Particulate Interactions in Dry Powder Formulation for Inhalation

by Zeng; Xian Ming

• ISBN13: 9780748409600
• ISBN10: 0748409602
• Edition: 1st
• Format: Hardcover
• Copyright: 2000-10-26
• Publisher: CRC Press

Summary

Interactions between drug particulates are crucial in determining drug dispersion and deaggregation, and ultimately delivery efficiency. This book combines principles and factors in pharmaceutical powder technology, critically reviews some of the studies carried out in dry powder formulation development, and proposes possible strategies for improving their efficiency. The majority of these principles are applicable to other pharmaceutical solid dosage forms (e.g. tablets and capsules).

Author Biography

Xian Ming Zeng is New Product Manager at the Inhalation Technology Department of Norton Healthcare Ltd., UK. His current interests are the delivery of drugs to the lungs Gary P. Martin is Reader in Pharmaceutics at King's College London, UK. His current research covers drug delivery through pulmonary, dermal and colonic routes Christopher Marriott is Professor of Pharmaceutics at King's College London, UK and also a member of the MCA sub-committee on Chemistry, Pharmacy and Standards

Table of Contents

Interparticulate Forces	1	(28)
Introduction	2	(3)
Van der Waals forces	5	(3)
Electrostatic forces	8	(1)
Capillary forces	9	(2)
Mechanical interlocking	11	(1)
Factors affecting particulate interactions	12	(17)
Particle size	12	(2)
Particle shape	14	(2)
Surface texture	16	(1)
Contact area	17	(3)
Surface energy	20	(2)
Hygroscopicity	22	(1)
Relative humidity	23	(1)
Electrical properties	24	(2)
References	26	(3)
Interparticulate Forces in Pharmaceutical Powders	29	(36)
Introduction	30	(1)
Mechanical properties	31	(4)
Electrical properties	35	(2)
Water vapour condensation	37	(5)
Particle morphology	42	(1)
Polymorphism and crystallinity	43	(4)
Processing conditions	47	(3)
Flow properties	50	(2)
Particle size	50	(1)
Particle shape	51	(1)
Electrostatic forces	51	(1)
Powder mixing	52	(2)
Agglomeration	54	(11)
References	59	(6)
Medicinal Aerosols	65	(38)
Introduction	66	(1)
Aerosol deposition in the respiratory tract	67	(5)
Inertial impaction	68	(1)
Sedimentation	69	(1)
Diffusion	70	(1)
Interception	71	(1)
Electrostatic precipitation	72	(1)
Delivery devices	72	(8)
Metered dose inhalers (MDIs)	72	(2)
Nebulisers	74	(1)
Dry powder inhalers	74	(6)
Physiology of the human respiratory tract	80	(4)
Breathing patterns	84	(2)
Flow rate	84	(1)
Tidal volume and breath-holding	85	(1)
Physico-chemical properties of drug particles	86	(17)
Particle size	86	(2)
Particle size distribution	88	(1)
Particle density	89	(1)
Particle shape	90	(1)
Hygroscopic growth of particles in the airways	91	(4)
References	95	(8)
Particle Interactions with Air Streams	103	(30)
Introduction	104	(2)
Drag forces of air streams	106	(3)
Particle entrainment	109	(5)
Particle detachment from stationary surfaces	110	(1)
Powder fluidisation	111	(3)
Particle dispersion	114	(2)
Factors affecting entrainment and dispersion of particles in air streams	116	(17)
Fluid properties	116	(3)
Particle properties	119	(4)
Particle-surface interaction	123	(5)
Exposure time of particles to the air stream	128	(1)
References	129	(4)
Particulate Interactions in Dry Powder Aerosols	133	(42)
Introduction	134	(2)
Generation of aerosol dry powders	136	(8)
Micronisation	137	(2)
Spray-drying	139	(2)
Crystallisation	141	(3)
Carrier particles	144	(1)
Carrier-free formulations	145	(1)
Particulate interactions between the drug and carrier particles	145	(30)
Morphology of carrier particles	147	(4)
Electrical properties	151	(4)
Drug-carrier formulations	155	(6)
Other physico-chemical properties	161	(1)
Preparative processes	162	(1)
Relative humidity	163	(2)
Drug properties	165	(3)
References	168	(7)
Measurement of Cohesion, Adhesion and Dispersion of Powders	175	(34)
Introduction	176	(1)
Cohesion of powders	177	(4)
Angle of repose and the angle of internal friction	177	(2)
Shear measurement of powder	179	(1)
Microbalance method	180	(1)
Adhesive forces	181	(5)
Tilted plane method	181	(2)
The gravity method	183	(1)
Centrifuge method	184	(2)
Microbalance methods	186	(1)
Aerodynamic methods	186	(6)
Measurement of powder dispersion	187	(1)
Sampling of airborne particles	188	(2)
Sample analysis	190	(2)
Characterisation of aerodynamic properties of medicinal aerosols.	192	(17)
Inertial impaction	192	(2)
Two-stage liquid impinger	194	(4)
Multistage liquid impinger	198	(3)
The Andersen Cascade Impactor	201	(2)
Other in vitro devices	203	(1)
References	204	(5)
Physical Characterisation of Pharmaceutical Powders	209	(42)
Introduction	210	(1)
Molecular properties	211	(9)
X-ray powder diffractometry	211	(2)
Thermal analysis	213	(2)
Vibrational spectroscopy	215	(2)
Nuclear magnetic resonance spectroscopy	217	(2)
Miscellaneous techniques	219	(1)
Particulate properties	220	(14)
Particle size and size distribution	220	(4)
Particle shape	224	(7)
Surface smoothness	231	(3)
Bulk properties of solids	234	(17)
Surface area	234	(4)
Flowability	238	(2)
Density	240	(4)
References	244	(7)
Index	251