Handoko Adi

Co-spray-dried mannitol-ciprofloxacin dry powder inhaler formulation for cystic fibrosis and chronic obstructive pulmonary disease.

The aim of this study was to assess the potential of delivering a combination therapy, containing mannitol (a sugar alcohol with osmotic characteristics), and ciprofloxacin hydrochloride (an antibacterial fluoroquinolone), as a dry powder inhaler (DPI) formulation for inhalation. Single and combination powders were produced by spray drying ciprofloxacin and mannitol, from aqueous solution, at different ratios and under controlled conditions, as to obtain similar particle size distributions. Each formulation was characterised using laser diffraction, scanning electron microscopy, differential scanning calorimetry, dynamic vapour sorption, X-ray powder diffraction, and colloidal force microscopy. The in vitro aerosol performance of each formulation was studied using an Aerolizer DPI device and a multi-stage liquid impinger (analysed using high performance liquid chromatography). In addition, a disk diffusion test was performed to assess the in vitro antimicrobial activity of each formulation and starting materials. All formulations had similar particle size distributions, however, the morphology, thermal properties and moisture sorption was dependent on the relative percentages of each component. In general, the combination formulation containing 50% (w/w) mannitol appeared to have the best aerosol performance, good stability and lowest particle cohesion (as measured by colloid probe microscopy). Furthermore, of the formulations tested, mannitol did not appear to alter the effectiveness of the ciprofloxacin antimicrobial activity to Staphylococcus aureus, Pseudomonas aeruginosa and Streptococcus pyogenes. The combination of co-spray-dried mannitol and ciprofloxacin from a DPI is an attractive approach to promote mucous clearance in the respiratory tract while simultaneously treating local chronic infection, such as chronic obstructive pulmonary disease and cystic fibrosis.

Micro-particle corrugation, adhesion and inhalation aerosol efficiency.

Atomic force microscopy (AFM) was used to evaluate the particle adhesion and surface morphology of engineered particles for dry powder inhaler (DPI) respiratory therapy to gain a greater understanding of interparticle forces and the aerosolisation process. A series of spherical model drug particles of bovine serum albumin (BSA) was prepared with different degrees of surface corrugation. The particles were evaluated in terms of particle size (laser diffraction) and microscopic morphology (scanning electron microscopy). Conventional tapping mode AFM was used to evaluate the nanoscopic morphology and derive specific roughness parameters, while AFM colloid probe microscopy was used to directly measure the interaction of functionalised probes. The physical characterisation and AFM measurements were evaluated in terms of in vitro aerosolisation performance, using a conventional Rotahaler((R)) DPI and multistage liquid impinger. A direct relationship between the root mean square roughness, particle adhesion and in vitro aerosol performance (measured as fine particle fraction, FPF) was observed suggesting that as the degree of corrugation increased, particle adhesion was reduced which, resulted in a concomitant increase in FPF. This study demonstrates that AFM may be used to predict the aerosolisation performance micron sized particles for inhalation based on their morphological properties.

Controlled release antibiotics for dry powder lung delivery.

Introduction: Two controlled release (CR) antibiotics intended for inhalation therapy were evaluated. Material and Methods: Ciprofloxacin and doxycycline (both hydrochlorides) were selected as model drugs. Microparticles containing 90:10 ratio of polyvinyl alcohol (PVA) and single antibiotics or combinations were obtained via spray drying. The microparticles were evaluated in terms of particle size, morphology, thermal properties, aerosol performance, and in vitro release. Results and Discussion: Analysis of the microparticle morphology indicated comparable size distributions (2.04 ± 0.06, 2.15 ± 0.01, and 2.21 ± 0.01 μm for ciprofloxacin, doxycycline, and co-spray-dried antibiotic formulations, respectively). Thermal analysis of the microparticles suggested similar responses, which were dominated by the endothermic peaks observed for PVA alone. Analysis of the aerosol performance suggested that the individual antibiotic formulations had different aerosol profiles that were dependent on the antibiotic used. In comparison, the combination CR antibiotics had identical aerosol profiles, suggesting that the microparticles were homogeneous. The release of antibiotics from the CR microparticles showed that ≤50% was released over a 6-hour period in comparison to ≥90% being released in the first hour for microparticles containing no PVA. Conclusions: The potential for antibiotic therapy, and specifically CR antibiotic therapy using dry powder inhalers, provides a promising route for the treatment of pulmonary infection.

Pulmonary Spray Dried Powders of Tobramycin Containing Sodium Stearate to Improve Aerosolization Efficiency

PurposeTobramycin microparticulate powders containing the hydrophobic adjunct sodium stearate were studied for their use as pulmonary formulations in dry powder inhalers.MethodsSpray-dried powders were characterized in terms of particle size distribution, morphology, crystallinity, drug dissolution rate, toxicity on epithelial lung cells and aerosol efficiency.ResultsThe presence of the sodium stearate had a direct influence on the aerosol performance of tobramycin spray-dried powders. Powders containing 1% w/w sodium stearate had fine particle fraction FPF of 84.3 ± 2.0% compared to 27.1 ± 1.9% for powders containing no adjunct. This was attributed to the accumulation of sodium stearate at the particle surface. Powders with higher sodium stearate concentrations (2% w/w) showed significantly lower FPF (66.4 ± 0.9%) and less accumulation of sodium stearate at the particle surface. This was attributed to the formation of adjunct micelles, which remained internalised in the particle structure due to their reduced tropism toward the drying drop surface and molecular mobility. Preliminary analysis of the toxicity effect of sodium stearate on A549 cell lines showed that the adjunct, in the concentration used, had no effect on cell viability over a 24-h period compared to particles of pure tobramycin.ConclusionsTobramycin pulmonary powders with low level of sodium stearate, presenting high respiration performances and no overt toxicity on lung cells, could be used to improve therapeutic outcomes of patient with Cystic Fibrosis (CF).

Can low-dose combination products for inhalation be formulated in single crystalline particles?

This study aims to produce and test the performance of novel crystalline respirable particles containing two low-dose active ingredients and mannitol. This technique overcomes the usual requirement of blending with lactose carriers in formulating combination inhalation products. Ternary powders were produced by co-spray drying solutions containing an inhaled corticosteroid (ICS), a long-acting beta2-agonist (LABA), and mannitol as a crystalline excipient. Two formulations comprising widely used ICS and LABA were studied: budesonide/formoterol fumarate dihydrate/mannitol (B/F/M-SD) and fluticasone propionate/salmeterol xinafoate/mannitol (F/S/M-SD). Various physicochemical properties of the powders were analyzed. Aerosol performance was evaluated by dispersing each powder from an Aerolizer at 60 and 100 L/min into a Next Generation Impactor. We obtained partially hollow spherical particles (volume median diameters of 2 microm) with drug-enriched surfaces. Both formulations contained alpha-mannitol, and the ICSs were crystalline. The content of each drug component in the powder was found to conform to the theoretical dose. The ternary powders generated high fine particle fractions (>50% of the loaded dose), with concomitant drug deposition on the impactor stages. The aerosol performance of B/F/M-SD was maintained after storage over silica gel at 22 degrees C for 11 weeks. In conclusion, co-spray dried particles of ICS/LABA/M-SD were largely crystalline, stable and showed excellent aerosol performance. They may provide an attractive alternative strategy to develop combination products without lactose blends.

Characterisation and aerosolisation of mannitol particles produced via confined liquid impinging jets.

Mannitol particles, produced by spray drying (SD), have been used commercially (Aridol) in bronchial provocation test. In this study, we propose an alternative method to produce inhalable mannitol powders. The elongated mannitol particles (number median length 4.0microm, and axial ratio of 3.5) were prepared using a confined liquid impinging jets (CLIJs) followed by jet milling (JM). Spray dried and jet milled raw mannitol particles were compared in an attempt to assess the performance of the particles produced by the new method. Aerosol performance of the three different powders (CLIJ, SD, and JM) was relatively poor (fine particle fraction or FPF(loaded) below 15%) when dispersed by the Rotahaler. Dispersion through the Aeroliser led to better aerosol performance of the CLIJ mannitol (FPF(loaded) 20.3%), which is worse than the JM (FPF(loaded) 30.3%) and SD mannitol particles (FPF(loaded) 45.7%) at 60 L/min, but comparable (FPF(loaded) 40.0%) with those of the JM (FPF(loaded) 40.7%) and SD (FPF(loaded) 45.5%) powders at 100L/min. Hence, the optimum use of these elongated mannitol particles can be achieved at increased air flow with a more efficient inhaler. In addition to crystallinity, morphology, and particle size distribution, the surface energies of these powders were measured to explain the differences in aerosol performance. A major advantage of using the CLIJ method is that it can be scaled up with a good yield as the precipitate can be largely collected and recovered on a filter, compared with spray drying which has a low collection efficiency for fine particles below 2microm.

A novel method for the production of crystalline micronised particles.

The aim of this study was to develop a method for converting an amorphous drug to a crystalline form to enhance its stability and inhalation performance. Spray-dried amorphous salbutamol sulphate powder was conditioned with supercritical carbon dioxide (scCO(2)) modified with menthol. The effect of menthol concentration, pressure, temperature and time on the characteristics of the resulting salbutamol sulphate powder was investigated. Pure scCO(2) had no effect on the physical properties of amorphous salbutamol sulphate; however, scCO(2) modified with menthol at 150bar and 50 degrees C was efficient in converting amorphous drug to crystalline form after 12h of conditioning. The average particle size of powders decreased slightly after the conditioning process because of reducing agglomeration between particles by increasing surface roughness. Emitted dose measured by the fine particle fraction (FPF(emitted)) of amorphous salbutamol sulphate was enhanced from 32% to 43% after conditioning with scCO(2)+menthol and its water uptake was significantly decreased. This study demonstrates the potential of scCO(2)+menthol for converting amorphous forms of powders to crystalline, while preserving the particle size.

Does electrostatic charge affect powder aerosolisation

To study if electrostatic charge initially present in mannitol powder plays a role in the generation of aerosols, mannitol was unipolarly charged to varying magnitudes by tumbling the powder inside containers of different materials. The resulting charge in the powder was consistent with predictions from the triboelectric charging theories, based on the work function values from literature and electron transfer tendencies from measurement of contact angle. The latter generated a parameter, gamma(-)/gamma+, which is a measure of the electron-donating capacity relative to the electron-accepting tendency of material. Lowering the work function value or increasing the gamma(-)/gamma+ ratio of the container material resulted in mannitol being more negatively charged, and vice versa. After charging, the powder was dispersed from an Aerolizer(R), at 30 and 60 L/min, to study the aerosol performance. Irrespective of the charge level, the powder showed similar fine particle fraction, emitted dose and device retention at a given flow rate, indicating that charge induced by different containers during tumbling does not play a significant role in mannitol powder aerosolisation.

Scanning White-Light Interferometry as a Novel Technique to Quantify the Surface Roughness of Micron-Sized Particles for Inhalation

A novel approach of measuring the surface roughness of spherical and flat micron-sized drug particles using scanning white-light interferometry was applied to investigate the surface morphology of micron-sized active pharmaceutical ingredients (APIs) and excipient particles used for inhalation aerosols. Bovine serum albumin (BSA) and alpha-lactose monohydrate particles were chosen as model API and excipient particles, respectively. Both BSA and lactose particles were prepared with different degrees of surface corrugation using either controlled spray drying (four samples of BSA) or decantation (two samples of lactose). Particle size distributions were characterized by laser diffraction, and particles were imaged by scanning electron microscopy (SEM). Surface roughness of the BSA and lactose particles was quantified by white-light optical profilometry using vertical scanning interferometry (VSI) at full resolution using a 50x objective lens with 2.0x and 0.5x fields of view for BSA and lactose, respectively. Data were analyzed using Vision software (version 32, WYKO), and surface roughness values are expressed as root-mean-square roughness ( Rrms). Furthermore, data were compared to topographical measurements made using conventional atomic force microscopy. Analysis of the optical profilometry data showed significant variation in BSA roughness ranging from 18.58 +/- 3.80 nm to 110.90 +/- 13.16 nm for the smoothest and roughest BSA particles, respectively, and from 81.20 +/- 15.90 nm to 229.20 +/- 68.20 nm for decanted and normal lactose, respectively. The Rrms values were in good agreement with the AFM-derived values. The particle morphology was similar to SEM and AFM images. In conclusion, scanning white-light interferometry provides a useful complementary tool for rapid evaluation of surface morphology and roughness in particles used for dry powder inhalation formulation.

Co-deposition of a triple therapy drug formulation for the treatment of chronic obstructive pulmonary disease using solution-based pressurised metered dose inhalers

Objectives  The formulation of multi‐drug pressurised metered dose inhalers (pMDIs) opens up exciting therapeutic opportunities for the treatment of asthma and chronic obstructive pulmonary disease (COPD). We have investigated the formulation of a solution‐based triple therapy pMDI containing ipratropium, formoterol, budesonide and ethanol as co‐solvent.