amino acid sequences of vl and vh domains of ab 19 and ab 17 in order to determine the formulation that would provide a high degree of stability to antibodies ab 17 and ab 19 , different excipients were tested by profiling the antibodies &# 39 ; structural stability while undergoing changes ( over time and ph ) and exposure to stressful conditions ( e . g . shear stress and slow freeze - thaw cycles ) including accelerated stability studies via incubation at 50 ° c . for one - to two - weeks . at several time points ( e . g . t 0 , t 7 , t 14 ) the stability of the molecules was examined with and without stress using the following tools : right angle light scatter ( rals ), intrinsic and extrinsic fluorescence ( if , ef ) in conjunction with analytical methods like high - performance size exclusion chromatography ( hp - sec ). rals is employed to detect and monitor the subtle changes in the associative behavior of the molecule , which can result in aggregation and / or precipitation . rals monitors macroscopic changes as a soluble molecule transitions to insoluble aggregates . the if assay measures stress - induced conformational changes in proteins as observed by changes in the tryptophan environment . ef utilizes an external , non - covalent , polarity - sensitive fluorescent probe to examine a protein &# 39 ; s apparent exposure of hydrophobic clefts and to monitor possible changes in this parameter as a function of various environmental stresses and conditions . after reading initial rals or turbidity , approximately 400 ˜ μl of sample was frozen slowly in an eppendorf tube by placing it in a − 80 ° c . freezer . after freezing was complete ( minimum of four hours ), all samples were thawed on the bench top ( room temperature ). the process was repeated for a total of 5 cycles . 750 ˜ μl of the tested formulation were shear stressed in a conical glass vial using a triangular stir bar . the samples were spun at 300 rpm ( no cavitation ) for 24 hours before removal from the magnetic stirrer for analysis . sodium dodecyl sulphate poly acrylamide gel electrophoresis ( sds - page ) was performed using bis - tris gradient of 4 - 12 %. 2 μg of the antibody combination were mixed with a native sample buffer ( invitrogen ) containing 50 mm dtt and incubated for 10 min at 100 ° c . prior to loading . the gels were run at 200v for about 30 min , and then rinsed twice in ddw for 3 min . the gels were then stained with coomasie blue ( gelcode ; pierce ) while shaking for one hour , and then rinsed in ddw over night . photographs of the gels were taken using the lis - cap program in a renium camera this example describes the selection of excipients for a liquid formulation comprising the human anti hbsag antibodies ab 19 and ab 17 , ab 19 having the amino acid sequence shown in fig1 a ( light chain ; seq id no . 1 ) and 1 b ( heavy chain ; seq id no . 2 ) and ab 17 having the amino acid sequence shown in fig1 c ( light chain ; seq id no . 3 ) and id ( heavy chain ; seq id no . 4 ). ab 19 and ab 17 may be produced by hybridoma cells ( deposited at the ecacc under accession nos . 96052169 and 96052168 ), or may be prepared by recombinant methods well known in the art , e . g . by cho expression systems transfected with the genes encoding the heavy and light chain of each antibody . several ph values for the formulation were compared ranging from 5 . 0 to 7 . 5 generated using different buffers : sodium citrate , histidine or succinic acid . ab 17 and ab 19 in the different buffers were examined by if , rals , ef and sec - hplc under different conditions : incubation at 50 ° c . for seven and fourteen days , exposure to shear stress and slow freeze - thaw cycles . the formulation containing citrate at ph 6 . 5 performed best in the assays and therefore sodium citrate was chosen as the preferred buffer for the formulation . using sodium citrate as a buffer , a set of formulations containing different amino acids at a concentration of 50 mm was generated . these formulations were examined by if , rals , ef and sec - hplc , and were subjected to shear stress and slow freeze - thaw cycles . the formulations containing glutamic acid and proline scored highest , followed by the formulation containing alanine . these three amino acids were further analyzed in order to establish the feasibility of concentrating the antibodies to 100 mg / ml . the formulation containing alanine scored best in the concentration studies . since glutamic acid had scored best in the previous study , these two amino acids were chosen as the preferred amino acid stabilizers and were reexamined in a combination study including additional formulation excipients as will be described below . carbohydrates are typically used as stabilizers , isotonic adjusters , and / or bulking agents ( in the case of lyophilization ). surfactants are typically used to protect proteins against shear stress . several formulations were generated containing each 20 mm sodium citrate , 50 mm glutamic acid and a different carbohydrate or surfactant . the following excipients were examined : lactose , mannose , mannitol , sorbitol , sucrose and trehalose ( 3 %), peg - 3350 and peg - 4000 ( 1 %), tween - 20 and tween - 80 ( 0 . 1 %). all formulations were examined by if , rals , ef and sec - hplc and were stressed by shear stress and slow freeze - thaw . the formulations containing trehalose and sorbitol scored the best over time . therefore both of these carbohydrates were chosen as preferred carbohydrates for the antibody formulation and would be further examined in the combination study . the formulation containing tween - 80 ( t80 ) scored best among the surfactants and therefore t80 was chosen as the preferred surfactant for the antibody formulation . finally , based on the data described above several formulations of the antibodies were prepared examining different combinations of stabilizing excipients in order to determine the preferred combination . these combinations were tested by if , rals , ef and sec - hplc . these assays indicated that sodium citrate at ph 6 . 5 provided the greatest stability to ab 17 and ab 19 . the amino acids alanine and glutamic acid were identified as lead stabilizers for ab 17 and ab 19 , and trehalose was selected over the other strong carbohydrate stabilizer , sorbitol . the surfactant , tween 80 , was found to reduce the shear stress of the molecule . based on these findings four liquid formulations containing the preferred excipients were evaluated for selection of a preferred clinical formulation for use in treatment or prevention of hbv infections . the formulations were as shown in table 1 below . these formulations were again examined using the assays described above . under subjection to temperature , shear and freeze - thaw stress , all formulations maintained both high purities and recoveries . overall , formulation 3 performed slightly better over a 28 day stability study . this suggests that a higher alanine concentration may help to stabilize the antibodies . the stock of ab 17 ( in pbs ) was diluted 1 : 1 prior to concentrating with a solution of 20 mm sodium citrate , 50 mm alanine and 100 mm nacl in order to provide stability while concentrating . the protein was then concentrated to ˜ 89 mg / ml by tangential - flow filtration ( tff ) over the course of 4 days . the concentrated ab 17 was slightly cloudy , and there was an 80 % recovery from the tff . the antibody was buffer exchanged using dialysis tubing ( mw cutoff = 25 , 000 ) into the preferred formulation as described above . this example describes the stability tests performed on the combination of antibodies ab 17 and ab 19 in formulation 3 . stability studies were performed on samples stored under controlled temperatures at 5 ° c ., 25 ° c . and 40 ° c . combination samples were prepared containing 90 mg / ml of ab 17 + 30 mg / ml of ab 19 in 2 ml ( final concentration 60 mg / ml ) in formulation 3 containing either 0 . 1 % tween 80 or 0 . 01 % tween 80 . the samples were subjected to sds - page under reduced conditions in order to check the purity of the sample and the presence of degradation products . fig2 and 3 show antibody samples after incubation for 4 weeks in different storage temperatures ( fig2 : formulation 3 containing 0 . 1 % t80 ; fig3 : formulation 3 containing 0 . 01 % t80 ). the antibody chains remain intact in all temperatures measured as can be seen by the two distinct bands representing each the heavy and light antibody chains . no impurities and no degradation products were detected . both tween 80 concentrations tested ( 0 . 1 % and 0 . 01 %) were effective in stabilizing the antibodies . a functional property of the antibodies , i . e . binding to hbsag was measured using an immuno assay and is shown in table 3 . the specific activity ( iu / mg ) was measured at time 0 ( t 0 ) at the beginning of the incubation and compared with the specific activity 4 weeks ( t 4 ) after incubation in different temperatures . as can be seen in table 3 the specific activity of the antibodies was not significantly changed after 4 weeks incubation , providing another indication to their stability in the tested formulations . the three month stability data above shows that some 40 ° c . formulations of 17 and 19 in combination fared as well or better than similar formulations of 17 or 19 alone . following the term “ about ” used to described amounts herein , the precise amount following the term “ about ” is also contemplated in each instance . all publications , patents , and patent applications cited herein are specifically incorporated herein by reference .
the present invention provides liquid formulations of antibodies or fragments thereof that specifically bind to a hepatitis b virus antigen , which formulations exhibit stability , low to undetectable levels of aggregations , and very little to no loss of the biological activities of the antibodies or antibody fragments , even during long periods of storage . furthermore , the invention provides methods of preventing , treating or ameliorating one or more symptoms associated with hbv infection utilizing the liquid formulations of the present invention .