Stability of sterile saline solutions of synthetic tuftsin, a naturally occurring immunomodulating peptide.
Tuftsin, Thr-Lys-Pro-Arg, is a natural immunomodulating peptide originally found as a phagocytosis-stimulating factor for polymorphonuclear leukocytes. The peptide is now known to elicit various other activities including antimicrobial, antiviral and antitumor effects in vivo. Preliminary human studies revealed antitumor and anti-AIDS activities. In view of this clinical potential, we performed studies on the stability of sterile saline solutions of tuftsin stored at 25 degrees C, 5 degrees C, -20 degrees C or -70 degrees C utilizing a phagocytosis assay and analytical HPLC. Tuftsin stored at -20 degrees C or -70 degrees C gradually lost its phagocytosis-stimulating activity; tuftsin stored at 25 degrees C or 5 degrees C lost its phagocytosis activity rather rapidly. By 6 months, tuftsin stored at 25 degrees C lost all activity, and by 12 months, it significantly inhibited phagocytosis. In contrast, HPLC analysis indicated very minor changes. While tuftsin stored at 25 degrees C lost almost all activity by 6 months, we detected appearance of only 1% impurities by HPLC. This study indicates that if its activity is to be preserved, solutions of tuftsin must be frozen for storage.
Nishioka
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K
University of Texas M.D. Anderson Cancer Center, Houston 77030.
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Rodriguez
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D000276:Adjuvants, Immunologic / Q000737:chemistry / Q000494:pharmacology; D000595:Amino Acid Sequence; D004355:Drug Stability; D006801:Humans; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D010587:Phagocytosis; D012965:Sodium Chloride; D013242:Sterilization; D014405:Tuftsin / Q000737:chemistry* / Q000494:pharmacology
D000276:Adjuvants, Immunologic; D012965:Sodium Chloride; D014405:Tuftsin