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Papers by Victoria Girona
Bollettino chimico farmaceutico
The stability of vinblastine sulphate diluted in 0.9% sodium chloride solution for injection was ... more The stability of vinblastine sulphate diluted in 0.9% sodium chloride solution for injection was studied. Vinblastine sulphate was reconstituted with 0.9% sodium chloride solution for injection to concentration of 1.0 mg/mL and stored in polypropylene syringes at 25 degrees C +/- 1 degree C protected from light. On different days the solutions were analysed and the vinblastine concentration was determined by high-performance liquid chromatography. An high-pressure liquid chromatographic method is described for the quantitative determination of vinblastine in the presence of its degradation products. The degradation of vinblastine was studied by examining the percentage changes from the theoretical concentrations for each solution. The results of these studies indicate that vinblastine solutions in 0.9% sodium chloride solution for injection (1 mg/mL) in polypropylene syringes at 25 degrees C +/- 1 degree C protected from light are stable for up to one month.
International Journal of Pharmaceutics, 1997
A degradation pathway for carboplatin in aqueous solution is described. Degraded solutions of car... more A degradation pathway for carboplatin in aqueous solution is described. Degraded solutions of carboplatin in water and in 5% glucose solution were analysed by high performance liquid chromatography; carboplatin and its degradation products were well separated. Three degradation products of carboplatin have been determined either in pure water and 5% glucose solution and they have been identified as l,l-cyclobutanedicarboxilate anion, its protonated forms and cis-diamminediaquoplatinum (II) complex.
The Journal of Physical Chemistry B, 2010
Time-lapse atomic force microscopy is used in this contribution to directly watch the growth of n... more Time-lapse atomic force microscopy is used in this contribution to directly watch the growth of nanofibers of a lipidated peptide on a mica surface. Specifically, the studied lipopeptide is the palmitoyl derivative of the fragment 505-514 of NS3 protein from the hepatitis G virus, abbreviated as Palmitoyl-NS3 (505-514). Data on the morphology, growth rate, and orientation of these peptide-amphiphile nanofibers have been obtained. From these data, it can be concluded that this synthetic lipopeptide forms two types of fiber-like aggregates: (i) half-spherical fibrous aggregates with lengths of hundreds of nanometers and (ii) spherical fibrous aggregates with lengths of several micrometers. In addition, when a fresh lipopeptide aqueous solution is deposited onto a mica surface, the aggregates spontaneously orient parallel to each other, yielding well-aligned nanofibers on large areas of the mica surface. A significant growth in both the length and the number of the fibers was observed during the first minutes after the solution deposition. Elongation of the fibrous aggregates from one end is more frequent, though elongation from both ends also occurs, with growth rates in the 4-5 nm/s range. The effects of dilution, mechanical perturbation, and pH on the aggregation behavior of Palmitoyl-NS3 (505-514) are also detailed in this paper.
Journal of Molecular Catalysis B: Enzymatic, 2003
Biochemistry, 2000
Small unilamelar vesicles of anionic phospholipids (SUV), such as 1-palmitoyl-2-oleoylglycerosn-3... more Small unilamelar vesicles of anionic phospholipids (SUV), such as 1-palmitoyl-2-oleoylglycerosn-3-phosphoglycerol (POPG), provide an interface where Thermomyces lanuginosa triglyceride lipase (TlL) binds and adopts a catalytically active conformation for the hydrolysis of substrate partitioned in the interface, such as tributyrin or p-nitrophenylbutyrate, with an increase in catalytic rate of more than 100-fold for the same concentration of substrate [Berg et al. (1998) Biochemistry 37, 6615-6627.]. This interfacial activation is not seen with large unilamelar vesicles (LUV) of the same composition, or with vesicles of zwitterionic phospholipids such as 1-palmitoyl-2-oleoylglycero-sn-3-phosphocholine (POPC), independently of the vesicle size. Tryptophan fluorescence experiments show that lipase binds to all those types of vesicles with similar affinity, but it adopts different forms that can be correlated with the enzyme catalytic activity. The spectral change on binding to anionic SUV corresponds to the catalytically active, or "open" form of the enzyme, and it is not modified in the presence of substrate partitioned in the vesicles, as demonstrated with inactive mutants. This indicates that the displacement of the lid characteristic of lipase interfacial activation is induced by the anionic phospholipid interface without blocking the accessibility of the active site to the substrate. Experiments with a mutant containing only Trp89 in the lid show that most of the spectral changes on binding to POPG-SUVs take place in the lid region that covers the active site; an increase in Trp anisotropy indicates that the lid becomes less flexible in the active form, and quenching experiments show that it is significantly buried from the aqueous phase. On the other hand, results with a mutant where Trp89 is changed to Leu show that the environment of the structural tryptophans in positions 117, 221, and 260 is somehow altered on binding, although their mobility and solvent accessibility remains the same as in the inactive form in solution. The form of TlL bound to POPC-SUV or-LUV vesicles as well as to LUV vesicles of POPG has the same spectral signatures and corresponds to an inactive or "closed" form of the enzyme. In these interfaces, the lid is highly flexible, and Trp89 remains accessible to solvent. Resonance energy transfer experiments show that the orientation of TlL in the interface is different in the active and inactive forms. A model of interaction consistent with these data and the available X-ray structures is proposed. This is a unique system where the composition and physical properties of the lipid interface control the enzyme activity. † Financial support from the E. C. (BIO4-97-2365) is gratefully acknowledged. Y.C. is supported by the Ministry for Science of Spain.
Journal of Pharmaceutical and Biomedical Analysis, 1994
The degradation of carboplatin (3.2 mg ml-1) in 5% glucose infusion solution at 25 degrees C and ... more The degradation of carboplatin (3.2 mg ml-1) in 5% glucose infusion solution at 25 degrees C and protected from light was investigated. The effects of the material of the container and temperature were also studied. Solutions were prepared in 5% glucose solution and stored in glass bottles, polyethylene (PE) and polypropylene (PP) containers at 40, 50 and 60 degrees C and at 25 degrees C +/- 1 degrees C. Samples were assayed by an HPLC method to determine the residual carboplatin concentration at each time of sampling. Carboplatin degradation followed pseudo-first-order kinetics and no dependence on the nature of the container was found. After 1 month at 25 degrees (+/- 1 degrees)C the change in carboplatin concentration was < 2% of the initial concentration in 5% glucose. These results are in agreement with those predicted by the application of the Arrhenius equation.
Biochimica Et Biophysica Acta-Biomembranes, 2014
Els estudiants del Grau de CTA i de NHD realitzen la docencia practica a la ULD, unitat gestionad... more Els estudiants del Grau de CTA i de NHD realitzen la docencia practica a la ULD, unitat gestionada segons el model EFQM. Per tal de coneixer el seu grau d’aprenentatge en relacio a la gestio de la qualitat total, s’ha alimentat una enquesta en iniciar i finalitzar les primeres practiques que els estudiants realitzen en aquests ensenyaments. Els resultats posen de manifest una millora en la seva formacio pel que fa a aspectes de gestio de la qualitat, seguretat, gestio de residus i sostenibilitat.
The beneficial effect of co-infection with the GB virus C (GBV-C) in HIV-infected patients has be... more The beneficial effect of co-infection with the GB virus C (GBV-C) in HIV-infected patients has been described (1), although its mechanism of action is yet to be determined. The physical principles governing interactions between peptides and lipids and peptide-peptide in lipid environments are important in the design of peptides with therapeutic properties, such as enveloped virus entry inhibiting peptides. P6-2-VIR576 (VIRLCDCPNGPWVWVPAVCQAVG) showed high potency in HIV replication trials performed on TZM-bl cells (2) thus, it was selected to ulterior studies. Here we investigate the importance of lipid phase in the interaction of P6-2-VIR576 with anionic lipid membrane systems composed by DMPC/DMPS (3:2) and DPPC/DPPS (3:2) by fluorescence spectrometry. The interaction was assessed by binding and quenching experiments. Binding experiments showed that the peptide interacts with DMPC/DMPS (3:2). Concerning acrylamide quenching assays figure 1 shows the quenching profiles in the prese...
Este estudio se ha podido llevar a cabo gracias a un Ajut per a Projectes d'Innovacio Docent ... more Este estudio se ha podido llevar a cabo gracias a un Ajut per a Projectes d'Innovacio Docent (UB, 2008PID-UB/117) a la Unidad de Audiovisuales de la UB y a todos los miembros del Personal de Administracion y Servicios de la ULD.
Un dels objectius de la ULD es millorar les competencies dels futurs graduats de la Facultat de F... more Un dels objectius de la ULD es millorar les competencies dels futurs graduats de la Facultat de Farmacia de la Universitat de Barcelona mitjancant la formacio addicional que es deriva de la implantacio del sistema de gestio de la qualitat en els laboratoris docents. Amb la finalitat de coneixer el grau d’aprenentatge dels estudiants que realitzen les practiques a la ULD en relacio a la gestio de la qualitat total, s’ha enquestat als estudiants en iniciar i un cop finalitzades les primeres practiques que realitzen en l’ensenyament de Farmacia. Els resultats posen de manifest una millora en la formacio en aspectes de gestio de la qualitat, seguretat, gestio de residus i sostenibilitat.
Colloids and Surfaces A: Physicochemical and Engineering Aspects
Abstract This study is an extension of our previous paper on the interaction of AcP6-2 and the VI... more Abstract This study is an extension of our previous paper on the interaction of AcP6-2 and the VIR576 peptides with DPPC: DPPS (3:2) and DMPC: DMPS (3:2) model membranes [Colloids and Surfaces A. 532 (2017) 483–492]. In the present contribution, the temperature effect and the role of the lipid phase in the lipid-peptide interaction were investigated. Moreover at the same time, relating them to HIV-1 FP inhibition. Several biophysics experiments as lipid-peptide binding, Trp fluorescence quenching and Atomic Force Microscopy (AFM) visualization were used to evidence the different interaction of the peptide depending on the physical state of the lipids. In addition, the inhibition effect of HIV-1 FP by P6-2 VIR576 peptide was conducted by fluorescence resonance energy transfer (FRET) and also by AFM microscopy. P6-2VIR576 showed a preference to the liquid crystalline phases from where the peptide can diffuse and interact with the gel phases. Firstly, P6-2VIR576 induces a rigidifying of the membrane to finally, promote the vanishing of these gel phases. Concerning to the inhibition of HIV-1 FP peptide by P6-2VIR576 peptide, FRET and AFM results evidencing P6-2VIR576 peptide is a promising structure to be in mind in the development of new or improved drugs in HIV therapies.
Colloids and Surfaces A: Physicochemical and Engineering Aspects
International Journal of Pharmaceutics
A new method is described for the determination of the broad-spectrum antibiotic Azlocillin sodiu... more A new method is described for the determination of the broad-spectrum antibiotic Azlocillin sodium by HPLC. This method is useful for stability studies, since it allows the separation of Azlocillin from its degradation products. This has been checked by TLC.
Revista Del Congres Internacional De Docencia Universitaria I Innovacio, Mar 12, 2015
Bollettino chimico farmaceutico
The stability of vinblastine sulphate diluted in 0.9% sodium chloride solution for injection was ... more The stability of vinblastine sulphate diluted in 0.9% sodium chloride solution for injection was studied. Vinblastine sulphate was reconstituted with 0.9% sodium chloride solution for injection to concentration of 1.0 mg/mL and stored in polypropylene syringes at 25 degrees C +/- 1 degree C protected from light. On different days the solutions were analysed and the vinblastine concentration was determined by high-performance liquid chromatography. An high-pressure liquid chromatographic method is described for the quantitative determination of vinblastine in the presence of its degradation products. The degradation of vinblastine was studied by examining the percentage changes from the theoretical concentrations for each solution. The results of these studies indicate that vinblastine solutions in 0.9% sodium chloride solution for injection (1 mg/mL) in polypropylene syringes at 25 degrees C +/- 1 degree C protected from light are stable for up to one month.
International Journal of Pharmaceutics, 1997
A degradation pathway for carboplatin in aqueous solution is described. Degraded solutions of car... more A degradation pathway for carboplatin in aqueous solution is described. Degraded solutions of carboplatin in water and in 5% glucose solution were analysed by high performance liquid chromatography; carboplatin and its degradation products were well separated. Three degradation products of carboplatin have been determined either in pure water and 5% glucose solution and they have been identified as l,l-cyclobutanedicarboxilate anion, its protonated forms and cis-diamminediaquoplatinum (II) complex.
The Journal of Physical Chemistry B, 2010
Time-lapse atomic force microscopy is used in this contribution to directly watch the growth of n... more Time-lapse atomic force microscopy is used in this contribution to directly watch the growth of nanofibers of a lipidated peptide on a mica surface. Specifically, the studied lipopeptide is the palmitoyl derivative of the fragment 505-514 of NS3 protein from the hepatitis G virus, abbreviated as Palmitoyl-NS3 (505-514). Data on the morphology, growth rate, and orientation of these peptide-amphiphile nanofibers have been obtained. From these data, it can be concluded that this synthetic lipopeptide forms two types of fiber-like aggregates: (i) half-spherical fibrous aggregates with lengths of hundreds of nanometers and (ii) spherical fibrous aggregates with lengths of several micrometers. In addition, when a fresh lipopeptide aqueous solution is deposited onto a mica surface, the aggregates spontaneously orient parallel to each other, yielding well-aligned nanofibers on large areas of the mica surface. A significant growth in both the length and the number of the fibers was observed during the first minutes after the solution deposition. Elongation of the fibrous aggregates from one end is more frequent, though elongation from both ends also occurs, with growth rates in the 4-5 nm/s range. The effects of dilution, mechanical perturbation, and pH on the aggregation behavior of Palmitoyl-NS3 (505-514) are also detailed in this paper.
Journal of Molecular Catalysis B: Enzymatic, 2003
Biochemistry, 2000
Small unilamelar vesicles of anionic phospholipids (SUV), such as 1-palmitoyl-2-oleoylglycerosn-3... more Small unilamelar vesicles of anionic phospholipids (SUV), such as 1-palmitoyl-2-oleoylglycerosn-3-phosphoglycerol (POPG), provide an interface where Thermomyces lanuginosa triglyceride lipase (TlL) binds and adopts a catalytically active conformation for the hydrolysis of substrate partitioned in the interface, such as tributyrin or p-nitrophenylbutyrate, with an increase in catalytic rate of more than 100-fold for the same concentration of substrate [Berg et al. (1998) Biochemistry 37, 6615-6627.]. This interfacial activation is not seen with large unilamelar vesicles (LUV) of the same composition, or with vesicles of zwitterionic phospholipids such as 1-palmitoyl-2-oleoylglycero-sn-3-phosphocholine (POPC), independently of the vesicle size. Tryptophan fluorescence experiments show that lipase binds to all those types of vesicles with similar affinity, but it adopts different forms that can be correlated with the enzyme catalytic activity. The spectral change on binding to anionic SUV corresponds to the catalytically active, or "open" form of the enzyme, and it is not modified in the presence of substrate partitioned in the vesicles, as demonstrated with inactive mutants. This indicates that the displacement of the lid characteristic of lipase interfacial activation is induced by the anionic phospholipid interface without blocking the accessibility of the active site to the substrate. Experiments with a mutant containing only Trp89 in the lid show that most of the spectral changes on binding to POPG-SUVs take place in the lid region that covers the active site; an increase in Trp anisotropy indicates that the lid becomes less flexible in the active form, and quenching experiments show that it is significantly buried from the aqueous phase. On the other hand, results with a mutant where Trp89 is changed to Leu show that the environment of the structural tryptophans in positions 117, 221, and 260 is somehow altered on binding, although their mobility and solvent accessibility remains the same as in the inactive form in solution. The form of TlL bound to POPC-SUV or-LUV vesicles as well as to LUV vesicles of POPG has the same spectral signatures and corresponds to an inactive or "closed" form of the enzyme. In these interfaces, the lid is highly flexible, and Trp89 remains accessible to solvent. Resonance energy transfer experiments show that the orientation of TlL in the interface is different in the active and inactive forms. A model of interaction consistent with these data and the available X-ray structures is proposed. This is a unique system where the composition and physical properties of the lipid interface control the enzyme activity. † Financial support from the E. C. (BIO4-97-2365) is gratefully acknowledged. Y.C. is supported by the Ministry for Science of Spain.
Journal of Pharmaceutical and Biomedical Analysis, 1994
The degradation of carboplatin (3.2 mg ml-1) in 5% glucose infusion solution at 25 degrees C and ... more The degradation of carboplatin (3.2 mg ml-1) in 5% glucose infusion solution at 25 degrees C and protected from light was investigated. The effects of the material of the container and temperature were also studied. Solutions were prepared in 5% glucose solution and stored in glass bottles, polyethylene (PE) and polypropylene (PP) containers at 40, 50 and 60 degrees C and at 25 degrees C +/- 1 degrees C. Samples were assayed by an HPLC method to determine the residual carboplatin concentration at each time of sampling. Carboplatin degradation followed pseudo-first-order kinetics and no dependence on the nature of the container was found. After 1 month at 25 degrees (+/- 1 degrees)C the change in carboplatin concentration was < 2% of the initial concentration in 5% glucose. These results are in agreement with those predicted by the application of the Arrhenius equation.
Biochimica Et Biophysica Acta-Biomembranes, 2014
Els estudiants del Grau de CTA i de NHD realitzen la docencia practica a la ULD, unitat gestionad... more Els estudiants del Grau de CTA i de NHD realitzen la docencia practica a la ULD, unitat gestionada segons el model EFQM. Per tal de coneixer el seu grau d’aprenentatge en relacio a la gestio de la qualitat total, s’ha alimentat una enquesta en iniciar i finalitzar les primeres practiques que els estudiants realitzen en aquests ensenyaments. Els resultats posen de manifest una millora en la seva formacio pel que fa a aspectes de gestio de la qualitat, seguretat, gestio de residus i sostenibilitat.
The beneficial effect of co-infection with the GB virus C (GBV-C) in HIV-infected patients has be... more The beneficial effect of co-infection with the GB virus C (GBV-C) in HIV-infected patients has been described (1), although its mechanism of action is yet to be determined. The physical principles governing interactions between peptides and lipids and peptide-peptide in lipid environments are important in the design of peptides with therapeutic properties, such as enveloped virus entry inhibiting peptides. P6-2-VIR576 (VIRLCDCPNGPWVWVPAVCQAVG) showed high potency in HIV replication trials performed on TZM-bl cells (2) thus, it was selected to ulterior studies. Here we investigate the importance of lipid phase in the interaction of P6-2-VIR576 with anionic lipid membrane systems composed by DMPC/DMPS (3:2) and DPPC/DPPS (3:2) by fluorescence spectrometry. The interaction was assessed by binding and quenching experiments. Binding experiments showed that the peptide interacts with DMPC/DMPS (3:2). Concerning acrylamide quenching assays figure 1 shows the quenching profiles in the prese...
Este estudio se ha podido llevar a cabo gracias a un Ajut per a Projectes d'Innovacio Docent ... more Este estudio se ha podido llevar a cabo gracias a un Ajut per a Projectes d'Innovacio Docent (UB, 2008PID-UB/117) a la Unidad de Audiovisuales de la UB y a todos los miembros del Personal de Administracion y Servicios de la ULD.
Un dels objectius de la ULD es millorar les competencies dels futurs graduats de la Facultat de F... more Un dels objectius de la ULD es millorar les competencies dels futurs graduats de la Facultat de Farmacia de la Universitat de Barcelona mitjancant la formacio addicional que es deriva de la implantacio del sistema de gestio de la qualitat en els laboratoris docents. Amb la finalitat de coneixer el grau d’aprenentatge dels estudiants que realitzen les practiques a la ULD en relacio a la gestio de la qualitat total, s’ha enquestat als estudiants en iniciar i un cop finalitzades les primeres practiques que realitzen en l’ensenyament de Farmacia. Els resultats posen de manifest una millora en la formacio en aspectes de gestio de la qualitat, seguretat, gestio de residus i sostenibilitat.
Colloids and Surfaces A: Physicochemical and Engineering Aspects
Abstract This study is an extension of our previous paper on the interaction of AcP6-2 and the VI... more Abstract This study is an extension of our previous paper on the interaction of AcP6-2 and the VIR576 peptides with DPPC: DPPS (3:2) and DMPC: DMPS (3:2) model membranes [Colloids and Surfaces A. 532 (2017) 483–492]. In the present contribution, the temperature effect and the role of the lipid phase in the lipid-peptide interaction were investigated. Moreover at the same time, relating them to HIV-1 FP inhibition. Several biophysics experiments as lipid-peptide binding, Trp fluorescence quenching and Atomic Force Microscopy (AFM) visualization were used to evidence the different interaction of the peptide depending on the physical state of the lipids. In addition, the inhibition effect of HIV-1 FP by P6-2 VIR576 peptide was conducted by fluorescence resonance energy transfer (FRET) and also by AFM microscopy. P6-2VIR576 showed a preference to the liquid crystalline phases from where the peptide can diffuse and interact with the gel phases. Firstly, P6-2VIR576 induces a rigidifying of the membrane to finally, promote the vanishing of these gel phases. Concerning to the inhibition of HIV-1 FP peptide by P6-2VIR576 peptide, FRET and AFM results evidencing P6-2VIR576 peptide is a promising structure to be in mind in the development of new or improved drugs in HIV therapies.
Colloids and Surfaces A: Physicochemical and Engineering Aspects
International Journal of Pharmaceutics
A new method is described for the determination of the broad-spectrum antibiotic Azlocillin sodiu... more A new method is described for the determination of the broad-spectrum antibiotic Azlocillin sodium by HPLC. This method is useful for stability studies, since it allows the separation of Azlocillin from its degradation products. This has been checked by TLC.
Revista Del Congres Internacional De Docencia Universitaria I Innovacio, Mar 12, 2015