CURRENT STATUS AND FUTURETRENDS IN INSULIN DELIVERYSYSTEMS TO DIABETIC PATIENTS
TYPES OF DIABETESThere are three types of diabetes*type-1Results from body’s failure to produce insulin*type-2Results from insulin resistance*gestational diabetesDuring pregnancy
INSULIN It was isolated in 1921 It is a harmone secreted from ß cells Insulin is protein consisting of two polypeptide chains, one of 21 amino acid residues and the other of 30, joined by two disulfide bridges. Insulin is the mainstay drug for the management of type I and many of type II DM. Sources of insulin are 1)animal sources 2)human biosynthetic sources(RDNA technology).
ROUTE OF ADMINISTRATION Transdermal Intrapulmonary Intranasal Oral Buccal And other ways
TRANSDERMAL ROUTE FOR THE DELIVERY OF INSULIN :Insulin syringes :• disposable• thinner needles• more sanitary
TRANSDERMAL ROUTE FOR THE DELIVERY OF INSULIN :Insulin Pens :• Ease of handling• More discrete use
TRANSDERMAL ROUTE FOR THE DELIVERY OF INSULIN :Jet Injectors :• sends insulin through the skin , using high pressure mechanism• an option for people with severe needle phobia
INTRAPULMONARY ROUTE FOR THE DELIVERY OF INSULIN:Intrapulmonary route offers the most feasible route for the delivery of insulin and similar products.Advantages and disadvantages of pulmonary drug delivery:Advantages:1) Large surface area.2) Avoidance of first pass metabolism.3) Absence of degrading acidic stomach and the GI degrading enzymesDisadvantages:1) Asthmatic patients may not be able to obtain the required dose2) Some metabolism do occur in the lungs3) Mucocililary clearance4) The need to control particle size
INTRANASAL ROUTE FOR THE DELIVERY OF INSULIN:This route offers certain advantages for drugs such as insulin.Advantages:1) Large surface area.2) Ease of accessibility3) The pharmacokinetic profile following intranasal absorption of insulin closely mimics the pulsatile pattern of insulin secretion during meal times.Disadvantages:1) Negligible absorption without absorption promoters.2) rapid removal of the drug from the site of deposition in the nasal cavity by mucocililary clearance, enzymatic degradation in the mucous layer and nasal epithelium.3) low permeability of the nasal epithelium and low and erratic bioavailability.
ORAL ROUTE FOR THE DELIVERY OF INSULIN:This route may be considered as the elusive goal since the discovery of insulin.From the patient compliance point of view, the oral route is the most convenient and desirable route for insulin delivery.Problems with oral delivery of insulin are mainly low bioavailability of <2% mainly because:1) The main barriers to its oral delivery include enzymatic degradation.2) Lack of sufficient permeability by intestinal epithelium.3) Insulin can also be degraded easily when subjected to the rigors of product development.
BUCCAL ROUTE FOR THE DELIVERY OF INSULIN:Advantage of buccal delivery:1) The liver is by-passed2) Drug stability3) Drug stability4) It is pain-free
DEVICES USED FOR ADMINISTRATION Insulin syringes Insulin infusion pumps Insulin pens Insulin patches Insulin jet indicators
BIOAVAILABILITY Poor absorption of intermediate-acting insulin preparations, or combinations of intermediate- and rapid-acting insulin preparations, explains the difficulty in lowering blood glucose in patients with type 2 diabetes mellitus who have had long-standing disease, are insulin resistant, and have a flat insulin response to a glucose load.
CURRENT RESEARCH1) Rectal method for delivering insulin2) Ocular route for delivering insulin3) The use of powder jet’s delivery system4) Implantable insulin pumps
FUTURE Pump technology continues to advance On the horizon: Pumping and monitoring by cell phone Cooler styles Smaller sizes Improved human interface More helpful data analysis Gradual progress toward a closed loop
CONCLUSION :1) “Prevention is better than cure”. Many of the studies indicate that type II DM is the result of changes in the life style brought about by urbanization.2) Insulin pens seems to be popular for many DM patients.3) Products delivering insulin by intrapulmonary route seem to be the first on the horizon. Nevertheless, the currently tested products do not include medium or long acting insulin.4) Insulin tablets taken orally would be the real break through in the delivery of insulin.5) For type I DM, the future focus should be the intervention to restore the secretive function of the β cells of the islets of Langerhans.