Validation of a UPLC-PDA method to study the content and stability of 5-chloro 8-hydroxyquinoline and 5,7-dichloro 8-hydroxyquinoline in medicated feed used in swine farming.

A new, rapid, simple and specific method to determine 5-chloro 8-hydroxyquinoline (5-HQ) and 5,7-dichloro 8-hydroxyquinoline (5,7-HQ) stability in swine feed was optimized and validated. A system consisting of an ACQUITY UPLC BEH C18 column (1.7 µm, 2.1 mm × 100 mm), a mobile phase of acetonitrile-0.1% o-phosphoric acid (55:45 v/v) with a 0.5 mL/min flow rate, and a PDA detector (247 nm) were used. The retention times of 5-HQ and 5,7-HQ, were 0.77 min and 1.6 min, respectively. The pure drug was subjected to acid and alkali hydrolysis, chemical oxidation and UV light degradation to perform forced degradation studies. 5,7-HQ was more susceptible to degradation than 5-HQ. The figures of merit of the method (linearity, accuracy, precision, and robustness) were determined. The method was successfully applied to estimate the stability of both analytes in medicated feed.

Liberación de pravastatina sódica formulada en matrices poliméricas a base de Quitosan/Pluronic F ̶ 127 / Release of pravastine sodium formulated in polymer chitosan/pluronic f-127 matrices

Introducción: el desarrollo de medicamentos transdérmicos manifiesta gran interés en los últimos años debido a las ventajas que ofrece; sin embargo, muchos de los sistemas desarrollados utilizan componentes solubles lo cual podría llevar a una ineficacia terapéutica si la matriz polimérica del sistema se solubiliza muy rápido, por ello se ensayan polímeros insolubles que permitan modular la liberación de un ingrediente farmacéuticamente activo. Objetivo: evaluar la liberación de pravastatina sódica en matrices poliméricas insolubles de quitosan/PF-127 con el método de paleta sobre disco para obtener su perfil cinético de liberación, con la finalidad de proponerse como matrices viables para la elaboración de parches transdérmicos. Métodos: se realizaron estudios de contenido químico, diámetro y espesor de las películas, calorimetrías de barrido diferencial y estudios de liberación. La cuantificación del principio activo se realizó mediante espectrofotometría UV-Vis a 238 nm. Resultados: se obtuvieron parches transdérmicos con buena uniformidad de contenido, espesor, diámetro, con una buena estabilidad en base a los estudios de calorimetría. El uso de PF-127 incrementó o retardó la liberación de pravastatina de la matriz polimérica dependiendo de su concentración y al realizarse los perfiles cinéticos de liberación las formulaciones se ajustaron a una cinética de orden 0 que describe el comportamiento de algunos sistemas transdérmicos. Conclusiones: los resultados manifiestan la posibilidad de usar esta matriz polimérica insoluble de quitosana con PF-127 para modular la liberación de pravastatina sódica y de fármacos con estructura similar a la misma por vía transdérmica, lo que generará de esta manera nuevas alternativas a las formas farmacéuticas orales para el tratamiento de padecimientos y enfermedades(AU)

Introduction: the development of transdermal drugs has aroused great interest in recent years due to their advantages, however many of the drug delivery systems use soluble matrix components which could trigger therapeutic problems due to a rapid release of the active ingredient. Therefore, insoluble polymers are being tested that can modulate the release of a pharmaceutically active ingredient. Objective: to evaluate the release of pravastatin sodium in insoluble polymer chitosan/PF-127 matrices by VER to obtain kinetic profile of release in order to submit them as viable systems for the manufacture of transdermal patches. Methods: studies on the chemical content, diameter and thickness of films, differential scanning calorimetry and release studies were performed. The UV-Vis spectrophotometry at 238 nm allowed quantitating the active principle. Results: transdermal patches with adequate uniform drug content, suitable thickness and diameter with good stability, based on calorimetric studies, were obtained. The use of PF-127 increased or delayed the release of pravastatin sodium from the polymeric matrix depending on concentration. When performing the kinetic profiles of release, the formulations were regulated to zero kinetic that describes the behavior of some transdernal systems. Conclusions: the results demonstrated the possibility of using these insoluble polymer chitosan/PF-127 matrices to modulate the release of pravastin sodium and of other structurally similar drugs, thus creating new alternatives to existing pharmaceutical oral forms for treatment of diseases(AU)

Microneedles: a valuable physical enhancer to increase transdermal drug delivery.

Transdermal drug delivery offers an attractive alternative to the conventional drug delivery methods of oral administration and injection. However, the stratum corneum acts as a barrier that limits the penetration of substances through the skin. Recently, the use of micron-scale needles in increasing skin permeability has been proposed and shown to dramatically increase transdermal delivery. Microneedles have been fabricated with a range of sizes, shapes, and materials. Most in vitro drug delivery studies have shown these needles to increase skin permeability to a broad range of drugs that differ in molecular size and weight. In vivo studies have demonstrated satisfactory release of oligonucleotides and insulin and the induction of immune responses from protein and DNA vaccines. Microneedles inserted into the skin of human subjects were reported to be painless. For all these reasons, microneedles are a promising technology to deliver drugs into the skin. This review presents the main findings concerning the use of microneedles in transdermal drug delivery. It also covers types of microneedles, their advantages and disadvantages, enhancement mechanisms, and trends in transdermal drug delivery.

Electroporation as an efficient physical enhancer for skin drug delivery.

Transdermal drug delivery offers an attractive alternative to the conventional drug delivery methods of oral administration and injection. However, the stratum corneum acts as a barrier that limits the penetration of substances through the skin. Application of high-voltage pulses to the skin increases its permeability (electroporation) and enables the delivery of various substances into and through the skin. The application of electroporation to the skin has been shown to increase transdermal drug delivery. Moreover, electroporation, used alone or in combination with other enhancement methods, expands the range of drugs (small to macromolecules, lipophilic or hydrophilic, charged or neutral molecules) that can be delivered transdermally. The efficacy of transport depends on the electrical parameters and the physicochemical properties of drugs. The in vivo application of high-voltage pulses is well tolerated, but muscle contractions are usually induced. The electrode and patch design is an important issue to reduce the discomfort of the electrical treatment in humans. This review presents the main findings in the field of electroporation-namely, transdermal drug delivery. Particular attention is paid to proposed enhancement mechanisms and trends in the field of topical and transdermal delivery.