Abstract:
Method and apparatus for recovering non-solvent fills from a gelatin-containing material by adding the gelatin-containing material to a suitable solvent to form a mixture including a solvent phase and a phase containing said non-solvent fill and then separating the solvent phase from the phase containing said non-solvent fill, followed by recovering the non-solvent fill.

Description:
RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/144,154 filed on Jul. 15, 1999 and U.S. Provisional Patent Application Ser. No. 60/193,440 filed on Mar. 30, 2000. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to a process for the recovery of non-aqueous type fills from gelatin capsules including hard and soft gelatin capsules in which the capsules are heated with a suitable solvent (e.g. water) until the capsules dissolve and separate into a lower solvent phase containing solvent, gelatin, plasticizer and, if applicable, solvent soluble dyes and other solvent soluble components and an upper non-solvent phase containing the non-solvent fill. The two phases are separated and the non-solvent phase may be further processed to remove any residual solvent and the solvent phase may be further processed to recover the gelatin, plasticizer and, if applicable, dyes and other solvent soluble components. 
     BACKGROUND OF THE INVENTION 
     Methods for recovering non-solvent type fills (e.g. non-aqueous fills as referred to hereinafter) from hard and soft gelatin materials, typically in the form of capsules, are known in the art. Such methods are inefficient and are generally only applicable to recovery of a few fills such as vitamin E. A typical prior art method includes chopping capsules into fine pieces and allowing the non-aqueous fill to either drip off the chopped capsules by gravity or, alternatively, vacuum is applied to the chopped capsules and the recovered non-aqueous fill collected. As used herein, the term capsules refers to any capsules obtained from a capsule producing process which are not saleable for reasons including, but not limited to, cloudiness, malformation, incorrect fill quantity, or expired commercial lots returned to the manufacturer. 
     Such prior art methods achieve only from about 30% to 70% recovery of the non-aqueous fill, principally due to the viscous nature of the recoverable material. 
     It would be a significant benefit in the art of removing non-solvent fills (e.g. non-aqueous fills) from gelatin capsules to improve the recovery of the non-aqueous fill, and especially for a process having recovery rates consistently exceeding 90%. 
     SUMMARY OF THE INVENTION 
     The present invention is generally directed to a process and apparatus for recovering non-solvent type fills (e.g. non-aqueous type fills as referred to hereinafter) from a gelatin-containing material, typically in the form of capsules including hard and soft gelatin capsules, in a cost efficient and effective manner. 
     In a particular aspect of the present invention there is provided a method and apparatus for recovering non-solvent fills from a gelatin-containing material comprising: 
     a) adding the gelatin-containing material to a suitable solvent to form a mixture including a solvent phase and a phase containing said non-solvent fill; 
     b) separating the solvent phase from the phase containing said non-solvent fill; and 
     c) recovering the non-solvent fill. 
     The process more specifically comprises adding gelatin capsules, with or without prior “grinding” thereof, to a suitable solvent (e.g. deionized water) typically in an amount of up to 5.0 volumes wt/wt, preferably from about 0.5 to 3 volumes wt/wt based on the quantity of capsules being processed. The addition step is typically carried out in a vessel at a temperature from about 40° C. to 70° C. with agitation, preferably by using a sweep mixer which is incorporated into the apparatus illustrated in FIGS. 2 and 3, at typically from about 5 rpm to 40 rpm to facilitate release of any residual non-aqueous fill from the aqueous phase and/or to homogenize the aqueous phase for enhanced processing. The above recited temperature and agitation are maintained until the capsules at least substantially dissolve which typically takes from about 15 to 60 minutes. 
     After dissolution, while maintaining the vessel temperature at from about 40° C. to 70° C. agitation is stopped and the dissolved capsules are allowed to at least substantially separate into a lower aqueous phase containing water, gelatin, plasticizer and, if applicable, dyes and other water soluble components and an upper phase containing the non-aqueous fill. 
     The separation may be achieved in any conventional manner including physical separation via a sight glass, using an apparatus such as that illustrated in FIG. 2, or through a mechanical skimmer such as an oil skimmer. The separation can also take place through various mechanical techniques such as, but not limited to, liquid-liquid centrifugation. Alternatively, the lower aqueous phase may be cooled and solidified and the non-aqueous phase collected by decanting or pouring from the top of the vessel using an apparatus such as that illustrated in FIG.  3 . 
     The non-aqueous phase thus separated may be further processed to remove any residual water, especially if the fill is hygroscopic. This optional step may be conducted, for example, by treating the non-aqueous phase with molecular sieves or drying agents such as, but not limited to, magnesium sulfate. Other methods to remove the residual water from the non-aqueous phase include heating the non-aqueous material at or about atmospheric pressure, or under vacuum using an apparatus such as that illustrated in FIG. 4, preferably operating at a pressure of from 22 inches to about 29 inches of vacuum, at a temperature from about 40° C. to 105° C. for a period of time sufficient to remove the residual water, typically from about 30 minutes to 24 hours, to form an at least substantially dried non-aqueous phase. 
     The thus recovered non-aqueous fill may then be filtered, to remove any residual particulate matter which may be present, and reused in the capsule filling process. The aqueous phase may be optionally processed to recover the gelatin and plasticizer and, if applicable, dyes and other water soluble components so that these components may be recycled as well. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following drawings illustrate an embodiment of the invention and are not intended to limit the application as encompassed by the claims forming part of the application. 
     FIG. 1 is a schematic view of an embodiment of the method of non-aqueous fill recovery provided in accordance with the present invention; and 
     FIGS. 2 through 4 are side views in cross-section of an apparatus which may be employed in the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, there is shown a process flow diagram wherein a suitable solvent (e.g. deionized water), in an amount of up to 5.0 volumes wt/wt, preferably from about 0.5 to 3 volumes wt/wt, to the quantity of capsules being processed, is charged via conduit  1  to a vessel  2 . Vessel  2  is preferably constructed of stainless steel and, depending on the non-aqueous fill to be processed, may be a design such as that illustrated in FIGS. 2 and 3 as described in detail hereinafter. 
     FIG. 2 illustrates an apparatus that may be utilized to process non-aqueous fills that contain dissolved and/or suspended solids such as, for example, co-enzyme Q10 in soy oil. It will be understood that all reference to “non-aqueous” fills is exemplary of fills that are not soluble in the solvent (e.g. water) chosen for operation of the recovery process. Other solvents and corresponding other fills may be employed in the present invention. 
     The apparatus  20  is equipped with a heating/cooling jacket  21  to approximately two-thirds of the vessel height; to apply heat primarily to the aqueous phase during processing. This jacket configuration may be desirable in the event the non-aqueous fill being processed has some degree of thermal sensitivity. The apparatus  20  is also equipped with a sweep mixer  22  designed in such a manner to perform a variety of functions including, but not limited to, dislodging molten gelatin from the walls and bottom of the vessel, homogenizing the aqueous phase for ease of processing/separating the aqueous phase, and dislodging residual non-aqueous fill trapped in residual molten gelatin. Additionally, the preferred mixer motor  25  is designed to operate at low speed. The apparatus  20  is also designed with a sloped bottom  23  and bottom center discharge  24  for enhanced separation of the aqueous and non-aqueous phases to minimize aqueous phase contamination of the non-aqueous phase. 
     FIG. 3 illustrates an apparatus  30  that may be utilized to process non-aqueous fills that do not contain dissolved and/or suspended solids such as natural and/or synthetic vitamin E. The apparatus is equipped with a heating/cooling jacket  31  to approximately two-thirds of the vessel height; to apply heat primarily to the aqueous phase during processing in the event the non-aqueous fill being processed is thermally sensitive and to apply cooling to primarily the aqueous phase to solidify the aqueous phase. The apparatus is also equipped with a sweep mixer  32  designed in such a manner to perform a variety of functions including, but not limited to, dislodging molten gelatin from the walls and bottom of the vessel, homogenizing the aqueous phase for ease of processing/separating the aqueous phase, and dislodging residual non-aqueous fill trapped in residual molten gelatin. Additionally, the preferred mixer motor  33  is designed to operate at low speed. The apparatus is equipped with a side discharge  34  at about three-quarters the vessel height and swivel arms  35  on each side of the vessel to allow the non-aqueous phase to be poured from the top of the vessel, after the aqueous phase has been solidified, for a very efficient separation and recovery of the non-aqueous phase. The apparatus is also designed with a sloped bottom  36  and bottom center discharge  37  for removing the aqueous phase once the non-aqueous phase is removed. 
     Alternatively, the apparatus  20  illustrated in FIG. 2, and described above, may be utilized to process non-aqueous fills that do not contain dissolved and/or suspended solids, if solidification of the solvent layer is not preferred or desired. 
     Referring again to FIG. 1, the deionized water in vessel  2  is heated, with agitation, to a temperature from about 40° C. to 70° C. Once the desired temperature has been achieved the agitation rate is lowered typically to about 5 to 40 rpm and the waste gelatin material containing a non-aqueous fill, typically in the form of capsules, is added to vessel  2  through a conduit  3 . The above recited temperature and agitation are maintained until the capsules are at least substantially dissolved, which typically takes from about 15 to 60 minutes, at which time the non-aqueous fill is at least substantially separated from the aqueous phase. Agitation is stopped once there is substantial separation between the non-aqueous fill and the aqueous phase. 
     Once agitation is stopped, the contents of vessel  2  may be held, while maintaining the above recited temperature range, for about 5 to 30 minutes to complete phase separation prior to physical separation. 
     Separation may be achieved in any conventional manner including, but not limited to, physical separation through a sight glass or an oil skimmer. The separation may also take place through various mechanical techniques such as, but not limited to, liquid-liquid centrifugation. Alternatively, the lower, gelatin containing aqueous phase may be solidified with cooling and the non-aqueous phase collected from the top by decanting or pouring. 
     In a preferred embodiment, for non-aqueous fills containing dissolved or suspended solids, the separation is achieved using the apparatus  20  as illustrated in FIG.  2 . The lower aqueous phase is separated, using a sight glass, and is conveyed via conduit  4  to an apparatus  5  where it may be further processed to recycle the gelatin, plasticizer and, if applicable, dyes and other water soluble components, or discarded. 
     The upper, non-aqueous phase is then sent, optionally, via a conduit  6  to a drying apparatus  7  where it may be at least substantially dried using a variety of techniques including, but not limited to, drying agents such as molecular sieves or magnesium sulfate, heating at atmospheric pressure for a given period of time at a given temperature, or heating under vacuum for a given period of time at a given temperature. 
     In the preferred embodiment heating under vacuum is employed using a vessel design such as that illustrated in FIG.  4 . This method of at least substantially drying the non-aqueous phase is preferred over atmospheric heating to avoid any potential thermal degradation when processing potentially heat sensitive products. Water may be removed at a lower temperature under vacuum conditions than at or about atmospheric conditions. This method is also preferred over drying agents in that no chemical additives are being utilized that may result in contamination of the non-aqueous phase. 
     FIG. 4 is illustrative of a preferred drying apparatus  7 . FIG. 4 shows a vessel  40  of stainless steel construction equipped with a heating/cooling jacket  41 , a mixer motor  42  and mixer  43  with a vacuum pump  44  capable of achieving from about 22 inches to 29 inches vacuum. The vessel is constructed to withstand the above recited vacuum range and has a sloped bottom  45  with side discharge  46  emanating from the center of the sloped bottom  45 . 
     Once the non-aqueous phase has been transferred to drying apparatus  7 , mixing is started and vacuum is applied typically in the range from about 22 inches to 29 inches. The contents may then be heated to from about 30° C. to 70° C. and held at the above recited vacuum and temperature until the non-aqueous phase is at least substantially dried, usually from about 15 minutes to 2 hours. 
     Drying without vacuum or the use of drying aids may require periods of 24 hours or longer and temperatures above 100° C. 
     Once the non-aqueous phase has been at least substantially dried it may be sent via conduit  8  as shown in FIG. 1 to an optional filtration apparatus  9  to at least substantially remove residual particulates. Filtration may be accomplished by a variety of techniques including, but not limited to, microporous bag filters as typically used in the gelatin capsule manufacturing industry. 
     Alternatively, if the non-aqueous phase does not require drying it may be sent directly to an optional filtration apparatus  9  via a conduit  8 A and processed as described above. 
     The non-aqueous phase may then be collected via a conduit  10  to be reused in the capsule filling process. 
     By way of illustration, the following examples as shown in Table 1 are given to demonstrate the increased recovery of non-aqueous fills from capsules in accordance with the present invention as compared with a conventional technique; including results of analytical analyses of the recovered non-aqueous fills. 
     
       
         
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                 Quantity 
                 Quantity 
                   
                   
                   
               
               
                 Non- 
                   
                 (g/Kg) of 
                 (g/Kg) of DI 
                 Prior Art 
                 Improved 
               
               
                 Aqueous 
                   
                 Capsules 
                 Water 
                 Recovery 
                 Recovery 
                 % 
               
               
                 Material 
                 Additives 
                 Recovered 
                 Used 
                 % 
                 % 
                 Assay 
               
               
                   
               
             
             
               
                 CoEnzymeQ10 
                 Soy oil 
                 250 g 
                 500 g 
                 30 
                 89.1 
                 105.6 
               
               
                   
                   
                   
                   
                   
                   
                 Passes Spec 
               
               
                 Nat. Vit. E 
                 None 
                 250 g 
                 500 g 
                 50 
                 97.3 
                 102.8 
               
               
                   
                   
                   
                   
                   
                   
                 Passes Spec 
               
               
                 Syn. Vit. E 
                 None 
                 250 g 
                 500 g 
                 50 
                 94.6 
                 99.2 
               
               
                   
                   
                   
                   
                   
                   
                 Passes Spec 
               
               
                 CoEnzymeQ10 
                 Soy oil 
                 13.8 kg 
                 27.6 kg 
                 30 
                 97.4 
                 Not 
               
               
                   
                   
                   
                   
                   
                   
                 Assayed (1) 
               
               
                 Syn. Vit. E 
                 None 
                 77 Kg 
                 154 Kg 
                 50 
                 Not 
                 98.8 
               
               
                   
                   
                   
                   
                   
                 Determined 
                 Passes Spec 
               
               
                 Saw Palmetto 
                 Soy Oil 
                 250 g 
                 500 g 
                 0 
                 90.9 
                 FA = 92.1% 
               
               
                   
                   
                   
                   
                   
                   
                 Sterols = 0.2% 
               
               
                   
                   
                   
                   
                   
                   
                 Passes Spec 
               
               
                 Shark Liver Oil 
                 Soy Oil 
                 250 g 
                 500 g 
                 0 
                 100 
                 21.7% 
               
               
                   
                   
                   
                   
                   
                   
                 alkoxyglyoerol- 
               
               
                   
                   
                   
                   
                   
                   
                 etherlipids 
               
               
                   
                   
                   
                   
                   
                   
                 Passes Spec 
               
               
                 Ginseng 
                 Soy Oil 
                 250 g 
                 500 g 
                 0 
                 95.7 
                 Passes TLC 
               
               
                 MultiComponent 
                 Soy Oil 
                 250 g 
                 500 g 
                 0 
                 76.7 
                 EPA141.8 mg 
               
               
                   
                   
                   
                   
                   
                   
                 DHA104.1 mg 
               
               
                   
                   
                   
                   
                   
                   
                 DLA95.4 mg 
               
               
                   
                   
                   
                   
                   
                   
                 Passes Spec 
               
               
                   
               
               
                 (1) Larger scale evaluated for percent recovery only. Assay results for CoEnzymeQ10 achieved in the first example above would also be expected for large scale recoveries.