Osmotic system with laminated wall comprising structurally different semipermeable lamina
First Claim
1. An oral osmotic system sized and adapted for the controlled administration of drug to an animal, said system comprising:
- a. a shaped laminated wall comprising (1) a lamina formed of a material that maintains its physical and chemical integrity in the presence of fluid, drug and during the dispensing of drug, and is permeable to the passage of fluid and impermeable to the passage of drug, said lamina formed of a material having the general formula;
##STR4## wherein R5 is a member selected from the group consisting of hydroxyl, alkoxy, alkylcarbonate, alkylcarbamate, alkylsulfonate, alkylsulfamate and acyloxy, and wherein n is a positive number greater than 5 and at least one R is acyloxy, said lamina laminated to (2) a lamina formed of a different material that maintains its physical and chemical integrity in the presence of fluid, drug and during the dispensing of drug, and is permeable to the passage of fluid and impermeable to the passage of drug, said lamina formed of the different material selected from the general formula;
##STR5## wherein R5 is a member selected from the group consisting of hydroxyl, alkoxy, alkylcarbonate, alkylcarbamate, alkylsulfonate, alkylsulfamate, and acyloxy, and wherein n is a positive number greater than 5 and at least one R is acyloxy;
the wall surrounding and forming,b. a compartment containing a member selected from the group consisting of locally and systemically acting drugs;
c. a passageway in the wall communicating with the compartment and the exterior of the system for administering drug from the system; and
,d. wherein in operation when the system is in the animal fluid therefrom is imbibed through the laminated wall into the compartment in a tendency towards osmotic equilibrium at a rate determined by the permeability of the laminated wall and the osmotic pressure gradient across the laminated wall thereby continuously dissolving drug that is administered according to the following equation;
space="preserve" listing-type="equation">h.sub.T /kπ
.sub.T = h.sub.1 /kπ
.sub.1 + h.sub.2 /kπ
.sub.2wherein hT is the thickness of the laminated wall, h1 is the thickness of lamina (1,) h2 is the thickness of lamina 2, kπ
T is the osmotic pressure of drug in the compartment times the permeability of the laminated wall to fluid, kπ
1 is the osmotic pressure of drug in the compartment times the permeability of lamina (1) to fluid and kπ
2 is the osmotic pressure of drug in the compartment times the permeability of lamina (2) to fluid, through the passageway at a controlled and continuous rate over a prolonged period of time.
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Abstract
An osmotic system for delivering a beneficial agent to an environment of use is disclosed. The system comprises a laminate surrounding a compartment and has a passageway through the laminate for releasing agent from the compartment. The laminate comprises at least two laminae; one consisting of a semipermeable, polymeric material that is permeable to the passage of an external fluid and maintains its physical and chemical integrity in the environment of use, and one consisting of a semipermeable polymeric material that is permeable to the passage of fluid, substantially impermeable to the passage of agent and maintains its physical and chemical integrity in the presence of agent. The compartment comprises an active agent that is either soluble in the external fluid and exhibits an osmotic pressure gradient across the laminate against the fluid, or the agent has limited solubility in the fluid and it is mixed with an osmotically effective compound that is soluble in the fluid and exhibits an osmotic pressure gradient across the laminate against the fluid. In operation, agent is released from the system by fluid being imbibed through the laminate into the compartment at a rate controlled by the permeability of the laminate and the osmotic pressure gradient across the laminate producing a solution containing agent, or a solution of compound containing agent which solution in either operation is released through the passageway at a controlled and continuous rate over a prolonged period of time.
63 Citations
11 Claims
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1. An oral osmotic system sized and adapted for the controlled administration of drug to an animal, said system comprising:
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a. a shaped laminated wall comprising (1) a lamina formed of a material that maintains its physical and chemical integrity in the presence of fluid, drug and during the dispensing of drug, and is permeable to the passage of fluid and impermeable to the passage of drug, said lamina formed of a material having the general formula;
##STR4## wherein R5 is a member selected from the group consisting of hydroxyl, alkoxy, alkylcarbonate, alkylcarbamate, alkylsulfonate, alkylsulfamate and acyloxy, and wherein n is a positive number greater than 5 and at least one R is acyloxy, said lamina laminated to (2) a lamina formed of a different material that maintains its physical and chemical integrity in the presence of fluid, drug and during the dispensing of drug, and is permeable to the passage of fluid and impermeable to the passage of drug, said lamina formed of the different material selected from the general formula;
##STR5## wherein R5 is a member selected from the group consisting of hydroxyl, alkoxy, alkylcarbonate, alkylcarbamate, alkylsulfonate, alkylsulfamate, and acyloxy, and wherein n is a positive number greater than 5 and at least one R is acyloxy;
the wall surrounding and forming,b. a compartment containing a member selected from the group consisting of locally and systemically acting drugs; c. a passageway in the wall communicating with the compartment and the exterior of the system for administering drug from the system; and
,d. wherein in operation when the system is in the animal fluid therefrom is imbibed through the laminated wall into the compartment in a tendency towards osmotic equilibrium at a rate determined by the permeability of the laminated wall and the osmotic pressure gradient across the laminated wall thereby continuously dissolving drug that is administered according to the following equation;
space="preserve" listing-type="equation">h.sub.T /kπ
.sub.T = h.sub.1 /kπ
.sub.1 + h.sub.2 /kπ
.sub.2wherein hT is the thickness of the laminated wall, h1 is the thickness of lamina (1,) h2 is the thickness of lamina 2, kπ
T is the osmotic pressure of drug in the compartment times the permeability of the laminated wall to fluid, kπ
1 is the osmotic pressure of drug in the compartment times the permeability of lamina (1) to fluid and kπ
2 is the osmotic pressure of drug in the compartment times the permeability of lamina (2) to fluid, through the passageway at a controlled and continuous rate over a prolonged period of time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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Specification