ENGINEERED INFLATED SPHERICAL LACTOSE PARTICLE AND ITS POTENTIAL USE AS A CARRIER FOR DRY POWDER FORMULATION AEROSOLS

Dry powder inhalation aerosol is usually formed by blending lactose carrier with micronized drug particles using an order mix. In this thesis, blends of either Salbutamol Sulphate (SS), Beclomethasone Dipropionate (BDP) or Fluticasone Propionate (FP) and coarse lactose particles were employed to investigate the effects of lactose morphological features on drug delivery by dry powder aerosols in-vitroor ex-vivousing recorded patients’inhalation profiles. Two lactose carriers were used in this study namely Lactohale and engineered lactose. Engineered lactose was prepared by a novel crystallisation technique from solid state using spray dried amorphous lactose prepared from lactose solution alone (10% w/v) or in the presence of additives (1% w/v) such as Polyvinyl Pyrrolidone (PVP K90) or sodium chloride (NaCl). A 10 g of amorphous spray dried particles ( Lactohale > PSDL30. A balanced drug roughness is needed for hydrophobic drugs to improve drug content uniformity and to facilitate drug detachment during aerosolisation. Ex-vivostudy using four patient profiles having the same inhaled volume (Vin) and acceleration (ACIM) at the start of the inhalation manoeuvre but having different maximum inhalation flow (MIF) were used to study the aerodynamic dose emission characteristics of SS with lactohale and engineered lactose carrier produced from spray dried lactose formed from spray dried suspension of lactose, which is commercially available(PSDL com). PSDLcom had the highest roughness in comparison to all carriers highlighted above and showed low FPD at all MIFs in comparison to Lactohale. This study confirmed again that smooth carrier such as Lactohale provides better drug deposition for hydrophilic drugs such as SS. In conclusion, the drug deposition study showed that there is no ideal carrier for all drugs with different physico-chemical properties such as hydrophilicity. To improve drug deposition from DPIs, hydrophilic drugs are better formulated with a smooth carrier and hydrophobic drugs require a moderate surface roughness