No-shaking and shake-fire delays affect respirable dose for suspension but not solution pMDIs.

It has long been accepted that suspension pressurized metered-dose inhalers (pMDIs) must be shaken if a correct dose is to be delivered, if not, it will usually be higher than the label claim. The purpose of this work was to investigate the influence of the device being unshaken, shaken and after a period of delay in pMDI actuation on the Fine Particle Mass (<5 µm), Extra Fine Particle Mass (<2 µm) and MMAD. Solution and suspension commercial pMDIs containing one, two or three components were used in the study. Most of the suspension pMDIs produced variable amounts of respirable size drug following the shake-fire delays tested in terms of the label claim dose. The effect was even more critical if the inhaler was not shaken and the FPM was found to be between -82 % for Symbicort and 363 % for Ventolin compared with the control values. In the case of MMAD measurements, Seretide and Serzyl inhalers showed the largest change from around 3 µm to 4.2-5.1 µm when not shaken. Conversely, the FPM and MMAD for the solution aerosols remained unchanged whether or not they were shaken or when a progressive increase in the delay in actuation after shaking was employed.

RespiCellTM: An Innovative Dissolution Apparatus for Inhaled Products.

To overcome some of the shortfalls of the types of dissolution testing currently used for pulmonary products, a new custom-built dissolution apparatus has been developed. For inhalation products, the main in vitro characterisation required by pharmacopoeias is the deposition of the active pharmaceutical ingredient in an impactor to estimate the dose delivered to the target site, i.e., the lung. Hence, the collection of the respirable dose (<5 µm) also appears to be an essential requirement for the study of the dissolution rate of particles, because it results as being a relevant parameter for the pharmacological action of the powder. In this sense, dissolution studies could become a complementary test to the routine testing of inhaled formulation delivered dose and aerodynamic performance, providing a set of data significant for product quality, efficacy and/or equivalence. In order to achieve the above-mentioned objectives, an innovative dissolution apparatus (RespiCell™) suitable for the dissolution of the respirable fraction of API deposited on the filter of a fast screening impactor (FSI) (but also of the entire formulation if desirable) was designed at the University of Parma and tested. The purpose of the present work was to use the RespiCell dissolution apparatus to compare and discriminate the dissolution behaviour after aerosolisation of various APIs characterised by different physico-chemical properties (hydrophilic/lipophilic) and formulation strategies (excipients, mixing technology).

Consequences of not-shaking and shake-fire delays on the emitted dose of some commercial solution and suspension pressurized metered dose inhalers.

BACKGROUND: Pressurized metered-dose inhalers (pMDIs) include hydrofluoroalkane (HFA) propellant to generate a drug aerosol upon actuation and drugs can be formulated as solution or suspension. Suspended particles can cream or sediment depending on density differences between drug and propellant and shaking the pMDI is an essential step to ensure a uniform drug dose release. RESEARCH DESIGN AND METHODS: The effect of the delay (0, 10, 30, 60 seconds) in pMDI actuation after shaking and the effect of no-shaking during the canister life on the emitted dose (ED) for commercial solution and suspension pMDIs was investigated. RESULTS: The ED for solutions was unaffected by no-shaking or by the progressive increasing delay in actuation after shaking (between 77% and 97%). For all the suspension products, shaking was demonstrated to be critical to assure the close to nominal drug delivery. In detail, the actuation delay after shaking led to an increase up to 380% or a drop to 32% of ED in relation to the label claim with high variability. CONCLUSION: The drug delivered can vary widely for no-shaking and over different shake-fire delays with suspension pMDIs while solution formulations appear to remain stable.

Excipient-free pulmonary insulin dry powder: Pharmacokinetic and pharmacodynamics profiles in rats.

A novel pure insulin spray-dried powder for DPI product (Ins_SD) was studied with respect to physico-chemical stability, in vitro respirability, bioavailability, activity and tolerability. Ins_SD powder exhibited a very high in vitro respirability, independently of the DPI product preparation (manual or semi-automatic). Physico-chemical characteristics of Ins_SD powder remained within the pharmacopoeia limits during 6 months of storage at room temperature. PK/PD profiles were measured in rats that received the pulmonary powders by intratracheal insufflation and compared with Afrezza inhalation insulin. Due to the low drug powder mass to deliver, both insulin powders were diluted with mannitol. Insulin from Ins_SD was promptly absorbed (tmax 15 min and Cmaxx4.9 ±â€¯1.5 mU/ml). Afrezza had a slower absorption (tmax 30 min and Cmax of 1.8 ±â€¯0.37 mU/ml). After glucose injection, Ins_SD determined a rapid reduction of glucose level, similar to Afrezza. As reference, insulin subcutaneous injection showed a long-lasting hypoglycemic effect due to the slow absorption that prolonged insulin plasma level. In summary, Ins_SD product is suitable for post-prandial glucose control, providing a convenient and compliant product, in particular in the event of using a disposable device. Albeit the product has to be stored in fridge, its stability at room temperature allows the diabetic individual to carry the daily dose in normal conditions.