Extended Pharmacopeial Characterization of Surfactant Aerosols Generated by a Customized eFlow Neos Nebulizer Delivered through Neonatal Nasal Prongs

The delivery of nebulized medications to preterm infants during Non-Invasive Ventilation (NIV) remains an unmet clinical need. In this regard, the effective delivery of nebulized surfactant has been particularly investigated in preclinical and clinical studies. In this work, we investigated the feasibility of delivering nebulized surfactant through various commercially available nasal prong types. We first performed a compendial characterization of surfactant aerosols generated by the eFlow Neos nebulizer, customized to be used in neonates, determining the amount of surfactant delivered by the device as well as the aerodynamic characteristics of surfactant aerosols. Additionally, we extended the compendial characterization by testing the effect of different nasal prong types on the estimated lung dose using a realistic Continuous Positive Airway Pressure (CPAP) circuit that included a cast of the upper airways of a preterm neonate. The compendial characterization of surfactant aerosols delivered through different nasal prongs achieved relatively high delivered surfactant doses (in the range 63-74% of the nominal dose), with aerodynamic characteristics displaying mass median aerodynamic diameters ranging between 2.52 and 2.81 µm. Nevertheless, when using a representative in vitro setup mimicking NIV in a clinical setting, significant differences were observed in terms of the estimated lung dose accounting for up to two-fold differences (from 10% to 20% estimated lung deposition of the nominal dose) depending on the chosen nasal prong type. Considering that surfactant lung deposition rates are correlated with therapeutic efficacy, this study points out the relevance of choosing the appropriate NIV interface to maximize the lung dose of nebulized medications.

From bench to bedside: in vitro and in vivo evaluation of a neonate-focused nebulized surfactant delivery strategy

Background

Non-invasive delivery of nebulized surfactant has been a neonatology long-pursued goal. Nevertheless, the clinical efficacy of nebulized surfactant remains inconclusive, in part, due to the great technical challenges of depositing nebulized drugs in the lungs of preterm infants. The aim of this study was to investigate the feasibility of delivering nebulized surfactant (poractant alfa) in vitro and in vivo with an adapted, neonate-tailored aerosol delivery strategy.

Methods

Particle size distribution of undiluted poractant alfa aerosols generated by a customized eFlow-Neos nebulizer system was determined by laser diffraction. The theoretical nebulized surfactant lung dose was estimated in vitro in a clinical setting replica including a neonatal continuous positive airway pressure (CPAP) circuit, a cast of the upper airways of a preterm neonate, and a breath simulator programmed with the tidal breathing pattern of an infant with mild respiratory distress syndrome (RDS). A dose-response study with nebulized surfactant covering the 100–600 mg/kg nominal dose-range was conducted in RDS-modelling, lung-lavaged spontaneously-breathing rabbits managed with nasal CPAP. The effects of nebulized poractant alfa on arterial gas exchange and lung mechanics were assessed. Exogenous alveolar disaturated-phosphatidylcholine (DSPC) in the lungs was measured as a proxy of surfactant deposition efficacy.

Results

Laser diffraction studies demonstrated suitable aerosol characteristics for inhalation (mass median diameter, MMD = 3 μm). The mean surfactant lung dose determined in vitro was 13.7% ± 4.0 of the 200 mg/kg nominal dose. Nebulized surfactant delivered to spontaneously-breathing rabbits during nasal CPAP significantly improved arterial oxygenation compared to animals receiving CPAP only. Particularly, the groups of animals treated with 200 mg/kg and 400 mg/kg of nebulized poractant alfa achieved an equivalent pulmonary response in terms of oxygenation and lung mechanics as the group of animals treated with instilled surfactant (200 mg/kg).

Conclusions

The customized eFlow-Neos vibrating-membrane nebulizer system efficiently generated respirable aerosols of undiluted poractant alfa. Nebulized surfactant delivered at doses of 200 mg/kg and 400 mg/kg elicited a pulmonary response equivalent to that observed after treatment with an intratracheal surfactant bolus of 200 mg/kg. This bench-characterized nebulized surfactant delivery strategy is now under evaluation in Phase II clinical trial (EUDRACT No.:2016–004547-36).

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1096-9) contains supplementary material, which is available to authorized users.

Making Medicines Baby Size: The Challenges in Bridging the Formulation Gap in Neonatal Medicine

The development of age-appropriate formulations should focus on dosage forms that can deliver variable yet accurate doses that are safe and acceptable to the child, are matched to his/her development and ability, and avoid medication errors. However, in the past decade, the medication needs of neonates have largely been neglected. The aim of this review is to expand on what differentiates the needs of preterm and term neonates from those of the older paediatric subsets, in terms of environment of care, ability to measure and administer the dose (from the perspective of the patient and carer, the routes of administration, the device and the product), neonatal biopharmaceutics and regulatory challenges. This review offers insight into those challenges posed by the formulation of medicinal products for neonatal patients in order to support the development of clinically relevant products.

Phospholipid components of the synthetic pulmonary surfactant CHF5633 probed by fluorescence spectroscopy

CHF5633 (Chiesi Farmaceutici, Italy) is a synthetic pulmonary surfactant currently under clinical development for the treatment of Respiratory Distress Syndrome in premature infants. The product is composed of phospholipids in liposomal organization, together with two peptide analogues of human surfactant proteins B and C. Phospholipids in liposomes can undergo oxidation of unsaturated lipids and hydrolysis, with formation of fatty acids and lysolipids, both affecting the physico-chemical properties of the formulation. We exploited two fluorescence probes, Prodan and ADIFAB, to evaluate the stability of the phospholipid components of CHF5633. While Prodan enters the phospholipid bilayer and probes the polarity of this environment, ADIFAB binds free fatty acids in the aqueous phase, allowing to determine their concentration. Changes of Prodan fluorescence emission indicated an increase in the polarity of the phospholipid bilayer as a function of time. This behavior is coupled with an increase in fatty acids concentration in the aqueous phase, as determined by ADIFAB, and an increase in lysolipids concentration, as determined by HPLC-MS. Prodan and ADIFAB resulted efficient probes to monitor phospholipids hydrolysis in liposomes, reporting an increased stability of CHF5633 at pH values higher than 6.5.

Performance of the Population Bioequivalence (PBE) Statistical Test Using an IPAC-RS Database of Delivered Dose from Metered Dose Inhalers

This article reports performance characteristics of the population bioequivalence (PBE) statistical test recommended by the US Food and Drug Administration (FDA) for orally inhaled products. A PBE Working Group of the International Pharmaceutical Aerosol Consortium on Regulation and Science (IPAC-RS) assembled and considered a database comprising delivered dose measurements from 856 individual batches across 20 metered dose inhaler products submitted by industry. A review of the industry dataset identified variability between batches and a systematic lifestage effect that was not included in the FDA-prescribed model for PBE. A simulation study was designed to understand PBE performance when factors identified in the industry database were present. Neglecting between-batch variability in the PBE model inflated errors in the equivalence conclusion: (i) The probability of incorrectly concluding equivalence (type I error) often exceeded 15% for non-zero between-batch variability, and (ii) the probability of incorrectly rejecting equivalence (type II error) for identical products approached 20% when product and between-batch variabilities were high. Neglecting a systematic through-life increase in the PBE model did not substantially impact PBE performance for the magnitude of lifestage effect considered. Extreme values were present in 80% of the industry products considered, with low-dose extremes having a larger impact on equivalence conclusions. The dataset did not support the need for log-transformation prior to analysis, as requested by FDA. Log-transformation resulted in equivalence conclusions that depended on the direction of product mean differences. These results highlight a need for further refinement of in vitro equivalence methodology.

In vitro and in vivo characterization of poractant alfa supplemented with budesonide for safe and effective intratracheal administration

BackgroundThe intratracheal (IT) administration of budesonide using surfactant as a vehicle has been shown to reduce the incidence of bronchopulmonary dysplasia (BPD) in preterm infants. The objective of this study was to characterize the in vitro characteristics and in vivo safety and efficacy of the extemporaneous combination of budesonide and poractant alfa.MethodsThe stability, minimum surface tension, and viscosity of the preparation were evaluated by means of high-performance liquid chromatography (HPLC), Wilhelmy balance, and Rheometer, respectively. The safety and efficacy of the IT administration of the mixture were tested in two respiratory distress syndrome (RDS) animal models: twenty-seventh day gestational age premature rabbits and surfactant-depleted adult rabbits.ResultsA pre-formulation trial identified a suitable procedure to ensure the homogeneity and stability of the formulation. Wilhelmy Balance tests clarified that budesonide supplementation has no detrimental effect on poractant alfa surface tension activity. The addition of budesonide to poractant alfa did not affect the physiological response to surfactant treatment in both RDS animal models, and was associated to a significant reduction of lung inflammation in surfactant-depleted rabbits.ConclusionOur in vitro and in vivo analysis suggests that the IT administration of a characterized extemporaneous combination of poractant alfa and budesonide is a safe and efficacious procedure in the context of RDS.

Chromosome translocations in couples with in-vitro fertilization implantation failure

Recurrent miscarriage is known to be associated with parental chromosomal abnormalities, particularly balanced reciprocal and Robertsonian translocations. The aim of this study was to test the hypothesis that couples with in-vitro fertilization (IVF) implantation failure, like those with recurrent miscarriage, have a higher than expected prevalence of translocations which may impact on pregnancy outcome. Patients who previously had at least 10 embryos transferred without achieving clinical pregnancy were evaluated for chromosome abnormalities as part of screening investigations for implantation failure. Recurrent miscarriage patients with a history of at least three consecutive first-trimester abortions were also tested. Results were compared to reports of infertility patients presenting for treatment and population neonatal screening programmes. Chromosomal abnormalities overall were detected in 13/514 individuals with implantation failure (2.5%), and 15/319 individuals with recurrent miscarriage (4. 7%). Translocations (reciprocal and Robertsonian) were found in 7/514 individuals (1.4%) and 7/219 couples (3.2%) with implantation failure (P < 0.0005 compared with infertile controls and P < 0.0001 compared with screened neonates). Translocations were found in 13/319 individuals (4.1%) and 12/130 couples (9.2%) with recurrent miscarriage. Balanced parental translocations may be implicated in the pathogenesis of IVF-implantation failure. Genetic evaluation should be considered as part of the investigation of these patients.

Delivery of normal twins following the intracytoplasmic injection of spermatozoa from a patient with 47,XXY Klinefelter's syndrome

Klinefelter's syndrome is a disorder of gonadal development and typically reveals a 47,XXY karyotype although mosaic forms also occur. Azoospermia is a common feature, but severe oligozoospermia and fertility have been reported. In this study, we have used intracytoplasmic sperm injection (ICSI) to achieve a live twin birth using spermatozoa from a 47,XXY man who has occasional spermatozoa present in the ejaculate. Spermatozoa were obtained from multiple ejaculates and frozen prior to commencing IVF treatment. Nine good quality embryos developed from the injection of 13 oocytes. All nine embryos were frozen. The initial transfer of two frozen-thawed embryos was unsuccessful. In the following cycle, the transfer of two additional frozen-thawed embryos resulted in the delivery of normal, healthy male and female twins. Five embryos remain frozen. It has generally been thought that the germ cells of 47,XXY men are unable to proceed through meiosis. Any spermatozoa produced have been assumed to come from a normal germ cell and therefore likely to have a normal karyotype. However, recent evidence suggests that meiosis of 47,XXY germ cells may be possible. Whether spermatozoa in these men arise from meiosis of 47,XXY germ cells, or from germ cells which have attained a normal karyotype by loss of an X chromosome, is unclear. Any risks in using spermatozoa from these patients have not yet been established. Patients need to be advised accordingly, and preimplantation or prenatal diagnosis should be considered. A cautious approach to the treatment of these patients is therefore warranted.

Prenatal diagnosis of Prader-Willi syndrome using PW71 methylation analysis--uniparental disomy and the significance of residual trisomy 15

Chorionic villus sampling (CVS) was performed on a 38-year-old woman at 10 weeks' gestation for advanced maternal age. Two long-term cultures showed true mosaicism of cells with a normal karyotype and cells with trisomy 15. Follow-up amniocentesis showed only cells with a normal karyotype. Methylation analysis of amniocyte DNA using the probe PW71B showed a result consistent with a diagnosis of Prader-Willi syndrome. This result was confirmed using dinucleotide microsatellite polymorphism analysis, which showed that the fetus had maternal uniparental heterodisomy for chromosome 15. This report describes the use of methylation analysis for prenatal diagnosis of uniparental disomy 15 but also indicates that there is some doubt regarding the methylation status of all amniocyte samples, as one of nine controls showed hypomethylation. Fetal skin was found to show low-level mosaicism for trisomy 15, indicating a prolonged persistence of mosaic trisomy 15, which raises questions regarding the management of pregnancies found to be mosaic for trisomy 15.

Confirmation of trisomy 22 in two cases using chromosome painting: comparison with t(11;22)

We present a nonmosaic case of trisomy 22 in a liveborn, abnormal infant and a second case of a fetus who died in utero. Both have been verified cytogenetically and confirmed by in situ hybridisation with a centromeric alphoid probe and chromosome painting. The accuracy of the combined cytogenetic and molecular cytogenetic approaches in the karyotype determination is highlighted by comparison with a case showing partial translocation of chromosome 22 in t(11;22) (q23;q11).