US4767402A
Expired / Lapsed
US
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Ultrasound enhancement of transdermal drug delivery
Assignee: Massachusetts Institute of Technology
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Filing: 1986-07-08
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Granted: 1988-08-30
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Expires: 2006-07-08
Abstract
Abstract The present invention is a method using ultrasound to enhance permeation of molecules through the skin and into the blood stream, at a controlled rate. Depending on the drug being infused through the skin, the rate of permeation is increased as well as the efficiency of transfer. Drugs which may not be effective under other conditions, for example, due to degradation within the gastrointestinal tract, can be effectively conveyed transdermally into the circulatory system by means of ultrasound.
Inventors
- 👤 Joseph Kost
- 👤 Drora Levy
- 👤 Robert S. Langer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:41
CPC Classifications
A; A61; A61M; A61M37/00; A61M37/0092; A61K; A61K41/00; A61K41/0047; A61K9/00; A61K9/0002; A61K9/0009; A61M35/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
116 words
A method for enhancing and controlling transdermal infusion of molecules comprising: (a) selecting the molecules having a low rate of permeability through the skin to be infused; (b) applying to the skin said molecules in a medium with an absorption coefficient similar to that of water; (c) applying ultrasound to said molecules in said medium at a frequency of between 20 kHz and 10 MHz and an intensity of between 0 and 3 W/cm 2 ; and (d) varying the frequency and intensity over time to transdermally infuse said molecules at an optimal rate into the circulatory system without delay or damaging the skin, wherein the optimal rate is determined by measurements of a physiological fluid.
Claim 2
Independent Claim
116 words
A method for enhancing and controlling transdermal infusion of molecules comprising: (a) selecting the molecules having a low rate of permeability through the skin to be infused; (b) applying to the skin said molecules in a medium with an absorption coefficient similar to that of water; (c) applying ultrasound to said molecules in said medium at a frequency of between 20 kHz and 10 MHz and an intensity of between 0 and 3 W/cm 2 ; and (d) varying the frequency and intensity over time to transdermally infuse said molecules at an optimal rate into the circulatory system without delay or damaging the skin, wherein the optimal rate is determined by measurements of a physiological fluid.
Claim 3
Dependent Claim
29 words
This method of claim 1 wherein the ultrasound frequency is applied at between 0.5 MHz and 1.5 MHz and an intensity of between 2 and 4 W/cm 2 .
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein the ultrasound is applied for less than 10 minutes.
Claim 5
Dependent Claim
17 words
The method of claim 1 further comprising suspending the molecules to be applied in an aqueous gel.
Claim 6
Dependent Claim
31 words
The method of claim 1 further comprising constructing a transdermal drug patch formed of a support, adhesive, a drug-containing matrix and a protective covering for applying the molecules to the skin.
Claim 7
Dependent Claim
11 words
The method of claim 1 wherein the ultrasound is applied continuously.
Claim 8
Dependent Claim
10 words
The method of claim 1 wherein the ultrasound is pulsed.
Claim 9
Dependent Claim
41 words
The method of claim 1 further comprising selecting said molecule from the group of molecules consisting of proteins, drugs, antigens, vitamins, inorganic compounds, organic compounds, and combinations thereof, wherein said molecule has a biological effect when infused into the circulatory system.
Claim 10
Dependent Claim
18 words
The method of claim 1 further comprising measuring the temperaure of the skin where the ultrasound is applied.
Claim 11
Dependent Claim
34 words
The method of claim 9 wherein the ultrasound is applied at a frequency and intensity over a period of time which does not cause an increase in skin temperature of more than 2° C.
Claim 12
Dependent Claim
25 words
The method of claim 1 further comprising measuring the concentration of said molecules in a physiological fluid during or immediately after administration of the ultrasound.
Claim 13
Dependent Claim
59 words
The method of claim 1 further comprising measuring the concentrations of said molecule in the physiological fluid over time, determining the rate of transdermal transfer for said molecules at specific frequencies, intensities and times of ultrasound application, wherein the molecules are subsequently infused using ultrasound at the frequency, intensity and time of application determined to yield a specific concentration.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-30 | 1992-02-29 | 1992-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-30 | 1996-02-29 | 1996-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-30 | 2000-02-29 | 2000-08-30 | $7700.00 | Window Closed / Lapsed |