Nano-engineering of ketorolac tromethamine platforms for ocular treatment of inflammatory disorders.

Aim: The development and optimization of Ketorolac tromethamine-loaded polylactic-co-glycolic acid nanoparticles (KT-NPs) for the treatment of inflammatory processes of the eye. Materials & methods: KT-NPs were developed by factorial design and characterized by assessing their physicochemical properties. Biopharmaceutical behavior studies, ocular tolerance, anti-inflammatory efficacy and bioavailability tests were performed on pigs. Results: Optimized KT-NPs of 112 nm, narrow distribution with encapsulation efficiency near 100% were obtained. KT release followed the Weibull model and there was significantly greater retention in the cornea and sclera than in the commercial reference. KT-NPs showed no signs of ocular irritancy and similar anti-inflammatory efficacy to the commercial reference. Conclusion: KT-NPs were a suitable alternative for the treatment of inflammatory disorders of the anterior and posterior segments of the eye as an alternative to conventional topical formulations.

Carprofen Permeation Test through Porcine Ex Vivo Mucous Membranes and Ophthalmic Tissues for Tolerability Assessments: Validation and Histological Study.

Carprofen (CP), a non-steroidal anti-inflammatory drug (NSAID), is profusely used in veterinary medicine for its analgesic and anti-inflammatory activity. Some undesirable effects are associated with its systemic administration. Alternative local routes are especially useful to facilitate its administration in animals. The main aim of this paper is to validate the suitability of ex vivo permeation experiments of CP with porcine mucous membranes (buccal, sublingual and vaginal) and ophthalmic tissues (cornea, sclera and conjunctiva) intended to be representative of naïve in vivo conditions. Chromatographic analysis of CP in membrane-permeated samples and drug-retained have been validated following standard bioanalytical guidelines. Then, recovery levels of drugs in tissue samples were assessed with aqueous phosphate buffered saline (PBS) buffer to preserve the histological integrity. Finally, as a proof of concept, a series of CP permeation tests in vertical Franz diffusion cells has been performed to evaluate permeation flux and permeability constants in all tissues, followed by a histological study for critical evaluation. Furthermore, synthetic tissue retention-like samples were prepared to verify the value of this experimental study. Results show linear relationships with good determination coefficient (R2 > 0.998 and R2 > 0.999) in the range of 0.78 to 6.25 mg/mL and 3.125 mg/mL to 100 mg/mL, respectively. Low limits of quantification around 0.40 µg/mL were allowed to follow permeation levels until a minimum of 0.40% of the locally-applied dose. This method showed a good accuracy and precision with values lower than 2%. After the recovery technique, reproducible values below 30% were achieved in all tissues, suggesting it is a non-damaging method with low efficiency that requires the use of further solvents to enhance the extraction percentages. After permeation and histology tests, no relevant peak interferences were detected, and no cell or tissue damage was found in any tissue. In conclusion, results demonstrate the suitability of this test to quantify the distribution of CP with good histological tolerability.

Ex Vivo Permeation of Carprofen Vehiculated by PLGA Nanoparticles through Porcine Mucous Membranes and Ophthalmic Tissues.

(1) Background: Carprofen (CP), 2-(6-chlorocarbazole) propionic acid, is used as an anti-inflammatory, analgesic and anti-pyretic agent and it belongs to the family of non-steroidal anti-inflammatory drugs (NSAIDs). CP has some adverse reactions in systemic administration; for this reason, topical administration with CP nanoparticles (CP-NPs) can be an optimal alternative. The main objective of this work is the investigation of ex vivo permeation of CP through different types of porcine mucous membranes (buccal, sublingual and vaginal) and ophthalmic tissues (cornea, sclera and conjunctiva) to compare the influence of CP-NPs formulation over a CP solution (CP-Solution). (2) Methods: The ex vivo permeation profiles were evaluated using Franz diffusion cells. Furthermore, in vivo studies were performed to verify that the formulations did not affect the cell structure and to establish the amount retained (Qr) in the tissues. (3) Results: Permeation of CP-NPs is more effective in terms of drug retention in almost all tissues (with the exception of sclera and sublingual). In vivo studies show that neither of the two formulations affects tissue structure, so both formulations are safe. (4) Conclusions: It was concluded that CP-NPs may be a useful tool for the topical treatment of local inflammation in veterinary and human medicine.

Ex vivo permeation of carprofen from nanoparticles: A comprehensive study through human, porcine and bovine skin as anti-inflammatory agent.

The purpose of this study was the development of poly(d,l-lactide-co-glycolide) acid (PLGA) nanoparticles (NPs) for the dermal delivery of carprofen (CP). The developed nanovehicle was then lyophilized using hydroxypropyl-ß-cyclodextrin (HPßCD) as cryoprotectant. The ex vivo permeation profiles were evaluated using Franz diffusion cells using three different types of skin membranes: human, porcine and bovine. Furthermore, biomechanical properties of skin (trans-epidermal water loss and skin hydration) were tested. Finally, the in vivo skin irritation and the anti-inflammatory efficacy were also assayed. Results demonstrated the achievement of NPs 187.32 nm sized with homogeneous distribution, negatively charged surface (-23.39 mV) and high CP entrapment efficiency (75.38%). Permeation studies showed similar diffusion values between human and porcine skins and higher for bovine. No signs of skin irritation were observed in rabbits. Topically applied NPs significantly decreased in vivo inflammation compared to the reference drug in a TPA-induced mouse ear edema model. Thus, it was concluded that NPs containing CP may be a useful tool for the dermal treatment of local inflammation.

Design and elaboration of freeze-dried PLGA nanoparticles for the transcorneal permeation of carprofen: Ocular anti-inflammatory applications.

This work aimed the design and development of poly(lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) for the ocular delivery of Carprofen (CP) by a central rotatable composite design 2(3)+ star. NPs showed adequate size for ocular administration (189.50 ± 1.67 nm), low polydispersity (0.01 ± 0.01), negative charge surface (-22.80 ± 0.66 mV) and optimal entrapment efficiency (74.70 ± 0.95%). Physicochemical analysis confirmed that CP was dispersed inside the NPs. The drug release followed a first order kinetic model providing greater sustained CP release after lyophilization. Ex vivo permeation analysis through isolated rabbit cornea revealed that a sufficient amount of CP was retained in the tissue avoiding excessive permeation and thus, potential systemic levels. Ex vivo ocular tolerance results showed no signs of ocular irritancy, which was also confirmed by in vivo Draize test. In vivo ocular anti-inflammatory efficacy test confirmed an optimal efficacy of NPs and its potential application in eye surgery.

Biopharmaceutical profile of pranoprofen-loaded PLGA nanoparticles containing hydrogels for ocular administration.

Two optimized pranoprofen-loaded poly-l-lactic-co glycolic acid (PLGA) nanoparticles (PF-F1NPs; PF-F2NPs) have been developed and further dispersed into hydrogels for the production of semi-solid formulations intended for ocular administration. The optimized PF-NP suspensions were dispersed in freshly prepared carbomer hydrogels (HG_PF-F1NPs and HG_PF-F2NPs) or in hydrogels containing 1% azone (HG_PF-F1NPs-Azone and HG_PF-F2NPs-Azone) in order to improve the ocular biopharmaceutical profile of the selected non-steroidal anti-inflammatory drug (NSAID), by prolonging the contact of the pranoprofen with the eye, increasing the drug retention in the organ and enhancing its anti-inflammatory and analgesic efficiency. Carbomer 934 has been selected as gel-forming polymer. The hydrogel formulations with or without azone showed a non-Newtonian behavior and adequate physicochemical properties for ocular instillation. The release study of pranoprofen from the semi-solid formulations exhibited a sustained release behavior. The results obtained from ex vivo corneal permeation and in vivo anti-inflammatory efficacy studies suggest that the ocular application of the hydrogels containing azone was more effective over the azone-free formulations in the treatment of edema on the ocular surface. No signs of ocular irritancy have been detected for the produced hydrogels.

Validation of a high performance liquid chromatography method for the stabilization of epigallocatechin gallate.

Epigallocatechin gallate (EGCG) is a green tea catechin with potential health benefits, such as anti-oxidant, anti-carcinogenic and anti-inflammatory effects. In general, EGCG is highly susceptible to degradation, therefore presenting stability problems. The present paper was focused on the study of EGCG stability in HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid) medium regarding the pH dependency, storage temperature and in the presence of ascorbic acid a reducing agent. The evaluation of EGCG in HEPES buffer has demonstrated that this molecule is not able of maintaining its physicochemical properties and potential beneficial effects, since it is partially or completely degraded, depending on the EGCG concentration. The storage temperature of EGCG most suitable to maintain its structure was shown to be the lower values (4 or -20 °C). The pH 3.5 was able to provide greater stability than pH 7.4. However, the presence of a reducing agent (i.e., ascorbic acid) was shown to provide greater protection against degradation of EGCG. A validation method based on RP-HPLC with UV-vis detection was carried out for two media: water and a biocompatible physiological medium composed of Transcutol®P, ethanol and ascorbic acid. The quantification of EGCG for purposes, using pure EGCG, requires a validated HPLC method which could be possible to apply in pharmacokinetic and pharmacodynamics studies.

Nanoemulsions (NEs), liposomes (LPs) and solid lipid nanoparticles (SLNs) for retinyl palmitate: effect on skin permeation.

The aim of this study was to develop biocompatible lipid-based nanocarriers for retinyl palmitate (RP) to improve its skin delivery, photostability and biocompatibility, and to avoid undesirable topical side effects. RP loaded nanoemulsions (NEs), liposomes (LPs) and solid lipid nanoparticles (SLNs) were characterized in terms of size, surface electrical charge, pH, drug encapsulation efficiency and morphology. Spherical-shaped nanocarriers with a negatively charged surface (>|40|mV) and mean size lower than 275 nm were produced with adequate skin compatibility. The rheological properties showed that aqueous dispersions of SLNs followed a non-Newtonian behavior, pseudoplastic fluid adjusted to Herschel-Bulkley equation, whereas LPs and NEs exhibited a Newtonian behavior. SLNs offered significantly better photoprotection than LPs and NEs for RP. The cumulative amount of drug permeated through human skin at the end of 38 h was 6.67 ± 1.58 µg, 4.36 ± 0.21 µg and 3.64 ± 0.28 µg for NEs, LPs and SLNs, respectively. NEs flux was significantly higher than SLNs and LPs: NEs (0.37 ± 0.12 µg/h) > LPs (0.15 ± 0.09 µg/h) > SLNs (0.10 ± 0.05 µg/h). LPs offered significant higher skin retention than NEs and SLNs. Finally, even though all developed nanocarriers were found to be biocompatible, according to histological studies, NE was the system that most disrupted the skin. These encouraging findings can guide in proper selection of topical carriers among the diversity of available lipid-based nanocarriers, especially when a dermatologic or cosmetic purpose is desired.

Semisolid formulations containing cetirizine: human skin permeation and topical antihistaminic evaluation in a rabbit model.

Cetirizine dihydrochloride (CTZ) is a second-generation histamine H1 antagonist, effective for the treatment of a wide range of allergic diseases. It has been utilized for managing the symptoms of chronic urticaria and atopic skin conditions. Thus, two novel semisolid formulations, nanoemulsion (NE) and hydrogel (HG) were developed to study their potential utility as vehicles including cetirizine (CTZ) and evaluate the potential use as topical H1-antihistamines agents. The physicochemical and stability properties of both vehicles were tested. Drug release kinetics and human skin permeation studies were performed using Franz cells. The antihistaminic activity was assayed in New Zealand rabbits and compared with two commercial first generation antihistamines. Both formulations were stable and provided a sustained drug release. Amounts of CTZ remaining in the skin were higher for HG, showing the maximum biological effect at 30 min, similar to topical first generation H1-antihistamines commercially available. These results suggest that CTZ-HG could be a promising system for the treatment of topical allergy bringing rapid antihistaminic relief.

[front][ign][titlegrp][ign][title language=es]Evaluación de cuatro métodos de detección del celo en novillas de doble propósito / Evaluation of Four Methods for Heat Detection in Dual Purpose Heifers

Un programa de Inseminación Artificial (IA) exitoso depende estrechamente de la eficiencia en la detección del celo. Se estima que la detección del celo se encuentra por debajo del 50% en la mayoría de los rebaños lecheros. En este orden de ideas, el objetivo del presente trabajo fue evaluar cuatro métodos de detección de celo que incluyen: Observación Visual (OV), Creyones Marcadores (CM), Kamar™ (K) y Estrotect™ (E). El ensayo se llevó a cabo en el fundo Tasajeras, ubicado en Encontrados, municipio Catatumbo, estado Zulia, Venezuela; utilizando 200 novillas mestizas doble propósito (DP) seleccionadas a través de un muestreo aleatorio simple, distribuidas en cuatro grupos experimentales, conformados por 50 animales cada uno. Grupo 1, Observación Visual; Grupo 2, aplicación de Creyones Marcadores; Grupo 3, colocación del dispositivo Kamar™; Grupo 4, aplicación del parche Estrotect™. En las novillas detectadas en celo se procedió a tomar una muestra de sangre de la vena yugular para determinar las concentraciones séricas de progesterona mediante la utilización de la técnica de radioinmunoanálisis (RIA). El diseño experimental consideró como variable dependiente el celo y como variable discreta e independiente el efecto del método de detección de celo. Todos los datos recopilados fueron analizados a través del procedimiento logístico (Proc Logistic) del SAS. Los resultados obtenidos arrojan una efectividad de 96% para el método de OV, 94% para E, 84% para K y un 14% para CM. Al mismo tiempo se presenta una diferencia significativa (P<0,05) entre el método OV vs CM y OV vs K, no demostrándose diferencia significativa (P>0,05) entre OV y el método K. Estos resultados indican que la participación del técnico inseminador (OV) en los programas de IA es insustituible, ratificándose una vez más la importancia de la OV como método efectivo para detectar celos.

A successful Artificial Insemination (AI) program depends strictly on heat detection. It is considered that heat detection rates are lower than 50% percent in most dairy herds. The purpose of this study was to evaluate four different methods for heat detection which include: Visual Observation (VO), Tail Painting (TP), Kamar™ (K) and Estrotect™ (E). The study was performed at Fundo Tasajeras, located in Encontrados, municipality of Catatumbo, state of Zulia, Venezuela; using 200 Dual Purpose Crossbreed Heifers (DP) selected using simple randomized sampling (SRS), which were gathered in four experimental groups of 50 animals each: Group 1, Visual Observation; Group 2, Tail Painting procedure; Group 3, placement of the Kamar™ Device; Group 4, using Estrotect™ patch. In heifers with heat detected, a blood sample was taken from the yugular vein in order to determine serum progesterone concentrations (P4), by using the radioinmunoanalysis technique (RIA). The experimental design, the method for heat detection was considered as an independent and discrete variable and for dependent variable was heat. All the gathered data were analyzed by using the Logistic Procedure (Proc Logistic) as per SAS. The results showed an effectiveness of 96% for the VO method, 94% for E, 84% for K, and 14% for TP. At the same time, significant differences (P<0.05) were found when comparing VO vs. TP and OV vs. K, unlike with the methods VO vs. K where no significant differences were evident (P>0.05). These results showed that the participation of insemination technicians (VO) in the programs of AI is a must, thus making evident the importance of the VO as an effective method for detecting heat.

[Intrathoracic kidney in a newborn with breathing difficulty syndrome secondary to congenital diaphragmatic hernia]. / Riñón intratorácico en recién nacido con síndrome de dificultad respiratoria por hernia diafragmática congénita.

UNLABELLED: Congenital diaphragmatic hernia (CDH) is found frequently in from 0.17 to 0.57 among 1000 newborns and is associated with intrathoracic kidney (IK) in 0.25%. The objective of the present work was to describe both present pathologies in a newborn and to review the literature in this respect. CLINICAL CASE: male newborns, who presented tachypnea sudden and persistent for the first 24 h of life. For the that was physical exam, we included breathing difficult, (eight points of Silverman's) and cyanosis; initial arterial gases: hypoxemia and hypocapnia (acute respiratory failure type I); thorax X-ray; increase of bronchial plot and of parahiliary density; normal lungs, pleuro-peritoneal membrane and solid mass superimposed on heart silhouette were observed and confirmed by echocardiogram. Computed axial tomography (CAT) revealed left kidney and part of spleen inside thorax, beside inferior lobe of left lung. Immediately, the patient was mechanically ventilated and after 2 days, was operated surgically for correction of CDH and descent of left kidney. After surgical intervention, initial symtomatology disappeared and evolution was satisfactory. The present case illustrates how the kidney on occasion can emigrate due to congenital default to the thorax of the wall of the diaphragm and be a casual discovery at the moment of radiologic exploration.

Riñón intratorácico en recién nacido con síndrome de dificultad respiratoria por hernia diafragmática congénita

La hernia diafragmática congénita (HDC) se presenta con frecuencia de 0.17 a 0.57 por 1000 recién nacidos vivos y se asocia con riñón intratorácico (RI) en 0.25%. El objetivo del presente trabajo es describir las dos patología presentes en un neonato y revisar la literatura al respecto. Caso clínico: recién nacido, masculino, quien a las cuatro horas de vida presentó taquipnea de aparición súbita y persistente. Al examen físico: dificultad respiratoria (Silverman de ocho puntos) y cianosis; gases arteriales a su ingreso: hipoxemia e hipocapnia (insuficiencia respiratoria tipo I). Radiografía de tórax: aumento discreto de la trama bronquial y de la densidad parahiliar; pulmones normales, evidencia de membrana pleuroperitoneal y masa sólida superpuesta sobre silueta cardiaca, confirmada por ecocardiograma. Tomografía axial computada (TAC): riñón izquierdo y parte de bazo dentro del tórax, al lado del lóbulo inferior del pulmón izquierdo. Inmediatamente se le instaló al paciente ventilación mecánica convencional y dos días después, se intervino quirúrgicamente para corrección de HDC y descenso de riñón izquierdo. Posterior al acto operatorio, desapareció la sintomatología inicial y su evolución posterior fue satisfactoria. El presente caso ilustra como el riñón en ocasiones puede emigrar al tórax por defecto congénito de la pared del diafragma y ser un hallazgo causal al momento de la exploración radiológica.

Congenital diaphragmatic hernia (CDH) is found frequently in from 0.17 to 0.57 among 1000 newborns and is associated with intrathoracic kidney (IK) in 0.25%. The objective of the present work was to describe both present pathologies in a newborn and to review the literature in this respect. Clinical case: male newborns, who presented tachypnea sudden and persistent for the first 24 h of life. For the that was physical exam, we included breathing difficulty (eight points of Silverman's) and cyanosis; initial arterial gases: hypoxemia and hypocapnia (acute respiratory failure type I); thorax X-ray; increase of bronchial plot and of parahiliary density; normal lungs, pleuroperitoneal membrane and solid mass superimposed on heart silhouette were observed and confirmed by echocardiogram. Computed axial tomography (CAT) revealed left kidney and part of spleen inside thorax, beside inferior lobe of left lung. Immediately, the patient was mechanically ventilated and after 2 days, was operated sourgically for correction of CDH and descent of left kidney. After surgical intervention, initial syntomatology disappeared and evolution was satisfactory. The present case illustrates how the kidney on occasion can emigrate due to congenital default to the thorax of the wall of the diaphragm and be a casual discovery at the moment of radiologic exploration.