in film type formulations (p<0.05). However, in erythema experiments there was no difference (p>0.05). CONCLUSION: There is no approved transdermal formulation of nitrofurantion on the market. Therefore, the prepared film formulations could be an alternative due to their high penetration through the rat skin, the presence of nitrofurantoin in urine and because they cause no irritation on the skin.

Therapeutic Corneal Transplant for Fungal Keratitis Refractory to Medical Therapy.

OBJECTIVES: To report the outcomes of therapeutic corneal transplant for managing fungal keratitis that is refractory to medical treatment. MATERIALS AND METHODS: Retrospective data analyses of the medical records was performed on 17 patients who underwent a therapeutic corneal transplant for severe culture-proven fungal keratitis between October 2006 and August 2013. We evaluated demographics, fungal organism type, surgical data, recurrence presentation, disease course, follow-up, and graft status. RESULTS: Mean patient age was 53.2 years (range, 33-81 y). The male/female ratio was 12/5. All patients had positive microscopic evaluation and positive culture results for fungal infection. The most common fungal agent was Fusarium sp. (35%). Nine patients reported a history of injury to the cornea and/or contact with plant material or soil. The mean best-corrected visual acuity at the initial visit was 2.45 logMAR unit (range, 0.52-3.10 logMAR unit). The mean follow-up was 14 months (range, 6-76 mo). Four patients underwent evisceration surgery because of graft lysis or uncontrolled recurrent disease. Recurrence of the fungal infection after corneal transplant was seen in 8 patients (47.05%). The graft rejection rate was 18.18%. At the final visit, 5 grafts were clear, 4 were translucent, and 2 were opaque. There were 2 phthisis bulbi owing to catastrophic disease. The mean final best-corrected visual acuity was 1.64 logMAR unit (range, 0.22-3.10 logMAR unit). CONCLUSIONS: Although therapeutic corneal transplant has a higher incidence of infection recurrence and graft failure, it continues to be an effective treatment for uncontrolled, refractory fungal keratitis cases to save the affected eye.

Reliability of intravitreal nepafenac in rabbits.

PURPOSE: The purpose of this experiment was to investigate the possible toxic effects of Nepafenac, a nonsteroidal anti-inflammatory molecule, after its intravitreal application in various concentrations. METHODS: Forty pigmented rabbits were randomly divided into 4 groups, each including 10 rabbits. The active ingredient Nepafenac was prepared to be applied in different doses, for intravitreal use. Under topical anesthesia, following pupil dilatation, 0.3, 0.5, 0.75, and 1.5 mg doses of Nepafenac was applied intravitreally into the right eye. In each rabbit, the right eye was considered to be the study group. Saline was injected intravitreally into the left eye of each rabbit, and these eyes were considered to be the control group. Immediately after the injection and at the 1st, 4th, and 8th weeks, fundus examination by indirect ophthalmoscopy and intraocular pressure measurement were conducted. Furthermore, electroretinographic (ERG) recordings were taken at the 4th and 8th weeks. At the end of the 8th week, eyes of the surviving 26 rabbits were enucleated, and then animals were sacrificed. Following necessary fixation procedures, histopathological investigations were conducted by using a light and electron microscope. In the histological cross sections, differences between the eyes with injection and the control group were evaluated, and total retinal thickness, inner nuclear layer thickness, and outer nuclear layer thickness were measured. RESULTS: No pathology was found by clinical examination of either group. In the photopic and scotopic full-field ERG, conducted before the injection and in the 4th and 8th weeks after the injection, no statistically significant difference was determined between the study group and the control group. In the histological evaluation of the preparations, there were no statistically significant differences in the retina thickness of control and study groups. In the electron microscopic examinations, there were no toxicity findings in the eyes with injection. CONCLUSIONS: Our data show that intravitreal application of 0.3, 0.5, 0.75, and 1.5 mg doses of Nepafenac active substance is nontoxic to the rabbit retina.

Preparation of naproxen-ethyl cellulose microparticles by spray-drying technique and their application to textile materials.

The objective of this study is to develop a new textile-based drug delivery system containing naproxen (NAP) microparticles and to evaluate the potential of the system as the carrier of NAP for topical delivery. Microparticles were prepared by spray-drying using an aqueous ethyl cellulose dispersion. The drug content and entrapment efficiency, particle size and distribution, particle morphology and in vitro drug release characteristics of microparticles were optimized for the application of microparticles onto the textile fabrics. Microparticles had spherical shape in the range of 10-15 µm and a narrow particle size distribution. NAP encapsulated in microparticles was in the amorphous or partially crystalline nature. Microparticles were tightly fixed onto the textile fabrics. In vitro drug release exhibited biphasic release profile with an initial burst followed by a very slow release. Skin permeation profiles were observed to follow near zero-order release kinetics.

Can the hydrogel form of sodium ascorbate be used to reverse compromised bond strength after bleaching?

PURPOSE: To assess the effect of the hydrogel form of different concentrations (2.5%, 5%, and 10%) of sodium ascorbate on the shear bond strength of composite after bleaching of the enamel with 10% carbamide peroxide gel. MATERIALS AND METHODS: Sixty flat buccal enamel surfaces obtained from 30 bovine incisors were divided into 6 treatment groups: group I, control (nonbleached); group II, no antioxidant treatment after bleaching; group III, 10% sodium ascorbate solution after bleaching; group IV, 2.5% sodium ascorbate hydrogel after bleaching; group V, 5% sodium ascorbate hydrogel after bleaching; group VI, 10% sodium ascorbate hydrogel after bleaching. The specimens were bonded with Clearfil SE Bond, then thermocycled and subjected to the shear test until failure. Fracture analysis of the bonded enamel surfaces was examined using a stereomicroscope. Statistical analysis was carried out using Kruskal-Wallis and the Mann-Whitney U-test. RESULTS: While the samples that were not treated with antioxidant after bleaching (group I) demonstrated significantly lower shear bond strengths and the 10% sodium ascorbate gel group (group VI) demonstrated significantly higher bond strengths than the control group (p < 0.05), no significant differences were found between the other groups and control group (p > 0.05). Among the antioxidant groups, only the groups treated with the 10% solution and the 10% hydrogel form of sodium ascorbate (group III and VI) revealed significantly higher bond strengths than the bleached group without antioxidant (group II) (p < 0.05). Higher scores were obtained with 10% sodium ascorbate gel (group VI) when compared with the other antioxidant-treated groups (p < 0.05). CONCLUSION: Within the limitations of this study, it can be concluded that the 10% hydrogel form of sodium ascorbate may be used in clinical procedures instead of its solution form. However, using sodium ascorbate hydrogel with concentrations lower than 10% may not be as reliable as using this agent in 10% concentration for reversing the compromised bond strength.

Reversal of compromised bonding in bleached enamel using antioxidant gel.

Many studies have shown a considerable reduction in the enamel bond strength of resin composite restorations when the bonding procedure is carried out immediately after bleaching. These studies claim that a certain waiting period is needed prior to performing the restoration in order to attain the original bond strength values. This study determined the most effective time duration for the application of sodium ascorbate prepared in gel form. The labial surfaces of 70 bovine incisors were polished with 600-grit silicon carbide paper on a water-irrigated metallurgical polishing wheel. The specimens were randomly divided into seven groups: 1) bleaching (10% Rembrandt Xtra-Comfort +) immersed in artificial saliva for seven days, 2) bonded immediately after bleaching, 3) bleaching + 10% sodium ascorbate (SA) gel for 10 minutes, 4) bleaching + 10% SA gel for 60 minutes, 5) bleaching + 10% SA gel for 120 minutes, 6) bleaching + 10% SA gel for 240 minutes and 7) bleaching + 10% SA gel for 480 minutes. After preparation, a standard-shaped resin composite was applied to all specimens. The teeth were stored in distilled water at 37 degrees C for 24 hours and a universal testing machine determined their shear bond strength. The data were evaluated using ANOVA and Tukey tests. Antioxidant gel proved to be effective for increasing the shear bond strength of the resin composite to enamel. For maximum effectiveness, antioxidant gel should be applied to enamel for at least 60 minutes. As the application period of the antioxidant increased, the bond strength of the composite on enamel tissue also increased. The increase noticed in Groups 5, 6 and 7 was statistically significant (p<0.05). Application of the antioxidant gel by the patient shortens the time spent in the clinic.