Insulin formulations biphasic insulins

The new, short-acting insulins can be bound to protamine, allowing the preparation of mixed formulations. In an open, randomized, single-dose, three-way, crossover trial biphasic insulin aspart 30 (30% aspart plus 70% protaminated aspart, BIAsp 30), biphasic insulin lispro 25 (25% lispro plus 75% protaminated lispro, Mix 25), and biphasic human insulin 30 (30% regular plus 70% isophane insulin, BHI 30) were compared in 45 patients (15). Biphasic insulin aspart improved postprandial control better. There were 23 episodes of hypoglycemia with BIAsp 30, 19 with Mix 25, and 11 with BHI 30 two episodes with BIAsp 30, five with Mix 25, and two with BHI 30 required third-party intervention. 

Mixed insulin zinc suspension is, confusingly, the approved name for proprietary mixtures of crystalline and amorphous zinc suspension. Mixed insulins are not, therefore, the same as biphasic insulins. While the different proprietary formulations in this group do have differing time courses of action (see Fig. 35.1) depending on their (unstated) proportions of amorphous and crystalline suspension, it is not expected that doctors or patients would vary the formulation prescribed. 

The treatment of type 1 diabetes is the subcutaneous injection of insulin, as insulin cannot be administered orally because it would be broken down in the stomach due to the low pH. Initially, animal insulin was used in the treatment of diabetes, since bovine and porcine insulin are structurally similar to human insulin. Nowadays, most of the insulin used in the treatment of diabetes is human insulin produced via recombinant DNA (see Ch. 27). There are a number of insulin formulations available, e.g. short-, intermediate- or long-acting and biphasic (a mixture short- and intermediate-acting insulin), and these are described in more detail in Chapter 27. There is a range of therapy protocols indicated, based on the individual condition of the patient. 

Hormones, proteins, and small peptides are not suitable for oral administration without complex modifications in the formulation. A variety of approaches for insulin delivery, as a model drug, have been attempted to improve on its bioavailability. Advances have been realized in the delivery of insulin through oral, nasal, rectal, dermatologic, and ocular routes. Proteins can also be delivered transdermally, using a lipid-based, biphasic delivery system in therapeutic quantity. 

Proteins can also be delivered transdermally using a lipid-based biphasic delivery system in therapeutic quantity. Insulin treatment (10-50 mg/g formulation) was administered by a transdermal patch adhered to the abdomen of anesthetized Sprague-Dawley rats made diabetic by a single injection of strep-tozotocin (55 mg/kg). Blood was sampled from a tail vein every 2-4 h for 48 h. Response to transdermally applied insulin was both pH and concentration dependent. Blood glucose was decreased by 55% in the treated animals with mean response duration of 15 h. Serum insulin level was 162 pg/mL. 

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