AU618096B2 - Controlled release of active ingredients from capsules having a salt sensitive shell material - Google Patents

Description

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i- 618996 v w Cr OPI DATE 24/11/89 AOJP DATE 21/12/89 APPLN. ID 35325 89 PCT NUMBER PCT/US89/01650 INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) International Patent Classification 4 (11) International Publication Number: WO 89/10117 A61K 9/50, C11D 17/00 Al A61K 7/00, A23L 1/22 (43) International Puwication Date: 2 November 1989 (02.11.89) A23P 1/04 (21) International Application Number: PCT/US89/01650 (81) Designated States: AT (European patent), AU, BE (European patent), CH (European patent), DE (European pa- (22) International Filing Date: 17 April 1989 (17.04.89) tent), FR (European patent), GB (European patent), IT (European patent), JP, LU (European patent), NL (European patent), SE (European patent).

Priority data: 183,591 19 April 1988 (19.04.88) US 333,189 4 April 1989 (04.04.89) US Published With international search report (71) Applicant: SOUTHWEST RESEARCH INSTITUTE With amended claims [US/US]; 6220 Culebra Road, P.O. Drawer 28510, San Antonio, TX 78284 (US).

(72) Inventor: LEW, Chel, Wing 9218 Old Homestead, San Antonio, TX 78230 (US).

(74) Agent: BOULWARE, Margaret, One Riverway, Suite 1100, Houston, TX 77056 (US).

(54) Title: CONTROLLED RELEASE OF ACTIVE INGREDIENTS FROM CAPSULES HAVING A SALT SENSITIVE SHELL MATERIAL (57) Abstract A method for release of an active ingredient from a capsule. The active ingredient is encapsulated in a material which is salt sensitive and the integrity of the capsule is maintained by keeping the capsule in an aqueous solution having a salt concentration higher than the concentration at which the salt sensitive material is soluble. When the release of the active ingredient is desired, the salt sensitive shell of the capsule is dissolved in the aqueous solution in which the capsule is being kept to release the active ingredient by decreasing the salt concentration of the solution. Depending upon the particular salt sensitive material selected for the shell, the release of the active ingredient may be facilitated by a change in the temperature of the aqueous solution.

WO 89/10117 PCT/US89/01650 -1- CONTROLLED RELEASE OF ACTIVE INGREDIENTS FROM CAPSULES HAVING A SALT SENSITIVE SHELL MATERIAL FIELD OF THE INVENTION This invention relates to a new method for release of an encapsulated active ingredient into an aqueous environment. The encapsulating material is a salt sensitive coating which maintains integrity at a preselected salt level and dissolves at a lower salt concentration. The capsules or microcapsules may be used in a variety of applications, including human intake.

BACKGROUND OF THE INVENTION Encapsulation processes have been developed to make very small capsules containing a selected compound or mixture coated with a layer of another composition. The capsules can be in the size range of about 1 micron to several millimeters. The smallest capsules can be used in emulsion formulas. The smaller capsules are sometimes referred to as microcapsules. Some microcapsules are designed to break under pressure so that the internal compound is released when rubbed over a surface. Microcapsules have been used containing therapeutic agents that are coated with films broken down when ingested due to pH increases in the gastric system. Other films or shells on capsules are Isoluble in particular solvents. Release f the internal soluble in particular solvents. Release of the internal 1- V 0 89/10117 PCr/S89/01 650 2 component is governed generally by solubility characteristics and the thickness of the shell.

Microcapsules are made by methods well known in the art and have been used in various industrial and commercial applications. Typical processes are centrifugal extrusion, pan coating and air suspension methods. U.S.

Patent Nos. 3,692,690, 3,015,128 and 3,310,612 are exemplary of encapsulation techniques known and practiced in the art. In addition to those illustrated by the patents, other techniques are available. The present. invention can utilize any of the available methods' for preparing capsules or microcapsules.

SUMMARY OF THE INVENTION The invention is a method of releasing an encapsulated active ingredient contained in an outer shell of a salt sensitive material. The salt sensitive capsules may be associated with an adhesive system. In describing this invention, the phrase "salt sensitive" will be used to refer to the integrity of the shell of the capsule or microcapsule in varying concentrations of salt in solution. The salt sensitive materials form a rigid gel, insoluble when the salt level in an aqueous solution is maintained at a preselected level.

Decreasing the level of salt by diluting the solution containing the capsules causes the salt sensitive shell to lose its structure, break down and dissolve. There are a number of polymers which are insoluble at certain preselected salt levels, depending on the polymer and salt used, and -soluble at a lower salt levels. The capsules could be used in dry form if kept in a moisture free envionment prior to use so that the salt sensitive shell is not adversely affected.

The adhesive system that may be associated with the salt sensitive encapsulated active ingredient does not affect the integrity of the capsule shell. The adhesive WO 89/10117 PCT/US89/01650 -3may be associated with the outer shell. The adhesive system may also be an adhesive in an aqueous gel with the salt concentration of the gel adjusted to a preselected level to maintain the integrity of the capsule shell.

The characteristics of the active ingredient to be encapsulated must be considered in designing a capsule for use in connection with the method of this invention.

A water soluble active ingredient is not to be encapsulated with a water soluble salt sensitive shell.

d If the active ingredient is water soluble, a water insoluble film layer must enclose the active ingredient which in turn is coated with the salt sensitive shell.

There would be a two layer process for encapsulation so that the internal soluble ingredient will be protected from the salt sensitive shell with the water insoluble layer. The water insoluble layer is water dispersible so that the active ingredient is released once the capsule is placed in sufficiently diluted concentrations of salt to dissolve the salt sensitive layer exposing the water insoluble layer.

The active ingredient for use in connection with the method of the present invention is any of a number of materials including washing concentrates, food concentrates, food additives, perfume oils, flavoring oils, anesthetics, antibiotics, breath fresheners, and mixtures of these materials. When the methods of the present invention are practiced using active ingredients to be released in the oral cavity or which are to be ingested, the use of nontoxic materials for the shell and dispersible film layer is required. The method of the present invention is contemplated as being particularly useful for use in connection with commercial products such as concentrates that have a number of additives. For instance, a washing concentrate could include a combination of a cleaning enzyme and bleach. The bleach typically denatures WO 89/10117 PCI/US89/01650 -4 proteins such as cleaning enzymes. Either or both the bleach and the cleaning enzyme would be encapsulated in a water dispersible layer such as an oil base compound and coated with a salt sensitive shell as both are water soluble. The oil bases selected would have to be non-reactive to the bleach and enzyme. The capsules would have to be contained in a concentrate solution which has the salt content adjusted to maintain shell integrity. Upon dilution of the concentrate in a washing machine, the salt concentration would be lowered so that the-; shell would dissolve.

Other- materials can be encapsulted and used in washing concentrates such as non-water soluble fabric softeners of the quaternary ammonium group which can be coated only with a salt sensitive shell. There are certain salt sensitive materials which are soluble only in hot or cold water or aqueous solution. Active ingredients desired to be released in hot or cold water cycles of, for instance, a conventional washing machine, can be coated with a shell material having appropriately selected solubility characteristics. The release of the active ingredient can depend on the thickness of the shell and how long it will take to dissolve in the diluted salt solution so that the shell thickness can be varied to control the time of release of the active ingredient.

The use of the salt sensitive shell is not intended to be limited to washing concentrates and can have utility in any application in which the release of an active. ingredient can be controlled by lowering the salt i concentration of a solution. For instance, encapsulated food concentrates or additives may be kept at a higher salt level for storage and diluted later. The capsules can, for instance, be designed so that when they are placed in the human mouth with the normal salt (electrolytes) concentration, the capsules dissolve. The shell's composition can be formulated to provide slow or

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WO 89/10117 PCT/US89/01 650 fast rate of dissolution. The capsules used with the adhesive system provide a mixture which can be placed inside the mouth on selected tissue. The capsules dissolve over a sustained period of time while the adhesive system holds them in place. The active ingredient is released over time in a specific region of the oral cavity.

DETAILED DESCRIPTION OF THE INVENTION h The following description of the invention is for particular methods of controlled release of an active ingredient using capsules including a salt sensitive shell which could encapsulate any type of active ingredient for medical, household, commercial or industrial use where a salt concentration level can be varied according to the release characteristics of the shell. Under a higher salt concentration level, the salt sensitive shell maintains its integrity as a rigid insoluble gel. The active ingredient is contained within the shell and is not released until the shell dissolves. The shell dissolves when exposed to a diluted aqueous salt concentration. The method also includes the association of the encapsulated active ingredient with an adhesive system in which the adhesive is part of the outer shell of the capsules or is a gel containing the capsules. The adhesive system is compatible with the salt sensitive shell such that the integrity of the shell is not affected by the adhesive.

A salt sensitive shell can be used in a single layer capsule to encapsulate a water insoluble active ingredient. A water soluble active ingredient cannot be effectively encapsulated with a salt sensitive material which reacts to water soluble compounds. Also, certain other active ingredients may be reactive with the material or materials selected for the salt sensitive shell. In instances where the active ingredient of the WO 89/10117 PCT/US89/01650 6 capsule cannot be in contact with the salt sensitive material, a water insoluble and/or nonreactive layer of film encapsulates the active ingredient which in turn is coated with an outer shell of salt sensitive material.

The capsule has a two layer coating. The water insoluble material should be water dispersible so that the active ingredient will be released in solution. The active ingredient of the capsule will be released upon the dissolution of the salt sensitive outer layer in a diluted salt concentration level and the following dispersal of the insoluble layer.

The capsules can be made as microcapsules using known encapsulation techniques such as centrifugal extrusion, pan coating and air suspension. The choice of salt sensitive shell material may also depend on solubility characteristics relating to water temperature. The following Table 1 lists examples of salt sensitive materials. The materials are salted out of solution at a certain level of salt concentration and are insoluble. Table 1 sets out the maximum salt concentration for solubility of such material.

TABLE 1 Salt Sensitive Material Max. Salt Conc. for Solubility wt.' in solutionn of salt NaC1 Na2SO 4 Na2CO Na2PO 4 24 23 24 Polyvinyl alcohol 14% 4% 4% 9%

(PVA)

Methyl Cellulose 11 6 4 2.9

(MC)

Hydroxypropyl Methyl- 17 6 5 3.9 (HPMC) Cellulose Ethylhydro:yethyl- 8 2.5 3 3 (EHEC) Cellulose *Information from Handbook of Water Soluble Gums and Resins by Robert L. Davidson (1980).

Other salt sensitive materials include polyethylene oxide and carrageenan. Methyl cellulose is an example

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WO 89/10117 PCT/US89/01650 7of a salt sensitive material that is soluble in cold water and insoluble in hot water. Also, PVAs have varying solubility characteristics based on the degree of hydrolysis.

An example of a film for use with a water soluble internal component is oil base Span. The Span materials are partial esters of fatty acids and hexitiol anhydrides. Also, edible fats such as triglycerides would be suitable particularly for capsules ingested for release I of the active ingredient. An oil base water dispersible coating wuld be a non-reactive layer suitable as a layer around a washing concentrate such as a bleach or enzyme cleaner such as the proteases commonly used. The bleach or enzyme would be contained in a capsule which would promote storage stability for these reactive compounds. In the case of washing concentrates, other active water insoluble ingredients that can be encapsulated include perfume oils and fabric softeners of the quaternary ammonium group, specifically dialkyldimethyl-, methyl dialkyl-, and methyl dialkoxyalkyl quaternary ammoniums.

The example of a washing concentrate having a salt sensitive shell encapsulated active ingredients can be formulated a variety of ways. All the components such as bleach, fabric softener, enzyme and fragrance can be encapsulated. Each component can be encapsulated with a salt sensitive shell the dissolution of which will be facilitated by a particular water temperature to achieve release at the desired washing cycle. Alternative formulations would include at least one active ingredient encapsulated and others in solution. Either alternative can be used to isolate active ingredients that would adversely offset each other's effectiveness if mixed together in solution, such as bleach denaturing a protease cleaning enzyme.

Other variables may affect release characteristics in addition to the material or mixture of materials for WO 89/10117 PCT/US89/01650 -8the shells. For instance, a thicker shell that will take longer to dissolve or disperse can be used to encapsulate an active ingredient to be released later in the washing process. Also, as noted above, temperature can be used to effect a change in the solubility of the material comprising the shell.

The formulation containing active ingredients with a salt sensitive shell must be kept at a preselected salt concentration that maintains the shells in a rigid gel state. The aqueous solution must be adjusted to a salt concentration level higher than the solubility level prior to introducing the capsules. For a liquid concentrate washing detergent, the addition of a relatively small amount of the formulation such as 4 ounces to washing machine using 10 to 15 gallons of water per cycle will dilute the concentrate well below 1% salt level.

In another example of a method that may be practice& in accordance with the present invention, the encapsulated washing concentrate is kept in a moisture-free environment for dispensing as a powder.

Such capsules, rather than having their integrity maintained by the high salt concentration of the solution in which they are kept, maintain their integrity as a result of the lack of water in which the salt sensitive material comprising the shell can dissolve. When the powder is then dispensed into an aqueous solution, the active ingredient is released.

Another example of a water insoluble active ingredient which is used to advantage in connection with the method of the present invention is ethyl aminobenzoate. This compound, also known as benzocaine, is used as a local or topical anesthetic in the mouth.

Benzocaine is relatively insoluble in water as one gram dissolves in about 2500 ml. Benzocaine is used at about to 20% strength in a suitable carrier for anesthetics. For the purpose of this specification and WO 89/10117 PCT/US89/01650 9 claims, the water insoluble active ingredients can have some slight solubility in water such as benzocaine.

Capsules of benzocaine are prepared using a salt sensitive shell. The shell is formulated to dissolve in the electrolyte concentration of the mouth releasing the benzocaine.

Other active ingredients to be encapsulated and delivered in accordance with the method of the present invention can be antibiotics capable of oral delivery such as vancomycin, gentamycin, imipenem and ceptazidime. As was the case with active ingredients such as washing concentrates, the antibiotics may be water soluble or water insoluble and are defined as oral antibiotics for the terminology of this invention.

The capsules may be included in an aqueous gel adhesive system which'has a salt concentration of a preselected level high enough to maintain the integrity of the outer shell of the capsule surrounding the active i ingredient. As noted above, more than one active ingredient may be included inside the shell as long as the active ingredient does not adversely affect the shell by chemical reactivity or otherwise. For instance, a water insoluble flavoring oil may be mixed with the benzocaine for an oral anesthetic. The encapsulated component may be a mixture of ingredients.

The active component can be any ingredient desired to be released in the mouth.

Examples of compounds which can be used as a capsule coating or in a gel adhesive system are calcium polycarbophil, polyacrylic acid, gelatin, CMC, natural gums such as karaya and tragacanth, algin, chitosan, HPMC, starches, pectins and mixtures thereof. Compounds such as CMC or HPMC may have adhesive qualities as well as salt sensitivity. The adhesives are coated on the capsule shell or. made part of the capsule shell provided there is compatibility with the shell composition to maintain integrity. The adhesives may be mixed with a WO 89/10117 PCT/US89/01650 hydrocarbon gel base, composed of polyethylene and mineral oil, with a preselected salt level to maintain the capsule integrity.

The adhesive gel is adjusted to a preselected salt concentration with a non-toxic salt. The capsules are dispersed in the gel. The gel containing the capsules is applied to the tissue in the oral cavity where the delivery of the active ingredient is desired. A typical adhesive aqueous gel system with benzocaine is comprised of CMC 1-30%, pectin gelatin 0.1-10.0% and polyethylene in mineral oil) 10-35%, and the remainder ifs water.

Adhesive systems for use in connection with the method of this invention allow the capsules to be placed in the mouth and adhere to the tissue in the oral cavity for a sustained period of time for delivery of the antibiotic, local anesthetic, breath freshener or other active ingredient.

The examples given are illustrative of the method of release of an active ingredient from a salt sensitive capsule. The specific compounds discussed are not intended to limit this invention to a method to be carried out with any specific chemical composition. All compounds that have the claimed characteristics are intended to be covered by this invention.

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Claims (19)

1. A method of delivering an active ingredient to the oral cavity comprising the steps of: encapsulating an active ingredient in a shell comprised of a salt sensitive material which is insoluble at a preselected salt level In an aqueous solution to form a microcapsule; associating a plurality of microcpsules with an adhesive system which does not affect the Integrity of the shell; maintaining the integrity of the microcapsules by keeping the capsule in an aqueous solution having a salt concentration higher than the concentration at which the salt sensitive material is soluble; and introducing the microcapsules with adhesive into the oral cavity, the adhesive system causing the microcapsules to adhere to a site in the oral cavity for a sustained period of time, the salt concentration present in the oral cavity being lower than the salt concentration at which the salt sensitive material is soluble such that material comprising the shell of the microcapsules dissolve to release the active ingredient in the oral cavity.

2. The method of claim 1 wherein the active ingredient comprises an antibiotic, a breath freshener, an anesthetic or a mixture of two or more thereof.

3. The method of claim 1 or claim 2 wherein the active ingredient comprises a mixture of more than one material.

4. The method of any one of claims 1 to 3 additionally comprising encapsulating the active ingredient with an inner shell layer with a water insoluble, water dispersible nonreactive film layer. The method of any one of claims 1 to 3 additionally comprising encapsulating an active ingredient with an inner shell of a water insoluble, water dispersible film layer before encapsulating with salt sensitive material.

6. The method of any one of claims 1 to 5 wherein the adhesive system is calcium polycarbophil, gelatin, polyacrylic acid, carboxymethyl cellulose, natural gums, algin, chitosan, hydroxypropylmethyl cellulose, starches, pectins, or a mixture of two or more thereof which are applied to the outside of the shell of the microcapsules.

7. A microcapsule for controlled release of an active ingredient comprising an outer shell layer of salt sensitive material that forms a rigid GSA/2440W r i I- 12 gel which is Insoluble in an aqueous solution at a preselected salt level; an inner layer of a water insoluble, water disperslble film; and at least one active ingredient encapsulated by the inner layer of water insoluble, water disperslble film and outer shell layer of salt sensitive material.

8. A microcapsule of claim 7 wherein the inner layer is an oil base compound, an edible fat or a mixture thereof.

9. A microcapsule of claim 7 or claim 8 wherein the outer shell is a salt sensitive material which solubility is also affected by the temperature of the aqueous solution. A microcapsule of any one of claims 7 to 9 wherein the active ingredient Is a washing concentrate, a food concentrate, a fuod additive, a perfume oil, a flavoring oil, an anesthetic, an antibiotic, a breath freshener or a mixture of two or more thereof.

11. A microcapsule of any one of claims 7 to 10 wherein the outer shell Is polyvinyl alcohol, methyl cellulose, hydroxypropylmethyl cellulose, ethylhydroxyethyl cellulose, polyethylene oxide, carrageenan, or a mixture of two or more thereof.

12. A microcapsule of any one of claims 7 to 11 wherein the inner layer is nonreactive.

13. A delivery system for the oral cavity for active ingredients comprising a plurality of microcapsules with a salt sensitive outer shell surrounding at least one active ingredient said outer shell is insoluble at a preselected salt level in an aqueous solution and dissolves in the oral cavity; an adhesive associated with the outer shell of the microcapsules which does not affect the integrity of the shell; said adhesive causing adhesion of the microcapsules to the oral cavity for a sustained period of time to allow dissolution of the shell and release of the active ingredient.

14. A delivery system of claim 30 wherein the adhesive is calcium polycarbophil, polyacrylic acid, gelatin, carboxymethyl cellulose, algin, chitosan, hydroxypropylmethyl cellulose, natural gums, pectins, starches, or a mixture of two or more thereof. A delivery system of claim 13 or claim 14 comprising an inner layer of the shell of a film of a water insoluble, water dispersible film.

16. A delivery system of claim 13 or claim 14 comprising an inner GSA/2440W tA/tV ~I kycw6~~ -_C Lr i 2 13 layer of the shell of a film of a water insoluble, water dispersible, nonreactive film.

17. A delivery system of any one of claims 13 to 16 wherein the active Ingredient is an antibiotic, a breath freshener, an anesthetic or a combination of two or more thereof. DATED this THIRD day of OCTOBER 1990 Southwest Research Institute Patent Attorneys for the Applicant SPRUSON FERGUSON GSA/2440W 1- ^M^S 1 I I INTERNATIONAL SEARCH REPORT International Application No PCT/US 89/01650 1 1 I I. CLASSIFICATION OF SUBJECT MATTER (if several classificlion symbols apply, Indicate all) According to International Patent Classification (IPC) or to both National Classification and IPC IP 4 A 61 K 9/50, C 11 D 17/00, A 61 K 7/00, A 23 L 1/22, A 23 P 1/04 II. FIELDS SEARCHED Minimum Documentation Searched 7 Classification System Classification Symbols IPC 4 A 61 K, C 11 D, A 23 L Documentation Saarched other than Minimum Documentation to the Extent that such Documents are Included In the Fields Searched I III. DOCUMENTS CONSIDERED TO BE RELEVANT* Category Citation of Document, re with Indication, where appropriate, of the relevant passages 1 Relevant to Claim No. X FR, A, 2132216 (UNILEVER 17.November 1,5-7,13,14, 1972, see the whole document 16 Y 2-4,8-11,15,

18-23 Y EP, A, 0101418 (ASTRA LAKEMEDEL AB) 18,19 22 February 1984, see page 2, lines 10-21; page 3, lines 11-20; page line 21 page 6, line 2; claim 4 Y GB, A, 931149 (THE UPJOHN CO.) 10 Jdly 2,3 1963, see claims 1-8 Y EP, A, 0153104 (A/S ALFRED BENZON) 4,10,11, 28 August 1985, see page 3, lines 20-22 16-25; page 9, lines 19-32; example 2; claims 1-4 Y EP, A, 0205282 (EUROCELTIQUE 8,9,23 17 December 1986, see example 1; claims 1-3 SSpeclal categories of cited documents: Io later document published after the International filing date document defining the goneral state of the art which is not or priority date and not in conflict with the ppelication but conidrad to b of prticular rlvanccited to understand the principle or theory underlying the earlier document but published on or after the International X" document of particular 'relevance: the claimed invention filing date cannot be considered novel or cannot be considered to document which may throw doubts on priority claim(s) or Involve an Inventive step which is cited to establish the publication date of another document of particular relevance; the claimed invention citation or other 3pecial reason (as specified) cannot be considered to Involve an Inventive step when the document referring to an oral disclosure, use, exhibition pr document is combined with one or more other such docu- other means ments, such combination being obvious to a person skilled document published prior to the international filing date but In the art. later than the priority date claimed document member of the same patent family IV. CERTIFICATION Date of the Actual Completion of the International Search I1st. August 1989 International Searching Authority EUROPEAN PATENT OFFICE Form PCTIISA/210 (second ahee:) (January 19S5) Date of Mailing of this International Search Report a International Appication No. PCT/ Us 89/01650 -2- Ill- OOCUMIENrSCONSIOERED TO 33 RIELEVANT, CCONTINUID FROM THII MEOND SHEET) Category Ctation of Domirnoent, wsth iwdcation. wtw* apwopwiatt, of theO rSloevini oassagos Relevant to Claitm No p N CH, A, 473890 (HENKEL CIE GmbH) 31 July 1969, see page 2, lines 3-20; page 3, lines 50-65; page 4, lines

25-32; page 6, lines 1-14 Wor, A, 8 6 06 626 (EURAND ITALIA S. p.A.) November 1986, see claims EP,-A, 0266796 (SHOWA DENKO 11 May 1988, see the whole document 1-11,13-16, 18-23 1-11,13-16, 18-23 Fboim PCT ISA,210 (extra sheet) fJenuary IM) lt- l--..--Cli~-il-il I ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION NO. US 8901650 SA 28276 This annex lists the patent family members relating to the patent documents cited in the above-mentioned international search report. The members are as contained in the European Patent Office EDP file on 17/08/89 The European Patent Office is in no way liable for these particulars which are merely given for the purpose of information. Patent document Publication Patent family Publication cited in search report date member(s) date FR-A- 2132216 17-11-72 GB-A- BE-A- CA-A- DE-A- NL-A- 1390503 781499 968248 2215441 7204416 16-04-75 02-10-72

27-05-75 12-10-72 03-10-72 EP-A- 0101418 22-02-84 AU-B- 561954 21-05-87 AU-A- 1594383 05-01-84 CA-A- 1214726 02-12-86 GB-A,B 2122490 18-01-84 JP-A- 59016822 28-01-84 GB-A- 931149 EP-A- 0153104 None S28-08-85 AU-B- AU-A- AU-B- AU-A- CA-A- CA-A- WO-A- WO-A- EP-A- JP-T- US-A- US-A- 570540 3935885 571312 3935985 1248023 1247009 8503436 8503437 0153105 61501151 4713248 4716041 17-03-88 27-08-85 14-04-88 27-08-85 03-01-89 20-12-88 15-08-85 15-08-85

28-08-85 12-06-86 15-12-87

29-12-87 EP-A- 0205282 17-12-86 AU-A- 5828486 18-12-86 JP-A- 61286321 16-12-86 CH-A- 473890 15-06-69 AU-A- 769866 BE-A- 683529 03-01-67 DD-A- 56326 DE-B- 1278669 FR-A- 1485163 GB-A- 1077903 NL-A- 6602531 04-01-67 US-A- 3441507 29-04-69 ZA-A- 663919 V :r t Fbrmore details about this annex see Official Journal of the European Patent Office, No. 12/82 International Application No, PCT/US 89/01650 FURTHER INFORMATION CONTINUED FROM THE SECOND SHEET V.)OBSERVATIONS WHERE CERTAIN CLAIMS WERE FOUND UNSEARCHABLE' This International search report has not been established in respect of certain claims under Article 17(2) for the following Msaeona: 1.D Claim numbers because they relate to subject matter not required to be searched by this Authority, namely, my. Claims 12,17 The methods of Claims 1 and 13 cannot additionally comprise the conditions claimed in the depending Claims 12 and 17. 2.rEJ Claim numbers because they relate to parts of the International application that do not comply with the p-sacribed require- ments to such an extent that no meaningful International searcht can be carried out, apecthcally: Clm numbers.......because Way wre deperciemt clims and are no drafted let sordance wth t esewt and Ift rd encae of PCT Rule 6.4(s). Vl.Q OBSERVATIONS WHERE UNITY OF IN4VENTION B5 LACKING This International Searching Authority found muttiple Inventions In this International application as follows,. IM As all required additional search fees were timely paid by the applicant, this International search report covere all sarchable claims of the International application. 2M As only some* of the required additional search fee$ were timely paid by the applicant, this international search report covers only those claims of the international application for which lees were paid, spectfically claims: N4 o required additional search tees were timely paid by the applicant, Consequently, this International searc h report is restricted to the Invention first mentioned In the claims; It Is covered by claim numbers-, 4-JAs all searchable claims could be searched without effort justifying an additional fee, the International Searching Authority did not Invite Payment oI any additional Ite. Remark an Protest QThe additional search fees were accompanied by applicant's protest ONo protest accompanied the payment ot additional search tees. Form PC1'IISAM2I (supplemental sheet (Jaary 1365) i t Page ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION NO. US 8901650 SA 28276 This annex lists the patent family members relating to the patent documents cited in the above-mentioned international search report. The members are as contained in the European Patent Office EDP file on 17/08/89 The European Patent Office is in no way liable for these particulars which are merely given for the purpose of information. Patent document Publication Patent family Publication cited in search report date member(s) date WO-A- 8606626 20-11-86 EP-A- 0222856 27-05-87 JP-T- 62502859 12-11-87 EP-A- 0266796 11-05-88 JP-A- 63252543 19-10-88 j i i MForrmore.details about this annex see Official Journal of the European Patent Office, No. 12/82