1. An electronic device, comprising:
a housing;
a plurality of bolts separately positioned within the housing;
a plurality of support members adjustably assembled to the top ends of the plurality of bolts, away from the housing, and the plurality of support members being adjusted to located at a same height; and
a display screen assembled within the housing, and supported by the plurality of support members.
2. The electronic device as claimed in claim 1, wherein each support member is substantially hemispherical shaped, and comprises a circular support ring, and a substantially hollow conical clamping portion extending from an inner circular edge of the support ring; the clamping portion of the support member is sleeved on and adjustably latched to the top end of the bolt.
3. The electronic device as claimed in claim 2, wherein the support member is manually adjustable upwardly and downwardly along an axis of the bolt.
4. The electronic device as claimed in claim 2, wherein a diameter of the hollow conical clamping portion is decreased along a direction away from the support ring.
5. The electronic device as claimed in claim 2, wherein each support member further comprises a plurality of elastic clamping arms extending from the clamping portion separately, along a circular direction of the clamping portion, and latching with the top end of the bolt.
6. The electronic device as claimed in claim 2, wherein a diameter of the distal end of the clamping portion is slightly less than or substantially the same as the outer diameter of the bolt.
7. The electronic device as claimed in claim 2, wherein each bolt defines a screw hole at the top end thereof; the display screen further comprises a plurality of positioning members extending from a surrounding region thereof, corresponding to the plurality of the bolts; each positioning member defines a positioning hole; the electronic device further comprises a plurality of fasteners passing through the positioning holes of the positioning members of the display screen and screwed into the screw holes of the bolts, respectively.
8. The electronic device as claimed in claim 2, wherein the housing comprises a bottom plate and a peripheral side wall extending from a peripheral edge of the bottom plate, the electronic device further comprises a plurality of cushion plates separately mounted on the bottom plate of the housing; the plurality of bolts are respectively fixed to the plurality of cushion plates, for supporting the display screen.
9. The electronic device as claimed in claim 8, wherein the electronic device further comprises a protective plate, and the protective plate is covered on the display screen for protecting the display screen.
10. The electronic device as claimed in claim 9, wherein the protective plate comprises a display area formed at a central portion thereof, and a shade area formed at a periphery thereof to surround the display area.
11. An electronic device, comprising:
a housing having a curved bottom plate and a peripheral side wall extending from a peripheral edge of the bottom plate;
a plurality of bolts separately fixed to the bottom plate and received within the housing;
a plurality of support members adjustably assembled to the top ends of the plurality of bolts, away from the housing, respectively; the plurality of support members being adjusted to be located at a same horizontal plane; and
a display screen assembled within the housing, and supported by the plurality of support members.
12. The electronic device as claimed in claim 11, wherein the display screen further comprises a plurality of positioning members extending from the surrounding regions thereof; the plurality of positioning members are fixed to the top ends of the plurality of the bolts, respectively.
13. The electronic device as claimed in claim 12, wherein each positioning member defines a positioning hole, each bolt defines a screw hole at the top end thereof; the electronic device further comprises a plurality of fasteners, the plurality of fasteners pass through the positioning holes of the positioning members of the display screen and are screwed to the top ends of the bolts, respectively.
14. The electronic device as claimed in claim 12, wherein each support member is substantially hemispherical shaped, and comprises a support ring, and a clamping portion extending from an inner circular edge of the support ring; the clamping portion of the support member is sleeved on and adjustably latched to the top end of the bolt.
15. The electronic device as claimed in claim 14, wherein a diameter of the hollow conical clamping portion is decreased along a direction away from the support ring.
16. The electronic device as claimed in claim 14, wherein each support member further comprises a plurality of elastic clamping arms extending from the clamping portion separately, along a circular direction of the clamping portion, and latching with the top end of the bolt.
17. The electronic device as claimed in claim 16, wherein the electronic device further comprises a protective plate covered on the display screen for protecting the display screen.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for reducing a solvent concentration in a plurality of microparticles, the method comprising:
contacting a mixture comprising the plurality of microparticles and the solvent with water to form an aqueous suspension, wherein a first portion of the solvent dissolves into the water of the aqueous suspension to reduce the solvent concentration in the plurality of microparticles from a first solvent concentration in the mixture to a second solvent concentration in the aqueous suspension;
transferring the aqueous suspension to a concentration unit that further reduces the solvent concentration in the plurality of microparticles from the second solvent concentration to a third solvent concentration by:
(i) introducing additional water to the aqueous suspension in the concentration unit; and
(ii) removing at least a portion of the water and at least a portion of the solvent from the aqueous suspension in the concentration unit, wherein the additional water is introduced at a slower rate than the water and the solvent are removed from the concentration unit to form a microparticle concentrate with the third solvent concentration;
transferring the microparticle concentrate to a washing unit, wherein the microparticle concentrate is contacted with a washing solution to form an amalgam of washed microparticles with a fourth solvent concentration; and
drying the amalgam of washed microparticles to form the plurality of microparticles with a reduced solvent concentration.
2. The method of claim 1, wherein the microparticles comprise biodegradable microspheres that contain a medically active agent.
3. The method of claim 2, wherein the biodegradable microspheres comprise poly(lactic-co-glycolic) acid.
4. The method of claim 2, wherein the medically active agent comprises PEGylated insulin.
5. The method of claim 1, wherein the solvent in the microparticles comprises a halogenated organic solvent.
6. The method of claim 5, wherein the halogenated organic solvent comprises methylene chloride.
7. The method of claim 1, wherein the first solvent concentration in the mixture is 10 to 20 wt. %, and the second solvent concentration in the suspension is 1 to 5 wt. %.
8. The method of claim 7, wherein the first solvent concentration in the mixture is about 15 wt. %, and the second solvent concentration in the suspension is about 2 wt. %.
9. The method of claim 1, wherein the forming of the aqueous suspension hardens the microparticles to reduce an amount of a medically active agent contained in the microparticles from dissolving into the water in the aqueous suspension.
10. The method of claim 1, wherein the concentration unit comprises a cross-flow filtration unit that removes the water and the solvent from the concentration unit without removing the microparticles.
11. The method of claim 1, wherein the third solvent concentration in the microparticle concentrate is about 0.5 wt. %.
12. The method of claim 2, wherein the microparticle concentrate comprises about 1 vol. % or more of the microspheres.
13. The method of claim 1, wherein the washing unit separates a first group of microparticles having a target diameter from a second group of microparticles having a size outside the target diameter.
14. The method of claim 13, wherein the washing unit uses a stack of porous screens to separate the first group of microparticles from the second group of microparticles.
15. The method of claim 13, wherein the first group of microparticles has a target diameter ranging from 25 \u03bcm to 63 \u03bcm.
16. The method of claim 1, wherein the washing solution comprises an inorganic base.
17. The method of claim 16, wherein the inorganic base comprises sodium bicarbonate.
18. The method of claim 17, wherein the sodium bicarbonate has a concentration of 0.1 to 1 ww %.
19. The method of claim 1, wherein the fourth solvent concentration in the amalgam of washed microparticles is 0.03 wt. % or less.
20. A system for reducing a solvent concentration in a plurality of microparticles, the system comprising:
a solvent extraction tank where a mixture comprising the plurality of microparticles and the solvent are contacted with water to form an aqueous suspension; wherein a first portion of the solvent dissolves into the water of the aqueous suspension to reduce the solvent concentration in the plurality of microparticles from a first solvent concentration in the mixture to a second solvent concentration in the aqueous suspension;
a concentration unit in fluid communication with the solvent extraction tank, wherein the concentration unit further reduces the solvent concentration in the plurality of microparticles from the second solvent concentration to a third solvent concentration by:
(i) introducing additional water to the aqueous suspension in the concentration unit; and
(ii) removing at least a portion of the water and at least a portion of the solvent from the aqueous suspension in the concentration unit, wherein the additional water is introduced at a slower rate than the water and the solvent are removed from the concentration unit to form a microparticle concentrate with the third solvent concentration; and
a washing unit adapted to receive the microparticle concentrate from the concentration unit, wherein the microparticle concentrate is contacted in the washing unit with a washing solution to form an amalgam of washed microparticles with a fourth solvent concentration.
21. The system of claim 20, wherein the solvent extraction tank comprises a mixer to keep the microparticles in the aqueous suspension from settling to the bottom of the solvent extraction tank.
22. The system of claim 20, wherein the concentration unit comprises a cross-flow filtration column in fluid communication with a second solvent extraction tank, wherein the cross-flow filtration column removes the water and the solvent from the second solvent extraction tank without removing the microparticles.
23. The system of claim 20, wherein the washing unit comprises a stack of porous screens to separate a first group of microparticles having a target diameter from a second group of microparticles having a size outside the target diameter.
24. The system of claim 20, wherein the washing unit further comprises a vacuum unit to evaporate the water and the solvent from the amalgam of washed microparticles to form dried microparticles with a reduced solvent concentration.
25. The system of claim 24, wherein the washing unit further comprises a dry gas supply to carry vapor of the water and the solvent to the vacuum unit.
26. The system of claim 25, wherein the dry gas supply comprises dry nitrogen gas.
27. The system of claim 24, further comprising a product bin to receive the dried microparticles with the reduced solvent concentration.
28. The system of claim 20, wherein the system further comprises a drying unit adapted to receive the amalgam of washed microparticles from the washing unit and dry the amalgam to form dried microparticles with a reduced solvent concentration.
29. The system of claim 20, wherein the microparticles comprise biodegradable microspheres that contain a medically active agent, and the solvent comprises a halogenated organic solvent.
30. The system of claim 29, wherein:
the biodegradable microspheres comprise poly(lactic-co-glycolic) acid;
the medically active agent comprises PEGylated insulin; and
the halogenated organic solvent comprises methylene chloride.
31. The system of claim 20, wherein:
the first solvent concentration is 10 to 20 wt. %;
the second solvent concentration is 1 to 5 wt. %;
the third solvent concentration is about 0.5 wt. %; and
the fourth solvent concentration is 0.03 wt. % or less.
32. The system of claim 20, wherein the washing solution comprises sodium bicarbonate.
33. A method of preparing a plurality of biodegradable microspheres with a medically active agent, wherein the biodegradable microspheres have a reduced level of a preparation solvent, the method comprising:
contacting a mixture comprising the plurality of biodegradable microspheres and the preparation solvent with water to form an aqueous suspension, wherein a first portion of the preparation solvent dissolves into the water of the aqueous suspension to reduce the solvent concentration in the plurality of biodegradable microspheres from a first solvent concentration in the mixture to a second solvent concentration in the aqueous suspension;
transferring the aqueous suspension to a concentration unit that further reduces the solvent concentration in the plurality of biodegradable microspheres from the second solvent concentration to a third solvent concentration by:
(i) introducing additional water to the aqueous suspension in the concentration unit; and
(ii) removing at least a portion of the water and at least a portion of the preparation solvent from the aqueous suspension in the concentration unit, wherein the additional water is introduced at a slower rate than the water and the solvent are removed from the concentration unit to form a biodegradable microsphere concentrate with the third solvent concentration;
transferring the biodegradable microsphere concentrate to a washing unit, wherein the biodegradable microsphere concentrate is contacted with a washing solution to form an amalgam of washed biodegradable microspheres with a fourth solvent concentration; and
drying the amalgam of washed biodegradable microspheres to form the plurality of biodegradable microspheres with a reduced solvent concentration.
34. The method of claim 33, wherein the biodegradable microspheres comprise poly(lactic-co-glycolic) acid.
35. The method of claim 33, wherein the medically active agent comprises PEGylated insulin.
36. The method of claim 33, wherein the preparation solvent comprises methylene chloride.
37. The method of claim 33, wherein:
the first solvent concentration is 10 to 20 wt. %;
the second solvent concentration is 1 to 5 wt. %;
the third solvent concentration is about 0.5 wt. %; and
the fourth solvent concentration is 0.03 wt. % or less.
38. A composition that can be dried with a vacuum unit into a powder for filling a syringe, the composition comprising:
a plurality of biodegradable microspheres, wherein the plurality of biodegradable microspheres comprises a medically activated agent;
a solvent at a concentration of 0.03 wt. % or less; and
a washing solution comprising an inorganic base, wherein the inorganic base has a concentration of 0.1 to 1 ww %.
39. The composition of claim 38, wherein the medically active agent comprises PEGylated insulin.
40. The composition of claim 38, wherein the plurality of biodegradable microspheres further comprises poly(lactic-co-glycolic) acid.
41. The composition of claim 38, wherein the solvent comprises a halogenated organic solvent.
42. The composition of claim 41, wherein the halogenated organic solvent comprises methylene chloride.
43. The composition of claim 38, wherein the inorganic base comprises sodium bicarbonate.
44. The composition of claim 38, wherein the plurality of microspheres has a diameter ranging from 25 \u03bcm to 63 \u03bcm.
45. The composition of claim 38, wherein the composition further comprises nitrogen gas.