In vitro evaluation of dry powder inhaler devices of corticosteroid preparations

Dry Powder Inhaler with the technical and practical obstacles, and forthcoming platform strategies

A Dry Powder Inhaler (DPI) is a technique as well as a device used to inhale formulation which is in the form of dry powder, and is inhaled through the nose or mouth. It was developed for the purpose of treating conditions like chronic obstructive pulmonary disease (COPD), Asthma, and even cystic fibrosis etc. The aim of the review is to discuss the different methods of preparation of dry powders along with the characterization of DPI. Here we present the outline of different methods like supercritical fluid extraction (SCF), spray drying, and milling. The review focussed on various devices including single and multi-dose devices used in the DPI. It also highlights on recent advances in the DPI including nano particulate system, siRNA-based medication, liposomes, and pro-liposomes based delivery. In COVID-19 silver nanoparticles-based DPIs provide very prominent results in the infected lungs. Moreover, this review states that the AI-based DPI development provides and improvement in the bioavailability and effectiveness of the drug along with the role of artificial neural networks (ANN). The study also showed that nasally administered drugs (nose to brain) can easily cross the blood-brain barrier (BBB) and enter the central nervous system (CNS) through the olfactory and trigeminal pathway which provides effective CNS concentrations at lower dosage. It is suggested that DPIs not only target respiratory complications but also treat CNS complications too. This review provides support and guides the researcher in the recent development and evaluation of DPI.

SIRT 1 Activator Loaded Inhaled Antiangiogenic Liposomal Formulation Development for Pulmonary Hypertension

Pulmonary hypertension (PH) is characterized by the rise in mean pulmonary arterial pressure (≥ 20 mmHg at rest) due to the narrowing of the pulmonary arterial networks. Current treatments provide symptomatic treatment and the underlying progress of PH continues leading to higher mortality rates due to non-reversal of the disease. This warrants the need for drug therapies targeting angiogenesis and vascular remodeling mechanisms. Resveratrol, SIRT 1 activator, alters various signaling pathways, inhibits apoptosis, and negatively regulates angiogenesis either by increasing the production of anti-angiogenic factors or inhibiting pro-angiogenic factors. Our work describes the liposomal formulation development, physicochemical characterization, and in vitro aerosolization performance of resveratrol liposomal dry powder formulation. The resveratrol liposomal dry powder formulation reduces the right ventricular systolic pressure measured during right jugular vein catheterization and significantly reverses the PH disease pathological changes as demonstrated by histological observations of pulmonary arterial lumen and ventricular hypertrophy. The developed resveratrol liposomal dry powder formulation alleviates the pulmonary arterial remodeling through its antiangiogenic mechanism and indicates a promising therapeutic strategy for PH treatment.

A mechanistic framework for a priori pharmacokinetic predictions of orally inhaled drugs

The fate of orally inhaled drugs is determined by pulmonary pharmacokinetic processes such as particle deposition, pulmonary drug dissolution, and mucociliary clearance. Even though each single process has been systematically investigated, a quantitative understanding on the interaction of processes remains limited and therefore identifying optimal drug and formulation characteristics for orally inhaled drugs is still challenging. To investigate this complex interplay, the pulmonary processes can be integrated into mathematical models. However, existing modeling attempts considerably simplify these processes or are not systematically evaluated against (clinical) data. In this work, we developed a mathematical framework based on physiologically-structured population equations to integrate all relevant pulmonary processes mechanistically. A tailored numerical resolution strategy was chosen and the mechanistic model was evaluated systematically against data from different clinical studies. Without adapting the mechanistic model or estimating kinetic parameters based on individual study data, the developed model was able to predict simultaneously (i) lung retention profiles of inhaled insoluble particles, (ii) particle size-dependent pharmacokinetics of inhaled monodisperse particles, (iii) pharmacokinetic differences between inhaled fluticasone propionate and budesonide, as well as (iv) pharmacokinetic differences between healthy volunteers and asthmatic patients. Finally, to identify the most impactful optimization criteria for orally inhaled drugs, the developed mechanistic model was applied to investigate the impact of input parameters on both the pulmonary and systemic exposure. Interestingly, the solubility of the inhaled drug did not have any relevant impact on the local and systemic pharmacokinetics. Instead, the pulmonary dissolution rate, the particle size, the tissue affinity, and the systemic clearance were the most impactful potential optimization parameters. In the future, the developed prediction framework should be considered a powerful tool for identifying optimal drug and formulation characteristics.

The use of orally inhaled drugs for treating lung diseases is appealing since they have the potential for lung selectivity, i.e. high exposure at the site of action –the lung– without excessive side effects. However, the degree of lung selectivity depends on a large number of factors, including physiochemical properties of drug molecules, patient disease state, and inhalation devices. To predict the impact of these factors on drug exposure and thereby to understand the characteristics of an optimal drug for inhalation, we develop a predictive mathematical framework (a “pharmacokinetic model”). In contrast to previous approaches, our model allows combining knowledge from different sources appropriately and its predictions were able to adequately predict different sets of clinical data. Finally, we compare the impact of different factors and find that the most important factors are the size of the inhaled particles, the affinity of the drug to the lung tissue, as well as the rate of drug dissolution in the lung. In contrast to the common belief, the solubility of a drug in the lining fluids is not found to be relevant. These findings are important to understand how inhaled drugs should be designed to achieve best treatment results in patients.

Formulation of Dry Powder Inhaler of Anti-tuberculous Drugs Using Spray Drying Technique and Optimization Using 23 Level Factorial Design Approach

Background:

Targeting anti-tubercular therapeutics to alveolar macrophages using microparticles technology mainly focuses on increasing local concentrations of therapeutics and potentially reducing the frequency of dosing requirements. Rifampicin (RIF), Ofloxacin (OFX) and Ethambutol (ETH) combination show synergism.

Objective:

In light of the above facts, the focus of the present study was to develop and characterize novel Dry powder Inhaler formulation incorporating novel drug combination as a pulmonary delivery for the effective eradication of Tuberculosis.

Method:

Biodegradable microparticles containing RIF, OFX and ETH were prepared by a spray drying technique using PLGA polymer through the critical process as well as polymer attributes were screened and optimized using 23 factorial design. The identified critical process parameters (CPP’s) viz. Inlet temperature, Aspiration rate, and feed rate were selected as independent variables while percentage yield, percentage entrapment efficiency, and particle size were selected as a response. The formulated microparticles were evaluated for particle size, drug-polymer compatibility study, aerodynamic behavior, morphology, particle size distribution, crystallinity, residual solvent content, in-vitro drug release study, and stability study.

Results:

By choosing the optimum spray drying conditions maximum yield of 73%, entrapment efficiency of 86% and particle size of 1.4 μm was attained of the optimized batch. Thus the results revealed that spherical microparticles are suitable for inhalation and sustained release for 12 h.

Conclusion:

The successful formulation and evaluation of dry powder could be used as an enhanced therapeutic alternative of the standard oral anti-tubercular regimen, rescuing oral dosing, shortening drug regimen and limiting toxicity. This will ultimately improve patient compliance and diminish the prevalence of MDR resistance.

Utility and effectiveness of Symbicort® Turbuhaler® (oral inhalation containing budesonide and formoterol) in a patient with severe asthma after permanent tracheostomy

Background

The utility and effectiveness of inhalational asthma therapy in patients with a permanent tracheostomy has not been established. Previously, a few studies reported the use of nebulizer-type inhalers for treating these patients. Symbicort® Turbuhaler® (Symbicort) is an orally inhaled dry powder containing the corticosteroid budesonide and the bronchodilator formoterol. There are no reports describing the successful use of Symbicort in patients with a permanent tracheostomy.

Case presentation

We describe the case of a woman with poorly controlled severe asthma after a permanent tracheostomy. She had developed thyroid cancer with tracheal invasion for which right thyroid lobectomy and tracheal and esophageal resection were performed, with subsequent construction of a permanent tracheostomy. In our case, prior to surgery, asthma control had been improved by adding a bronchodilator-the long-acting muscarinic antagonist tiotropium-and the anti-IgE antibody agent omalizumab to single maintenance and reliever therapy (SMART) using Symbicort; surgery was then performed. After surgery, asthma control worsened as a result of a change from Symbicort to budesonide nebulizer and a tulobuterol patch. In order to resume SMART therapy, an In-Check® inspiratory flow meter was used to measure and assess whether the inspiratory flow rate was sufficient for a dry-powder inhaler. Inhalation guidance was provided. On inhalation with the tracheostomy closed at the same time, the inspiratory flow rate was 43 L/min at the maximum. This was judged to be sufficient for the effect of Symbicort, and thus the inhaler was changed to Symbicort. Asthma symptoms promptly improved, and the patient was subsequently discharged.

Conclusions

The use of Symbicort resulted in improved asthma control in a patient with severe asthma following a permanent tracheostomy. Thus, it is suggested that inhalation powder could be an option for patients with permanent tracheostomy.

Numerical simulation of emitted particle characteristics and airway deposition distribution of Symbicort(®) Turbuhaler(®) dry powder fixed combination aerosol drug

One of the most widespread dry powder fixed combinations used in asthma and chronic obstructive pulmonary disease (COPD) management is Symbicort(®) Turbuhaler(®). The aim of this study was to simulate the deposition distribution of both components of this drug within the airways based on realistic airflow measurements. Breathing parameters of 25 healthy adults (11 females and 14 males) were acquired while inhaling through Turbuhaler(®). Individual specific emitted doses and particle size distributions of Symbicort(®) Turbuhaler(®) were determined. A self-developed particle deposition model was adapted and validated to simulate the deposition of budesonide (inhaled corticosteroid; ICS) and formoterol (long acting β2 agonist; LABA) in the upper airways and lungs of the healthy volunteers. Based on current simulations the emitted doses varied between 50.4% and 92.5% of the metered dose for the ICS, and between 38% and 96.1% in case of LABA component depending on the individual inhalation flow rate. This variability induced a notable inter-individual spread of the deposited lung doses (mean: 33.6%, range: 20.4%-48.8% for budesonide and mean: 29.8%, range: 16.4%-42.9% for formoterol). Significant inter-gender differences were also observed. Average lung dose of budesonide was 29.2% of the metered dose for females and 37% for males, while formoterol deposited with 26.4% efficiency for females and 32.5% for males. Present results also highlighted the importance of breath-holding after inhalation of the drug. About a half of the total lung deposition occurred during breath-hold at 9.6s average breath-hold time. Calculated depositions confirmed appropriate lung deposition of Symbicort(®) Turbuhaler(®) for both genders, however more effort for optimal inhalation technique is advised for persons with low vital capacity. This study demonstrated the possibility of personalized prediction of airway deposition of aerosol drugs by numerical simulations. The methodology developed in this study will be applicable also to other marketed drugs in the future.

Computer modeling of airway deposition distribution of Foster(®) NEXThaler(®) and Seretide(®) Diskus(®) dry powder combination drugs

Asthma is a serious global health problem with rising prevalence and treatment costs. Due to the growing number of different types of inhalation devices and aerosol drugs, physicians often face difficulties in choosing the right medication for their patients. The main objectives of this study are (i) to elucidate the possibility and the advantages of the application of numerical modeling techniques in aerosol drug and device selection, and (ii) to demonstrate the possibility of the optimization of inhalation modes in asthma therapy with a numerical lung model by simulating patient-specific drug deposition distributions. In this study we measured inhalation parameter values of 25 healthy adult volunteers when using Foster(®) NEXThaler(®) and Seretide(®) Diskus(®). Relationships between emitted doses and patient-specific inhalation flow rates were established. Furthermore, individualized emitted particle size distributions were determined applying size distributions at measured flow rates. Based on the measured breathing parameter values, we calculated patient-specific drug deposition distributions for the active components (steroid and bronchodilator) of both drugs by the help of a validated aerosol lung deposition model adapted to therapeutic aerosols. Deposited dose fractions and deposition densities have been computed in the entire respiratory tract, in distinct anatomical regions of the airways and at the level of airway generations. We found that Foster(®) NEXThaler(®) deposits more efficiently in the lungs (average deposited steroid dose: 42.32±5.76% of the nominal emitted dose) than Seretide(®) Diskus(®) (average deposited steroid dose: 24.33±2.83% of the nominal emitted dose), but the variance of the deposition values of different individuals in the lung is significant. In addition, there are differences in the required minimal flow rates, therefore at certain patients Seretide(®) Diskus(®) or pMDIs could be a better choice. Our results show that validated computer deposition models could be useful tools in providing valuable deposition data and assisting health professionals in the personalized drug selection and delivery optimization. Patient-specific modeling could open a new horizon in the treatment of asthma towards a more effective personalized medicine in the future.

Comparison of the clinical effects of combined salmeterol/fluticasone delivered by dry powder or pressurized metered dose inhaler

The salmeterol/fluticasone combination (SFC) inhaler is currently the most widely used maintenance drug for asthmatics worldwide. Although the effectiveness of SFC as either a dry powder inhaler (DPI) or a pressurized metered dose inhaler (pMDI) is well documented, there is limited data comparing the clinical efficacies of the two devices. To address this issue, we carried out a randomized crossover trial in which asthmatic patients (n = 47; mean age, 62.5 ± 16.5 years old) received a 12-week treatment of SFC DPI (50/250 μg twice daily) or SFC pMDI (four puffs of 25/125 μg daily). After a 4-week washout period, patients received another crossover treatment for 12 weeks. Respiratory resistance and reactance were measured by forced oscillation technique (MostGraph-01), spirometry, fractional exhaled nitric oxide (FeNO), and an asthma control test (ACT) every 4 weeks. The mean forced expiratory volume1.0 at the baseline was 2.16 ± 0.86 (L). Respiratory system resistance at 5 Hz (R5), the difference between R5 and R at 20 Hz (R5 - R20), and FeNO improved in both treatment groups, while reactance at 5 Hz (X5) and ACT score improved only in the pMDI group. In patients >70 years old (n = 21), R5, R5 - R20, ΔX5, and FeNO improved only in the pMDI group. These results suggest that SFC by pMDI produces a stronger anti-inflammatory and bronchodilatory effect even in patients whose asthma is well controlled by SFC delivered by DPI.

Comparison of early effects of budesonide/formoterol maintenance and reliever therapy with fluticasone furoate/vilanterol for asthma patients requiring step-up from inhaled corticosteroid monotherapy

BACKGROUND

If asthma patients fail to achieve symptom control using a medium dose of inhaled corticosteroid (ICS) alone, addition of a long-acting β2 agonist (LABA) is the preferred treatment. Currently, there are several combinations of ICS/LABA that are available, each of which has a different property. Here, we aimed to compare the early effects of budesonide/formoterol (BUD/FM; Symbicort(®)) for maintenance and reliever therapy (SMART) with a fixed dose of fluticasone furoate/vilanterol (FF/VI; Relvar(®)).

METHODS

Inadequately controlled asthma patients (defined as having an Asthma Control Questionnaire, 5-item version [ACQ5] score≥1.5) with a fractional exhaled nitric oxide (FeNO) value > 35 ppb, who had been treated with a medium dose of ICS alone, were enrolled. Patients were randomized into two groups and treated with two inhalations twice-daily of BUD/FM 160/4.5 μg plus as-needed BUD/FM (SMART group, n = 15) or one inhalation once-daily of FF/VI 100/25 μg plus as-needed procaterol (FF/VI group, n = 15) for 4 weeks. Outcomes including FeNO, impulse oscillometry (IOS) parameters and ACQ5 scores were measured at 0, 2 and 4 weeks.

RESULTS

Both groups showed improvement in airway inflammation, pulmonary function and symptoms from baseline to 2 weeks. From 2 to 4 weeks, the SMART group exhibited continuous improvement in most measured parameters, whereas improvement in the FF/VI group seemed to reach a plateau transiently. Consequently, the SMART group showed significant improvement in the FeNO, IOS parameters (resonance frequency and integrated area of low frequency reactance) and ACQ5 score as compared with the FF/VI group at 4 weeks.

CONCLUSION

As compared with the FF/VI group, the SMART group achieved a greater improvement in FeNO, small airway parameters regarding IOS and ACQ score, in patients with airway inflammation and uncontrolled symptoms treated with a medium dose of ICS alone. In this 4-week study, these two ICS/LABA combination therapies showed different treatment outcomes; they must be investigated further to clarify suitable patient characters and the long term efficacies for each combination.

Extra-fine particle inhaled corticosteroids, pharma-cokinetics and systemic activity in children with asthma

During recent years, extra-fine particle inhaled corticosteroids with a median aerodynamic diameter ≤2 μm have been introduced in the treatment of asthma. The aim of this paper was to review pharmacokinetics and systemic activity of extra-fine particle hydroalkane pressurized metered dose inhaled (pMDI) ciclesonide and beclomethasone dipropionate in children. A literature review was performed. Systemic bioavailability of oral and pulmonary deposition of extra-fine ciclesonide and beclomethasone dipropionate was 52% and 82%, the half-life in serum 3.2 and 1.5 h and first-pass hepatic metabolism >99% and 60%, respectively. Secondary analyses of urine cortisol/creatinine excretion found no effects of ciclesonide pMDI between 40 and 320 μg/day or of beclomethasone dipropionate pMDI between 80 and 400 μg/day. Ciclesonide pMDI 40, 80 and 160 μg/day caused no effects on short-term lower leg growth rate as assessed by knemometry. Ciclesonide 320 μg/day was associated with a numerically short-term growth suppression equivalent to 30% which was similar to 25% and 36% suppression caused by beclomethasone dipropionate HFA and CFC 200 μg/day, respectively. Consistent with the differences in key pharmacokinetic features, beclomethasone dipropionate is associated with a systemic activity detected by knemometry at a lower dose than ciclesonide. Whether that correlates with a clinically important difference remains to be explored. Assessments of systemic activity of beclomethasone dipropionate <200 μg/day and of ciclesonide >180 μg/day as well as head-to-head comparisons are warranted. Preferably, such studies should apply the sensitive method of knemometry.

Pharmacological consequences of inhaled drug delivery to small airways in the treatment of asthma

Small peripheral airways are an important target for the anti-inflammatory treatment of asthma. To make anti-inflammatory drugs (inhaled corticosteroids [ICS]) effectively reach small airways, they should be delivered using inhalation techniques containing high proportions of fine or super-fine particles. Higher proportions of fine particles are associated with higher systemic absorption of ICS leading to an increased risk of endogenous cortisol suppression. Ciclesonide, despite the highest proportion of fine and super-fine particle fractions, is the only ICS not associated with an increased risk of systemic adverse effects, including cortisol suppression. In contrary to ICS, bronchodilators should not be administered to peripheral airways. This does not improve their efficacy and may increase their risk of cardiotoxicity. Thus, from a pharmacological point of view and the theory of aerosols' deposition, fixed combinations of ICS and long-acting beta agonists are always suboptimal. In many cases, the best solution may be to use fine-particle ciclesonide and a non-fine particle beta agonist administered from separate inhalers.