US2427786A

US2427786A - Apparatus for concentrating drugs

Info

Publication number: US2427786A
Application number: US557054A
Authority: US
Inventors: Cyril N Hoyler
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1944-10-03
Filing date: 1944-10-03
Publication date: 1947-09-23
Anticipated expiration: 1964-09-23

Description

Sept. 23, 1947. y c. N. HoYLl-:R 2,427,786

APPARATUS FOR CONCENTRATING DRUGS Filed oct. s, 1944 @P7/gg, y [A Patented Sept. 23, 1947 UNITED STATE 2,427,786 APPARATUS FOR CONCENTRATING DRUGS cyril N. noyier, Princeton, N. J., assigner to Radio Corporation of America, a corporation ot Delaware Application October 3, 1944, Serial No. 557,054

2 Claims. 1

This invention relates to improvements in the art of concentrating or desiccating drug solutions and other fluent matter o f the type which eiervesce when subjected to heat and to a vacuum.

The iinal step in the manufacture of the rare drug penicillin consists in dehydrating or desiccating the preconcentrated liquor in which the X-iactor or active ingredient" of the drug ls contained. Usually, an ether extraction process is employed in pre-concentrating the mother liquor and, as a. result, the concentrated liquor may boil with almost explosive violence if an attempt is made to dehydrate it in an ordinary stili The highly ebullient nature of pre-concentrated penicillin liquor had led to the use of so-called freeze drying" in preparing the drug for market. This method (see U. S. Patents 994,555 and Reissue 20,969) obviates losses due to effervescence and has the further advantage of providing a zo readily dissoluble sponge-like or a pulverulent product. However, freeze-drying is extremely costly, not only because of the expensive nature of the high-vacuum apparatus which is necessarily employed in practicing this prior art method but because the sublimation of even a few cubic centimeters of the frozen liquor may take several hours on the pump.

A much more rapid and economical method and apparatus for desiccating ebullient drug liquors in dosage quantities" is described in copending application of Rudolph A. Bierwirth, Serial No. 557,053, led October 3, 1944. Bierwirth subjects the bottles or ampoules in 'which the liquor is contained to an electric ileld, applied in vacuo, while rotatingthe bottles so rapidly that the centrifugal force applied to the material prevents the release of bubbles or other liquid emanations therefrom. The disadvantage (if such it be) of Bierwirths method is that the ultimate product comprises neither a powder nor a sponge-like mass but a dry film or deposit upon the inner walls of the container. While the drug in this form is no less potent and no less soluble than it is when in the form of a powder or spongelike mass, a casual inspection of 4one of Bierwirths bottles might, in some cases, lead the uninitiated tobelleve it to be empty.

Accordingly, the principal object of the present invention is to provide a rapid and economical method of dehydratng or desiccating penicillin liquor and other ebullient matter, and one which in its practice provides a readily soluble cellular or honey-combed product. I

Another and important object of the present in- (Cl. 159-3l) vention is to provide an improved "ampouledrier, and one characterized by the simplicity and economy of its parts and .by its trouble-free performance.

The foregoing and other objects are-achieved in accordance with the method of the invention lient material, to heat and to a degreel of vacuum sufllciently high to cause the material to efferverse and then, uum, directing a fine stream of air upon the bubbles or foam in order to break-up thesaid liquid emanations and to prevent them l'from being drawn oil with the gaseous emanations or vapor. The invention may also be said to reside in the provision of a novel and simple form of apparatus, shown in the accompanying drawing. for carrying the above described principle into practical commercial use.

The single figure is an elevated side view, shown in section, oi the apparatus used to carry out the pIOcess.

The embodiment of the invention which has been selected for illustration comprises a metal 25 platform or base I and a bell jar 3 of special construction which is shown supported on a vacuum tight gasket on the said base. 'Ihe space 1 within the bell jar 3 is evacuated through a port 8, in the metal base I, and is connected to a suitable vacuum pump (not shown) through a water cooled condenser Il. The ampoules or bottles I3 which contain the penicillin liquor or other ebullient liquid I5 are supported in an upright position preferably in circular array, within the evacuable chamber 1 by means of a multiplicity of pairs of spaced-apart electrodes I1 and I9, re-` spectively. One electrode of each pair, say the electrodes I1, is grounded to the metal base I and the other electrodes, I9, are electrically connected through a common lead 2 I, which extends through an insulating bushing 23 in the base I, to a source of radio 'frequency energy, exemplified -by the concentric transmission line 25.

The electric field which is established between the electrodes I1 and I9 of each pair serves to heat the contents of the ampoule or bottle I3 which is supported there-between, The said liquid foams when subjected to a vacuum and the foaming is augmented when the liquid is heated.

As previously set forth the inflated liquid iilms or bubbles which emanate from the liquid are conilned within the ampoules or bottles I3 and are then broken-up by directing a fine stream of air upon the foaming liquid through the open top of each bott1e. To this end, the lbell jar 3 is proby subjecting the penicillin liquor, or other ebulwhile maintaining the vacvided. preferably near its top, with a valved port y 21 through which air may be drawn with considerable force when the chamber 1 is on the pump. A flexible hose 29 extends from the port 21 to a small plenum chamber or distributor" 3l. The part 3| is supported for movement in a vertical direction on a rod33 which has a slideable fit in an air-tight bushing 35 within the handle or knob 31 at the top of the bell jar 3.

The air or other gas which enters the plenum chamber 3| through the port 21 and hose 29 is distributed among the\several bottles I3 through rigid or semirlgid pipes 33., `These pipes 33 depend from the base of the distributor chambery 3l and are arranged each in register with the open top of one of the bottles I3, hence the free-end of each pipe 39 is adapted to be inserted in, or withdrawn from, its bottle as determined by the direction in which the rod or plunger 33 is moved. Each pipe 33 may be provided, adjacent to its free end, with an inverted cup-shape shield 4| to prevent bacteria or other foreign matter from dropping into the bottles while they are in the vacuum chamber.

In applying the method of the present invention to the desiccation of penicillin liquor each of the bott1esl3 had a capacity of about 20 cubicv centimeters of liquid and each was provided with a partial iilling of about 1 cubic centimeter. (The liquor had been pre-concentrated in the lapparatus disclosed in copending application Serial No. 536,491 to George H. Brown and the instant applicant, and had a concentration of approximately 100,000 Oxford units per c. c.) The electrical energy employed in heating the liquor was supplied by a 0.75 kilowatt oscillator operating at a frequency of 150 megacycles per second and the vacuum pump was adjusted to maintain a vacuum in the main chamber 1 of the order of from 40 to '70 millimeters of mercury when the port 21 was opened to admit a ne blast of air into the several bottles. The pipes 39 through which the air passed each had an inside diameter of about ik of an inch with a hole at the end of a diameter of about 0.003 inch. The drying time was approximately 3 minutes in the R. F. field,y

and 5'1 minutes in a vacuum of 10 mm. with 65 F. on the electrodes. prised a potent and readily soluble cellular or "honey-combed mass having an'appearance similar to that of dry soap-bubbles or froth While the invention lhas been described as applied to the desiccation of penicillin liquor it will be apparent that the disclosure in this respect is illustrative and should not be interpreted in a limiting sense except as required by the prior art and by the spirit ofthe appended claims.

The dried product com` What is claimed is:

1. Apparatus for treating fluent materials of the type which eiIervesce when subjected to a vacuum, said apparatus comprising an evacuable chamber, means for supporting an open-topped container for said fluent material within said chamber, said supporting means for said container comprising a plurality of spaced-apart electrodes through which an electric field may be applied to said container for the purpose of heating the contents thereof, a port in a wall of said chamber through which air may be drawn when said chamber is evacuated, and means connected to said port and adapted t'o be entered into said container through the open top thereof for directing said air in a fine stream upon the surface of said eifervescent material whereby to control the effervescent condition of said material.

2. Apparatus for treating fluent materials ofI the type which effervesce when subjected to a vacuum, said apparatus comprising an evacuable chamber, means for supporting a plurality of open-topped containers for said fluent material in spaced array within said chamber, a port in a wall of said chamber through which air may be drawn when said chamber is evacuated, a plenum chamber mounted for movement within said evacuable chamber, a flexible connection for said air between said'port and said plenum chamber. a plurality of spaced-apart pipes individual to said containers connected to said plenum chamber and leach having a free-end adapted to be entered into one of said containers through the open-top thereof for directing said air in a fine stream upon the surface of said effervescent material whereby to control the effervescent condition of said material, and means extending to the exterior of said evacuable chamber for moving said plurality of pipes into and out of said opentopped containers.

CYRIL N. HOYLER..

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS