title: Availability of soluble insulin in mixed preparations of crystalline and ultralente biosynthetic human insulin.
abstract: This study investigates potential interactions between human insulins of recombinant DNA origin, specifically ultralente and crystalline Humulin, mixed in different proportions and incubated for five minutes, one hour, or 24 hours. Using insulin mixtures tested within five minutes of preparation, a mixture of less than 50% ultralente insulin produced no reduction in soluble insulin contents, whereas preparations containing greater than 80% ultralente had significantly less soluble insulin content. When premixed insulins were incubated for 24 hours before analysis, the data obtained were similar to the results after five minutes of incubation, although mixtures containing a high proportion of ultralente insulin (greater than or equal to 80% ultralente) retained somewhat more of their regular insulin content after 24 hours of interaction than after five minutes. Studies were also performed after one hour of incubation of insulin mixtures. Soluble insulin was reduced more than at either of the other two time periods investigated. Mixtures that contained greater than or equal to 70% ultralente insulin showed a reduction of greater than or equal to 50% in regular insulin content after one hour of incubation. In intensified insulin therapy programs it is usually recommended that regular insulin be administered separately from animal-source ultralente insulin preparations. The data of the present study clearly demonstrate only minor modifications of soluble insulin activity in clinically common mixtures of human ultralente and regular insulin of recombinant DNA origin. These findings are particularly important for diabetes management protocols that emphasize near normal glycemic control.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, Baylor College of Medicine, Houston, Texas.
authors.forename: D M
authors.initials: DM
authors.lastname: Huffman
authors.forename: A J
authors.initials: AJ
authors.lastname: Garber
mesh_terms: D002626:Chemistry, Pharmaceutical; D004347:Drug Interactions; D004355:Drug Stability; D007328:Insulin / Q000737:chemistry*; D049528:Insulin, Long-Acting / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry; D012995:Solubility; D013997:Time Factors
chemical_list: D007328:Insulin; D049528:Insulin, Long-Acting; D011994:Recombinant Proteins