Maria Palmira Daflon Gremião - Academia.edu (original) (raw)
Papers by Maria Palmira Daflon Gremião
European Journal of Pharmaceutical Sciences, 2018
Nanostructured polyelectrolytes complexes (nano PECs) loaded with methotrexate (MTX) were obtaine... more Nanostructured polyelectrolytes complexes (nano PECs) loaded with methotrexate (MTX) were obtained by the polyelectrolyte complexation of chitosan (CS) and hyaluronic acid (HA), further incorporating hypromellose phthalate (HP). The mean diameter of nano PECs ranged from 325 to 458 nm, with a narrow size distribution. Zeta potential was close to +30 mV, decreasing to +21 mV after the incorporation of HP, a range of values that favour the physical stability of system as the interaction with cationic biological membranes. The electrostatic interactions between the different components were indicated by the FTIR data. The mucoadhesiveness of nano PECs was demonstrated and MTX and HP influenced this property. The cell viability assays showed the biosafety of the isolated polymers and nano PECs in intestinal HT29-MTX and Caco-2 cell lines at 4 h of test. The permeability values of MTX loaded in CS/HA nano PECs were 7.6 and 4-fold higher than those of CS/HA/HP nano PECS and free drug, respectively, in the Caco-2 monoculture. In mucus secreting co-culture cell model these values were 3 and 6.5 fold, respectively. Such features indicate that nano PECs developed in this work can be promising carriers for MTX in the treatment of local or systemic diseases.
Revista de ciencias farmaceuticas, Dec 1, 2004
Revista de ciencias farmaceuticas, 1995
Revista de farmacia e bioquimica da Universidade de Sao Paulo, 1988
Infarma - Ciências Farmacêuticas, 2002
Journal of Pharmacy Research, 2012
Universidade Estadual Paulista Julio de Mesquita Filho, Faculdade de Ciencias Farmaceuticas de Ar... more Universidade Estadual Paulista Julio de Mesquita Filho, Faculdade de Ciencias Farmaceuticas de Araraquara, Araraquara, Rod Araraquara-Jau Km1, CEP 14801-902, SP, Brasil
SPG BioMed, 2019
The effect of efflux bomb and the transmural potential difference in the permeation of azidothymi... more The effect of efflux bomb and the transmural potential difference in the permeation of azidothymidine across the small intestine of the rat. SPG BioMed 1(2).
Arabian Journal of Chemistry, Nov 1, 2017
A simple, rapid, and sensitive analytical procedure has been developed and validated for the in v... more A simple, rapid, and sensitive analytical procedure has been developed and validated for the in vitro measurement of curcumin in samples from mucosae retention studies. Curcumin was analyzed by HPLC using a C 18 column with UV detection at 425 nm. The mobile phase was acetonitrile and water (50:50 v/v) acidified with 2% acetic acid at a flow rate of 1.2 mL min À1. The curve range was linear for the receptor solution concentration range 0.5-75 lg mL À1. The specificity showed no interference with the biological matrix and excipients of the acceptor media. Intra and inter-day accuracy, and precision values were lower than 5% and were not statically different (P < 0.05). Recoveries ranged from 99.7% to 108%. The limits of detection and quantitation were 11.61 and 500 ng mL À1 , respectively. The method is adequate to assay curcumin from esophageal porcine samples, enabling the determination of penetration profiles for in situ gelling curcuminloaded liquid crystals by in vitro studies, and fulfilled the requirements for reliability and feasibility for application to the quantitative analysis of curcumin in porcine esophageal mucosae.
Journal of The Mechanical Behavior of Biomedical Materials, 2017
The retrogradation of high amylose starch (5% or 10%), by isothermal cycles at 4 1C (method 1) or... more The retrogradation of high amylose starch (5% or 10%), by isothermal cycles at 4 1C (method 1) or by alternating thermal cycles (method 2) was efficient and promoted important structural modifications. Hydrogels of gellan gum and starch retrograded blends, containing or not ketoprofen, were prepared by ionic and dual cross-linking, at different concentrations of polymer and cross-linkers, and characterized by texture and rheological analysis, X-ray diffraction and morphological analysis. The ionic cross-linking and starch retrograded by method 1 contributed to the improvement of hardness and cohesiveness of hydrogels while the dual cross-linking and starch retrograded by method 2 favored the adhesiveness. The rising of polymer concentration lead to the improvement of all mechanical parameters. Rheological data demonstrated that non-cross-linked dispersions showed a behavior of weak gels and the cross-linked hydrogels presented a predominantly elastic behavior (G 0 cG″), peculiar of strong gels. X-ray diffraction, rheological data and the scanning electron microscopy (FEG-SEM) revealed that the increase of polymers and crosslinkers concentration and the presence of drug resulted in stronger and more stable tridimensional structures. The suitable adhesiveness and high strength and elasticity of hydrogels H253IC-KT, H255IC-KT, H21053DC-KT and H21055DC-KT make them more promising materials for the design of mucoadhesive drug delivery systems.
Advanced therapeutics, Jan 22, 2023
Brazilian Journal of Pharmaceutical Sciences, Dec 1, 2016
Zidovudine (AZT) mucoadhesive solid dispersions (SD) were prepared using a sodium starch glycolat... more Zidovudine (AZT) mucoadhesive solid dispersions (SD) were prepared using a sodium starch glycolate (SSG) and hypromellose phthalate (HPMCP) mixtures as carrier to enhance the intestinal permeability and bioavailability of zidovudine. SDs were prepared using the co-precipitation method followed by solvent evaporation and characterized according to their physicochemical properties such as particle size, crystallinity, thermal behavior, and liquid uptake ability. In vitro drug dissolution, mucoadhesiveness and AZT intestinal permeability were also determined. Thermal behavior and X-ray diffraction patterns demonstrated the amorphous state of AZT in SD systems. The HPMCP polymer restricted the liquid uptake ability in the acid medium; however, this property significantly increased with higher pH values. SDs allowed drug dissolution to occur in a controlled manner. HPMCP decreased the dissolution rates in the acid medium. The mucoadhesiveness of SDs was demonstrated and the permeability of AZT carried in solid dispersions was significantly improved. The effect of the SD carrier polymers on blocking efflux pump can be an important approach to improve the bioavailability of AZT.
Carbohydrate Polymers, Feb 1, 2021
Nanostructured polyelectrolyte complexes (nano PECs) based on biopolymers are an important techno... more Nanostructured polyelectrolyte complexes (nano PECs) based on biopolymers are an important technological strategy to target drugs to the action and/or absorption site in a more effective way. In this work, computational studies were performed to predict the ionization, spatial arrangement and interaction energies of chitosan (CS), hyaluronic acid (HA), and hypromellose phthalate (HP), for the design of nano PEC carriers for methotrexate (MTX). The optimal pH range (5.0-5.5) for preparing nano PECs was selected by experimental and computational methodologies, favoring the polymers interactions. CS, HA, HP and MTX addition order was also rationalized, maximizing their interactions and MTX entrapment. Spherical nano-sized particles (256-575 nm, by dynamic light scattering measurement) with positive surface charge (+25.5 to +29.2 mV) were successfully prepared. The MTX association efficiency ranged from 20 to 32 %. XRD analyses evidenced the formation of a new material with an organized structure, in relation to raw polymers.
Nanomaterials, Jan 30, 2018
Melanoma is the most aggressive and lethal type of skin cancer, with a poor prognosis because of ... more Melanoma is the most aggressive and lethal type of skin cancer, with a poor prognosis because of the potential for metastatic spread. The aim was to develop innovative powder formulations for the treatment of metastatic melanoma based on micro-and nanocarriers containing 5-fluorouracil (5FU) for pulmonary administration, aiming at local and systemic action. Therefore, two innovative inhalable powder formulations were produced by spray-drying using chondroitin sulfate as a structuring polymer: (a) 5FU nanoparticles obtained by piezoelectric atomization (5FU-NS) and (b) 5FU microparticles of the mucoadhesive agent Methocel™ F4M for sustained release produced by conventional spray drying (5FU-MS). The physicochemical and aerodynamic were evaluated in vitro for both systems, proving to be attractive for pulmonary delivery. The theoretical aerodynamic diameters obtained were 0.322 ± 0.07 µm (5FU-NS) and 1.138 ± 0.54 µm (5FU-MS). The fraction of respirable particles (FR%) were 76.84 ± 0.07% (5FU-NS) and 55.01 ± 2.91% (5FU-MS). The in vitro mucoadhesive properties exhibited significant adhesion efficiency in the presence of Methocel™ F4M. 5FU-MS and 5FU-NS were tested for their cytotoxic action on melanoma cancer cells (A2058 and A375) and both showed a cytotoxic effect similar to 5FU pure at concentrations of 4.3 and 1.7-fold lower, respectively.
Brazilian Journal of Pharmaceutical Sciences, Mar 1, 2009
A simple, rapid, accurate and sensitive method was developed for quantitative analysis of dexamet... more A simple, rapid, accurate and sensitive method was developed for quantitative analysis of dexamethasone acetate in microemulsions using high performance liquid chromatography (HPLC) with UV detection. The chromatography parameters were stainless steel Lichrospher 100 RP-18 column (250 mm x 4 mm i.d., 5 µm particle size), at 30 ± 2 ºC. The isocratic mobile phase was methanol:water (65:35; v/v) at a flow rate of at 1.0 mL.min-1. The determinations were performed using UV-Vis detector set at 239 nm. Samples were prepared with methanol and the volume injected was 20 µL. The analytical curve was linear (r 2 0.9995) over a wide concentration range (2.0-30.0 µg.mL-1). The presence of components of the microemulsion did not interfere in the results of the analysis. The method showed adequate precision, with a relative standard deviation (RSD) smaller than 3%. The accuracy was analyzed by adding a standard drug and good recovery values were obtained for all drug concentrations used. The HPLC method developed in this study showed specificity and selectivity with linearity in the working range and good precision and accuracy, making it very suitable for quantification of dexamethasone in microemulsions. The analytical procedure is reliable and offers advantages in terms of speed and low cost of reagents. Uniterms: Dexamethasone acetate/determination. Microemulsions/quantitative analysis. High performance liquid chromatography/quantitative analysis. Analytical method/validation. Um método simples, rápido, preciso e sensível foi desenvolvido para a análise quantitativa de acetato de dexametasona em microemulsões usando cromatografia líquida de alta eficiência (CLAE). Os parâmetros cromatográficos foram: coluna cromatográfica Lichrospher 100 RP-18, (250 mm x 4 mm i.d., 5 µm partícula tamanho), com temperatura de coluna de 30 ± 2 ºC. A fase móvel foi composta de metanol: água (65:35; v/v) com fluxo isocrático de 1 mL.min-1 e volume de injeção de 20 µL. As determinações foram realizadas utilizando detector UV-Vis no comprimento de onda de 239 nm. A curva analítica mostrou-se linear (r 2 0,999) em uma ampla faixa de concentração (2,0-30,0 µg.mL-1). A presença de componentes da microemulsão não interferiu nos resultados da análise. O método mostrou precisão adequada, com desvio padrão relativo menor que 3%. A exatidão foi analisada pela adição de padrões do fármaco e valores de recuperação dentro dos limites recomendáveis foram obtidos para todas as concentrações estudadas. O método por CLAE mostrou especificidade e seletividade com linearidade dentro da faixa de concentração utilizada e precisão e exatidão que tornam o método adequado para a análise de dexametasona em microemulsões. O procedimento analítico é fidedigno e oferece vantagens em termos de velocidade e custo de reativos. Unitermos: Acetato de dexametasona/determinação. Microemulsões/análise quantitativa. Cromatografia líquida de alta eficiência/análise quantitativa. Método de análise/validação. Recebido para publicação em 23 de novembro de 2007. Aceito para publicação em 06 de outubro de 2008.
European Journal of Pharmaceutics and Biopharmaceutics, 2021
Understanding the role of colon-specific microparticles based on retrograded starch/pectin in the... more Understanding the role of colon-specific microparticles based on retrograded starch/pectin in the delivery of chitosan nanoparticles along the gastrointestinal tract,
RBCF. Revista Brasileira de Ciências Farmacêuticas, Dec 1, 2006
Polymeric nanoparticles have received great attention as potential controlled drug delivery syste... more Polymeric nanoparticles have received great attention as potential controlled drug delivery systems. Biodegradable polymers has been extensively used in the development of these drug carriers, and the polyesters such as polylactic acid, polyglycolic acid and their copolymers as poly-lactide-co-glycolide are the most used, considering its biocompatibility and biodegradability. Thermal analysis techniques have been used for pharmaceutical substances for more than 30 years and are routine methods for screening drugexcipient interactions. The aim of this work is to use thermal analysis to characterize PLGA nanoparticles containing a hydrophobic drug, praziquantel. The results show that the drug is in an amorphous state or in disordered crystalline phase of molecular dispersion in the PLGA polymeric matrix and that the microencapsulation process did not interfere with the chemical structure of the polymer, mantaining the structural drug integrity.
Journal of Nanoscience and Nanotechnology, 2015
International Journal of Pharmaceutics, Mar 1, 2023
European Journal of Pharmaceutical Sciences, 2018
Nanostructured polyelectrolytes complexes (nano PECs) loaded with methotrexate (MTX) were obtaine... more Nanostructured polyelectrolytes complexes (nano PECs) loaded with methotrexate (MTX) were obtained by the polyelectrolyte complexation of chitosan (CS) and hyaluronic acid (HA), further incorporating hypromellose phthalate (HP). The mean diameter of nano PECs ranged from 325 to 458 nm, with a narrow size distribution. Zeta potential was close to +30 mV, decreasing to +21 mV after the incorporation of HP, a range of values that favour the physical stability of system as the interaction with cationic biological membranes. The electrostatic interactions between the different components were indicated by the FTIR data. The mucoadhesiveness of nano PECs was demonstrated and MTX and HP influenced this property. The cell viability assays showed the biosafety of the isolated polymers and nano PECs in intestinal HT29-MTX and Caco-2 cell lines at 4 h of test. The permeability values of MTX loaded in CS/HA nano PECs were 7.6 and 4-fold higher than those of CS/HA/HP nano PECS and free drug, respectively, in the Caco-2 monoculture. In mucus secreting co-culture cell model these values were 3 and 6.5 fold, respectively. Such features indicate that nano PECs developed in this work can be promising carriers for MTX in the treatment of local or systemic diseases.
Revista de ciencias farmaceuticas, Dec 1, 2004
Revista de ciencias farmaceuticas, 1995
Revista de farmacia e bioquimica da Universidade de Sao Paulo, 1988
Infarma - Ciências Farmacêuticas, 2002
Journal of Pharmacy Research, 2012
Universidade Estadual Paulista Julio de Mesquita Filho, Faculdade de Ciencias Farmaceuticas de Ar... more Universidade Estadual Paulista Julio de Mesquita Filho, Faculdade de Ciencias Farmaceuticas de Araraquara, Araraquara, Rod Araraquara-Jau Km1, CEP 14801-902, SP, Brasil
SPG BioMed, 2019
The effect of efflux bomb and the transmural potential difference in the permeation of azidothymi... more The effect of efflux bomb and the transmural potential difference in the permeation of azidothymidine across the small intestine of the rat. SPG BioMed 1(2).
Arabian Journal of Chemistry, Nov 1, 2017
A simple, rapid, and sensitive analytical procedure has been developed and validated for the in v... more A simple, rapid, and sensitive analytical procedure has been developed and validated for the in vitro measurement of curcumin in samples from mucosae retention studies. Curcumin was analyzed by HPLC using a C 18 column with UV detection at 425 nm. The mobile phase was acetonitrile and water (50:50 v/v) acidified with 2% acetic acid at a flow rate of 1.2 mL min À1. The curve range was linear for the receptor solution concentration range 0.5-75 lg mL À1. The specificity showed no interference with the biological matrix and excipients of the acceptor media. Intra and inter-day accuracy, and precision values were lower than 5% and were not statically different (P < 0.05). Recoveries ranged from 99.7% to 108%. The limits of detection and quantitation were 11.61 and 500 ng mL À1 , respectively. The method is adequate to assay curcumin from esophageal porcine samples, enabling the determination of penetration profiles for in situ gelling curcuminloaded liquid crystals by in vitro studies, and fulfilled the requirements for reliability and feasibility for application to the quantitative analysis of curcumin in porcine esophageal mucosae.
Journal of The Mechanical Behavior of Biomedical Materials, 2017
The retrogradation of high amylose starch (5% or 10%), by isothermal cycles at 4 1C (method 1) or... more The retrogradation of high amylose starch (5% or 10%), by isothermal cycles at 4 1C (method 1) or by alternating thermal cycles (method 2) was efficient and promoted important structural modifications. Hydrogels of gellan gum and starch retrograded blends, containing or not ketoprofen, were prepared by ionic and dual cross-linking, at different concentrations of polymer and cross-linkers, and characterized by texture and rheological analysis, X-ray diffraction and morphological analysis. The ionic cross-linking and starch retrograded by method 1 contributed to the improvement of hardness and cohesiveness of hydrogels while the dual cross-linking and starch retrograded by method 2 favored the adhesiveness. The rising of polymer concentration lead to the improvement of all mechanical parameters. Rheological data demonstrated that non-cross-linked dispersions showed a behavior of weak gels and the cross-linked hydrogels presented a predominantly elastic behavior (G 0 cG″), peculiar of strong gels. X-ray diffraction, rheological data and the scanning electron microscopy (FEG-SEM) revealed that the increase of polymers and crosslinkers concentration and the presence of drug resulted in stronger and more stable tridimensional structures. The suitable adhesiveness and high strength and elasticity of hydrogels H253IC-KT, H255IC-KT, H21053DC-KT and H21055DC-KT make them more promising materials for the design of mucoadhesive drug delivery systems.
Advanced therapeutics, Jan 22, 2023
Brazilian Journal of Pharmaceutical Sciences, Dec 1, 2016
Zidovudine (AZT) mucoadhesive solid dispersions (SD) were prepared using a sodium starch glycolat... more Zidovudine (AZT) mucoadhesive solid dispersions (SD) were prepared using a sodium starch glycolate (SSG) and hypromellose phthalate (HPMCP) mixtures as carrier to enhance the intestinal permeability and bioavailability of zidovudine. SDs were prepared using the co-precipitation method followed by solvent evaporation and characterized according to their physicochemical properties such as particle size, crystallinity, thermal behavior, and liquid uptake ability. In vitro drug dissolution, mucoadhesiveness and AZT intestinal permeability were also determined. Thermal behavior and X-ray diffraction patterns demonstrated the amorphous state of AZT in SD systems. The HPMCP polymer restricted the liquid uptake ability in the acid medium; however, this property significantly increased with higher pH values. SDs allowed drug dissolution to occur in a controlled manner. HPMCP decreased the dissolution rates in the acid medium. The mucoadhesiveness of SDs was demonstrated and the permeability of AZT carried in solid dispersions was significantly improved. The effect of the SD carrier polymers on blocking efflux pump can be an important approach to improve the bioavailability of AZT.
Carbohydrate Polymers, Feb 1, 2021
Nanostructured polyelectrolyte complexes (nano PECs) based on biopolymers are an important techno... more Nanostructured polyelectrolyte complexes (nano PECs) based on biopolymers are an important technological strategy to target drugs to the action and/or absorption site in a more effective way. In this work, computational studies were performed to predict the ionization, spatial arrangement and interaction energies of chitosan (CS), hyaluronic acid (HA), and hypromellose phthalate (HP), for the design of nano PEC carriers for methotrexate (MTX). The optimal pH range (5.0-5.5) for preparing nano PECs was selected by experimental and computational methodologies, favoring the polymers interactions. CS, HA, HP and MTX addition order was also rationalized, maximizing their interactions and MTX entrapment. Spherical nano-sized particles (256-575 nm, by dynamic light scattering measurement) with positive surface charge (+25.5 to +29.2 mV) were successfully prepared. The MTX association efficiency ranged from 20 to 32 %. XRD analyses evidenced the formation of a new material with an organized structure, in relation to raw polymers.
Nanomaterials, Jan 30, 2018
Melanoma is the most aggressive and lethal type of skin cancer, with a poor prognosis because of ... more Melanoma is the most aggressive and lethal type of skin cancer, with a poor prognosis because of the potential for metastatic spread. The aim was to develop innovative powder formulations for the treatment of metastatic melanoma based on micro-and nanocarriers containing 5-fluorouracil (5FU) for pulmonary administration, aiming at local and systemic action. Therefore, two innovative inhalable powder formulations were produced by spray-drying using chondroitin sulfate as a structuring polymer: (a) 5FU nanoparticles obtained by piezoelectric atomization (5FU-NS) and (b) 5FU microparticles of the mucoadhesive agent Methocel™ F4M for sustained release produced by conventional spray drying (5FU-MS). The physicochemical and aerodynamic were evaluated in vitro for both systems, proving to be attractive for pulmonary delivery. The theoretical aerodynamic diameters obtained were 0.322 ± 0.07 µm (5FU-NS) and 1.138 ± 0.54 µm (5FU-MS). The fraction of respirable particles (FR%) were 76.84 ± 0.07% (5FU-NS) and 55.01 ± 2.91% (5FU-MS). The in vitro mucoadhesive properties exhibited significant adhesion efficiency in the presence of Methocel™ F4M. 5FU-MS and 5FU-NS were tested for their cytotoxic action on melanoma cancer cells (A2058 and A375) and both showed a cytotoxic effect similar to 5FU pure at concentrations of 4.3 and 1.7-fold lower, respectively.
Brazilian Journal of Pharmaceutical Sciences, Mar 1, 2009
A simple, rapid, accurate and sensitive method was developed for quantitative analysis of dexamet... more A simple, rapid, accurate and sensitive method was developed for quantitative analysis of dexamethasone acetate in microemulsions using high performance liquid chromatography (HPLC) with UV detection. The chromatography parameters were stainless steel Lichrospher 100 RP-18 column (250 mm x 4 mm i.d., 5 µm particle size), at 30 ± 2 ºC. The isocratic mobile phase was methanol:water (65:35; v/v) at a flow rate of at 1.0 mL.min-1. The determinations were performed using UV-Vis detector set at 239 nm. Samples were prepared with methanol and the volume injected was 20 µL. The analytical curve was linear (r 2 0.9995) over a wide concentration range (2.0-30.0 µg.mL-1). The presence of components of the microemulsion did not interfere in the results of the analysis. The method showed adequate precision, with a relative standard deviation (RSD) smaller than 3%. The accuracy was analyzed by adding a standard drug and good recovery values were obtained for all drug concentrations used. The HPLC method developed in this study showed specificity and selectivity with linearity in the working range and good precision and accuracy, making it very suitable for quantification of dexamethasone in microemulsions. The analytical procedure is reliable and offers advantages in terms of speed and low cost of reagents. Uniterms: Dexamethasone acetate/determination. Microemulsions/quantitative analysis. High performance liquid chromatography/quantitative analysis. Analytical method/validation. Um método simples, rápido, preciso e sensível foi desenvolvido para a análise quantitativa de acetato de dexametasona em microemulsões usando cromatografia líquida de alta eficiência (CLAE). Os parâmetros cromatográficos foram: coluna cromatográfica Lichrospher 100 RP-18, (250 mm x 4 mm i.d., 5 µm partícula tamanho), com temperatura de coluna de 30 ± 2 ºC. A fase móvel foi composta de metanol: água (65:35; v/v) com fluxo isocrático de 1 mL.min-1 e volume de injeção de 20 µL. As determinações foram realizadas utilizando detector UV-Vis no comprimento de onda de 239 nm. A curva analítica mostrou-se linear (r 2 0,999) em uma ampla faixa de concentração (2,0-30,0 µg.mL-1). A presença de componentes da microemulsão não interferiu nos resultados da análise. O método mostrou precisão adequada, com desvio padrão relativo menor que 3%. A exatidão foi analisada pela adição de padrões do fármaco e valores de recuperação dentro dos limites recomendáveis foram obtidos para todas as concentrações estudadas. O método por CLAE mostrou especificidade e seletividade com linearidade dentro da faixa de concentração utilizada e precisão e exatidão que tornam o método adequado para a análise de dexametasona em microemulsões. O procedimento analítico é fidedigno e oferece vantagens em termos de velocidade e custo de reativos. Unitermos: Acetato de dexametasona/determinação. Microemulsões/análise quantitativa. Cromatografia líquida de alta eficiência/análise quantitativa. Método de análise/validação. Recebido para publicação em 23 de novembro de 2007. Aceito para publicação em 06 de outubro de 2008.
European Journal of Pharmaceutics and Biopharmaceutics, 2021
Understanding the role of colon-specific microparticles based on retrograded starch/pectin in the... more Understanding the role of colon-specific microparticles based on retrograded starch/pectin in the delivery of chitosan nanoparticles along the gastrointestinal tract,
RBCF. Revista Brasileira de Ciências Farmacêuticas, Dec 1, 2006
Polymeric nanoparticles have received great attention as potential controlled drug delivery syste... more Polymeric nanoparticles have received great attention as potential controlled drug delivery systems. Biodegradable polymers has been extensively used in the development of these drug carriers, and the polyesters such as polylactic acid, polyglycolic acid and their copolymers as poly-lactide-co-glycolide are the most used, considering its biocompatibility and biodegradability. Thermal analysis techniques have been used for pharmaceutical substances for more than 30 years and are routine methods for screening drugexcipient interactions. The aim of this work is to use thermal analysis to characterize PLGA nanoparticles containing a hydrophobic drug, praziquantel. The results show that the drug is in an amorphous state or in disordered crystalline phase of molecular dispersion in the PLGA polymeric matrix and that the microencapsulation process did not interfere with the chemical structure of the polymer, mantaining the structural drug integrity.
Journal of Nanoscience and Nanotechnology, 2015
International Journal of Pharmaceutics, Mar 1, 2023