Connection for medical device
09962500 ยท 2018-05-08
Assignee
Inventors
- Marc Holtwick (Frankfurt am Main, DE)
- Jeffrey Zajac (Franklin, MA, US)
- James Alexander Davies (Warwickshire, GB)
- Simon Lewis Bilton (Warwickshire, GB)
- David Moore (Leicestershire, GB)
- Steven Wimpenny (Warwickshire, GB)
- Christopher Nigel Langley (Warwickshire, GB)
Cpc classification
A61M5/343
HUMAN NECESSITIES
A61M5/34
HUMAN NECESSITIES
International classification
Abstract
The invention faces the technical problem of providing a tight connection between a tube and an dispense interface, while at the same time the biocompatibility of the connection can be improved. The technical problem is solved by an apparatus comprising a tube configured to guide a medium and a dispense interface. The tube comprises a first opening and a second opening, while the dispense interface comprises a recess. The recess has a first opening and a second opening and the tube is at least in part inserted into the recess. The tube is permanently affixed to the dispense interface by a combination of an interference fit and an adhesive, such that the interference fit prevents the adhesive from contaminating the medium.
Claims
1. An apparatus comprising: a first piercing needle and a second piercing needle, each of the first piercing needle and the second piercing needle comprising a proximal piercing end and a distal end, and wherein each of the first piercing needle and the second piercing needle is configured to guide a medium, and a dispense interface, comprising a mounting hub configured for releasable connection to a needle assembly, wherein each of said first piercing needle and said second piercing needle comprises a first opening and a second opening, wherein said dispense interface comprises a first recess and a second recess wherein said first recess has a first opening and said second recess has a second opening, wherein said distal end of said first piercing needle is at least partially inserted into said first recess, and said distal end of said second piercing needle is at least partially inserted into said second recess, wherein said first piercing needle and said second piercing needle are permanently affixed to said dispense interface by a combination of an interference fit and an adhesive, such that said interference fit prevents said adhesive from contaminating said medium, wherein said first recess and second recess each comprise a first section configured to accept said adhesive, wherein said first recess and said second recess each comprise a second section adjacent to said first section configured to provide said interference fit between said first piercing needle and said second piercing needle respectively and said dispense interface, wherein said second section comprises a tapered section and a substantially cylindrical portion between said first section and said second opening, wherein said substantially cylindrical portion provides said interference fit, and wherein said dispense interface is configured to attach to a distal end of a reservoir holder comprising a first reservoir and a second reservoir such that the proximal piercing end of said first needle pierces the first reservoir and such that the proximal piercing end of said second needle pierces the second reservoir.
2. The apparatus according to claim 1, wherein said first piercing needle and said second piercing needle each are a needle or a cannula.
3. The apparatus according to claim 1, wherein said dispense interface is configured to attach to a medical device comprising a first cartridge of primary medicament and a second cartridge of secondary medicament.
4. The apparatus according to claim 1, wherein said first recess and said second recess are each at least in part gradually tapering.
5. The apparatus according to claim 1, wherein said second section tapers at least in part from said first section towards said second opening.
6. The apparatus according to claim 1, wherein said first section tapers at least in part from said first opening towards said second section.
7. The apparatus according to claim 1, wherein each recess is tapered such that said interference fit is provided when said second opening of said piercing needle is positioned in a region of said second opening of said recess.
8. The apparatus according to claim 1, wherein said inner body is made from Cyclo Olefin Polymer (COP).
9. The apparatus according to claim 1, wherein each piercing needle is made from metal.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) These as well as other advantages of various aspects of the present invention will become apparent to those of ordinary skill in the art by reading the following detailed description, with appropriate reference to the accompanying drawings, in which:
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DETAILED DESCRIPTION
(19) The drug delivery device illustrated in
(20) The main body 14 contains a micro-processor control unit, an electro-mechanical drive train, and at least two medicament reservoirs. When the end cap or cover 18 is removed from the device 10 (as illustrated in
(21) The drive train may exert a pressure on the bung of each cartridge, respectively, in order to expel the doses of the first and second medicaments. For example, a piston rod may push the bung of a cartridge forward a pre-determined amount for a single dose of medicament. When the cartridge is empty, the piston rod is retracted completely inside the main body 14, so that the empty cartridge can be removed and a new cartridge can be inserted.
(22) A control panel region 60 is provided near the proximal end of the main body 14. Preferably, this control panel region 60 comprises a digital display 80 along with a plurality of human interface elements that can be manipulated by a user to set and inject a combined dose. In this arrangement, the control panel region comprises a first dose setting button 62, a second dose setting button 64 and a third button 66 designated with the symbol OK. In addition, along the most proximal end of the main body, an injection button 74 is also provided (not visible in the perspective view of
(23) The cartridge holder 40 can be removably attached to the main body 14 and may contain at least two cartridge retainers 50 and 52. Each retainer is configured so as to contain one medicament reservoir, such as a glass cartridge. Preferably, each cartridge contains a different medicament.
(24) In addition, at the distal end of the cartridge holder 40, the drug delivery device illustrated in
(25) Once the device is turned on, the digital display 80 shown in
(26) As shown in
(27) As mentioned above when discussing
(28) In
(29)
(30) The needle assembly 400 illustrated in
(31) Similarly, a second or proximal piercing end 406 of the needle assembly 400 protrudes from an opposite side of the circular disc so that it is concentrically surrounded by the sleeve 403. In one needle assembly arrangement, the second or proximal piercing end 406 may be shorter than the sleeve 403 so that this sleeve to some extent protects the pointed end of the back sleeve. The needle cover cap 420 illustrated in
(32) Referring now to
(33) a. a main outer body 210,
(34) b. an first inner body 220,
(35) c. a second inner body 230,
(36) d. a first piercing needle 240,
(37) e. a second piercing needle 250,
(38) f. a valve seal 260, and
(39) g. a septum 270.
(40) The main outer body 210 comprises a main body proximal end 212 and a main body distal end 214. At the proximal end 212 of the outer body 210, a connecting member is configured so as to allow the dispense interface 200 to be attached to the distal end of the cartridge holder 40. Preferably, the connecting member is configured so as to allow the dispense interface 200 to be removably connected the cartridge holder 40. In one preferred interface arrangement, the proximal end of the interface 200 is configured with an upwardly extending wall 218 having at least one recess. For example, as may be seen from
(41) Preferably, the first and the second recesses 217, 219 are positioned within this main outer body wall so as to cooperate with an outwardly protruding member located near the distal end of the cartridge housing 40 of the drug delivery device 10. For example, this outwardly protruding member 48 of the cartridge housing may be seen in
(42) The main outer body 210 and the distal end of the cartridge holder 40 act to form an axially engaging snap lock or snap fit arrangement that could be axially slid onto the distal end of the cartridge housing. In one alternative arrangement, the dispense interface 200 may be provided with a coding feature so as to prevent inadvertent dispense interface cross use. That is, the inner body of the hub could be geometrically configured so as to prevent an inadvertent cross use of one or more dispense interfaces.
(43) A mounting hub is provided at a distal end of the main outer body 210 of the dispense interface 200. Such a mounting hub can be configured to be releasably connected to a needle assembly. As just one example, this connecting means 216 may comprise an outer thread that engages an inner thread provided along an inner wall surface of a needle hub of a needle assembly, such as the needle assembly 400 illustrated in
(44) The dispense interface 200 further comprises a first inner body 220. Certain details of this inner body are illustrated in
(45) In addition, as can be seen in
(46) Preferably, this dispense interface 200 further comprises a valve arrangement. Such a valve arrangement could be constructed so as to prevent cross contamination of the first and second medicaments contained in the first and second reservoirs, respectively. A preferred valve arrangement may also be configured so as to prevent back flow and cross contamination of the first and second medicaments.
(47) In one preferred system, dispense interface 200 includes a valve arrangement in the form of a valve seal 260. Such a valve seal 260 may be provided within a cavity 231 defined by the second inner body 230, so as to form a holding chamber 280. Preferably, cavity 231 resides along an upper surface of the second inner body 230. This valve seal comprises an upper surface that defines both a first fluid groove 264 and second fluid groove 266. For example,
(48) Together, the first and second grooves 264, 266 converge towards the non-return valves 262 and 268 respectively, to then provide for an output fluid path or a holding chamber 280. This holding chamber 280 is defined by an inner chamber defined by a distal end of the second inner body both the first and the second non return valves 262, 268 along with a pierceable septum 270. As illustrated, this pierceable septum 270 is positioned between a distal end portion of the second inner body 230 and an inner surface defined by the needle hub of the main outer body 210.
(49) The holding chamber 280 terminates at an outlet port of the interface 200. This outlet port 290 is preferably centrally located in the needle hub of the interface 200 and assists in maintaining the pierceable seal 270 in a stationary position. As such, when a double ended needle assembly is attached to the needle hub of the interface (such as the double ended needle illustrated in
(50) The hub interface 200 further comprises a second inner body 230. As can be seen from
(51) Axially sliding the main outer body 210 over the distal end of the drug delivery device attaches the dispense interface 200 to the multi-use device. In this manner, a fluid communication may be created between the first needle 240 and the second needle 250 with the primary medicament of the first cartridge and the secondary medicament of the second cartridge, respectively.
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(53) When the interface 200 is first mounted over the distal end of the cartridge holder 40, the proximal piercing end 244 of the first piercing needle 240 pierces the septum of the first cartridge 90 and thereby resides in fluid communication with the primary medicament 92 of the first cartridge 90. A distal end of the first piercing needle 240 will also be in fluid communication with a first fluid path groove 264 defined by the valve seal 260.
(54) Similarly, the proximal piercing end 254 of the second piercing needle 250 pierces the septum of the second cartridge 100 and thereby resides in fluid communication with the secondary medicament 102 of the second cartridge 100. A distal end of this second piercing needle 250 will also be in fluid communication with a second fluid path groove 266 defined by the valve seal 260.
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(56) As illustrated in
(57) In one preferred arrangement, the dispense interface is configured so that it attaches to the main body in only one orientation, that is it is fitted only one way round. As such as illustrated in
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(59) One exemplary difference between the dispense interface 200 and the dispense interface 2000 is the outer shape. In particular, the dispense interface 2000 is attachable to a drug deliver device by axial attachment means as described above and at least partially insertable in the drug delivery device. For instance, once the dispense interface 2000 is attached to the distal end of the drug delivery device, the distal end of the main body of the drug delivery device covers a portion of the dispense interface 2000.
(60) As will now be discussed in greater detail, in one preferred arrangement, the dispense interface 2000 illustrated in
(61) a. a main outer body 2100;
(62) b. an inner body 2200;
(63) c. a manifold 2300;
(64) d. a first piercing needle 240;
(65) e. a second piercing needle 250;
(66) f. a lock-out spring 2600;
(67) g. a first diaphragm valve (e.g. diaphragm 2700);
(68) h. a second diaphragm valve (e.g. diaphragm 2750); and
(69) i. an outer septum 270.
(70) In
(71) In the exploded view illustrated in
(72) The manifold can in particular provide a y-channel which guides a fluid form the first and second circular reservoirs 2050 and 2054 into the holding chamber 280.
(73)
(74) As illustrated in
(75) The proximal piercing end 244 of the first piercing needle 240 pierces the septum of the first cartridge 90 and thereby resides in fluid communication with the primary medicament 92 of the first cartridge 90. A distal end of the first piercing needle 240 will also be in fluid communication with the first reservoir 2050 defined by the inner body 2000.
(76) Similarly, the proximal piercing end 254 of the second piercing needle 250 resides in fluid communication with the secondary medicament 102 of the second cartridge 100. A distal end of the second piercing needle 250 will also be in fluid communication with the second circular reservoir 2054 defined by the inner body 2000.
(77) For instance, as pressure builds up in the first cartridge 90 and the second cartridge 100, fluidic pressure will build up in both the first and second piercing needles 240, 250. As such, the pressure will be built up in both the first and second reservoirs 2050, 2054 and this fluidic pressure will invert the first and second diaphragms 2700, 2750. For instance, a fluidic pressure threshold has to be overcome to invert the first and second diaphragm valves.
(78) This inversion of the first diaphragm 2700 will allow the first medicament 92 to flow out of the first reservoir 2050, around the now inverted first diaphragm 2700 and then into a fluid groove of the manifold 2300 (not shown). Similarly, this inversion of the second diaphragm 2750 will allow the second medicament 102 to flow out of the second reservoir 100, around the now inverted second diaphragm 2750 and then into a fluid groove of the manifold 2300. Under this continued pressure, the medicaments will then flow into the holding chamber 280 of the inner body 2200. Alternatively or additionally, the medicament may then flow out of the outlet 290 of the dispense interface 2000.
(79)
(80) Here, the tube is designed as a needle, in particular a piercing needle 240. The dispense interface, in this case, is the inner body 2200 of the dispense interface 2000. Though, the dispense interface can as well be the first inner body 220 illustrated in
(81) The needle 240 is inserted into the recess 308. The recess 308 comprises a first section 310 and a second section 312. The first section 310 is tapered with a larger angle to the axial direction of the recess 308 or the needle 240 than the second region 312. The first region gradually tapers from the first opening 314 of the recess 308 towards the second region 312 and provides a volume to accept an adhesive 318. The second region 312 gradually tapers from the first region 310 towards the second opening 316 of the recess 308 and thus provides the interference fit for the needle 240. The second opening 306 of the needle 240 is substantially aligned with the second opening 316 of recess 308. It is as well possible that the tapering is provided in different geometric forms, departing from a gradual tapering. It is also possible to provide a recess 308, which provides an interference fit, without any tapering at all. Though, by the tapering of the recess 308 an easy assembly of the needle 240 and the inner body 2200 is provided since a centering or alignment during the insertion of the needle 240 takes place. Moreover the insertion force is evenly distributed and the growing force by the recess 308 on the needle 240 occurs gradually instead of all at once. This also reduces the total force necessary to insert the needle 240 into the recess 308. Hence the insertion during the assembly process is made smoother and better controllable. The state depicted in
(82) Thus
(83) As illustrated in
(84)
(85) The needle 240 and the adhesive 318 can be inserted into the recess the same way as it is illustrated in
(86) The inner body 2200 may be made from Cyclo Olefin Polymer (COP), which is a biocompatible substance and which can be easily molded into the given geometric shape. Since a higher rigidity is needed for the piercing needle 240, it is preferably made from metal and in particular from steel. The needle 240 and the inner body 2200 can also be made from other materials, as long as a sufficient biocompatibility is guaranteed.
(87) The term drug or medicament, as used herein, means a pharmaceutical formulation containing at least one pharmaceutically active compound,
(88) wherein in one embodiment the pharmaceutically active compound has a molecular weight up to 1500 Da and/or is a peptide, a proteine, a polysaccharide, a vaccine, a DNA, a RNA, an enzyme, an antibody or a fragment thereof, a hormone or an oligonucleotide, or a mixture of the above-mentioned pharmaceutically active compound,
(89) wherein in a further embodiment the pharmaceutically active compound is useful for the treatment and/or prophylaxis of diabetes mellitus or complications associated with diabetes mellitus such as diabetic retinopathy, thromboembolism disorders such as deep vein or pulmonary thromboembolism, acute coronary syndrome (ACS), angina, myocardial infarction, cancer, macular degeneration, inflammation, hay fever, atherosclerosis and/or rheumatoid arthritis,
(90) wherein in a further embodiment the pharmaceutically active compound comprises at least one peptide for the treatment and/or prophylaxis of diabetes mellitus or complications associated with diabetes mellitus such as diabetic retinopathy,
(91) wherein in a further embodiment the pharmaceutically active compound comprises at least one human insulin or a human insulin analogue or derivative, glucagon-like peptide (GLP-1) or an analogue or derivative thereof, or exedin-3 or exedin-4 or an analogue or derivative of exedin-3 or exedin-4.
(92) Insulin analogues are for example Gly(A21), Arg(B31), Arg(B32) human insulin; Lys(B3), Glu(B29) human insulin; Lys(B28), Pro(B29) human insulin; Asp(B28) human insulin; human insulin, wherein proline in position B28 is replaced by Asp, Lys, Leu, Val or Ala and wherein in position B29 Lys may be replaced by Pro; Ala(B26) human insulin; Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) human insulin.
(93) Insulin derivates are for example B29-N-myristoyl-des(B30) human insulin; B29-N-palmitoyl-des(B30) human insulin; B29-N-myristoyl human insulin; B29-N-palmitoyl human insulin; B28-N-myristoyl LysB28ProB29 human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin; B30-N-myristoyl-ThrB29LysB30 human insulin; B30-N-palmitoyl-ThrB29LysB30 human insulin; B29-N(N-palmitoyl-Y-glutamyl)-des(B30) human insulin; B29-N(N-lithocholyl-Y-glutamyl)-des(B30) human insulin; B29-N-(-carboxyheptadecanoyl)-des(B30) human insulin and B29-N-(-carboxyheptadecanoyl) human insulin.
(94) Exendin-4 for example means Exendin-4(1-39), a peptide of the sequence
(95) TABLE-US-00001 HHis-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg- Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2.
(96) Exendin-4 derivatives are for example selected from the following list of compounds:
(97) H-(Lys)4-des Pro36, des Pro37 Exendin-4(1-39)-NH2,
(98) H-(Lys)5-des Pro36, des Pro37 Exendin-4(1-39)-NH2,
(99) des Pro36 [Asp28] Exendin-4(1-39),
(100) des Pro36 [IsoAsp28] Exendin-4(1-39),
(101) des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),
(102) des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),
(103) des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),
(104) des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),
(105) des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),
(106) des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39); or
(107) des Pro36 [Asp28] Exendin-4(1-39),
(108) des Pro36 [IsoAsp28] Exendin-4(1-39),
(109) des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),
(110) des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),
(111) des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),
(112) des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),
(113) des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),
(114) des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39),
(115) wherein the group -Lys6-NH2 may be bound to the C-terminus of the Exendin-4 derivative;
(116) or an Exendin-4 derivative of the sequence
(117) H-(Lys)6-des Pro36 [Asp28] Exendin-4(1-39)-Lys6-NH2,
(118) des Asp28 Pro36, Pro37, Pro38Exendin-4(1-39)-NH2,
(119) H-(Lys)6-des Pro36, Pro38 [Asp28] Exendin-4(1-39)-NH2,
(120) H-Asn-(Glu)5des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-NH2,
(121) des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,
(122) H-(Lys)6-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,
(123) H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,
(124) H-(Lys)6-des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,
(125) H-des Asp28 Pro36, Pro37, Pro38 [Trp(O2)25] Exendin-4(1-39)-NH2,
(126) H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-NH2,
(127) H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-NH2,
(128) des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
(129) H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
(130) H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
(131) H-(Lys)6-des Pro36 [Met(O)14, Asp28] Exendin-4(1-39)-Lys6-NH2,
(132) des Met(O)14 Asp28 Pro36, Pro37, Pro38 Exendin-4(1-39)-NH2,
(133) H-(Lys)6-desPro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,
(134) H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,
(135) des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
(136) H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
(137) H-Asn-(Glu)5 des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
(138) H-Lys6-des Pro36 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,
(139) H-des Asp28 Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25] Exendin-4(1-39)-NH2,
(140) H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28] Exendin-4(1-39)-NH2,
(141) H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-NH2,
(142) des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2,
(143) H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(S1-39)-(Lys)6-NH2,
(144) H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28] Exendin-4(1-39)-(Lys)6-NH2;
(145) or a pharmaceutically acceptable salt or solvate of any one of the afore-mentioned Exedin-4 derivative.
(146) Hormones are for example hypophysis hormones or hypothalamus hormones or regulatory active peptides and their antagonists as listed in Rote Liste, ed. 2008, Chapter 50, such as Gonadotropine (Follitropin, Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin), Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin, Buserelin, Nafarelin, Goserelin.
(147) A polysaccharide is for example a glucosaminoglycane, a hyaluronic acid, a heparin, a low molecular weight heparin or an ultra low molecular weight heparin or a derivative thereof, or a sulphated, e.g. a poly-sulphated form of the above-mentioned polysaccharides, and/or a pharmaceutically acceptable salt thereof. An example of a pharmaceutically acceptable salt of a poly-sulphated low molecular weight heparin is enoxaparin sodium.
(148) Antibodies are globular plasma proteins (150 kDa) that are also known as immunoglobulins which share a basic structure. As they have sugar chains added to amino acid residues, they are glycoproteins. The basic functional unit of each antibody is an immunoglobulin (Ig) monomer (containing only one Ig unit); secreted antibodies can also be dimeric with two Ig units as with IgA, tetrameric with four Ig units like teleost fish IgM, or pentameric with five Ig units, like mammalian IgM.
(149) The Ig monomer is a Y-shaped molecule that consists of four polypeptide chains; two identical heavy chains and two identical light chains connected by disulfide bonds between cysteine residues. Each heavy chain is about 440 amino acids long; each light chain is about 220 amino acids long. Heavy and light chains each contain intrachain disulfide bonds which stabilize their folding. Each chain is composed of structural domains called Ig domains. These domains contain about 70-110 amino acids and are classified into different categories (for example, variable or V, and constant or C) according to their size and function. They have a characteristic immunoglobulin fold in which two sheets create a sandwich shape, held together by interactions between conserved cysteines and other charged amino acids.
(150) There are five types of mammalian Ig heavy chain denoted by , , , , and . The type of heavy chain present defines the isotype of antibody; these chains are found in IgA, IgD, IgE, IgG, and IgM antibodies, respectively.
(151) Distinct heavy chains differ in size and composition; and contain approximately 450 amino acids and approximately 500 amino acids, while and have approximately 550 amino acids. Each heavy chain has two regions, the constant region (CH) and the variable region (VH). In one species, the constant region is essentially identical in all antibodies of the same isotype, but differs in antibodies of different isotypes. Heavy chains , and have a constant region composed of three tandem Ig domains, and a hinge region for added flexibility; heavy chains and have a constant region composed of four immunoglobulin domains. The variable region of the heavy chain differs in antibodies produced by different B cells, but is the same for all antibodies produced by a single B cell or B cell clone. The variable region of each heavy chain is approximately 110 amino acids long and is composed of a single Ig domain.
(152) In mammals, there are two types of immunoglobulin light chain denoted by and . A light chain has two successive domains: one constant domain (CL) and one variable domain (VL). The approximate length of a light chain is 211 to 217 amino acids. Each antibody contains two light chains that are always identical; only one type of light chain, or , is present per antibody in mammals.
(153) Although the general structure of all antibodies is very similar, the unique property of a given antibody is determined by the variable (V) regions, as detailed above. More specifically, variable loops, three each the light (VL) and three on the heavy (VH) chain, are responsible for binding to the antigen, i.e. for its antigen specificity. These loops are referred to as the Complementarity Determining Regions (CDRs). Because CDRs from both VH and VL domains contribute to the antigen-binding site, it is the combination of the heavy and the light chains, and not either alone, that determines the final antigen specificity.
(154) An antibody fragment contains at least one antigen binding fragment as defined above, and exhibits essentially the same function and specificity as the complete antibody of which the fragment is derived from. Limited proteolytic digestion with papain cleaves the Ig prototype into three fragments. Two identical amino terminal fragments, each containing one entire L chain and about half an H chain, are the antigen binding fragments (Fab). The third fragment, similar in size but containing the carboxyl terminal half of both heavy chains with their interchain disulfide bond, is the crystallizable fragment (Fc). The Fc contains carbohydrates, complement-binding, and FcR-binding sites. Limited pepsin digestion yields a single F(ab)2 fragment containing both Fab pieces and the hinge region, including the HH interchain disulfide bond. F(ab)2 is divalent for antigen binding. The disulfide bond of F(ab)2 may be cleaved in order to obtain Fab. Moreover, the variable regions of the heavy and light chains can be fused together to form a single chain variable fragment (scFv).
(155) Pharmaceutically acceptable salts are for example acid addition salts and basic salts. Acid addition salts are e.g. HCl or HBr salts. Basic salts are e.g. salts having a cation selected from alkali or alkaline, e.g. Na+, or K+, or Ca2+, or an ammonium ion N+(R1)(R2)(R3)(R4), wherein R1 to R4 independently of each other mean: hydrogen, an optionally substituted C1-C6-alkyl group, an optionally substituted C2-C6-alkenyl group, an optionally substituted C6-C10-aryl group, or an optionally substituted C6-C10-heteroaryl group. Further examples of pharmaceutically acceptable salts are described in Remington's Pharmaceutical Sciences 17. ed. Alfonso R. Gennaro (Ed.), Mark Publishing Company, Easton, Pa., U.S.A., 1985 and in Encyclopedia of Pharmaceutical Technology.
(156) Pharmaceutically acceptable solvates are for example hydrates.