United States Patent:  6,051,238

Assignee:  Merck & Co., Inc. (Rahway, NJ)

Filed:  December 18, 1997

Vaccine stabilizers, vaccine formulations and lyophilized vaccines with enhanced thermostability are disclosed. The vaccine formulations comprise an increased amount of a 6-carbon polyhydric alcohol (such as sorbitol), an increase amount of a disaccharide (such as sucrose) and an amount of a physiologically active buffer to adjust the pH from about 6.0 to about 7.0.

SUMMARY OF THE INVENTION

The present invention relates to vaccine stabilizers, vaccine formulations, and live attenuated lyophilized vaccines which impart increased thermostability.

The vaccine formulation of the present invention comprises viral and stabilizer components which result on a gram per liter basis from about 15 to about 90 grams per liter of a 6-carbon polyhydric alcohol, including but not limited to sorbitol, mannitol and dulcitol; from about 10 to about 70 grams per liter of a disaccharide, including but not limited to sucrose, lactose, maltose or trehalose and an amount of a physiologically active buffer to adjust the pH from about 6.0 to about 7.0. It is preferred in the present invention that the 6-carbon polyhydcic alcohol be sorbitol and the disaccharide be sucrose.

In another embodiment of the present invention, the vaccine formulation contains sorbitol as the 6-carbon polyhydric alcohol, from about 15 to about 90 grams per liter; the disaccharide sucrose, from about 10 to about 70 grams per liter; and, the pH of the vaccine formulation is controlled through citrate-phosphate combinations to ensure buffering across a pH range of about 6.0 to about 7.0 by one of two approaches: addition of phosphate at a concentration from about 7.5 mM to about 75 mM or addition of a phosphate:citrate combination with a phosphate concentration from about 7.5 mM to about 75 mM and a citrate concentration from about 30 mM to about 0.4M.

In an additional embodiment of the present invention, the vaccine formulation contains sorbitol as the 6-carbon polyhydric alcohol, from about 15 to about 90 grams per liter; the disaccharide sucrose, from about 10 to about 70 grams per liter; and, the pH of the vaccine formulation is controlled through addition of a phosphate buffer to ensure buffering across the preferred pH range of about 6.0 to about 7.0

The vaccine formulations of the present invention preferably include one or more additional components, alone or in a biologically effective combination, which provides a vaccine with enhanced thermostability characteristics; including but not limited to hydrolyzed gelatin from about 10 to 50 grams per liter, sodium chloride from about 1 to about 6 grams per liter; sodium bicarbonate in amounts to about 1.5 g/l, preferable from about 0.2 g/l to about 1.2 g/l; human serum albumin at about 0.5 to 1.0 gram per liter, or approximately 0.3 to about 1.0% by dry weight of the lyophilized form of the vaccine; and cell culture medium which is a nutrient medium which promotes cell growth in vitro, including but not limited to known cell culture media such as Solution 199, Medium T, Medium O, Dubecco's Modified Eagles Medium, Mjninl Essential Medium, and Basal Medium Eagle. Preferred media components include biologically effective amounts of Medium O, Medium T and Solution 199. Other components of the vaccine formulation of the present invention may include, but are not limited to, biologically active amounts of an antibiotic (e.g., neomycin) and a pH indicator (e.g., phenol red).

Therefore, vaccine formulations of the present invention may comprise sorbitol as the 6-carbon polyhydric alcohol, from about 15 to about 90 grams per liter; the disaccharide sucrose, from about 10 to about 70 grams per liter; a biologically effective concentration of a cell culture medium (preferably Medium O), a biologically effective concentration of a salt (preferably NaCl), a biologically effective concentration of a bicarbonate (preferably NaHCO₃), a citrate-phosphate combination to ensure buffering across the preferred pH range as well as several additional components, including but not limited to neomycin and phenol red. The addition of bicarbonate in varying amounts may alter the formulation pH within a biologically acceptable range.

The vaccine formulations of the present invention may also comprise sorbitol as the 6-carbon polyhydric alcohol, from about 15 to about 90 grams per liter; the disaccharide sucrose, from about 10 to about 70 grams per liter; a biologically effective concentration of a cell culture medium (preferably Medium O), a biologically effective concentration of a salt (preferably NaCl), a biologically effective concentration of a bicarbonate (preferably NaHCO₃), a phosphate buffer to ensure the preferred pH range as well as several additional components, including but not limited to neomycin and phenol red. Again, the addition of bicarbonate in varying amounts may alter the formulation pH within a biologically acceptable range.

An integral aspect of a preferred portion of the vaccine formulations of the present invention is the dual presence of sucrose and sorbitol. The range of sorbitol is from about 15 to about 90 grams per liter while sucrose is present in the range from about 10 to about 70 grams per liter. A preferred range of sorbitol in the vaccine formulations of the present invention is from about 35 to about 75 grams per liter. An especially preferred range of sorbitol in the vaccine formulation of the present invention is from about 45 grams per liter to about 60 grams per liter. A preferred range of sucrose in the vaccine formulations of the present invention is from about 15 to about 55 grams per liter. An especially preferred range of sucrose in the vaccine formulation of the present invention is from about 20 grams per liter to about 45 grams per liter.

Claim 1 of 18 Claims

1. A vaccine comprising an attenuated virus and stabilizer, wherein said vaccine comprises

28.94 grams per liter of hydrolyzed gelatin, 48.94 grams per liter of sorbitol, 10.59 grams per liter of phosphate, 4.92 grams per liter NaCl, 43.74 grams per liter of sucrose, 0.34 grams per liter bicarbonate, 0.66 grams per liter glucose, 0.62 grams per liter HSA, and 2.53 grams per liter of citrate;

wherein the virus includes at least an attenuated mumps virus.

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