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Asthma is a common chronic disease affecting the airways in the lungs. The receptors of allergic cytokines, including interleukin (IL)-4, IL-5, and IL-13, trigger the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, which involves the pathogenesis of asthma. GDC-0214 is a JAK inhibitor that was developed as a potent and selective target for the treatment of asthma, specifically targeting the lungs. While inhaled GDC-0214 is a promising novel treatment option against asthma, improvement is still needed to achieve increased potency of the powder formulation and a reduced number of capsules containing powder to be inhaled. In this study, high-potency amorphous powder formulations containing GDC-0214 nanoaggregates for dry powder inhalation were developed using particle engineering technology, thin film freezing (TFF). A high dose per capsule was successfully achieved by enhancing the solubility of GDC-0214 and powder conditioning. Lactose and/or leucine as excipients exhibited optimum stability and aerosolization of GDC-0214 nanoaggregates, and aerosolization of the dose was independent of air flow through the device between 2 and 6 kPa pressure drops. In the rat PK study, formulation F20, which contains 80% GDC-0214 and 20% lactose, resulted in the highest AUC0-24h in the lungs with the lowest AUC0-24h in the plasma that corresponds to a 4.8-fold higher ratio of the lung-to-plasma exposures compared to micronized crystalline GDC-0214 powder administered by dry powder inhalation. Therefore, GDC-0214 nanoaggregates produced by TFF provided an improved dry powder for inhalation that can lead to enhanced therapeutic efficacy with a lower risk of systemic toxicity.
Assuntos
Asma , Inibidores de Janus Quinases , Ratos , Animais , Pós/química , Congelamento , Lactose , Administração por Inalação , Asma/tratamento farmacológico , Inaladores de Pó Seco , Tamanho da Partícula , Aerossóis e Gotículas RespiratóriosRESUMO
PURPOSE: This study aims to understand the impact of spray drying nozzles on particle surface composition and aerosol stability. METHODS: The combination formulations of colistin and azithromycin were formulated by 2-fluid nozzle (2 N) or 3-fluid (3 N) spray drying in a molar ratio of 1:1. A 3-factor, 2-level (23) factorial design was selected to investigate effects of flow rate, inlet temperature and feed concentration on yield of spray drying and the performance of the spray dried formulations for the 3 N. RESULTS: FPF values for the 2 N formulation (72.9 ± 1.9% for azithromycin & 73.4 ± 0.8% for colistin) were higher than those for the 3 N formulation (56.5 ± 3.8% for azithromycin & 55.1 ± 1.6% for colistin) when stored at 20% RH for 1 day, which could be attributed to smaller physical size for the 2 N. There was no change in FPF for both drugs in the 2 N formulation after storage at 75% RH for 90 days; however, there was a slight increase in FPF for colistin in the 3 N formulation at the same storage conditions. Surface enrichment of hydrophobic azithromycin was measured by X-ray photoelectron spectroscopy for both 2 N and 3 N formulations and interactions were studied using FTIR. CONCLUSIONS: The 3-fluid nozzle provides flexibility in choosing different solvents and has the capability to spray dry at higher feed solid concentrations. This study highlights the impact of hydrophobic azithromycin enrichment on particle surface irrespective of the nozzle type, on the prevention of moisture-induced deterioration of FPF for hygroscopic colistin.
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Antibacterianos/química , Azitromicina/química , Colistina/química , Tecnologia Farmacêutica/instrumentação , Administração por Inalação , Aerossóis , Antibacterianos/administração & dosagem , Azitromicina/administração & dosagem , Colistina/administração & dosagem , Composição de Medicamentos , Estabilidade de Medicamentos , Desenho de Equipamento , Umidade , Interações Hidrofóbicas e Hidrofílicas , Tamanho da Partícula , Pós , Solubilidade , Solventes/química , Propriedades de Superfície , Fatores de TempoRESUMO
This study aimed to develop dry powder inhaler (DPI) combination formulations of ciprofloxacin and colistin for use in respiratory infections. Effects of colistin on physical stability and aerosolization of spray-dried ciprofloxacin were examined. The combination DPI formulations were produced by co-spray drying colistin and ciprofloxacin in mass ratios of 1:1, 1:3, and 1:9. Colistin and ciprofloxacin were also co-sprayed with l-leucine in the mass ratio of 1:1:1. The physical and aerosolization stability of the selected co-sprayed formulations stored at 20, 55, and 75% relative humidity (RH) were examined. Formulation characterizations were carried out using powder X-ray diffraction (PXRD) for crystallinity, scanning electron microscopy for morphology and particle size distribution, and dynamic vapor sorption for moisture sorption. Particle surface analysis was performed using X-ray photoelectron spectroscopy, energy dispersive X-ray spectrometry, and nano-time-of-flight secondary ion mass spectrometry. Potential intermolecular interactions were studied using Fourier-transform infrared spectroscopy (FTIR). Aerosol performance was evaluated using a multistage liquid impinger with a RS01 monodose inhaler device. PXRD diffractograms showed that the co-spray-dried colistin-ciprofloxacin formulation in the mass ratio (1:1) was amorphous at 55% RH for up to 60 days; whereas the co-spray-dried colistin-ciprofloxacin (1:3) and colistin-ciprofloxacin (1:9) crystallized after storage for 3 days at 55% RH. However, the extent of crystallization for the combination formulations was less as compared to the spray-dried ciprofloxacin alone formulation. Surface morphology of the co-spray-dried formulations at different concentrations did not change even after storage at 55% RH for 60 days, unlike the spray-dried ciprofloxacin alone powder which became rougher after 3 days of storage at 55% RH. Surface analysis data indicated surface enrichment of colistin in the co-spray-dried formulations. Increasing colistin concentration on the composite particles surfaces improved aerosol performance of ciprofloxacin. FTIR data demonstrated intermolecular interactions between colistin and ciprofloxacin, thereby delaying and/or preventing crystallization of ciprofloxacin when co-spray-dried. Co-spray drying ciprofloxacin with colistin in the mass ratio (1:1) completely prevented crystallization of ciprofloxacin at 55% RH for up to 60 days. However, the colistin-ciprofloxacin formulation (1:1) began to fuse when stored at 75% RH due to moisture absorption resulting in a compromised aerosol performance. In contrast, the colistin-ciprofloxacin-leucine (1:1:1) formulation demonstrated no particle fusion, enabling a stable aerosol performance at 75% RH for 7 days. This study demonstrated that incorporation of colistin in the spray-dried formulations can improve physical stability and aerosolization of amorphous ciprofloxacin at 55% RH. At 75% RH, further addition of l-leucine in the formulation prevented particle fusion and deterioration in aerosol performance, attributed to the enrichment of nonhygroscopic l-leucine on the particle surface.
Assuntos
Aerossóis/química , Ciprofloxacina/química , Colistina/química , Administração por Inalação , Estabilidade de Medicamentos , Sinergismo Farmacológico , Inaladores de Pó Seco , Excipientes/química , Leucina/química , Tamanho da Partícula , Difração de Raios XRESUMO
PURPOSE: This study aims to develop liposomal formulations containing synergistic antibiotics of colistin and ciprofloxacin for the treatment of infections caused by multidrug-resistant Pseudomonas aeruginosa. METHODS: Colistin (Col) and ciprofloxacin (Cip) were co-encapsulated in anionic liposomes by ammonium sulfate gradient. Particle size, encapsulation efficiency, in vitro drug release and in vitro antibiotic activities were evaluated. RESULTS: The optimized liposomal formulation has uniform sizes of approximately 100 nm, with encapsulation efficiency of 67.0% (for colistin) and 85.2% (for ciprofloxacin). Incorporation of anionic lipid (DMPG) markedly increased encapsulation efficiency of colistin (from 5.4 to 67.0%); however, the encapsulation efficiency of ciprofloxacin was independent of DMPG ratio. Incorporation of colistin significantly accelerated the release of ciprofloxacin from the DMPG anionic liposomes. In vitro release of ciprofloxacin and colistin in the bovine serum for 2 h were above 70 and 50%. The cytotoxicity study using A549 cells showed the liposomal formulation is as non-toxic as the drug solutions. Liposomal formulations of combinations had enhanced in vitro antimicrobial activities against multidrug resistant P. aeruginosa than the monotherapies. CONCLUSIONS: Liposomal formulations of two synergistic antibiotics was promising against multidrug resistant P. aeruginosa infections.
Assuntos
Anti-Infecciosos/farmacologia , Ciprofloxacina/farmacologia , Colistina/farmacologia , Fosfolipídeos/química , Pseudomonas aeruginosa/efeitos dos fármacos , Células A549 , Anti-Infecciosos/química , Sobrevivência Celular/efeitos dos fármacos , Ciprofloxacina/química , Colistina/química , Composição de Medicamentos , Farmacorresistência Bacteriana , Sinergismo Farmacológico , Humanos , Fosfatidilcolinas/química , Propriedades de SuperfícieRESUMO
PURPOSE: This study aims to investigate the influence of different storage humidity conditions on crystallization and aerosol performance of inhalable spray dried amorphous powder formulations (Ciprofloxacin hydrochloride as the model drug). METHODS: The spray dried samples were stored at 20%, 55% and 75% relative humidity (RH). Crystallinity was monitored by Powder X-ray diffraction (PXRD), and particle morphology was measured by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Aerosol performance was evaluated using a multi-stage liquid impinger (MSLI). RESULTS: PXRD diffractograms showed the spray dried Ciprofloxacin stored at 20% RH for three weeks were amorphous; whereas those stored at 55% RH and 75% RH started crystallizing after one hour. Fine particle fraction (FPF) of the particles was improved from 28% to 42% after storage at 55% RH for three days. Such improvement was attributed to the crystallization of amorphous powders, which led to increased particle roughness and reduced particulate contact area, as visualized by SEM and quantified by AFM. A linear relationship was observed between degree of crystallinity/crystallite size and FPF (R2 = 0.94 and R2 = 0.96, respectively). However, deterioration in aerosol performance was observed after storage at 75% RH due to formation of inter-particulate liquid/solid bridges, as confirmed by SEM. CONCLUSIONS: This study provides a fundamental understanding in moisture-induced physical and aerosol instability of the spray dried powder formulations.
Assuntos
Aerossóis/química , Cristalização/métodos , Composição de Medicamentos/métodos , Pós/química , Vapor , Administração por Inalação , Varredura Diferencial de Calorimetria , Cromatografia Líquida de Alta Pressão/métodos , Ciprofloxacina , Humanos , Umidade , Cinética , Microscopia de Força Atômica/métodos , Microscopia Eletrônica de Varredura/métodos , Tamanho da Partícula , Propriedades de Superfície , Difração de Raios X/métodosRESUMO
Page 4, right column, under section heading "In-Vitro Aerosol Performance", line 11.
RESUMO
PURPOSE: Dissolution behavior of dry powder inhaler (DPI) antibiotic formulations in the airways may affect their efficacy especially for poorly-soluble antibiotics such as azithromycin. The main objective of this study was to understand the effects of surface composition on the dissolution of spray dried azithromycin powders by itself and in combination with colistin. METHODS: Composite formulations of azithromycin (a poorly water-soluble molecule) and colistin (a water-soluble molecule) were produced by spray drying. The resultant formulations were characterized for particle size, morphology, surface composition, solid-state properties, solubility and dissolution. RESULTS: The results demonstrate that surfaces composition has critical impacts on the dissolution of composite formulations. Colistin was shown to increase the solubility of azithromycin. For composite formulations with no surface colistin, azithromycin released at a similar dissolution rate as the spray-dried azithromycin alone. An increase in surface colistin concentration was shown to accelerate the dissolution of azithromycin. The dissolution of colistin from the composite formulations was significantly slower than the spray-dried pure colistin. In addition, FTIR spectrum showed intermolecular interactions between azithromycin and colistin in the composite formulations, which could contribute to the enhanced solubility and dissolution of azithromycin. CONCLUSIONS: Our study provides fundamental understanding of the effects of surface concentration of colistin on azithromycin dissolution of co-spray-dried composite powder formulations.
Assuntos
Azitromicina/química , Colistina/química , Composição de Medicamentos/métodos , Pós/química , Administração por Inalação , Aerossóis/química , Antibacterianos/administração & dosagem , Antibacterianos/química , Azitromicina/administração & dosagem , Química Farmacêutica , Colistina/administração & dosagem , Inaladores de Pó Seco , Humanos , Tamanho da Partícula , Pós/administração & dosagem , Propriedades de SuperfícieRESUMO
High drug load inhalable particles were prepared by co-spray drying a hydrophobic, crystalline, small molecule drug with various lipid or phospholipid excipients at a 9:1 molar ratio to understand the primary drivers of aerosol performance. The effect of excipient structure on solid-state, surface characteristics, and aerodynamic performance of the co-spray dried particles was studied while keeping the spray drying parameters constant. Spray drying of the drug with lipids produced crystalline drug particles, whereas phospholipids produced partially amorphous drug particles. All of the co-spray dried particles were nearly spherical with a smooth surface, except for the spray dried drug particles without excipients - which showed the presence of rough crystals on the surface. All co-spray dried particles showed surface enrichment of the excipient. The surface enrichment of the phospholipids was higher compared to the lipids. Co-spray dried particles that showed higher surface enrichment of excipients showed improved aerosol performance. In comparing all the excipients studied, distearyolphosphatidylcholine (DSPC) showed maximum enrichment on the particle surface and thereby significantly improved aerosol performance. This study demonstrated that the addition of small amounts of lipid excipients during spray drying can change surface morphology, composition, and cohesion, impacting aerosol performance of drugs.
Assuntos
Inaladores de Pó Seco , Excipientes , Administração por Inalação , Aerossóis/química , Excipientes/química , Tamanho da Partícula , Fosfolipídeos , Pós/químicaRESUMO
Introduction: Dry powder inhalers (DPIs) are popular for pulmonary drug delivery. Various techniques have been employed to produce inhalation drug particles and improve the delivery efficiency of DPI formulations. Physical stability of these DPI formulations is critical to ensure the delivery of a reproducible dose to the airways over the shelf-life.Areas covered: This review focuses on the impact of solid-state stability on aerosolization performance of DPI drug particles manufactured by powder production approaches and particle-engineering techniques. It also highlights the different analytical tools that can be used to characterize the physical instability originating from production and storage.Expert opinion: A majority of the DPI literature focuses on the effects of physico-chemical properties such as size, morphology, and density on aerosolization. While little has been reported on the physical stability, particularly the stability of engineered drug particles for use in DPIs. Literature data have shown that different particle-engineering methods and storage conditions may cause physical instability of dry powders for inhalation and can significantly change the aerosol performance. A systematic examination of physical instability mechanisms in DPI formulations is necessary during formulation development in order to select the optimum formulation with satisfactory stability. In addition, the use of appropriate characterization tools is critical to detect and understand physical instability during the development of DPI formulations.
Assuntos
Estabilidade de Medicamentos , Inaladores de Pó Seco , Preparações Farmacêuticas/administração & dosagem , Pós/química , Administração por Inalação , Aerossóis/química , Animais , Sistemas de Liberação de Medicamentos , Humanos , Pulmão/metabolismo , Tamanho da Partícula , Preparações Farmacêuticas/químicaRESUMO
Combinational antibiotic formulations have emerged as an important strategy to combat antibiotic resistance. The main objective of this study was to examine effects of individual components on the antimicrobial activity, physico-chemical properties, aerosolization and dissolution of powder aerosol formulations when three synergistic drugs were co-spray dried. A ternary dry powder formulation consisting of meropenem (75.5 %w/w), colistin (15.1 %w/w) and rifampicin (9.4 %w/w) at the selected ratio was produced by spray drying. The ternary formulation was characterized for in-vitro antibacterial activity, physico-chemical properties, surface composition, aerosol performance and dissolution. All of the formulations demonstrated excellent aerosolization behavior achieving a fine particle fraction of >70%, which was substantially higher than those for the Meropenem-SD and Colistin-Meropenem formulations. The results indicated that rifampicin controlled the surface morphology of the ternary and binary combination formulations resulting in the formation of highly corrugated particles. Advanced characterization of surface composition by XPS supported the hypothesis that rifampicin was enriched on the surface of the combination powder formulations. All spray-dried formulations were amorphous and absorbed substantial amount of water at the elevated humidity. Storage at the elevated humidity caused a substantial decline in aerosolization performance for the Meropenem-SD and Colistin-Meropenem, which was attributed to increased inter-particulate capillary forces or particle fusion. In contrast, the ternary combination and binary Meropenem-Rifampicin formulations showed no change in aerosol performance at the elevated storage humidity conditions; attributable to the enriched hydrophobicity of rifampicin on the particle surface that acted as a barrier against moisture condensation and particle fusion. Interestingly, in the ternary formulation rifampicin enrichment on the surface did not interfere with the dissolution of other two components (i.e. meropenem and colistin). Our study provides an insight on the impact of each component on the performance of co-spray dried combinational formulations.
Assuntos
Aerossóis/química , Colistina/química , Combinação de Medicamentos , Liberação Controlada de Fármacos , Meropeném/química , Pós/química , Rifampina/química , Aerossóis/farmacologia , Antibacterianos/química , Fenômenos Químicos , Colistina/farmacologia , Dessecação/métodos , Composição de Medicamentos/métodos , Estabilidade de Medicamentos , Meropeném/farmacologia , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Pós/farmacologia , Rifampina/farmacologia , Propriedades de SuperfícieRESUMO
Co-jet-milling drugs and lubricants may enable simultaneous particle size reduction and surface coating to achieve satisfactory aerosolization performance. This study aims to establish the relationship between surface lubricant coverage and aerosolization behavior of a model drug (ciprofloxacin HCl) co-jet-milled with lubricants [magnesium stearate (MgSt) or l-leucine]. The co-jet-milled formulations were characterized for particle size, morphology, cohesion, Carr's index, and aerosolization performance. The surface lubricant coating was assessed by probing surface chemical composition using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary-ion mass spectrometry (ToF-SIMS). The effects of co-jet-milling on the surface energy and in vitro dissolution of ciprofloxacin were also evaluated. Our results indicated that, in general, the ciprofloxacin co-jet-milled with l-leucine at >0.5% w/w showed a significant higher fine particle fraction (FPF) compared with the ciprofloxacin jet-milled alone. The FPF values plateau at or above 5% w/w for both MgSt and l-leucine. We have established the quantitative correlations between surface lubricant coverage and aerosolization in the tested range for each of the lubricants. More importantly, our results suggest different mechanisms to improve aerosolization for MgSt-coating and l-leucine-coating, respectively: MgSt-coating reduces inter-particulate interactions through the formation of low surface energy coating films, while l-leucine-coating not only reduces the surface energy but also creates rough particle surfaces that reduce inter-particulate contact area. Furthermore, surface coatings with 5% w/w MgSt (which is hydrophobic) did not lead to substantial changes in in vitro dissolution. Our findings have shown that the coating structure/quality and their effects could be highly dependent on the process and the coating material. The findings from this mechanistic study provide fundamental understanding of the critical effects of MgSt and l-leucine surface coverages on aerosolization and powder flow properties of inhalation particles.
Assuntos
Antibacterianos/química , Ciprofloxacina/química , Inaladores de Pó Seco , Leucina/química , Lubrificantes/química , Ácidos Esteáricos/química , Aerossóis , Composição de Medicamentos , Liberação Controlada de Fármacos , Excipientes/química , Tamanho da Partícula , Pós , Propriedades de SuperfícieRESUMO
The aim of this study is to investigate the influence of excipients on physical and aerosolization stability of spray dried Ciprofloxacin dry powder inhaler formulations. The model drug, Ciprofloxacin hydrochloride, was co-spray dried with excipients such as disaccharides (sucrose, lactose, trehalose), mannitol and l-leucine. The spray dried samples were stored at two different relative humidity (RH) conditions of: (1) 20% and (2) 55% RH at 20⯰C. Ciprofloxacin co-spray dried with disaccharides and l-leucine in the mass ratio of 1:1 demonstrated an increase in fine particle fraction (FPF) as compared with the spray dried Ciprofloxacin alone when stored at 20% RH. However, deterioration in FPF of Ciprofloxacin co-spray dried with disaccharide and mannitol was observed upon storage at 55% RH as compared to the corresponding formulations stored at 20% RH due to particle agglomeration. Whereas, 10% and 50% w/w l-leucine in the formulation showed no change in aerosol performance (FPF of 71.1⯱â¯3.5% and 79.5⯱â¯3.1%, respectively) when stored at 55% RH for 10â¯days as compared to 20% RH (FPF of 68.1⯱â¯0.3% and 73.6⯱â¯7.1%, respectively). l-Leucine demonstrated aerosolization stability by alleviating crystallization of Ciprofloxacin to some extent and preventing significant change in particle morphology. l-Leucine is well-recognized as aerosolization enhancer; our study has shown l-leucine is also a physical and aerosolization stabilizer for spray dried Ciprofloxacin DPI formulations. Such stability enhancing activities were attributed to the enrichment of l-leucine on the particle surface as confirmed by XPS data, and intermolecular interactions between l-leucine and Ciprofloxacin as measured by FT-IR.
Assuntos
Antibacterianos/química , Ciprofloxacina/química , Excipientes/química , Administração por Inalação , Aerossóis , Dessecação , Dissacarídeos/química , Composição de Medicamentos , Estabilidade de Medicamentos , Umidade , Leucina/química , Manitol/química , Tamanho da Partícula , PósRESUMO
BACKGROUND: Polycystic ovarian syndrome is a common endocrine disorder of reproductive age women. Many controlled ovarian stimulation (COS) strategies have been offered for the treatment of patients with PCOS undergoing in vitro fertilization, but the optimal protocol is still a controversy. There is no compelling evidence for the advantage of one stimulation protocol over the other. MATERIALS AND METHODS: This is a single-center prospective controlled study comparing long agonist and antagonist protocol in PCOS women. RESULTS: There was no significant difference in live birth rate and clinical pregnancy rate. Rate of ovarian hyperstimulation syndrome was significantly higher in the agonist group. Number of oocytes retrieved, number of follicles and peak estradiol levels were significantly more in the agonist group. CONCLUSION: The GnRH antagonist protocol is an equally effective but safer protocol in PCOS patients compared with the long agonist protocol.
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BACKGROUND: The purpose of present study was to evaluate the role of pre-ovulatory GnRH agonist therapy on IVF outcomes in GnRH antagonist cycles. METHODS: In this prospective study we recruited 100 infertile women undergoing IVF cycles with GnRH antagonists. The patients were assigned to two groups: Group A (the study group, n = 42) were assigned for receiving hCG + triptorelin for the final oocyte maturation and group B (the control group, n = 58) were assigned for only hCG. The t-test, chi-square (χ(2)), and Fisher's exact test were used for data analysis. A p < 0.05 was taken as statistically significant. The results are presented by mean± SD, and in percents (%). RESULTS: LH levels significantly (p < 0.001) increased in the study group on the day of oocyte retrieval. All embryological parameters including the number of mature oocytes, fertilization and cleavage rates, number of high quality embryos and number of cases whose embryos were frozen were non-significantly higher in the study group. There were small but non-significant improvements in the clinical pregnancy, ongoing pregnancy, live birth and implantation rates in the study group. CONCLUSION: Administering a single dose of GnRH agonist before oocyte retrieval in antagonist cycles may be helpful in improving the pregnancy rate but the results need to be verified in a larger trials.
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BACKGROUND: Management of repeated implantation failure despite transfer of good-quality embryos still remains a dilemma for ART specialists. Scrapping of endometrium in the nontransfer cycle has been shown to improve the pregnancy rate in the subsequent IVF/ET cycle in recent studies. AIM: The objective of this randomized controlled trial (RCT) was to determine whether endometrial injury caused by Pipelle sampling in the nontransfer cycle could improve the probability of pregnancy in the subsequent IVF cycle in patients who had previous failed IVF outcome. SETTING: Tertiary assisted conception center. DESIGN: Randomized controlled study. MATERIALS AND METHODS: 100 eligible patients with previous failed IVF despite transfer of good-quality embryos were randomly allocated to the intervention group and control groups. In the intervention group, Pipelle endometrial sampling was done twice: One in the follicular phase and again in the luteal phase in the cycle preceding the embryo transfer cycle. OUTCOME MEASURE: The primary outcome measure was live birth rate. The secondary outcome measures were implantation and clinical pregnancy rates. RESULTS: The live birth rate was significantly higher in the intervention group compared to control group (22.4% and 9.8% P = 0.04). The clinical pregnancy rate in the intervention group was 32.7%, while that in the control group was 13.7%, which was also statistically significant (P = 0.01). The implantation rate was significantly higher in the intervention group as compared to controls (13.07% vs 7.1% P = 0.04). CONCLUSIONS: Endometrial injury in nontransfer cycle improves the live birth rate, clinical pregnancy and implantation rates in the subsequent IVF-ET cycle in patients with previous unsuccessful IVF cycles.
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BACKGROUND: Estradiol levels fall rapidly in the luteal phase of ART cycles. So far, the effect of this estradiol decline on pregnancy outcome has remained controversial. AIM: To study the effect of early and midluteal estradiol decline on pregnancy and miscarriage rate. We also sought to determine whether estradiol fall was related to increased risk of bleeding per vagina in the first trimester among pregnancies which crossed 12 weeks. SETTING: Tertiary Assisted conception center. DESIGN: Retrospective study. MATERIALS AND METHODS: We analyzed data of 360 consecutive patients who underwent IVF-ET/ICSI cycles using one of the three protocols: Midluteal downregulation, short flare, and antagonist protocol. STATISTICAL METHODS: Statistical evaluation was performed with the Student's t test, Chi square, Fischer's exact test, analysis of variance, and Mann-Whitney tests were appropriate using SPSS for Windows, Standard version 11.0. RESULTS: The mean % EL-E2 and % ML-E2 declines were not significantly different in the pregnant and nonpregnant groups when analyzed separately in the three protocols. Also, the degree of midluteal estradiol decline did not correlate with pregnancy outcome. Moreover, the mean % early and midluteal estradiol decline did not differ significantly in patients with preclinical, clinical abortions, and ongoing pregnancy. The estradiol decline was not found to influence the risk of bleeding in the first trimester. CONCLUSIONS: Our results show that the degree of estradiol fall in the luteal phase of ART cycles does not influence pregnancy and first trimester miscarriage rate.