The postmodern subject from a psychopolitical perspective: An analysis from logotherapy. / El sujeto posmoderno desde una visión psicopolítica: análisis desde la logoterapia.

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.

Intervención clínica cognitiva en paciente con trastorno esquizoide de personalidad: reporte de caso / Cognitive clinical intervention in a patient with schizoid personality disorder: Case report

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.

Cognitive clinical intervention in a patient with schizoid personality disorder: Case report. / Intervención clínica cognitiva en paciente con trastorno esquizoide de personalidad: reporte de caso.

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.

In situ Formed Implants, Based on PLGA and Eudragit Blends, for Novel Florfenicol Controlled Release Formulations.

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.

An analysis of the microencapsulation of ceftiofur in chitosan particles using the spray drying technology.

Ceftiofur is a third-generation cephalosporin approved to treat numerous infections in production animals. Its commercial formulations are administered daily due to the mean life time, leading to several inconveniences, like operative challenges and non-uniform plasma levels. The objective of this work was to microencapsulate ceftiofur in chitosan particles using spray drying technology to extend the delivery and consequently reduce the dosage frequency. The effect of formulation factors on particle features was studied using a multilevel factorial design. In addition, ceftiofur thermal stability was assayed by differential scanning calorimetry and microbiological assays. Finally, a pharmacokinetic model was developed to predict theoretical plasma concentration in goats. Results showed that ceftiofur thermal stability increased after microencapsulation, indicating a protective effect of chitosan particles. Besides, MIC, IC50 and inhibition halos against E. coli and S. aureus were similar than those of the commercial product. In addition, suitable plasma levels can be theoretically maintained in goats during 48 h with a single injection. These findings suggest that chitosan microparticles could be a good vehicle for ceftiofur administration.

Design and evaluation of a recyclable intravaginal device made of ethylene vinyl acetate copolymer for bovine estrus synchronization.

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.

Progesterone loaded thermosensitive hydrogel for vaginal application: Formulation and in vitro comparison with commercial product.

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.

Food safety assessment and risk for toxoplasmosis in school restaurants in Armenia, Colombia.

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.

Paclitaxel/ß-Cyclodextrin interactions, a perspective from pulsed NMR spectroscopy experiments.

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.

FRET-based analysis and molecular modeling of the human GPN-loop GTPases 1 and 3 heterodimer unveils a dominant-negative protein complex.

GPN-loop GTPases 1 and 3 are required for RNA polymerase II (RNAPII) nuclear import. Gpn1 and Gpn3 display some sequence similarity, physically associate, and their protein expression levels are mutually dependent in human cells. We performed here Fluorescence Resonance Energy Transfer (FRET), molecular modeling, and cell biology experiments to understand, and eventually disrupt, human Gpn1-Gpn3 interaction in live HEK293-AD cells. Transiently expressed EYFP-Gpn1 and Gpn3-CFP generated a strong FRET signal, indicative of a very close proximity, in the cytoplasm of HEK293-AD cells. Molecular modeling of the human Gpn1-Gpn3 heterodimer based on the crystallographic structure of Npa3, the Saccharomyces cerevisiae Gpn1 ortholog, revealed that human Gpn1 and Gpn3 associate through a large interaction surface formed by internal α-helix 7, insertion 2, and the GPN-loop from each protein. In site-directed mutagenesis experiments of interface residues, we identified the W132D and M227D EYFP-Gpn1 mutants as defective to produce a FRET signal when coexpressed with Gpn3-CFP. Simultaneous but not individual expression of Gpn1 and Gpn3, with either or both proteins fused to EYFP, retained RNAPII in the cytoplasm and markedly inhibited global transcription in HEK293-AD cells. Interestingly, the W132D and M227D Gpn1 mutants that showed an impaired ability to interact with Gpn3 by FRET were also unable to delocalize RNAPII in this assay, indicating that an intact Gpn1-Gpn3 interaction is required to display the dominant-negative effect on endogenous Gpn1/Gpn3 function we described here. Altogether, our results suggest that a Gpn1-Gpn3 strong interaction is critical for their cellular function.

Paclitaxel delivery system based on poly(lactide-co-glycolide) microparticles and chitosan thermo-sensitive gel for mammary adenocarcinoma treatment.

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.

Preparation of TPP-crosslinked chitosan microparticles by spray drying for the controlled delivery of progesterone intended for estrus synchronization in cattle.

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.

Nanoparticles obtained by confined impinging jet mixer: poly(lactide-co-glycolide) vs. Poly-ε-caprolactone.

This paper is focused on the production and characterization of polymeric nanoparticles obtained by nanoprecipitation. The method consisted of using a confined impinging jet mixer (CIJM), circumventing high-energy equipment. Differences between the use of poly-ε-caprolactone (PCL) and poly(lactide-co-glycolide) (PLGA) as concerns particle mean size, zeta potential, and broad-spectrum antibiotic florfenicol entrapment were investigated. Other analyzed variables were polymer concentration, solvent, and anti-solvent flow rates, and antibiotic initial concentration. To our knowledge, no data were found related to PLGA and PCL nanoparticles comparison using CIJM. Also, florfenicol encapsulation within PCL or PLGA nanoparticles by nanoprecipitation has not been reported yet. The complexity of the nanoprecipitation phenomena has been confirmed, with many relevant variables involved in particles formation. PLGA resulted in smaller and more stable nanoparticles with higher entrapping of florfenicol than PCL.

Effect of particle size, polydispersity and polymer degradation on progesterone release from PLGA microparticles: Experimental and mathematical modeling.

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.

Novel Poly(Diol Sebacate)s as Additives to Modify Paclitaxel Release From Poly(Lactic-co-Glycolic Acid) Thin Films.

Paclitaxel (PTX) incorporation in poly(lactic-co-glycolic acid) (PLGA) matrices produce films with high tensile rigidity and slow release that fail to deliver the required release rate for most biomedical applications such as in drug eluting stents and cancer treatments. To modify and improve this behavior, a set of poly(diol sebacate)s were synthesized and fully characterized as possible additives. The tensile properties of PLGA blends were evaluated as these materials could be used as coatings in drug eluting stent applications. A significant improvement in mechanical flexibility was observed with 20% additive content, as it reduced the Young's modulus value and increased the maximum deformation at break. PTX release was studied and correlated with the release of additive from PLGA films. An increase in the initial burst release phase was observed on all blends when compared to the control films of PLGA. Modulation of PTX release was achieved by altering the hydrophilicity degree of the additive or its percentage content on the blend. This supports the possibility that PTX was partitioned into the additive phase. Cytotoxicity analyses of novel additives were performed on mouse embryonic fibroblasts NIH/3T3.

Poly(polyol sebacate) Elastomers as Coatings for Metallic Coronary Stents.

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.

The Use of Cellulose Membrane to Eliminate Burst Release from Intravaginal Rings.

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 (∼10(-8) cm(2) s(-1)) than in matrix (∼10(-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.

In vitro evaluation of suspoemulsions for in situ-forming polymeric microspheres and controlled release of progesterone.

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.

The optimization of an intravaginal ring releasing progesterone using a mathematical model.

PURPOSE: Progering® is the only intravaginal ring intended for contraception therapies during lactation. It is made of silicone and releases progesterone through the vaginal walls. However, some drawbacks have been reported in the use of silicone. Therefore, ethylene vinyl acetate copolymer (EVA) was tested in order to replace it. METHODS: EVA rings were produced by a hot-melt extrusion procedure. Swelling and degradation assays of these matrices were conducted in different mixtures of ethanol/water. Solubility and partition coefficient of progesterone were measured, together with the initial hormone load and characteristic dimensions. A mathematical model was used to design an EVA ring that releases the hormone at specific rate. RESULTS: An EVA ring releasing progesterone in vitro at about 12.05 ± 8.91 mg day(-1) was successfully designed. This rate of release is similar to that observed for Progering®. In addition, it was observed that as the initial hormone load or ring dimension increases, the rate of release also increases. Also, the device lifetime was extended with a rise in the initial amount of hormone load. CONCLUSIONS: EVA rings could be designed to release progesterone in vitro at a rate of 12.05 ± 8.91 mg day(-1). This ring would be used in contraception therapies during lactation. The use of EVA in this field could have initially several advantages: less initial and residual hormone content in rings, no need for additional steps of curing or crosslinking, less manufacturing time and costs, and the possibility to recycle the used rings.

Recent advances in chitosan films for controlled release of drugs.

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.