Powder Delivery Devices

Abstract

A nasal delivery device for delivering substance to a nasal cavity of a subject, the delivery device comprising: a substance supply unit for supplying a dose of substance to be delivered to the nasal cavity of the subject, the substance supply unit including an inlet and an outlet; a nosepiece unit including a nosepiece for fitting to a nasal cavity of the subject and being in fluid communication with the outlet of the substance supply unit; and a mouthpiece unit including a mouthpiece in fluid communication with the inlet of the substance supply unit and through which the subject in use exhales such as to entrain substance from the container chamber and deliver the same through the nosepiece, and at least one temperature modifier for reducing a temperature of the exhaled air flow such as to reduce the absolute humidity thereof.

1 . A nasal delivery device for delivering substance to a nasal cavity of a subject, the delivery device comprising:
 a substance supply unit for supplying a dose of substance to be delivered to the nasal cavity of the subject, the substance supply unit including an inlet and an outlet;   a nosepiece unit including a nosepiece for fitting to a nasal cavity of the subject and being in fluid communication with the outlet of the substance supply unit; and   a mouthpiece unit including a mouthpiece in fluid communication with the inlet of the substance supply unit and through which the subject in use exhales such as to entrain substance from the substance supply unit and deliver the same through the nosepiece, and at least one temperature modifier for reducing a temperature of the exhaled air flow such as to reduce the absolute humidity thereof.   
     
     
         2 . The delivery device of  claim 1 , wherein the at least one temperature modifier comprises at least one elongate channel. 
     
     
         3 . The delivery device of  claim 2 , wherein the at least one temperature modifier comprises a plurality of elongate channels. 
     
     
         4 . The delivery device of  claim 2  or  3 , wherein the mouthpiece unit includes a plurality of temperature modifiers which can be fluidly connected successively to the mouthpiece, and a switching mechanism which allows for one of the temperature modifiers to be fluidly connected to the mouthpiece. 
     
     
         5 . The delivery device of  claim 4 , wherein, when the one of the temperature modifiers is fluidly connected to the mouthpiece, the at least one other temperature modifier is vented to atmosphere. 
     
     
         6 . The delivery device of  claim 4  or  5 , wherein the switching mechanism comprises a rotatable member to which the temperature modifiers are disposed, whereby rotation of the switching mechanism provides for the one of the temperature modifiers to be in fluid communication with the mouthpiece. 
     
     
         7 . The delivery device of any of  claims 1  to  6 , wherein the substance supply unit comprises a container chamber for receiving a substance-containing container which contains a dose of substance. 
     
     
         8 . The delivery device of  claim 7 , wherein the container chamber is substantially cylindrical in shape. 
     
     
         9 . The delivery device of  claim 7 , wherein the container chamber is substantially spherical in shape. 
     
     
         10 . The delivery device of any of  claims 7  to  9 , wherein the container chamber and the nosepiece comprise a unitary, replaceable component. 
     
     
         11 . The delivery device of any of  claims 7  to  10 , wherein the substance supply unit comprises a rupturing mechanism for rupturing the container as contained in the container chamber. 
     
     
         12 . The delivery device of any of  claims 7  to  11 , wherein the container is formed of a material which exhibits insufficient tackiness in the presence of moisture such as not to adhere to an inner surface of the container chamber during emptying of the container. 
     
     
         13 . The delivery device of  claim 12 , wherein the container is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 5 s following exhalation. 
     
     
         14 . The delivery device of  claim 13 , wherein the container is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 2 s following exhalation. 
     
     
         15 . The delivery device of  claim 14 , wherein the container is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 1 s following exhalation. 
     
     
         16 . The delivery device of any of  claims 7  to  15 , wherein the container is formed substantially of a cellulose derivative. 
     
     
         17 . The delivery device of  claim 16 , wherein the container is formed substantially of one of hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose, methylcellulose, ethylcellulose and carboxymethylcellulose. 
     
     
         18 . The container of any of  claims 7  to  11 , wherein the container is formed substantially of gelatine. 
     
     
         19 . The delivery device of any of  claims 7  to  15 , wherein the container is formed of a plastics material. 
     
     
         20 . The delivery device of any of  claims 7  to  15 , wherein the container includes a coating of a material which exhibits insufficient tackiness in the presence of moisture such as not to adhere to an inner surface of the container chamber during emptying of the container. 
     
     
         21 . The delivery device of  claim 20 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 5 s following exhalation. 
     
     
         22 . The delivery device of  claim 21 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 2 s following exhalation. 
     
     
         23 . The delivery device of  claim 22 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 1 s following exhalation. 
     
     
         24 . The delivery device of any of  claims 20  to  23 , wherein the coating comprises substantially one of parylene, hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose, methylcellulose, ethylcellulose, carboxymethylcellulose, polyvinyl alcohol, acrylic acid polymer, methacrylic acid polymer, ethyl acrylic acid polymer, cellulose acetate phthalate, polyvinyl acetate phthalate, hydroxypropyl methylcellulose phthalate and hydroxyl methylcellulose acetate succinate, or any combination of layers thereof. 
     
     
         25 . The delivery device of any of  claims 20  to  24 , wherein the container comprises a body of gelatine. 
     
     
         26 . The delivery device of any of  claims 7  to  25 , wherein the container comprises a capsule. 
     
     
         27 . The delivery device of  claim 26 , wherein the capsule is substantially cylindrical in shape. 
     
     
         28 . The delivery device of  claim 26 , wherein the capsule is substantially spherical in shape. 
     
     
         29 . The delivery device of any of  claims 1  to  28 , wherein the at least one temperature modifier is configured to reduce the temperature of the exhaled air flow by more than about 5° C. 
     
     
         30 . The delivery device of  claim 29 , wherein the at least one temperature modifier is configured to reduce the temperature of the exhaled air flow by at least about 12° C. 
     
     
         31 . The delivery device of any of  claims 1  to  30 , wherein the at least one temperature modifier is configured to allow a flow therethrough at a flow rate of at least about 10 I/min at a pressure of less than about 2 kPa, and preferably less than about 1 kPa. 
     
     
         32 . The delivery device of  claim 31 , wherein the at least one temperature modifier is configured to allow a flow therethrough at a flow rate of at least about 20 I/min at a pressure of less than about 2 kPa, and preferably less than about 1 kPa. 
     
     
         33 . The delivery device of  claim 32 , wherein the at least one temperature modifier is configured to allow a flow therethrough at a flow rate of at least about 30 I/min at a pressure of less than about 2 kPa, and preferably less than about 1 kPa. 
     
     
         34 . The delivery device of  claim 33 , wherein the at least one temperature modifier is configured to allow a flow therethrough at a flow rate of at least about 40 I/min at a pressure of less than about 2 kPa, and preferably less than about 1 kPa. 
     
     
         35 . The delivery device of  claim 34 , wherein the at least one temperature modifier is configured to allow a flow therethrough at a flow rate of at least about 50 I/min at a pressure of less than about 2 kPa, and preferably less than about 1 kPa. 
     
     
         36 . The delivery device of any of  claims 1  to  35 , wherein the at least one temperature modifier is configured such as to provide a pressure drop of not more than about 0.5 kPa to the exhaled air flow. 
     
     
         37 . The delivery device of  claim 36 , wherein the at least one temperature modifier is configured such as to provide a pressure drop of not more than about 0.25 kPa to the exhaled air flow. 
     
     
         38 . The delivery device of  claim 37 , wherein the at least one temperature modifier is configured such as to provide a pressure drop of not more than about 0.10 kPa to the exhaled air flow. 
     
     
         39 . The delivery device of  claim 38 , wherein the at least one temperature modifier is configured such as to provide a pressure drop of not more than about 0.05 kPa to the exhaled air flow. 
     
     
         40 . The delivery device of  claim 39 , wherein the at least one temperature modifier is configured such as to provide a pressure drop of not more than about 0.025 kPa to the exhaled air flow. 
     
     
         41 . The delivery device of any of  claims 1  to  40 , wherein the at least one temperature modifier comprises a thermoelectric device. 
     
     
         42 . A nasal delivery device for delivering substance to a nasal cavity of a subject, the delivery device comprising:
 a substance supply unit for supplying a dose of substance to be delivered to the nasal cavity of the subject, the substance supply unit comprising a substance-receiving chamber including an inlet and an outlet, and a Venturi unit for drawing a flow of ambient air through the substance-receiving chamber;   a nosepiece unit including a nosepiece for fitting to the nasal cavity of the subject and being in fluid communication with the Venturi unit; and   a mouthpiece unit including a mouthpiece in fluid communication with the Venturi unit and through which the subject in use exhales such as to entrain substance from the substance-receiving chamber and deliver the same through the nosepiece.   
     
     
         43 . The delivery device of  claim 42 , wherein the substance-receiving chamber comprises a container chamber for receiving a substance-containing container which contains a dose of substance. 
     
     
         44 . The delivery device of  claim 43 , wherein the container chamber is substantially cylindrical in shape. 
     
     
         45 . The delivery device of  claim 43 , wherein the container chamber is substantially spherical in shape. 
     
     
         46 . The delivery device of any of  claims 43  to  45 , wherein the container chamber and the nosepiece comprise a unitary, replaceable component. 
     
     
         47 . The delivery device of any of  claims 43  to  46 , wherein the substance supply unit comprises a rupturing mechanism for rupturing the substance-containing container as contained in the container chamber. 
     
     
         48 . The delivery device of any of  claims 43  to  47 , wherein the container is formed of a material which exhibits insufficient tackiness in the presence of moisture such as not to adhere to an inner surface of the container chamber during emptying of the container. 
     
     
         49 . The delivery device of  claim 48 , wherein the container is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 5 s following exhalation. 
     
     
         50 . The delivery device of  claim 49 , wherein the container is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 2 s following exhalation. 
     
     
         51 . The delivery device of  claim 50 , wherein the container is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 1 s following exhalation. 
     
     
         52 . The delivery device of any of  claims 43  to  51 , wherein the container is formed substantially of a cellulose derivative. 
     
     
         53 . The delivery device of  claim 52 , wherein the container is formed substantially of one of hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose, methylcellulose, ethylcellulose and carboxymethylcellulose. 
     
     
         54 . The delivery device of any of  claims 43  to  47 , wherein the container is formed substantially of gelatine. 
     
     
         55 . The delivery device of any of  claims 43  to  51 , wherein the container is formed of a plastics material. 
     
     
         56 . The delivery device of any of  claims 43  to  51 , wherein the container includes a coating of a material which exhibits insufficient tackiness in the presence of moisture such as not to adhere to an inner surface of the container chamber during emptying of the container. 
     
     
         57 . The delivery device of  claim 56 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 5 s following exhalation. 
     
     
         58 . The delivery device of  claim 57 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 2 s following exhalation. 
     
     
         59 . The delivery device of  claim 58 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 1 s following exhalation. 
     
     
         60 . The delivery device of any of  claims 56  to  59 , wherein the coating comprises substantially one of parylene, hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose, methylcellulose, ethylcellulose, carboxymethylcellulose, polyvinyl alcohol, acrylic acid polymer, methacrylic acid polymer, ethyl acrylic acid polymer, cellulose acetate phthalate, polyvinyl acetate phthalate, hydroxypropyl methylcellulose phthalate and hydroxyl methylcellulose acetate succinate, or any combination of layers thereof. 
     
     
         61 . The delivery device of any of  claims 56  to  60 , wherein the container comprises a body of gelatine. 
     
     
         62 . The delivery device of any of  claims 43  to  61 , wherein the container comprises a capsule. 
     
     
         63 . The delivery device of  claim 62 , wherein the capsule is substantially cylindrical in shape. 
     
     
         64 . The delivery device of  claim 62 , wherein the capsule is substantially spherical in shape. 
     
     
         65 . The delivery device of any of  claims 42  to  64 , wherein the Venturi unit comprises a first, driving air flow inlet which is in fluid communication with the mouthpiece unit and provides a constriction which acts to accelerate the exhaled air flow to deliver a driving air flow at a higher velocity, a second, substance air flow inlet which is in fluid communication with the substance supply unit and through which is in use drawn a substance air flow from the substance-receiving chamber which, entrains substance as contained therein, and an air flow outlet which is in fluid communication with the nosepiece unit and through which the driving air flow and the substance air flow are in use delivered. 
     
     
         66 . The delivery device of  claim 65 , wherein the driving air flow is directed substantially perpendicularly to the substance air flow. 
     
     
         67 . The delivery device of  claim 65 , wherein the driving air flow is directed substantially parallel to the substance air flow. 
     
     
         68 . The delivery device of any of  claims 42  to  67 , wherein the mouthpiece unit is fluidly connected to the substance supply unit, such as to provide a supplemental air flow to the substance-receiving chamber on exhalation by the subject into the mouthpiece unit. 
     
     
         69 . The delivery device of  claim 68 , wherein the mouthpiece unit includes a flow channel which is fluidly connected to the inlet of the substance-receiving chamber. 
     
     
         70 . A nasal delivery device for delivering substance to a nasal cavity of a subject, the delivery device comprising:
 a substance supply unit for supplying a dose of substance to be delivered to the nasal cavity of the subject, the substance supply unit comprising a substance-receiving chamber including an inlet and an outlet, and a gas supply unit for delivering a gas flow through the substance-receiving chamber such as in use to provide a gas flow entraining substance from the outlet of the substance-receiving chamber;   a nosepiece unit including a nosepiece for fitting to the nasal cavity of the subject and being in fluid communication with the outlet of the substance-receiving chamber; and   a mouthpiece unit including a mouthpiece in fluid communication with the outlet of the substance-receiving chamber and the nosepiece and through which the subject in use exhales such as to entrain substance as delivered from the substance-receiving chamber and deliver the same through the nosepiece.   
     
     
         71 . The delivery device of  claim 70 , wherein the substance-receiving chamber comprises a container chamber for receiving a substance-containing container which contains a dose of substance. 
     
     
         72 . The delivery device of  claim 71 , wherein the container chamber is substantially cylindrical in shape. 
     
     
         73 . The delivery device of  claim 71 , wherein the container chamber is substantially spherical in shape. 
     
     
         74 . The delivery device of any of  claims 71  to  73 , wherein the container chamber and the nosepiece comprise a unitary, replaceable component. 
     
     
         75 . The delivery device of any of  claims 71  to  74 , wherein the substance supply unit comprises a rupturing mechanism for rupturing the container as contained in the container chamber. 
     
     
         76 . The delivery device of any of  claims 71  to  75 , wherein the container is formed of a material which exhibits insufficient tackiness in the presence of moisture such as not to adhere to an inner surface of the container chamber during emptying of the container. 
     
     
         77 . The delivery device of  claim 76 , wherein the container is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 5 s following exhalation. 
     
     
         78 . The delivery device of  claim 77 , wherein the container is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 2 s following exhalation. 
     
     
         79 . The delivery device of  claim 78 , wherein the container is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 1 s following exhalation. 
     
     
         80 . The delivery device of any of  claims 71  to  79 , wherein the container is formed substantially of a cellulose derivative. 
     
     
         81 . The delivery device of  claim 80 , wherein the container is formed substantially of one of hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose, methylcellulose, ethylcellulose and carboxymethylcellulose. 
     
     
         82 . The delivery device of any of  claims 71  to  75 , wherein the container is formed substantially of gelatine. 
     
     
         83 . The delivery device of any of  claims 71  to  79 , wherein the container is formed of a plastics material. 
     
     
         84 . The delivery device of any of  claims 71  to  79 , wherein the container includes a coating of a material which exhibits insufficient tackiness in the presence of moisture such as not to adhere to an inner surface of the container chamber during emptying of the container. 
     
     
         85 . The delivery device of  claim 84 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 5 s following exhalation. 
     
     
         86 . The delivery device of  claim 85 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 2 s following exhalation. 
     
     
         87 . The delivery device of  claim 86 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 1 s following exhalation. 
     
     
         88 . The delivery device of any of  claims 84  to  87 , wherein the coating comprises substantially one of parylene, hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose, methylcellulose, ethylcellulose, carboxymethylcellulose, polyvinyl alcohol, acrylic acid polymer, methacrylic acid polymer, ethyl acrylic acid polymer, cellulose acetate phthalate, polyvinyl acetate phthalate, hydroxypropyl methylcellulose phthalate and hydroxyl methylcellulose acetate succinate, or any combination of layers thereof. 
     
     
         89 . The delivery device of any of  claims 84  to  88 , wherein the container comprises a body formed substantially of gelatine. 
     
     
         90 . The delivery device of any of  claims 71  to  89 , wherein the container comprises a capsule. 
     
     
         91 . The delivery device of  claim 90 , wherein the capsule is substantially cylindrical in shape. 
     
     
         92 . The delivery device of  claim 90 , wherein the capsule is substantially spherical in shape. 
     
     
         93 . The delivery device of any of  claims 70  to  92 , wherein the gas supply unit comprises a volume of pressurized gas which, when released, provides the entraining gas flow. 
     
     
         94 . The delivery device of any of  claims 70  to  92 , wherein the gas supply unit comprises a charged turbine which, when released, provides the entraining gas flow. 
     
     
         95 . The delivery device of any of  claims 70  to  94 , wherein the gas supply unit is a breath-actuated unit. 
     
     
         96 . The delivery device of  claim 95 , wherein the gas supply unit is actuated in response to generation of a predeterminable flow rate through the mouthpiece unit. 
     
     
         97 . The delivery device of  claim 95 , wherein the gas supply unit is actuated in response to generation of a predeterminable pressure at the mouthpiece unit. 
     
     
         98 . The delivery device of any of  claims 70  to  94 , wherein the gas supply unit is a manually-actuated unit. 
     
     
         99 . A capsule for containing a powdered substance which exhibits insufficient tackiness, and preferably no surface tackiness, in the presence of moisture such as not to adhere to an inner surface of a capsule chamber which contains the capsule during emptying of the capsule. 
     
     
         100 . The capsule of  claim 99 , where formed of a material which exhibits insufficient tackiness in the presence of moisture in an exhalation air flow for a period of up to about 5 s. 
     
     
         101 . The capsule of  claim 100 , where formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 2 s. 
     
     
         102 . The capsule of  claim 100 , where formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 1 s. 
     
     
         103 . The capsule of any of  claims 99  to  102 , where formed substantially of a cellulose derivative. 
     
     
         104 . The capsule of  claim 103 , where formed substantially of one of hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose, methylcellulose, ethylcellulose and carboxymethylcellulose. 
     
     
         105 . The capsule of any of  claims 99  to  102 , where formed of a plastics material. 
     
     
         106 . The capsule of any of  claims 99  to  102 , where including a coating of a material which exhibits insufficient tackiness in the presence of moisture such as not to adhere to an inner surface of the capsule chamber during emptying of the capsule. 
     
     
         107 . The capsule of  claim 106 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in an exhalation air flow for a period of up to about 5 s. 
     
     
         108 . The capsule of  claim 107 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 2 s. 
     
     
         109 . The capsule of  claim 108 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 1 s. 
     
     
         110 . The capsule of any of  claims 106  to  109 , wherein the coating comprises substantially one of parylene, hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose, methylcellulose, ethylcellulose, carboxymethylcellulose, polyvinyl alcohol, acrylic acid polymer, methacrylic acid polymer, ethyl acrylic acid polymer, cellulose acetate phthalate, polyvinyl acetate phthalate, hydroxypropyl methylcellulose phthalate and hydroxyl methylcellulose acetate succinate, or any combination of layers thereof. 
     
     
         111 . The capsule of any of  claims 106  to  110 , where comprising a body formed substantially of gelatine. 
     
     
         112 . The capsule of any of  claims 102  to  111 , wherein the capsule is substantially cylindrical in shape. 
     
     
         113 . The capsule of any of  claims 102  to  111 , wherein the capsule is substantially spherical in shape. 
     
     
         114 . The capsule of any of  claims 102  to  113 , where comprising a body of thin-wall section. 
     
     
         115 . The capsule of  claim 114 , wherein the body has a thickness of not more than about 0.25 mm. 
     
     
         116 . The capsule of  claim 115 , wherein the body has a thickness of not more than about 0.20 mm. 
     
     
         117 . Use of a capsule, containing a powdered substance, which exhibits insufficient tackiness, and preferably no surface tackiness, in the presence of moisture such as not to adhere to an inner surface of a capsule chamber which contains the same during emptying of the capsule in an exhaled air flow. 
     
     
         118 . The use of  claim 117 , wherein the capsule is formed of a material which exhibits insufficient tackiness in the presence of moisture in an exhalation air flow for a period of up to about 5 s. 
     
     
         119 . The use of  claim 118 , wherein the capsule is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 2 s. 
     
     
         120 . The use of  claim 119 , wherein the capsule is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 1 s. 
     
     
         121 . The use of any of  claims 117  to  120 , wherein the capsule is formed substantially of a cellulose derivative. 
     
     
         122 . The use of  claim 121 , wherein the capsule is formed substantially of one of hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose, methylcellulose, ethylcellulose and carboxymethylcellulose. 
     
     
         123 . The use of any of  claims 117  to  120 , wherein the capsule is formed of a plastics material. 
     
     
         124 . The use of any of  claims 117  to  120 , wherein the capsule includes a coating of a material which exhibits insufficient tackiness in the presence of moisture such as not to adhere to an inner surface of the capsule chamber during emptying of the capsule. 
     
     
         125 . The use of  claim 124 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in an exhalation air flow for a period of up to about 5 s. 
     
     
         126 . The use of  claim 125 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 2 s. 
     
     
         127 . The use of  claim 126 , wherein the coating is formed of a material which exhibits insufficient tackiness in the presence of moisture in the exhalation air flow for a period of up to about 1 s. 
     
     
         128 . The use of any of  claims 124  to  127 , wherein the coating comprises substantially one of parylene, hydroxypropyl methylcellulose (HPMC), hydroxypropylcellulose, methylcellulose, ethylcellulose, carboxymethylcellulose, polyvinyl alcohol, acrylic acid polymer, methacrylic acid polymer, ethyl acrylic acid polymer, cellulose acetate phthalate, polyvinyl acetate phthalate, hydroxypropyl methylcellulose phthalate and hydroxyl methylcellulose acetate succinate, or any combination of layers thereof. 
     
     
         129 . The use of any of  claims 124  to  128 , wherein the capsule comprises a body formed substantially of gelatine. 
     
     
         130 . The use of any of  claims 117  to  129 , wherein the capsule is substantially cylindrical in shape. 
     
     
         131 . The use of any of  claims 117  to  129 , wherein the capsule is substantially spherical in shape. 
     
     
         132 . The use of any of  claims 117  to  131 , wherein the capsule comprises a body of thin-wall section. 
     
     
         133 . The use of  claim 132 , wherein the body has a thickness of not more than about 0.25 mm. 
     
     
         134 . The use of  claim 133 , wherein the body has a thickness of not more than about 0.20 mm. 
     
     
         135 . A nasal delivery device for delivering substance to a nasal cavity of a subject, the delivery device comprising:
 a substance supply unit for supplying a dose of substance to be delivered to the nasal cavity of the subject, the substance supply unit including an inlet and an outlet;   a nosepiece unit including a nosepiece for fitting to a nasal cavity of the subject and being in fluid communication with the outlet of the substance supply unit; and   a mouthpiece unit including a mouthpiece in fluid communication with the inlet of the substance supply unit and through which the subject in use exhales such as to entrain substance from the substance supply unit and deliver the same through the nosepiece.   
     
     
         136 . A method of delivering substance to a nasal cavity of a subject, the method comprising the steps of:
 supplying a dose of substance to be delivered to the nasal cavity of the subject;   fitting a nosepiece unit including a nosepiece to the nasal cavity of the subject; and   the subject exhaling through a mouthpiece unit such as to entrain the supplied dose of substance and deliver the same through the nosepiece to the nasal cavity of the subject, wherein the mouthpiece unit includes at least one temperature modifier for reducing a temperature of the exhaled air flow such as to reduce the absolute humidity thereof.   
     
     
         137 . A method of delivering substance to a nasal cavity of a subject, the method comprising the steps of:
 providing a dose of substance to be delivered to the nasal cavity of the subject in a substance-receiving chamber;   fitting a nosepiece unit including a nosepiece to the nasal cavity of the subject;   providing a Venturi unit which is operative to draw a flow of ambient air through the substance-receiving chamber; and   the subject delivering an exhaled air flow to the Venturi unit such as to draw a flow of ambient air through the substance-receiving chamber which entrains the powdered substance therein, and to the nosepiece such as to deliver the exhaled air flow entraining the powdered substance to the nasal cavity of the subject.   
     
     
         138 . A method of delivering substance to a nasal cavity of a subject, the method comprising the steps of:
 providing a dose of substance to be delivered to the nasal cavity of the subject in a substance-receiving chamber;   fitting a nosepiece unit including a nosepiece to the nasal cavity of the subject;   providing a gas flow of ambient air through the substance-receiving chamber, which entrains the powdered substance therein; and   the subject delivering an exhaled air flow to the nosepiece which entrains the gas flow entraining the powdered substance, such as to deliver the powdered substance to the nasal cavity of the subject.