Anti-Tuberculosis Bacteriophage D29 Delivery with a Vibrating Mesh Nebulizer,Jet Nebulizer,and Soft Mist Inhaler

Purpose

To compare titer reduction and delivery rate of active anti-tuberculosis bacteriophage (phage) D29 with three inhalation devices.

Methods

Phage D29 lysate was amplified to a titer of 11.8 ± 0.3 log₁₀(pfu/mL) and diluted 1:100 in isotonic saline. Filters captured the aerosolized saline D29 preparation emitted from three types of inhalation devices: 1) vibrating mesh nebulizer; 2) jet nebulizer; 3) soft mist inhaler. Full-plate plaque assays, performed in triplicate at multiple dilution levels with the surrogate host Mycobacterium smegmatis, were used to quantify phage titer.

Results

Respective titer reductions for the vibrating mesh nebulizer, jet nebulizer, and soft mist inhaler were 0.4 ± 0.1, 3.7 ± 0.1, and 0.6 ± 0.3 log₁₀(pfu/mL). Active phage delivery rate was significantly greater (p < 0.01) for the vibrating mesh nebulizer (3.3x10⁸ ± 0.8x10⁸ pfu/min) than for the jet nebulizer (5.4x10⁴ ± 1.3x10⁴ pfu/min). The soft mist inhaler delivered 4.6x10⁶ ± 2.0x10⁶ pfu per 11.6 ± 1.6 μL ex-actuator dose.

Conclusions

Delivering active phage requires a prudent choice of inhalation device. The jet nebulizer was not a good choice for aerosolizing phage D29 under the tested conditions, due to substantial titer reduction likely occurring during droplet production. The vibrating mesh nebulizer is recommended for animal inhalation studies requiring large amounts of D29 aerosol, whereas the soft mist inhaler may be useful for self-administration of D29 aerosol.

     

SPECT-CT Comparison of Lung Deposition using a System combining a Vibrating-mesh Nebulizer with a Valved Holding Chamber and a Conventional Jet Nebulizer: a Randomized Cross-over Study

Purpose

To compare in vivo the total and regional pulmonary deposition of aerosol particles generated by a new system combining a vibrating-mesh nebulizer with a specific valved holding chamber and constant-output jet nebulizer connected to a corrugated tube.

Methods

Cross-over study comparing aerosol delivery to the lungs using two nebulizers in 6 healthy male subjects: a vibrating-mesh nebulizer combined with a valved holding chamber (Aerogen Ultra®, Aerogen Ltd., Galway, Ireland) and a jet nebulizer connected to a corrugated tube (Opti-Mist Plus Nebulizer®, ConvaTec, Bridgewater, NJ). Nebulizers were filled with diethylenetriaminepentaacetic acid labelled with technetium-99 m (^99mTc-DTPA, 2 mCi/4 mL). Pulmonary deposition of ^99mTc-DTPA was measured by single-photon emission computed tomography combined with a low dose CT-scan (SPECT-CT).

Results

Pulmonary aerosol deposition from SPECT-CT analysis was six times increased with the vibrating-mesh nebulizer as compared to the jet nebulizer (34.1?±?6.0% versus 5.2?±?1.1%, p?<?0.001). However, aerosol penetration expressed as the three-dimensional normalized ratio of the outer and the inner regions of the lungs was similar between both nebulizers.

Conclusions

This study demonstrated the high superiority of the new system combining a vibrating-mesh nebulizer with a valved holding chamber to deliver nebulized particles into the lungs as comparted to a constant-output jet nebulizer with a corrugated tube.

     

Inhalable Spray-Freeze-Dried Powder with L-Leucine that Delivers Particles Independent of Inspiratory Flow Pattern and Inhalation Device

Purpose

The purpose of this study was to develop inhalable particles that can reach deep into the lungs efficiently independent of inhalation patterns of patients and inhalation devices. We prepared porous particles including L-leucine (Leu), a dispersive agent, by a spray-freeze-drying (SFD) method and examined the influence of inspiratory flow patterns and inhalation devices with various inhalation resistances.

Methods

Four types of SFD powder with different Leu contents (0–10%) were prepared. Scanning electron microscopy and laser diffraction were used to measure the morphology and size distribution of the powders. In-vitro inhalation characteristics were determined using a twin-stage liquid impinger equipped with an inspiratory flow pattern simulator. The effects of Leu on the adhesion force and electrostatic property of the particles were evaluated.

Results

The inhalation performance of the powders was improved by the addition of Leu. The powders with Leu showed a high inhalation performance regardless of inspiratory flow patterns and devices. The addition of Leu decreased the adhesion force and increased the surface potential of the powders.

Conclusions

The SFD particles with Leu showed high inhalation performance regardless of the inhalation patterns and devices, which was attributed to the decreased adhesion force between particles and increased dispersibility.

     

Formulating Inhalable Dry Powders Using Two-Fluid and Three-Fluid Nozzle Spray Drying

Purpose

The spray drying process is widely applied for pharmaceutical particle engineering. The purpose of this study was to investigate advantages and disadvantages of two-fluid nozzle and three-fluid nozzle spray drying processes to formulate inhalable dry powders.

Methods

Budesonide nanocomposite microparticles (BNMs) were prepared by co-spray drying of budesonide nanocrystals suspended in an aqueous mannitol solution by using a two-fluid nozzle spray drying process. Budesonide-mannitol microparticles (BMMs) were prepared by concomitant spray drying of a budesonide solution and an aqueous mannitol solution using a spray drier equipped with a three-fluid nozzle. The resulting dry powders were characterized by using X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and Raman microscopy. A Next Generation Impactor was used to evaluate the aerodynamic performance of the dry powders.

Results

XRPD and DMA results showed that budesonide remained crystalline in the BNMs, whereas budesonide was amorphous in the BMMs. Spray drying of mannitol into microparticles resulted in a crystalline transformation of mannitol, evident from XRPD, DSC and Raman spectroscopy analyses. Both BMMs and BNMs displayed a faster dissolution rate than bulk budesonide. The yield of BNMs was higher than that of BMMs. The mass ratio between budesonide and mannitol was preserved in the BNMs, whereas the mass ratio in the BMMs was higher than the theoretical ratio.

Conclusions

Spray drying is an enabling technique for preparation of budesonide amorphous solid dispersions and nanocrystal-embedded microparticles. Two-fluid nozzle spray drying is superior to three-fluid nozzle spray drying in terms of yield.

     

Preparation and Evaluation of Palm Oil-Based Polyesteramide Solid Dispersion for Obtaining Improved and Targeted Dissolution of Mefenamic Acid

Purpose

The aim of this work was to investigate the functional role of newly synthesised palm oil-based polyesteramide (POPEA) and stearic acid-based polyesteramide (SAPEA) in mefenamic acid (MA) solid dispersion (SD).

Methods

Solid dispersions of MA were prepared by hot melt method, using a combination of POPEA/SAPEA as a polymer carrier. The effects of POPEA/SAPEA mixture ratio, drug loading percentage and influence of different Mw of POPEA (4000–17,000 Da) in SD were investigated. The SDs were characterised for drug content, solubility, dissolution behaviour and physico-chemical characteristics by DSC and FTIR. Comparisons were made with pure drug, physical mixture and a marketed MA formulation.

Results

All SDs demonstrated faster dissolution rate than pure MA and SD 6 formulated with SAPEA/POPEA 4000 Da, 8:2 showed the highest T ₅₀ release rate (45 min) with no significant difference (P?>?0.05) compared to marketed formulation. All SDs showed improved drug release (85.48?±?1.17 to 90.66?±?1.53%) against marketed formulation (81.30?±?1.26%) and MA (56.27?±?1.08%) after 6 h of dissolution. DSC endothermic peak for MA in SD 6 was broadened and shifted to lower temperature (194 °C). FTIR spectroscopy confirmed no chemical changes in MA SD, but establishment of hydrogen bonding between hydroxyl groups of PEA with amine groups of MA was observed by the red shift of OH band in SD samples. The SD was stable (P?>?0.05) at ambient condition for up to 90 days, reflecting by the drug content, dissolution profiles and solubility of the formulation.

Conclusions

POPEA demonstrated surface lowering and wettability effects in improving the aqueous solubility and dissolution rate of MA in SD. The crystalline drug was transformed to amorphous formulation, via solubilisation and crystallisation inhibition effect of the PEA.

     

Evaluation of Pharmacokinetics of Bioreducible Gene Delivery Vectors by Real-time PCR

Purpose

To investigate pharmacokinetics of reversibly stabilized DNA nanoparticles (rSDN) using a single-step lysis RT-PCR.

Methods

rSDN were prepared by coating bioreducible polycation/DNA polyplexes with multivalent N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers. Targeted polyplexes were formulated by linking cyclic RGD ligand (c(RGDyK)) to the HPMA surface layer of rSDN. The pharmacokinetic parameters in tumor-bearing mice were analyzed by PKAnalyst®.

Results

The pharmacokinetics of naked plasmid DNA, simple DNA polyplexes, rSDN, and RGD-targeted rSDN exhibited two-compartment model characteristics with area under the blood concentration–time curve (AUC) increasing from 1,102 ng?ml^?1?min^?1 for DNA to 3,501 ng?ml^?1?min^?1 for rSDN. Non-compartment model analysis revealed increase in mean retention time (MRT) from 4.5 min for naked DNA to 22.9 min for rSDN.

Conclusions

RT-PCR is a sensitive and convenient method suitable for analyzing pharmacokinetics and biodistribution of DNA polyplexes. Surface stabilization of DNA polyplexes can significantly extend their MRT and AUC compared to naked DNA. DNA degradation in rSDN in blood circulation, due to a combined effect of disulfide reduction and competitive reactions with charged molecules in the blood, contributes to DNA elimination.

     

Effects of Moisture-Induced Crystallization on the Aerosol Performance of Spray Dried Amorphous Ciprofloxacin Powder Formulations

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.

     

Lomustine Nanoparticles Enable Both Bone Marrow Sparing and High Brain Drug Levels – A Strategy for Brain Cancer Treatments

Purpose

The blood brain barrier compromises glioblastoma chemotherapy. However high blood concentrations of lipophilic, alkylating drugs result in brain uptake, but cause myelosuppression. We hypothesised that nanoparticles could achieve therapeutic brain concentrations without dose-limiting myelosuppression.

Methods

Mice were dosed with either intravenous lomustine Molecular Envelope Technology (MET) nanoparticles (13 mg kg^?1) or ethanolic lomustine (6.5 mg kg^?1) and tissues analysed. Efficacy was assessed in an orthotopic U-87 MG glioblastoma model, following intravenous MET lomustine (daily 13 mg kg^?1) or ethanolic lomustine (daily 1.2 mg kg^?1 - the highest repeated dose possible). Myelosuppression and MET particle macrophage uptake were also investigated.

Results

The MET formulation resulted in modest brain targeting (brain/ bone AUC_0-4h ratios for MET and ethanolic lomustine?=?0.90 and 0.53 respectively and brain/ liver AUC_0-4h ratios for MET and ethanolic lomustine?=?0.24 and 0.15 respectively). The MET formulation significantly increased mice (U-87 MG tumours) survival times; with MET lomustine, ethanolic lomustine and untreated mean survival times of 33.2, 22.5 and 21.3 days respectively and there were no material treatment-related differences in blood and femoral cell counts. Macrophage uptake is slower for MET nanoparticles than for liposomes.

Conclusions

Particulate drug formulations improved brain tumour therapy without major bone marrow toxicity.

     

Preparation,Physicochemical Characterization and Anti-fungal Evaluation of Nystatin-Loaded PLGA-Glucosamine Nanoparticles

Purpose

Nystatin loaded PLGA and PLGA-Glucosamine nanoparticles were formulated. PLGA were functionalized with Glucosamine (PLGA-GlcN) to enhance the adhesion of nanoparticles to Candida Albicans (C.albicans) cell walls.

Method

Quasi-emulsion solvent diffusion method was employed using PLGA and PLGA-GlcN with various drug–polymer ratios for the preparation of nanoparticles. The nanoparticles were evaluated for size, zeta potential, polydispersity index, drug crystallinity, loading efficiency and release properties. DSC, SEM, XRPD, ¹H-NMR, and FT-IR were performed to analyze the physicochemical properties of the nanoparticles. Antifungal activity of the nanoparticles was evaluated by determination of MICs against C.albicans.

Results

The spectra of ¹H-NMR and FT-IR analysis ensured GlcN functionalization on PLGA nanoparticles. SEM characterization confirmed that particles were in the nanosize range and the particle size for PLGA and PLGA-GlcN nanoparticles were in the range of 108.63?±?4.5 to 168.8?±?5.65 nm and 208.76?±?16.85 nm, respectively. DSC and XRPD analysis ensured reduction of the drug crystallinity in the nanoparticles. PLGA-GlcN nanoparticles exhibit higher antifungal activity than PLGA nanoparticles.

Conclusion

PLGA-GlcN nanoparticles showed more antifungal activity with appropriate physicochemical properties than pure Nystatin and PLGA nanoparticles.

     

A Computational/Experimental Assessment of Antitumor Activity of Polymer Nanoassemblies for pH-Controlled Drug Delivery to Primary and Metastatic Tumors

Purpose

Polymer nanoassemblies (PNAs) with drug release fine-tuned to occur in acidic tumor regions (pH?<?7) while sparing normal tissues (pH?=?7.4) were previously shown to hold promise as nanoparticle drug carriers to effectively suppress tumor growth with reduced systemic toxicity. However, therapeutic benefits of pH-controlled drug delivery remain elusive due to complex interactions between the drug carriers, tumor cells with varying drug sensitivity, and the tumor microenvironment.

Methods

We implement a combined computational and experimental approach to evaluate the in vivo antitumor activity of acid-sensitive PNAs controlling drug release in pH 5?~?7.4 at different rates [PNA1 (fastest)?>?PNA2?>?PNA3 (slowest)].

Results

Computational simulations projecting the transport, drug release, and antitumor activity of PNAs in primary and metastatic tumor models of colorectal cancer correspond well with experimental observations in vivo. The simulations also reveal that all PNAs could reach peak drug concentrations in tumors at 11 h post injection, while PNAs with slower drug release (PNA2 and PNA3) reduced tumor size more effectively than fast drug releasing PNA1 (24.5 and 20.3 vs 7.5%, respectively, as fraction of untreated control).

Conclusion

A combined computational/experimental approach may help to evaluate pH-controlled drug delivery targeting aggressive tumors that have substantial acidity.

     

Stabilization of Live Attenuated Influenza Vaccines by Freeze Drying,Spray Drying,and Foam Drying

Purpose

The goal of this research is to develop stable formulations for live attenuated influenza vaccines (LAIV) by employing the drying methods freeze drying, spray drying, and foam drying.

Methods

Formulated live attenuated Type-A H1N1 and B-strain influenza vaccines with a variety of excipient combinations were dried using one of the three drying methods. Process and storage stability at 4, 25 and 37°C of the LAIV in these formulations was monitored using a TCID₅₀ potency assay. Their immunogenicity was also evaluated in a ferret model.

Results

The thermal stability of H1N1 vaccine was significantly enhanced through application of unique formulation combinations and drying processes. Foam dried formulations were as much as an order of magnitude more stable than either spray dried or freeze dried formulations, while exhibiting low process loss and full retention of immunogenicity. Based on long-term stability data, foam dried formulations exhibited a shelf life at 4, 25 and 37°C of >2, 1.5 years and 4.5 months, respectively. Foam dried LAIV Type-B manufactured using the same formulation and process parameters as H1N1 were imparted with a similar level of stability.

Conclusion

Foam drying processing methods with appropriate selection of formulation components can produce an order of magnitude improvement in LAIV stability over other drying methods.

     

Stabilization of HAC1 Influenza Vaccine by Spray Drying: Formulation Development and Process Scale-Up

Purpose

Stable vaccines with long shelf lives and reduced dependency on the cold chain are ideal for stockpiling and rapid deployment during public emergencies, including pandemics. Spray drying is a low-cost process that has potential to produce vaccines stable at a wide range of temperatures. Our aim was to develop a stable formulation of a recombinant H1N1 influenza hemagglutinin vaccine candidate and take it to pilot-scale spray-drying production.

Methods

Eight formulations containing different excipients were produced and assayed for antigen stability, powder characteristics, and immunogenicity after storage at a range of temperatures, resulting in the identification of four promising candidates. A pilot-scale spray-drying process was then developed for further testing of one formulation.

Results

The pilot-scale process was used to reproducibly manufacture three batches of the selected formulation with yields >90%. All batches had stable physical properties and in vitro potency for 6 months at temperatures from ?20°C to +50°C. Formulations stored for 3 months elicited immunogenic responses in mice equivalent to a frozen lot of bulk vaccine used as a stability control.

Conclusions

This study demonstrates the feasibility of stabilizing subunit vaccines using a spray-drying process and the suitability of the process for manufacturing a candidate product.

     

The pharmacokinetic profile of recombinant human erythropoietin is unchanged in patients undergoing cardiac surgery

Background

In anticipation of future studies, we examined the pharmacokinetics profile of erythropoietin (EPO) in patients undergoing cardiac surgery.

Methods

Cardiac surgical patients were enrolled into one of six groups: four cardiopulmonary bypass (CPB) groups [placebo (n?=?6), 250 IU/kg EPO (n?=?3), 500 IU/kg EPO (n =?3), and 500 IU/kg EPO, two doses (n =?6)] and two off-pump coronary artery bypass (OPCAB) groups [placebo (n?=?3) and 500 IU/kg EPO (n?=?3)]. The EPO was administered prior to anesthesia and 10 min after CPB (if required). Blood samples for serum EPO were collected at baseline, 10 min after dosing, 5 min after sternotomy, during CPB or the equivalent for OPCAB (5, 15, 45, 60 min), and post-CPB (5, 15, 45, and 60 min, 6, 12 and 24 h, and daily until day 5).

Results

Endogenous EPO increased within 24 h of surgery in the placebo group and remained elevated. There was approximately a 40% decrease in serum EPO concentration at the initiation of CPB due to an increase in circulatory blood volume. There were no differences in apparent volume of distribution in the plasma (Vc) (42.2?±?9.9, 39.8?±?6.3, 42.3?±?14.0 mL/kg), clearance (CL) (4.63?±?1.14, 3.44?±?0.68, 4.27?±?0.52 mL h/kg), and t_½ (16.4?±?8.0 16.9?±?10.6, 22.4?±?9.3 h) between the CPB treatment groups. The pharmacokinetic profile of EPO in the OPCAB group was similar to that for the CPB groups: Vc = 39.3?±?7.0 mL/kg, CL = 4.98?±?0.17 mL h/kg and t_½ = 17.1?±?18.1 h.

Conclusions

CPB had no apparent effect on the pharmacokinetics of EPO.

     

Identification of D-Amino Acids in Light Exposed mAb Formulations

Purpose

We previously demonstrated that D-amino acids can form as a result of photo-irradiation of a monoclonal antibody (mAb) at both λ?=?254 nm and λ?>?295 nm (λ_max?=?305 nm), likely via reversible hydrogen transfer reactions of intermediary thiyl radicals. Here, we investigate the role of various excipients (sucrose, glucose, L-Arg, L-Met and L-Leu) on D-amino acid formation, and specifically the distribution of D-amino acids in mAb monomers and aggregates present after light exposure.

Methods

The mAb-containing formulations were photo-irradiated at λ?=?254 nm and λ_max?=?305 nm, followed by fractionation of aggregate and monomer fractions using size exclusion chromatography. These aggregate and monomer fractions were subjected to hydrolysis and subsequent amino acid analysis.

Results

Both aggregate and monomer fractions collected from all formulations showed the formation of D-Glu and D-Val, whereas the formation of D-Ala was limited to the aggregate fraction collected from an L-Arg-containing formulation. Interestingly, quantitative analysis revealed higher yields of D-amino acids in the L-Arg-containing formulation.

Conclusions

Generally, D-amino acids accumulated to similar extents in monomers and aggregates.

     

<Emphasis Type="BoldItalic">In Vitro</Emphasis> Performance Testing of the Novel Medspray® Wet Aerosol Inhaler Based on the Principle of Rayleigh Break-up

Purpose

A new inhaler (Medspray®) for pulmonary drug delivery based on the principle of Rayleigh break-up has been tested with three different spray nozzles (1.5; 2.0 and 2.5 μm) using aqueous 0.1% (w/w) salbutamol and 0.9% (w/w) sodium chloride solutions.

Materials and methods

Particle size distributions in the aerosol were measured with the principles of time of flight (APS) and laser diffraction (LDA).

Results

The Medspray® inhaler exhibits a highly constant droplet size distribution in the aerosol during dose emission. Droplets on the basis of Rayleigh break-up theory are monodisperse, but due to some coalescence the aerosols from the Medspray® inhaler are slightly polydisperse. Mass median aerodynamic diameters at 60 l.min^?1 from APS are 1.42; 1.32 and 1.27 times the theoretical droplet diameters (TD’s) and median laser diffraction diameters are 1.29; 1.14 and 1.05 times TD for 1.5; 2.0 and 2.5 μm nozzles (TD: 2.84; 3.78 and 4.73 μm respectively).

Conclusions

The narrow particle size distribution in the aerosol from the Medspray® is highly reproducible for the range of flow rates from 30 to 60 l.min^?1. The mass median aerodynamic droplet diameter can be well controlled within the size range from 4 to 6 μm at 60 l.min^?1.

     

Population Pharmacokinetic Modeling of Etoposide Free Concentrations in Solid Tumor

Purpose

This study aimed to determine free etoposide (ETO) concentrations in two regions of Walker-256 (W256) solid tumor using microdialysis and to establish a population pharmacokinetic (popPK) model to describe simultaneously free tumor and total plasma concentrations.

Methods

W256 tumor-bearing Wistar rats received ETO 10 or 20 mg/kg i.v. bolus. Free ETO concentrations were sampled from central and peripheral regions of the tumor via CMA/20 probes for up to 7 h, whereas blood samples were collected via carotid artery cannulation. Total plasma and free tumor concentration-time profiles were analyzed by non-compartmental approach using WinNonlin® v. 5.3. PopPK modeling was conducted using MONOLIX v.4.3.3.

Results

ETO penetration was higher in the periphery (61?±?15% and 61?±?29%) than in tumor center (34?±?6% and 28?±?11%) following 10 and 20 mg/kg doses, respectively (ANOVA, α?=?0.05). A 4-compartment model fitted ETO concentration-time profiles in all sampling compartments.

Conclusions

The popPK model allowed the simultaneous fitting of plasma and tumor concentrations and a better understanding of ETO distribution in solid tumors. ETO plasma concentrations are not a good surrogate for tumoral exposure, emphasizing the importance of knowing intratumoral concentrations to predict drug response.

     

Rapid,Non-destructive Inspection and Classification of Inhalation Blisters Using Low-Energy X-ray Imaging

Purpose

Dry powders packaged in aluminum foil blisters are an increasingly common dosage form found in inhalation drug products. Filling of inhalation blisters often involves compressing bulk aerated powder into dense compacts. Sealed blisters are conditioned, e.g., by ultrasonic vibration, to loosen the consolidated powder within, to enable ready dispersion to a respirable aerosol when actuated by an inhaler device. Currently, the presence of residual powder consolidation within the blister is monitored manually by cutting open blisters for visual inspection.

Methods

X-ray imaging has gained increased acceptance as a non-destructive analytical technique for pharmaceutical capsules and tablets, typically with masses on the order of ~?100 mg. Here, an X-ray inspection approach was investigated for inhalation blisters having a significantly smaller powder fill mass of 2 mg. The challenge of sensing a small powder mass (2 mg) packaged within a significantly heavier blister (~?75 mg) was met using a low-energy X-ray imaging system. The measurement principle relies on denser, consolidated powder appearing as darker regions in the recorded image.

Results and Conclusion

Proof-of-concept experiments were performed using empty blister strips, and blister strips filled with 2 mg of placebo powder, half of which were subjected to ultrasonic conditioning. The tests demonstrated that a supervised machine learning approach based on digitally processed X-ray images reliably distinguished between the three types of blisters tested, i.e., empty blisters and conditioned and un-conditioned blisters of 2-mg fill mass. Using independent training and validation sets of 948 images each, an automated classification accuracy ≥?99.8% was demonstrated.

     

Aerosolization,Drug Permeation and Cellular Interaction of Dry Powder Pulmonary Formulations of Corticosteroids with Hydroxypropyl-β-Cyclodextrin as a Solubilizer

Purpose

The purpose of this study was to assess the feasibility of hydroxypropyl-β-cyclodextrin as a solubilizer for the corticosteroids prednisolone and fludrocortisone acetate in dry powder inhalation formulations.

Methods

The dry particles were simultaneously produced and coated with nanosized L-leucine crystals using an aerosol flow reactor method. The aerosolization performances of carrier-free powders were studied using Easyhaler® and Twister? at 2 and 4 kPa pressure drops over the inhalers. Drug permeation properties of the formulations were tested across a Calu-3 cell monolayer. Toxicity and reactive oxygen species induction were tested against Calu-3 and A549 cell lines.

Results

The hydroxypropyl-β-cyclodextrin in the powders promoted the dissolution of fludrocortisone the most, followed by that of prednisolone. Fine particle fractions were 52–70% from emitted doses which showed good repeatability with a coefficient variation of 0.9–0.17. In addition, hydroxypropyl-β-cyclodextrin enhanced the permeation of the corticosteroids. The powders showed no statistically significant toxicity nor reactive oxygen species induction in the tested cell lines.

Conclusions

This study demonstrated the preparation and function of fine powder formulations which combine improved dissolution of poorly soluble drugs with good aerosolization performance. These results are expected to promote particle engineering as a way to develop new types of therapeutic pulmonary powders.

     

Effects of <Emphasis Type="Italic">CYP2C19</Emphasis> and <Emphasis Type="Italic">CYP2C9</Emphasis> genotypes on pharmacokinetic variability of valproic acid in Chinese epileptic patients: nonlinear mixed-effect modeling

Purpose

To evaluate the effects of CYP2C19 and CYP2C9 genotypes on the pharmacokinetic variability of valproic acid (VPA) in epileptic patients using a population pharmacokinetic (PPK) approach.

Methods

VPA concentrations were measured in 287 epileptic patients, who were genotyped for CYP2C19*2/*3 and CYP2C9*3. Patients who were on monotherapy with VPA were divided into two groups, a PPK-model group (n?=?177) and a PPK-valid group (n?=?110). The PPK parameter values for VPA were calculated in the PPK-model group by using the NONMEM software. Ultimately, a biological model and a final model were established. Each model was then used to independently predict the concentrations of the PPK-valid group to validate the two models.

Results

There was a significant effect of the CYP2C19 and CYP2C9 genotypes on the pharmacokinetic (PK) variability (P?<?0.01) in the final PPK model of CL/F. The interindividual CL was calculated according to the final model: CL/F?=?0.0951?×?(1?+?e^{0.0267?×?(3???genotype)})?+?0.0071?×?age (L/h). The coefficient of variation (CV) (omega CL/F) of the final model was 29.3%, while that of the biological model was 31.7%. Based on the genotype, the individual PK parameters can be calculated more accurately than before.

Conclusion

The CYP2C19 and CYP2C9 genotypes significantly influenced the PK variability of VPA, as quantified by NONMEM software.