Encapsulation of naproxen in nanostructured system: structural characterization and in vitro release studies

Nanoparticles were produced by solvent emulsification evaporation method with the following characteristics: nanometric size (238 ± 3 nm), narrow polydispersity index (0.11), negative zeta potential (-15.1 mV), good yield of the process (73 ± 1.5%), excellent encapsulation efficiency (81.3 ± 4.2%) and spherical shape. X-rays diffraction demonstrated the loss of drug crystallinity after encapsulation; however, the profile of the diffractograms of the poly-ε-caprolactone (PCL) nanoparticles was kept. Differential scanning calorimetry thermograms, correspondingly, exhibited the loss of drug melting peak and the increasing of the melting point of the PCL nanoparticles, evidencing an interaction drug-polymer. Naproxen release was low and sustained obeying the Higuchi´s kinetic. The results show that nanoparticles are promising sustained release system to the naproxen

HPLC assay of lidocaine in in vitro dissolution test of the Poloxamer 407 gels

Apresenta-se método simples de cromatografia líquida de alta eficiência (CLAE) para análise da lidocaína em meio aquoso, após estudo de liberação in vitro. A lidocaína foi analisada usando-se coluna LichroCART RP-18 (5 mm, 125x4 mm), fase móvel constituída de acetonitrila: tampão fosfato de sódio 0,05 M, pH 6 (35:65), adicionada de 0,05% de dietilamina com fluxo de 1 mL/min. O tempo de retenção foi de 7,9 min. O comprimento de onda de análise utilizado foi de 210 nm. A linearidade do método foi de 1,25 a 25 µg/mL com coeficiente de variação intraensaio e inter-ensaio menor que 3,5 %. A metodologia desenvolvida e validada mostrou sensibilidade e especificidade para a realização dos estudos propostos, considerando-se que as amostras obtidas a partir dos estudos de liberação in vitro contêm concentrações muito baixas do fármaco, além de outras substâncias do meio de dissolução que podem interferir no doseamento. A quantificação do fármaco e dos interferentes pode não ser possível se for efetuada por outras metodologias analíticas convencionais. Assim, o método desenvolvido é de grande importância para a quantificação do fármaco nas alíquotas obtidas nos ensaios de liberação in vitro.A simple high performance liquid chromatography method to assay lidocaine hydrochloride in aqueous receiving media, following in vitro release, is presented. Lidocaine hydrochloride was analysed using a 5 mm LichroCART® RP-18 column (125 x 4 mm i.d.). The mobile phase was acetonitrile: 0.05 M sodium phosphate buffer, pH 6.0 (35:65) and 0.05% of diethylamine at a flow rate of 1 mL/min. The retention time was 7.9 min. Detection was carried out at 210 nm at room temperature (28 ºC). The method was found to be linear in the range 1.25 to 25 mg/mL, showing average intraassay and inter-assay coefficients of variation below 3.5%. The proposed method was validated for linearity, specificity, precision and accuracy and was shown to be useful for the analysis of lidocaine hydrochloride in in vitro release studies

Preparation of extemporaneous oral liquid in the hospital pharmacy

At the hospital, the pharmacist is constantly challenged to prepare extemporaneous solutions from tablets, capsules or drug powder for patients unable to swallow, such as pediatric, elderly and patients that use nasoenteric and nasogastric tubes. The preparation of extemporaneous solutions from capsules, tablets and drug powder requires stability studies analysis. This article is a bibliographic review of preparation of extemporaneous oral liquid from solid oral dosage forms used in clinical practice. The selected articles contain all the information regarding manipulation techniques, pharmaceutical excipients, packaging, storage conditions and results of stability studies above 90% performed by HPLC analysis. In addition, a situational analysis of the strategies for the preparation of the extemporaneous solution was described to help the manipulator in the decision. The preparation of extemporaneous solution from solid oral dosage forms is based on information from official compendium or scientific literature, to ensure safe and effective manipulated medicine

l-Tyrosine-loaded nanoparticles increase the antitumoral activity of direct electric current in a metastatic melanoma cell model

Inhibition of tumor growth induced by treatment with direct electric current (DC) has been reported in several models. One of the mechanisms responsible for the antitumoral activity of DC is the generation of oxidative species, known as chloramines. With the aim of increasing chloramine production in the electrolytic medium and optimizing the antitumoral effects of DC, poly(ɛ-caprolactone) (PCL) nanoparticles (NPs) loaded with the amino acid tyrosine were obtained. The physical–chemical characterization showed that the NPs presented size in nanometric range and monomodal distribution. A slightly negative electrokinetic potential was also found in both blank NPs and l-tyrosine-loaded PCL NPs. The yield of the loading process was approximately 50%. Within 3 h of dissolution assay, a burst release of about 80% l-tyrosine was obtained. The in vitro cytotoxicity of DC was significantly increased when associated with l-tyrosine-loaded NPs, using a murine multidrug-resistant melanoma cell line model. This study showed that the use of the combination of nanotechnology and DC has a promising antineoplastic potential and opens a new perspective in cancer therapy

Improving the phototoxicity of the zinc phthalocyanine by encapsulation in nanoparticles: preparation, characterization and phototherapy studies

Nanoparticles are widely utilized to overcome drugs insolubility problems and sustain release improving the bioavailability. Zinc phthalocyanine, a hydrophobic photosensitizer with solubility problems, was loaded in PLA nanoparticles. Photosensitizer loaded in polymeric nanoparticles was produced with the following characteristics: size in the 200-300 nm range, negative zeta potential (-15 to -19 mV), low polydispersity index (2 ) or incubation time (2 to 4 h). The phototoxicity of the zinc phthalocyanine was improved by encapsulation in nanoparticles and this nanocarrier is a promising delivery system for photodynamic therapy use.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Development, characterization and evaluation of the dissolution profile of sulfasalazine suspensions

;O trabalho reporta o desenvolvimento, caracterização e estudo ;in vitro; de dissolução de suspensões de sulfassalazina para uso em doenças inflamatórias crônicas intestinais. Desenvolveram-se três formulações baseadas em fornecedores diferentes de pó de sulfassalazina. A sulfassalazina foi caracterizada quanto a Teor, Infravermelho por Transformada de Fourier (FTIR), Calorimetria Diferencial de Varredura (DSC), Difração de Raios-X (XRD), distribuição de tamanho das partículas, índice de polidispersão e solubilidade. A suspensão foi desenvolvida e caracterizada quanto a pH, viscosidade, densidade, tamanho de partícula, volume de sedimentação, teor e estudo de dissolução. Os valores de pH determinados foram levemente ácidos. O método de preparo das suspensões reduziu o tamanho das partículas e tornou a distribuição de tamanho mais homogênea. Os estudos de dissolução mostraram que a suspensão de sulfassalazina tem problemas de solubilidade em meios de caráter ácido, entretanto, sofre dissolução rápida acima de 85% em meios neutros ou contendo 0,5% de tensoativos como Polissobato 80. Além disso, as suspensões de sulfassalazina foram classificadas como formulações de dissolução imediata porque a partir de 20 minutos sofrem dissolução em torno de 100%.;This paper reports the development, characterization and;in vitro;dissolution behavior of sulfasalazine suspensions for treatment of chronic intestinal inflammatory diseases. Three formulations were developed, from powdered sulfasalazine obtained from different suppliers. The sulfasalazine was characterized regarding concentration, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), X-Ray Diffraction (XRD), particle size distribution, polydispersion and solubility. The suspensions were developed and characterized regarding pH, viscosity, density, particle size, sedimentation volume, concentration and dissolution. The pH values were slightly acidic. The method of preparing the suspensions reduced the particle sizes and made the size distribution more homogeneous. The dissolution studies showed that the sulfasalazine suspensions had low solubility in acidic media, but dissolve quickly, reaching levels of 85%, in neutral media or media containing 0.5% of surfactants such as polysorbate 80. Besides this, the sulfasalazine suspensions were classified as having immediate dissolution because they reached dissolution levels near 100% in 20 minutes

Nanoemulsão óleo em água e seu processo de produção

DepositadaA presente invenção descreve uma nanoemulsão óleo em água consistida de entre 5 a 40% massa/massa (m/m) de ao menos um tensoativo, entre 1 a 50% m/m de ao menos um óleo; e, opcionalmente, aproximadamente 30% um ou mais solventes; seu processo de produção e ainda, seu uso na veiculação de compostos hidrofóbicos, podendo ser fármaco, cosmético, vitamina ou um composto alimentar

Macromolecular confinement of therapeutic protein in polymeric particles for controlled release: insulin as a case study

Sustained release systems for therapeutic proteins have been widely studied targeting to improve the action of these drugs. Molecular entrapping of proteins is particularly challenging due to their conformational instability. We have developed a micro-structured poly-epsilon-caprolactone (PCL) particle system loaded with human insulin using a simple double-emulsion w/o/w method followed by solvent evaporation method. This formulation is comprised by spheric-shaped microparticles with average size of 10 micrometers. In vitro release showed a biphasic behavior such as a rapid release with about 50% of drug delivered within 2 hours and a sustained phase for up to 48 h. The subcutaneous administration of microencapsulated insulin showed a biphasic effect on glycemia in streptozotocin-induced diabetic mice, compatible with short and intermediate-acting behaviors, with first transition peak at about 2 h and the second phase exerting effect for up to 48h after s.c. administration. This study reveals that a simplified double-emulsion system results in biocompatible human-insulin-loaded PCL microparticles that might be used for further development of optimized sustained release formulations of insulin to be used in the restoration of hormonal levels

Thermoresponsive Hydrogel Containing Viscum album Extract for Topic and Transdermal Use: Development, Stability and Cytotoxicity Activity

Viscum album L. (Santalaceae), also known as European mistletoe, is a semi-parasitic plant that grows on different host trees. Our group recently demonstrated the antitumoral activity of ethanolic V. album extracts in vitro, depending on the dose and the host tree, V. album ssp abietis from Abies alba being the most active extract. The goal of this work focused on the development of a new topical formulation containing V. album extracts, evaluation of in vitro toxicity and ex vivo skin permeation assays. The Poloxamer 407 hydrogel containing 5% of dry (VA_DEH) or aqueous (VA_AEH) extract presented dermal compatible pH and microbiological stability for 180 days. The hydrogels flow curve presented a non-linear relation, characteristic of non-Newtonian fluids, and the mean viscosity for the VA_DEH and VA_AEH was 372.5 ± 7.78 and 331.0 ± 2.83 Pa.s, respectively, being statistically different (Welch’s t test; p < 0.01). Additionally, WST-1 in vitro assays revealed a dose-dependent toxicity for both formulations and VA_DEH presented a higher activity than the VA_AEH. The promising cytotoxic potential of VA_DEH lead to the ex vivo skin permeation assay with 2.73 ± 0.19 µg/cm(2) of chlorogenic acid, which permeated at 8 h, showing a transdermal potential. These in vitro results support the idea that VA_DEH is a novel promising candidate for mistletoe therapy. Therefore, further in vivo and pre-clinical experiments should be performed to evaluate the safety and efficacy of this new dermic delivery system