RESUMO
En este ensayo se abordó la nueva pandemia psíquica desde una interpretación hermenéutica. Esta pandemia configura una tipología de persona psicopolítica, dada por enjambres digitales y una psicología de masas que, desde la logoterapia, se puede percibir como neurosis colectivas postmodernas. También se puede analizar como fenómenos sociales de la psicopolítica. Esta es una hiperreflexión del propio yo, el sufrimiento como represión y el amor de consumo narcisista. El consolidar un sentido de vida como ethos social, es la respuesta para hallar compromisos y responsabilidad ante la misión personal que tiene cada ser humano como miembro de una comunidad y sociedad.
From a hermeneutic interpretation, this article analyzed the new psychic pandemic configuring a typology of psychopolitical man, provided by digital swarms and mass psychology, that, from logotherapy, can be perceived as a postmodern collective neurosis. We also analyze a self's hyper-reflection as a social phenomenon of psychopolitics, suffering as repression, and the love of narcissistic consumption. Consolidating a sense of life as a social ethos is the answer to finding compromises and responsibility for the individual mission that every human being has as a member of a community and society.
RESUMO
From a hermeneutic interpretation, this article analyzed the new psychic pandemic configuring a typology of psychopolitical man, provided by digital swarms and mass psychology, that, from logotherapy, can be perceived as a postmodern collective neurosis. We also analyze a self's hyper-reflection as a social phenomenon of psychopolitics, suffering as repression, and the love of narcissistic consumption. Consolidating a sense of life as a social ethos is the answer to finding compromises and responsibility for the individual mission that every human being has as a member of a community and society.En este ensayo se abordó la nueva pandemia psíquica desde una interpretación hermenéutica. Esta pandemia configura una tipología de persona psicopolítica, dada por enjambres digitales y una psicología de masas que, desde la logoterapia, se puede percibir como neurosis colectivas postmodernas. También se puede analizar como fenómenos sociales de la psicopolítica. Esta es una hiperreflexión del propio yo, el sufrimiento como represión y el amor de consumo narcisista. El consolidar un sentido de vida como ethos social, es la respuesta para hallar compromisos y responsabilidad ante la misión personal que tiene cada ser humano como miembro de una comunidad y sociedad.
Assuntos
Política , Humanos , COVID-19 , NarcisismoRESUMO
The present case report describes a 19-year-old male patient whose main symptoms were emotional coldness, absence of close relationships, difficulty experiencing pleasure with other people, and lack of motivation to work or to continue his studies. A schizoid personality disorder was diagnosed as a product of early maladaptive patterns such as inhibition, emotional deprivation, social isolation, and inadequacy. Likewise, a rigid and fragmented family context was evidenced, with an affective absence of parents and a focus on strict behavioral rules. The study aimed to intervene, from a cognitive clinical approach, the early maladaptive patterns and symptoms that maintained the features of schizoid personality disorder in the patient. For this purpose, cognitive behavioral therapy was carried out, with techniques such as debates, images to reparentalize, assignment of tasks, use of humor, and social skills training, among others. In conclusion, it can be stated that the early maladaptive patterns maintained the schizoid personality symptomatology. Finally, it was demonstrated through clinical and psychometric criteria that cognitive behavioral therapy decreased schizoid personality behaviors in the patient.
El presente reporte de caso describe a un paciente varón de 19 años, que presentaba como principales síntomas frialdad emocional, ausencia de relaciones cercanas, problemas para experimentar placer con otras personas y carencia de motivación para trabajar o retomar sus estudios. Se diagnosticó un trastorno de personalidad esquizoide, producto de esquemas maladaptativos tempranos como inhibición, privación emocional, aislamiento social e inadecuación. Asimismo, se evidenció un contexto familiar rígido y fragmentado, con ausencia afectiva de padres y direccionado hacia normas estrictas en la conducta. El objetivo del estudio fue intervenir desde un enfoque clínico cognitivo los esquemas maladaptativos tempranos y síntomas que mantenían los rasgos de trastorno esquizoide de la personalidad en el paciente. Para esto se realizó una terapia cognitiva conductual, con técnicas como debates, imágenes para reparentalizar, asignación de tareas, uso del humor, entrenamiento de habilidades sociales, entre otros. Como conclusión se puede manifestar que los esquemas maladaptativos tempranos mantenían la sintomatología de personalidad esquizoide. Por último, se demostró a través de un criterio clínico y psicométrico que la terapia cognitiva conductual disminuyo las conductas de personalidad esquizoide en el paciente.
Assuntos
Emoções , Transtorno da Personalidade Esquizoide , Masculino , Humanos , Adulto Jovem , Adulto , Transtorno da Personalidade Esquizoide/diagnóstico , Transtorno da Personalidade Esquizoide/psicologia , Pais , Isolamento Social , CogniçãoRESUMO
El presente reporte de caso describe a un paciente varón de 19 años, que presentaba como principales síntomas frialdad emocional, ausencia de relaciones cercanas, problemas para experimentar placer con otras personas y carencia de motivación para trabajar o retomar sus estudios. Se diagnosticó un trastorno de personalidad esquizoide, producto de esquemas maladaptativos tempranos como inhibición, privación emocional, aislamiento social e inadecuación. Asimismo, se evidenció un contexto familiar rígido y fragmentado, con ausencia afectiva de padres y direccionado hacia normas estrictas en la conducta. El objetivo del estudio fue intervenir desde un enfoque clínico cognitivo los esquemas maladaptativos tempranos y síntomas que mantenían los rasgos de trastorno esquizoide de la personalidad en el paciente. Para esto se realizó una terapia cognitiva conductual, con técnicas como debates, imágenes para reparentalizar, asignación de tareas, uso del humor, entrenamiento de habilidades sociales, entre otros. Como conclusión se puede manifestar que los esquemas maladaptativos tempranos mantenían la sintomatología de personalidad esquizoide. Por último, se demostró a través de un criterio clínico y psicométrico que la terapia cognitiva conductual disminuyo las conductas de personalidad esquizoide en el paciente.
The present case report describes a 19-year-old male patient whose main symptoms were emotional coldness, absence of close relationships, difficulty experiencing pleasure with other people, and lack of motivation to work or to continue his studies. A schizoid personality disorder was diagnosed as a product of early maladaptive patterns such as inhibition, emotional deprivation, social isolation, and inadequacy. Likewise, a rigid and fragmented family context was evidenced, with an affective absence of parents and a focus on strict behavioral rules. The study aimed to intervene, from a cognitive clinical approach, the early maladaptive patterns and symptoms that maintained the features of schizoid personality disorder in the patient. For this purpose, cognitive behavioral therapy was carried out, with techniques such as debates, images to reparentalize, assignment of tasks, use of humor, and social skills training, among others. In conclusion, it can be stated that the early maladaptive patterns maintained the schizoid personality symptomatology. Finally, it was demonstrated through clinical and psychometric criteria that cognitive behavioral therapy decreased schizoid personality behaviors in the patient.
Assuntos
Humanos , Masculino , Adulto , Adulto Jovem , Transtorno da Personalidade Esquizoide/diagnóstico , Transtorno da Personalidade Esquizoide/psicologia , Emoções , Pais , Isolamento Social , CogniçãoRESUMO
Drug controlled release technologies (DCRTs) represent an opportunity for designing new therapies. Main objectives are dose number optimization and secondary effects reduction to improve the level of patient/client acceptance. The present work studies DCRTs based in blended polymeric implants for single dose and long-term therapies of florfenicol (FF), a broad spectrum antibiotic. Polymers used were PLGA and Eudragit E100/S100 types. Eudragit/PLGA and FF/PLGA ratios were the main studied factors in terms of encapsulation efficiencies (EEs) and drug release profiles. In addition, morphological and physicochemical characterization were carried out. EEs were of 50-100% depending on formulation composition, and the FF releasing rate was increased or diminished when E100 or S100 were added, respectively. PLGA hydrolytic cleavage products possibly affect Eudragit solubility and matrix stability. Different mathematical models were used for better understanding and simulating release processes. Implants maintained the antimicrobial activity against Pseudomonas aeruginosa up to 12 days on agar plates. The developed DCRTs represents a suitable alternative for florfenicol long-term therapies.
Assuntos
Ácidos Polimetacrílicos , Tianfenicol , Preparações de Ação Retardada , Humanos , Solubilidade , Tianfenicol/análogos & derivadosRESUMO
In bovine estrus synchronization, intravaginal devices made of silicone are used to administer exogenous progesterone with the aim of maintain plasmatic levels above 2 ng ml-1 during the treatment. After their use, devices must be discarded. There is an important concern on the environmental impact of the disposal of these used products due mainly to the non-degradability of the silicone and to the residual content of the hormone. Different alternatives are being studied, and the use of ecological materials appears as the more important. The objective of the present contribution was to design and evaluate a recyclable intravaginal prototype using ethylene vinyl acetate copolymer (EVA). Devices were fabricated by an injection-molding technique and characterized in terms of dimensions, loading efficiency, release rate, and wing tension. An analysis was first conducted to compare three different matrices and two supports. Secondly, the best candidate prototype was assayed in both beef and dairy cattle. Finally, used matrices were recycled measuring the progesterone content in the resulting devices and testing them in vitro. According to release tests, no differences were observed between the three matrices both in vitro and in vivo. On the contrary, a better performance was achieved when a support with a more flexible Y shape was used in comparison with a rigid T geometry. Successful results were observed in non-lactating cows, with plasma concentrations above the threshold value defined for the synchronization therapy. However, lower progesterone levels resulted when devices were tested in animals with large milk production. By last, recycled matrices presented a similar initial content and in vitro release rate than original matrices. These findings could open the possibility to use recyclable EVA devices as an alternative to the non-degradable silicone intravaginal inserts. Future research must be carried out to optimize the performance of the recycled matrices in dairy cattle. Modifications of the release surface and/or the initial loading can give a solution to the lower values observed in these animals. Graphical abstract.
Assuntos
Sincronização do Estro , Progesterona , Compostos de Vinila , Administração Intravaginal , Animais , Bovinos , Etilenos , Feminino , HumanosRESUMO
Progesterone (PGT) is a natural hormone that stimulates and regulates various important functions, such as the preparation of the female body for conception and pregnancy. Due to its low water solubility, it is administered in a micronized form and/or in vehicles with specific solvents requirements. In order to improve the drug solubility, inclusion complexes of PGT and ß-cyclodextrins were obtained by the freeze-drying method. Two ß-cyclodextrins (native and methylated) in two solvents (water and water:ethanol) and different molar ratio of the reagents were the variables tested for the selection of the best condition for the preparation of the complexes. The PGT/randomly methylated-ß-cyclodextrin complexes were incorporated into chitosan thermosensitive hydrogels, as an alternative formulation for the vaginal administration of PGT. Neither the micro and macroscopic characteristics of the gels nor the transition time from solution to gel were modified after the complexes incorporation. In addition, chitosan gels with complexes resisted better the degradation in simulated vaginal fluid in comparison to commercial gel (Crinone®). The chitosan gel with inclusion complexes and Crinone® were tested in vitro in a diffusion assay to evaluate the delivery of the hormone and its diffusion through porcine epithelial mucosa obtained from vaginal tissue. Chitosan gel presented sustained diffusion similar to the exhibited by commercial gel. The use of chitosan gels with inclusion complexes based on cyclodextrins would be a viable alternative for vaginal administration of PGT.
RESUMO
We assessed the risk for toxoplasmosis in 10 school restaurants in Armenia (Quindio, Colombia). We analyzed the presence of Toxoplasma gondii DNA in the food, water, and living and inert surfaces of school restaurants, and we correlated these findings with the results of food safety inspection scores and with the prevalence of specific anti-T. gondii antibodies in children who ate at these restaurants. Of the 213 samples, 6.1% were positive using PCR to test for T. gondii DNA. Positive samples were found in meat, water, cucumber, guava juice, inert surfaces, and living surfaces. In 60% (6/10) of the public school restaurants, there was at least one PCR T. gondii-positive sample. In 311 serum samples from children who attended the restaurants, 101 (33%) were positive for IgG and 12 (3.9%) for IgM anti-T. gondii. The median of the compound score for the fulfillment of inspection for food safety conditions was of 60.7% (range 50-72). Higher T. gondii PCR positivity in surfaces, food, or water at each restaurant was correlated with lower inspection scores for water supply and water storage conditions. Lower scores in physical infrastructure and disinfection procedures and higher scores in furniture were correlated with a higher prevalence of IgG anti-T. gondii in children who ate at those restaurants. Inspection scores can identify restaurants with a higher risk for the presence of T. gondii.
Assuntos
Contaminação de Alimentos/análise , Parasitologia de Alimentos , Toxoplasma/isolamento & purificação , Toxoplasmose/epidemiologia , Animais , Anticorpos Anti-Idiotípicos/sangue , Anticorpos Antiprotozoários/sangue , Armênia/epidemiologia , Criança , Colômbia/epidemiologia , Feminino , Inocuidade dos Alimentos , Humanos , Masculino , Carne/parasitologia , Prevalência , Restaurantes/estatística & dados numéricos , Fatores de Risco , Instituições Acadêmicas/estatística & dados numéricos , Toxoplasma/classificação , Toxoplasma/genética , Toxoplasmose/sangue , Toxoplasmose/diagnóstico , Toxoplasmose/parasitologiaRESUMO
Cyclodextrins are cyclic cone shaped oligosaccharides. A guest molecule can be incorporated into the hydrophobic inner of the cyclodextrin to form non-covalent complexes. The formation of these complexes in general, increases the solubility, stability, dissolution rate, and bioavailability of drugs with poor water solubility. Different techniques were applied to gain insights about the interaction between paclitaxel and randomly methylated-ß-cyclodextrin during the formation of an inclusion complex. Results from infrared spectroscopy, differential scanning calorimetry, nuclear magnetic resonance and scanning electron microscopy were compared. The fast and economical pulsed nuclear magnetic resonance spectroscopy allows to explain that mol paclitaxel:mol RAMEß-CD 1:20 was the best ratio to obtain inclusion complexes. In addition, the preferred aromatic ring for the inclusion is that in the position 3' of the side chain of paclitaxel molecule.
Assuntos
Paclitaxel/química , beta-Ciclodextrinas/química , Espectroscopia de Ressonância Magnética , SolubilidadeRESUMO
OBJECTIVES: To evaluate the combination of more than one release system in the same formulation as a useful strategy to achieve paclitaxel delivery in a more sustained and controlled manner. METHODS: The present study deals with the preparation of poly(lactide-co-glycolide) microparticles loaded with paclitaxel and included in a chitosan thermo-sensitive gelling solution. The microparticles were characterized by their size, shape and drug loading. The formulation was characterized by scanning electron microscopy, in vitro release experiments and was evaluated in mice bearing mammary adenocarcinoma. KEY FINDINGS: The formation of paclitaxel crystals in a pharmaceutical formulation reduces its efficacy. In this work, the use of microparticles avoided this phenomenon. Combining more than one delivery system allowed delivering paclitaxel in a more sustained and controlled manner leading to a long-term effect in the site of action. The formulation showed an inhibition in tumour volume of 63.0% in comparison with the control group. CONCLUSIONS: One intratumour injection of gelling solution containing the microparticles was at least as efficacious as four intraperitoneal injections of a commercial formulation. In addition, the delivery system was nontoxic, and the treated mice presented the highest percentage of tumour regression and median survival time.
Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos Fitogênicos/farmacologia , Quitosana/química , Portadores de Fármacos , Neoplasias Mamárias Animais/tratamento farmacológico , Paclitaxel/farmacologia , Poliglactina 910/química , Temperatura , Adenocarcinoma/patologia , Animais , Antineoplásicos Fitogênicos/química , Química Farmacêutica/métodos , Preparações de Ação Retardada , Composição de Medicamentos , Liberação Controlada de Fármacos , Feminino , Géis , Cinética , Neoplasias Mamárias Animais/patologia , Camundongos Endogâmicos BALB C , Paclitaxel/química , Tamanho da Partícula , Carga Tumoral/efeitos dos fármacosRESUMO
PURPOSE: Planned reproduction in cattle involves regulation of estrous cycle and the use of artificial insemination. Cycle control includes the administration of exogenous progesterone during 5-8 days in a controlled manner allowing females to synchronize their ovulation. Several progesterone delivery systems are commercially available but they have several drawbacks. The aim of the present contribution was to evaluate chitosan microparticles entrapping progesterone as an alternative system. METHODS: Microparticles were prepared by spray drying. The effect of formulation parameters and experimental conditions on particle features and delivery was studied. A mathematical model to predict progesterone plasma concentration in animals was developed and validated with experimental data. RESULTS: Microparticle size was not affected by formulation parameters but sphericity enhances as Tween 80 content increases and it impairs as TPP content rises. Z potential decreases as phosphate content rises. Particles remain stable in acidic solution but the addition of surfactant is required to stabilize dispersions in neutral medium. Encapsulation efficiencies was 69-75%. In vitro delivery studies showed burst and diffusion-controlled phases, being progesterone released faster at low pH. In addition, delivery extend in cows was affected mainly by particle size and hormone initial content, while the amount injected altered plasma concentration. Theoretical predictions with excellent accuracy were obtained. CONCLUSION: The mathematical model developed can help to find proper particle features to reach specific delivery rates in the animals. This not only save time, money and effort but also minimized experimentation with animals which is desired from an ethical point of view.
Assuntos
Composição de Medicamentos/métodos , Sistemas de Liberação de Medicamentos/métodos , Sincronização do Estro/efeitos dos fármacos , Progesterona/administração & dosagem , Animais , Bovinos , Quitosana/química , Reagentes de Ligações Cruzadas/química , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/farmacocinética , Liberação Controlada de Fármacos , Feminino , Modelos Biológicos , Tamanho da Partícula , Polifosfatos/química , Progesterona/farmacocinéticaRESUMO
Poly(lactic-co-glycolic acid) (PLGA) microparticles containing progesterone were prepared by the solvent extraction/evaporation and microfluidic techniques. Microparticles were characterized by their size distribution, encapsulation efficiency, morphology and thermal properties. The effect of particle size, polydispersity and polymer degradation on the in vitro release of the hormone was studied. A triphasic release profile was observed for larger microparticles, while smaller microspheres showed a biphasic release profile. This behavior is related to the fact that complete drug release was achieved in a few days for smaller microparticles, during which polymer degradation effects are still negligible. A mathematical model was developed that predicts the progesterone release profiles from different-sized PLGA microspheres. The model takes into account both the dissolution and diffusion of the drug in the polymeric matrix as well as the autocatalytic effect of polymer degradation. The model was adjusted and validated with novel experimental data. Simulation results are in very good agreement with experimental results.
Assuntos
Ácido Láctico/química , Ácido Poliglicólico/química , Polímeros/química , Progesterona/química , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos/efeitos dos fármacos , Microesferas , Modelos Teóricos , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido PoliglicólicoRESUMO
Biocompatible polymeric coatings for metallic stents are desired, as currently used materials present limitations such as deformation during degradation and exponential loss of mechanical properties after implantation. These concerns, together with the present risks of the drug-eluting stents, namely, thrombosis and restenosis, require new materials to be studied. For this purpose, novel poly(polyol sebacate)-derived polymers are investigated as coatings for metallic stents. All pre-polymers reveal a low molecular weight between 3000 and 18 000 g mol-1 . The cured polymers range from flexible to more rigid, with E-modulus between 0.6 and 3.8 MPa. Their advantages include straightforward synthesis, biodegradability, easy processing through different scaffolding techniques, and easy transfer to industrial production. Furthermore, electrospraying and dip-coating procedures are used as proof-of-concept to create coatings on metallic stents. Biocompatibility tests using adipose stem cells lead to promising results for the use of these materials as coatings for metallic coronary stents.
Assuntos
Tecido Adiposo/metabolismo , Materiais Revestidos Biocompatíveis , Stents Farmacológicos , Teste de Materiais , Polímeros , Células-Tronco/metabolismo , Tecido Adiposo/citologia , Adulto , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Feminino , Humanos , Pessoa de Meia-Idade , Polímeros/química , Polímeros/farmacologia , Células-Tronco/citologiaRESUMO
Burst release was observed when ethylene vinyl acetate copolymer (EVA) intravaginal rings were tested for progesterone release in our previous work (Helbling et al. Pharm Res. 31(3):795-808, 2014). Burst release is undesirable in controlled delivery devices because release is uncontrollable and higher levels of active pharmaceutical ingredient could lead to the occurrence of adverse effect. The present contribution is about the use of membranes to coat EVA rings to eliminate burst release. Physicochemical state of progesterone in uncoated rings and the solubility and diffusion coefficient in membrane were studied. Hormone delivery from several rings of different sizes was compared. A mathematical model was used to analyze the effects of membrane properties on delivery rate. No chemical interactions were detected between hormone and polymer. Hormone was mainly forming amorphous aggregates inside rings, and migration to membrane was not observed during storage. Diffusion coefficient was smaller in membrane (â¼10(-8) cm(2) s(-1)) than in matrix (â¼10(-7) cm(2) s(-1)). Zero-order release kinetics were obtained for coated rings, and release rate decreases as the thickness of the coat increases. Cellulose membrane successfully eliminates burst release and controls the delivery from EVA rings. The equations developed can be used to determine the appropriate coat thickness to produce specific release rate.
Assuntos
Celulose , Polivinil/química , Preparações de Ação Retardada , Cinética , SolubilidadeRESUMO
One possibility to obtain a higher dose of drug in a lower formulation volume can be by using of saturated quantity of drug in one of the phases of an emulsion. These formulations are called suspoemulsions (S/O/W). When a hydrophobic polymer is added to the organic phase of suspoemulsions, these formulations can be used to entrap the drug inside microspheres after in situ precipitation of the polymer-drug-excipients mix. In this work, performance and stability of progesterone suspensions in triacetin as organic phase of suspoemulsions were evaluated. These formulations were compared with O/W emulsions. Mathematical models were used to study in vitro release profiles. The results confirmed that S/O/W systems could be an attractive alternative to O/W formulations for the entrapment of progesterone inside poly(d,l-lactide-co-glycolide) microspheres. Diffusive-based models fit the in vitro release of progesterone from in situ-formed microspheres. For longer release periods, a time-dependent diffusion coefficient was successfully estimated.
Assuntos
Preparações de Ação Retardada , Sistemas de Liberação de Medicamentos , Microesferas , Progesterona/administração & dosagem , Química Farmacêutica , Difusão , Portadores de Fármacos , Emulsões , Excipientes , Ácido Láctico/química , Modelos Teóricos , Poloxâmero/química , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros/química , Polissorbatos/química , Progesterona/química , Triacetina/químicaRESUMO
Chitosan is a versatile carrier for biologically active agent from a small molecule such as an antibiotic to macromolecules such as proteins and nucleic acids. In addition, drug delivery devices based on chitosan can be available in a variety of morphologies including films, fibers, nanoparticles and microspheres. Otherwise the inherent advantages of this polymer such as biocompatibility, tissue adhesions and hydrophilic nature, chitosan can be modified to accomplish a specific purpose, for example improves release kinetics. In this review, recent patents of chitosan-based film systems for drug delivery are presented and discussed. This review include matrix type systems, membrane coated systems and film forming solution. For each one of these systems, several examples of manufacture processes, bioactive agents to be delivered and specifics applications are considered. This work highlights the use of chitosan in the film technology for drug delivery, presenting examples of chitosan used in an unmodified state and examples of modifications of the polymer backbone.
Assuntos
Quitosana/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Animais , Preparações de Ação Retardada , Humanos , Patentes como Assunto , Preparações Farmacêuticas/administração & dosagem , Preparações Farmacêuticas/química , Tecnologia Farmacêutica/métodosRESUMO
A mathematical modeling of controlled release of drug from one-layer torus-shaped devices is presented. Analytical solutions based on Refined Integral Method (RIM) are derived. The validity and utility of the model are ascertained by comparison of the simulation results with matrix-type vaginal rings experimental release data reported in the literature. For the comparisons, the pair-wise procedure is used to measure quantitatively the fit of the theoretical predictions to the experimental data. A good agreement between the model prediction and the experimental data is observed. A comparison with a previously reported model is also presented. More accurate results are achieved for small A/C(s) ratios.
Assuntos
Dispositivos Anticoncepcionais Femininos , Portadores de Fármacos , Modelos Químicos , Modelos Estatísticos , Preparações Farmacêuticas/química , Polímeros/química , Tecnologia Farmacêutica/métodos , Administração Intravaginal , Animais , Química Farmacêutica , Simulação por Computador , Preparações de Ação Retardada , Difusão , Composição de Medicamentos , Feminino , Humanos , Cinética , Preparações Farmacêuticas/administração & dosagem , Reprodutibilidade dos Testes , SolubilidadeRESUMO
A mathematical modeling of controlled release of drug from one-layer and two-layer torus-shaped devices with external mass transfer resistance is presented. Analytical solutions based on the pseudo-steady state approximation are derived. The validity of the equations is established in two stages. In the first stage, the validity of the models derived for more complex systems is determined by comparison with profiles predicted by the simplest model, in asymptotic cases. In the second stage, the reliability and usefulness of the models are ascertained by comparison of the simulation results with vaginal rings experimental release data reported in the literature. In order to measures quantitatively the fit of the theoretical models to the experimental data, the pair-wise procedure is used. A good agreement between the prediction of the models and the experimental data is observed. The models are applicable only to torus-shaped systems in where the initial load of drug is higher than its solubility in the polymer.
Assuntos
Sistemas de Liberação de Medicamentos , Modelos Teóricos , Preparações Farmacêuticas/administração & dosagem , Simulação por Computador , Dispositivos Anticoncepcionais Femininos , Sistemas de Liberação de Medicamentos/instrumentação , Sistemas de Liberação de Medicamentos/métodos , Feminino , Humanos , Preparações Farmacêuticas/química , SolubilidadeRESUMO
A mathematical modeling of controlled release of drug from torus-shaped single-layer devices is presented. Analytical solutions based on the pseudo-steady state approximation are derived. The reliability and usefulness of the model are ascertained by comparison of the simulation results with matrix-type vaginal ring experimental release data reported in the literature. A good agreement between the model prediction and the experimental data is observed. An analysis of the effect of the variation in torus design parameters on the solute release is also presented. The model is applicable only to torus-shaped single-layer systems wherein the initial load of drug is higher than its solubility in the polymer.
Assuntos
Dispositivos Anticoncepcionais Femininos , Sistemas de Liberação de Medicamentos/instrumentação , Preparações Farmacêuticas/administração & dosagem , Simulação por Computador , Difusão , Feminino , Humanos , Modelos QuímicosRESUMO
Analytical solutions for the case of controlled dispersed-drug release from planar non-erodible polymeric matrices, based on Refined Integral Method, are presented. A new adjusting equation is used for the dissolved drug concentration profile in the depletion zone. The set of equations match the available exact solution. In order to illustrate the usefulness of this model, comparisons with experimental profiles reported in the literature are presented. The obtained results show that the model can be employed in a broad range of applicability.