This study investigated the potential of excipient coating to enhance the aerosol performance of micronized drugs in carrier excipient-drug blends, used in dry powder inhalers. Both EC and PVP were used as coating agents to study polymers with significantly different chemistry. Carriers were prepared via sieve fractioning followed by spray drying from a saturated lactose suspension with and without polymer additive. Each uncoated and coated carrier systems were evaluated in terms of particle size, morphology, drug carrier adhesion, and aerosolisation performance of blended micronized salbutamol sulphate (in terms of both in vitro mass deposition and electrostatic charge). Furthermore, each formulation was studied directly after blending and after storage for 24 hours. All the carrier-based systems prepared had similar particle sizes, as measured by laser diffraction and similar morphologies (as studied using atomic force microscopy and electron microscopy). Interestingly, the surface chemistries of the carriers were significantly different as was drug-carrier adhesion and aerosolisation performance. Particle adhesion between salbutamol sulphate and each carrier followed the rank: PVP coated > un-coated > EC coated lactose. Similarly the aerosol performance (fine particle fraction; FPF) of salbutamol sulphate followed the rank order PVP coated > un-coated > EC coated lactose, correlating well with the adhesion studies. This rank order could be attributed to the surface energy measured by contact goniometry and related to the chemistry of lactose and each polymer. Interestingly, storage did not significantly affect aerosol performance, however a rank increase in mean FPF value was observed for uncoated and EC coated lactose. Finally the net charge across the aerosol cloud (measured via an electrostatic NGI) indicated that the EC coated lactose transferred less charge to the salbutamol sulphate particles. In general, modification of lactose carrier surface chemistry via coating can be used to alter the aerosol performance of attached drug. By careful selection of the coating polymer, drug-carrier adhesion, electrostatic charge and thus aerosol performance can be controlled.
Polymer coating of carrier excipients modify aerosol performance of adhered drugs used in dry powder inhalation therapy
SCALIA, Santo;
2012
Abstract
This study investigated the potential of excipient coating to enhance the aerosol performance of micronized drugs in carrier excipient-drug blends, used in dry powder inhalers. Both EC and PVP were used as coating agents to study polymers with significantly different chemistry. Carriers were prepared via sieve fractioning followed by spray drying from a saturated lactose suspension with and without polymer additive. Each uncoated and coated carrier systems were evaluated in terms of particle size, morphology, drug carrier adhesion, and aerosolisation performance of blended micronized salbutamol sulphate (in terms of both in vitro mass deposition and electrostatic charge). Furthermore, each formulation was studied directly after blending and after storage for 24 hours. All the carrier-based systems prepared had similar particle sizes, as measured by laser diffraction and similar morphologies (as studied using atomic force microscopy and electron microscopy). Interestingly, the surface chemistries of the carriers were significantly different as was drug-carrier adhesion and aerosolisation performance. Particle adhesion between salbutamol sulphate and each carrier followed the rank: PVP coated > un-coated > EC coated lactose. Similarly the aerosol performance (fine particle fraction; FPF) of salbutamol sulphate followed the rank order PVP coated > un-coated > EC coated lactose, correlating well with the adhesion studies. This rank order could be attributed to the surface energy measured by contact goniometry and related to the chemistry of lactose and each polymer. Interestingly, storage did not significantly affect aerosol performance, however a rank increase in mean FPF value was observed for uncoated and EC coated lactose. Finally the net charge across the aerosol cloud (measured via an electrostatic NGI) indicated that the EC coated lactose transferred less charge to the salbutamol sulphate particles. In general, modification of lactose carrier surface chemistry via coating can be used to alter the aerosol performance of attached drug. By careful selection of the coating polymer, drug-carrier adhesion, electrostatic charge and thus aerosol performance can be controlled.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
