Miscibility of human and bovine ultralente insulin with soluble insulin

Effect of storage temperature of insulin on pharmacokinetics and pharmacodynamics of insulin mixtures injected subcutaneously in subjects with type 1 (insulin-dependent) diabetes mellitus

These studies were undertaken to assess the influence of storage temperature of insulin vials on pharmacokinetics and pharmacodynamics of a mixture of lente insulin (Monotard HM) and regular insulin (Actrapid HM) injected subcutaneously. Seven subjects with Type 1 (insulin-dependent) diabetes mellitus were studied twice after overnight normalization of plasma glucose. A mixture of lente insulin (0.22 U/kg) and regular insulin (0.11 U/kg) was prepared from insulin vials kept either refrigerated (approximately 4 degrees C) or at room temperature (approximately 18 degrees C) and injected subcutaneously (abdomen). Euglycaemia was maintained for the following 16 h by glucose infusion at variable rate. With refrigerated insulin, the plasma free insulin peak was greater (53 +/- 5 versus 45 +/- 6 mU/l) and occurred earlier (2.5 +/- 0.2 versus 6 +/- 0.3 h), and the glucose infusion rate showed a greater (16.5 +/- 1.2 versus 14.5 +/- 0.9 mumol.kg-1.min-1) and earlier peak (3.2 +/- 0.2 versus 6 +/- 0.4 h) as compared to that occurring with the non-refrigerated insulin (p less than 0.05). However, 6 h after insulin injection, both plasma free insulin and glucose infusion rate were 30% lower with the mixture of refrigerated as compared to that of non-refrigerated insulin (p less than 0.05). In contrast, when NPH-insulin (Protaphane HM) was mixed with regular insulin and injected in 4 out of the 7 diabetic patients, the storage temperature of insulin vials had no effect on the pharmacokinetics and pharmacodynamics of the mixture.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin pharmacology

Insulin initially became available for therapy in the 1920s. Over the years, a variety of insulin preparations have been formulated; preparations differ on the basis of purity, species of origin, and time course of action. Currently, highly purified preparations of human insulin are available with a variety of profiles of action.

Mixtures of human intermediate and human regular insulin in type 1 diabetic patients. Evaluation of free insulin levels and insulin action on glucose metabolism after combined and separate subcutaneous administration

Recent resorption studies in healthy subjects suggest that intermediate human zinc insulin preparations might diminish the absorption and activity of human short-acting insulin when the two insulins are administered as a single, combined preparation. This study was designed to investigate whether combined and separate administration of human zinc or human NPH insulin with soluble human insulin have different pharmacokinetic characteristics, as evaluated by glucose clamp studies and determination of free insulin levels. Eight type 1 diabetic patients received, in random order, four different, subcutaneously injected preparations of human insulin. Zinc insulin (Monotard HM, Novo-M) and protamine insulin (Protaphan HM, Novo-P) were each given with short-acting insulin (Actrapid HM, Novo-A). These insulins were administered either as a single combined preparation (MA;PA) or as two separate injections (M + A; P + A). Prior to the insulin injection euglycemia was achieved by an overnight intravenous insulin infusion. After the subcutaneous injection of insulin, glucose was monitored at 10-min intervals and euglycemia was maintained by a variable glucose infusion rate for 6 h. The total glucose infusion rate during this period was significantly lower following MA compared with M + A (total glucose infusion: 643 +/- 117 vs. 817 +/- 130 mg/kg, P = 0.009) whereas the glucose infusion rate did not differ between PA and P + A (878 +/- 122 vs. 914 +/- 118 mg/kg, NS(ABSTRACT TRUNCATED AT 250 WORDS)

Miscibility of semisynthetic human ultralente insulin with short-acting insulin in insulin-dependent diabetic patients

In 15 insulin dependent diabetics (IDDM), treated with human monocomponent insulin, the absorption of Actrapid HM mixed with Ultratard HM was evaluated. Thirty U of Ultratard HM and 10 U of Actrapid HM were injected separately or together immediately after mixing. Free insulin and plasma glucose (PG) were measured four hours after the administration. Free insulin levels were significantly higher after 15 (2p less than 0.01), 60 (2p less than 0.05) and 90 min (2p less than 0.005) when the two insulins were injected separately. PG values were significantly lower (2p less than 0.05) (7.63 +/- 4.06 mmol/l) at 120 min when the two insulins were injected separately compared to the mixture (9.45 +/- 4.22 mmol/l). In conclusion, mixing Ultratard HM and Actrapid HM 3:1, we observed a decrease of early Actrapid absorption and a slower lowering of PG values.

Stability of insulin mixtures in disposable plastic insulin syringes

The miscibility of short and long acting porcine, human and bovine insulins has been investigated using HPLC. Soluble insulin is rapidly lost from solution when mixed with both isophane and zinc insulin, although the mechanism may be different in these two cases. The time for up to 50% or more to be lost is often less than 2 min. The percentage lost is dependent upon the ratio of the mixture and the type and origin of the insulin. In the case of soluble: zinc mixtures it is greatest for porcine and least for bovine, in the case of soluble: isophane mixtures it was least for human and greatest for bovine. The greater the original amount of soluble insulin present the less the loss. The results help explain recent clinical reports that mixtures of soluble and zinc insulins fail to achieve satisfactory control of post-prandial blood sugar levels.

Stability and reproducibility of the biologic activity of premixed short-acting and intermediate-acting insulins

Mixtures of short-acting and intermediate-acting insulins often represent an effective regimen to achieve near-normal blood glucose values, yet controversy exists concerning the stability and predictability of such mixtures. In a study of diabetic patients, the biologic activity of a specific intermediate-acting insulin (insulatard) and a short-acting insulin (Velosulin) premixed in a 70:30 ratio was reproducible at three intervals and was stable for a period of up to three months. The serum levels of free insulin and the rate of onset and extent of the blood glucose lowering effects were not altered, showed two distinct peaks, and were comparable to those experienced with separate injections of equivalent doses of the intermediate-acting and short-acting insulins.