The effects of surface morphology on the aerosol performance of spray-dried particles within HFA 134a based metered dose formulations

The aim of this study was to produce fine particles with different corrugated degree of surface by spray-drying and to investigate the effect of surface morphology on in vitro aerosol performance of the particles within HFA 134a based metered dose formulations.Compositions of rizatriptan and scutellarin were spray-dried using different spray-drying parameters,and particles were suspended within HFA 134a.The surface morphology were determined using scanning electron microscopy(SEM),while the aerodynamic performance of MDIs was evaluated using a next generation pharmaceutical impactor.The surface morphology of spraydried particles could vary from smooth to moderately corrugated,and to raisin-like depending upon spray-drying parameters and preparation compositions.In general,increasing inlet temperature,decreasing feed concentration and/or adding leucine to the feed solution tended to increase the corrugated degree of particle surface.Deposition results indicated that raisinlike particle based MDIs for all compositions of the two drugs produced significantly better aerodynamic performance in terms of fine particle fractions and mass median aerodynamic diameters relative to the formulations of the corresponding smooth or slightly corrugated particles when the particle compositions were the same.The present results demonstrated that wrinkled particles increased fine particle fractions within surfactant-free MDI formulations.

Practical,regulatory and clinical considerations for development of inhalation drug products

The formulation and device collectively constitute an inhalation drug product.Development of inhaled drugs must consider the compatibility between formulation and device in order to achieve the intended pharmaceutical performance and usability of the product to improve patient compliance with treatment instruction.From the points of formulation,device and patient use,this article summarizes the inhalation drugs,including pressurized metered dose inhaler(pMDI),dry powder inhaler(DPI),and nebulizer that are currently available in the US and UK markets.It also discusses the practical considerations for the development of inhalers and provides an update on the corresponding regulations of the FDA(U.S.Food and Drug Administration)and the EMA(European Medicines Agency).