https://www.shelflife.hq.dla.mil/fda_slep.aspxEXTENDING THE SHELF LIFE OF CRITICAL CHEMICAL BIOLOGICAL, NUCLEAR AND RADIOLOGICAL (CBRN) MEDICAL MATERIEL USING THE FDA/DOD SHELF LIFE EXTENSION PROGRAM
Introduction
To assure preparedness for war or other contingencies, the Department of Defense (DoD) maintains significant pre-positioned stocks of critical medical materiel. All drugs possess finite, labeled expiration dating. Routine replacement of them can be quite costly for the DoD and the taxpayer. To reduce overall costs, and taxpayer burden for these stocks, the DoD participates in cooperative product evaluation program with the U.S. Food and Drug Administration (FDA).
The FDA/DoD Shelf Life Extension Program is a key component of the Medical Readiness Strategic Plan (MRSP) as developed by the Office of the Secretary of Defense for Health Affairs and the Military Medical Departments in response to Congressional concern over the conservation of military medical resources. The program’s focus is to defer drug replacement costs for date sensitive pre-positioned stocks by extending their useful life. The following organizations participate in the program: the FDA, the Defense Medical Standardization Board (DMSB), Army, Navy, Air Force, Marine Corps, Defense Supply Center-Philadelphia (DSCP) and the Department of Health and Human Services’ Strategic National Stockpile (SNS) and the Veterans Administration Emergency Preparedness Program. The DSCP manages the medical materiel for the DoD to include the depot system. The SNS manages our Nation’s medical materiel stocks for responding to Chemical, Biological, Nuclear/Radiological, or conventional weapon terrorist attacks on the American people and the Veterans Administration maintains its own pre-positioned stocks for a CBRN event.
The FDA evaluates candidate materiel for shelf life extension by testing samples submitted from the SLEP Participants. The DMSB coordinates the program and acts as the single interface between the SLEP Participant and the FDA. The SLEP Participant funds the program, manages their portions of the program, and receives the benefit of deferred materiel replacement costs. The Shelf Life Extension Program (SLEP) assures only safe and effective drugs are provided to personnel during war or other contingencies.
History
Prior to the introduction of the program, the Services were investing significant funds in replacement costs for pharmaceutical products of potency dated pre-positioned stocks, war reserves and depot stocked pharmaceuticals. Replacement costs for these drugs in 1986 totaled $2.5 million. One of the methods suggested to limit expenditures and defer drug replacement costs for this materiel was testing for potential extension of their useful life.
In July of 1985, representatives from the Air Force Surgeon General’s Office and the FDA met to determine the feasibility of testing drugs for extension. An agreement was reached at this meeting to establish a pilot project for testing. The Air Force identified a list of items representing stock costing $3,000 or more and within 12 to 18 months of its expiration. The FDA screened the list and established test protocols for 56 of the items. Samples of the items were sent to the FDA for testing. After 8 months of testing, the final results exceeded expectations. 80% of the items were tested, and 84% of all lots tested, were extended. Although the FDA was conservative in their estimates, some of the tested items were granted extensions of up to 3 years beyond their initial expiration date.
In January of 1986, an interagency agreement was signed forming the FDA/DoD Shelf Life Extension Program (SLEP). The DMSB was tasked as the Quad-Service, DoD focal point for the program. Testing of items submitted by the Services and DSCP was not started until fiscal year (FY) 87. By FY 91, the program had grown enough for the FDA to increase dedicated program resources (facilities and personnel) to support requirements for new as well as retest projects.
The program has changed significantly over time, as pharmaceutical industry practices and knowledge about product safety and stability have evolved. Today the SLEP is geared towards the testing of “military significant” products, those that are either military-unique, possessing no commercial (non-DoD) market, or those drugs for which the DoD procures such large quantities for pre-positioned stocks that vendors are unwilling to accept them for credit upon expiration.
FDA Testing
The FDA is the independent evaluator and proponent for quality control of medical materiel, performing all required testing of items entered into the FDA/DoD SLEP. The FDA uses the U.S. Pharmacopoeia or the original manufacturer’s test data on each item to establish a protocol for testing. Accelerated testing (also called stress testing) is the method used most often to predict the extension period. The accelerated testing protocols are designed to increase the rate of chemical or physical degradation of the drug substance by using exaggerated storage conditions. Each item is "stressed" (placed in chamber which maintains a temperature of 50 degrees centigrade and 75% humidity) for 60 days. The potency of the stressed samples is compared with the standard for each item, and using the comparison, the FDA estimates the extendable life of the product. The FDA testing process, from the time the DMSB presents the project’s candidate list until the results are received by the DMSB, requires approximately six months.
The FDA will not test all items presented to them as program candidates. The FDA’s Center for Biologics Research (CBER) has never permitted the testing of any biological products (vaccines, toxoids, serums, blood products, etc.) in the SLEP. In addition, nutritional products and products with a history of poor performance in the SLEP testing process (i.e., water purification tablets and Mefloquine) are not accepted for testing nor are items where the testing is time and/or cost prohibitive.
The testing conducted by the FDA is comprehensive and scientifically sound. The FDA bases their expiration date extensions on conservative estimates of the useful life of the product as substantiated by the test results. Statistical methods are employed to predict when each product would be expected to breach the acceptable potency specification, and a date less than that expected breach is chosen. The FDA grants the extensions for all SLEP Participates having the materiel as specified by lot number, expiration date, and manufacturer that has been stored under appropriate conditions. Testing of SLEP products is an ongoing process. Annual or biannual the materiel is retested to confirm extended dating (or even permit further extensions). This is a mandatory requirement for all materiel remaining in the SLEP. Products that fail testing at any time will be destroyed. Products that are not tested or do not receive additional extensions are destroyed upon reaching their final expiration date.
The Current SLEP Process
All pre-positioned stocks should be rotated when possible; however, quantities often exceed peacetime requirements. In June 2005, the FDA/DoD Shelf Life Extension Program moved from an Access database that could only be accessed on Ft Detrick to a Web Based Oracle database that may be accessed by all users of the SLEP system through the internet. The system requires all Users to enter their on-hand inventory of CBRN medical materiel, pandemic influenza, and anti-malaria medicals as soon as they receive those items. They are then required to update their inventory once a quarter. Service POCs now use this data for budgeting, reporting and management of CBRN and anti-malaria materiel
Once a quarter, the DMSB SLEP Program Manager pulls the on-hand inventories of all materiel that is going to expire in the next 180 days. This list is scrubbed against the total on-hand quantities and the original expiration date of the item. No item will be extended beyond 10 years from its original manufacturer’s expiration date. Some items have a shorter period that the FDA will consider them for extension, e.g. silver sulfadiazine cream which turns brown after 5 years of testing. The FDA requires that there be at least $10,000.00 of a lot still on hand to test, otherwise it is not cost effective to test. Great importance is placed on SLEP Users to ensure all stock is identified in the SLEP website to ensure testing decisions are based on the most accurate data. There are exceptions, if an item is in short supply and required for possible/actual event/operation.
Once a lot has been identified as a possible test candidate, it is marked in the system with a Lot Status: Add to Test. At this time, the FDA gets the list of all possible test candidates for the next 180 days and request samples. Samples are requested through the automated system to the Customer (Service) POCs. Service POCs turn notify one of their Activities’ that they are to provide x amount of materiel, by lot and NSN, to the FDA and it is to be shipped to one of two FDA sites. Sometime the FDA will only request a copy of the label on the product. This is usually when the manufacturer produced several lots from one batch. This is usually a one-time request in the testing history of the lot. The FDA usually requests enough materiel for the first test, plus two more test, since most item are usually tested three times before they fail or their on-hand quantity falls below the testing threshold. . The FDA requires sample receipt within 45 days of the request. If an item’s samples are not received in 45 days, the item is dropped from the project and testing on the samples that were received begins. Timely submission of samples is critical to successful completion of a project.
When the FDA has received all the samples for new test, or it has been 45 days since the request for samples was sent, The FDA assigns a project number, sends the list of products by lot numbers that will be tested and, a list of lot numbers that will not be tested to DMSB. DMSB enters this information in to the System and then sends an email message out to all user of the SLEP system as well as a message through the Defense Messaging System to identified Commands.
Upon completion of testing, the FDA forwards the results to the DMSB who inputs them the SLEP System, and then sends an email message out to all user of the SLEP system as well as a message through the Defense Messaging System to identified Commands. Any SLEP participating activity having those declared items in the database by lot number may extend that materiel to the new expiration date, but only if that materiel has been properly stored in accordance with the manufacturer’s specifications. Once a product has been tested, it will be re-tested biannually or annually until the product fails testing or stocks are depleted.
The direction of the program has changed since its inception. The switch from a large, DoD depot supply system to one supported predominantly by prime vendor suppliers and just-in-time deliveries for day-to-day requirements has refocused the program on pre-positioned CBRN, pandemic influenza, and anti-malaria materiel. The prime vendor system has reduced the need for centrally controlled warehousing of drugs and therefore reduced the pool of products that are eligible for testing. Additionally, all Medical Treatment Facilities in DoD have the ability to return goods for credit or replacement of expiring stocks of medication in individual facility inventories. Return goods assure replacement of expired products with little or no cost to the facility.
The DoD enjoys a high rate of success with the SLEP because only products known to have a high probability of being extended are included in test projects. Due to the DoD’s history and knowledge gained with the program, items with low probability of being extended are not included unless there is a compelling reason for the testing.
Labeling Requirements and Guidance
The FDA requires that product be labeled and relabeled in accordance with the Food, Drug and Cosmetic Act of 1938 (or subsequent amendments) or the Food and Drug Modernization Act of 1997. Products not relabeled in accordance with these laws or FDA regulations are considered misbranded if they are sold, distributed, or dispensed and are in violation of these Acts.
The FDA Center for Drugs (CDER) compliance office recommends for the DoD, that the extended product be relabeled with the lot number, new expiration date and FDA project number. The new sticker does not have to be the same font and color as the old label. However, the new sticker must not obscure the writing on the original label and the new sticker must be legible. In addition, the sticker must adhere to the old label in such a way that if it was peeled off, what was underneath it would also peel off. It is not necessary nor is it advised to remove the original label on a product and put a new label. The FDA does not want the original product label removed. Putting on a new label on the product will require approval by the FDA compliance office. The intent of this is to instill confidence in the ultimate user, that the products they are given or administered are of high quality and safety, and will work effectively as expected.
The FDA has authorized a deferral of the requirement to have every individual unit of issue relabeled, but only while the materiel is maintained under centralized SLEP Participants control. This was requested in order to reduce the cost for multiple relabeling efforts, as SLEP products may be extended multiple times prior to being issued to individual service members. The FDA will permit SLEP Participants to label only the outer cartons of products with the updated information so long as they remain in centralized storage, control, and management. This materiel must be relabeled completely, down to the individual units of issue, before being distributed/issued to activities or individuals. Due to the requirements for immediate readiness of all SNS drugs, they have opted to relabel all SLEP items immediately after the FDA grants extensions.
Sampling of Data from Items Tested under SLEP
The table provided below represents a number of products tested over several years in the FDA/DoD SLEP.
Table 1. Sample of SLEP Testing History
Product Length of Original Dating Average Total Years Extended Total Shelf Life Obtained
Atropine Sulfate 2mg/ml, 25ml multidose vial 2 years 13 years 15 years
Atropine 2mg/0.7ml Autoinjector 5 years 5 years 10 years
Atropine Sulfate Inhalation Aerosol 4 years 4 years 8 years
Pralidoxime Chloride 600mg/2ml Autoinjector 5 years 13 years 18 years
Pyridostigmine Bromide 30mg tablets 5 years 5 years 10 years
Diazepam 10mg/2ml Autoinjector 4 years 5 years 9 years
Doxycycline 100mg tablets 2 years 5 years 7 years
Ciprofloxacin 500mg tablets 3 years 10 years 13 years
Sodium Nitrite 300mg/10ml vial or ampoule 2 years 8 years 10 years
Sodium Thiosulfate 12.5gm/50ml vial 2 years 14 years 16 years
It is important to note that products tested under this program are maintained under tightly managed, controlled conditions at a limited number of locations. Extrapolation of these data to drugs stored by others would be inappropriate. Storage conditions may vary widely across the population and SLEP data are not generalizable unless storage conditions are identical and verifiable. Even within the SLEP, products known to have been stored under adverse conditions (i.e., high temperature or low temperatures) by SLEP Participates are excluded from the program, unless they are marked and tested separately from “normal” stocks.
The SLEP Program never considers individual prescriptions issued to patients for extension. Items issued to individuals are considered dispensed prescriptions and are never permitted back into the supply chain, regardless of SLEP testing results, since the storage conditions of these items by individuals cannot be assured. Dispensed products that are turned in after completion of an operation are destroyed. Similar practices are executed in routine peacetime care in both DoD facilities and civilian medical practice.
The number of drugs being tested has reduced to an average of 13 every year, but the size of the lots, and number of lots of each drug has drastically increased.
This program is a large cost saver to the taxpayer but is only for large stockpiles of medical materiel, or for medical materiel, that has limited commercial use (i.e., antidotes for chemical agents). The FDA will not normally test any materiel that has less then $10,000 of a lot on hand by the SLEP Participants. This program is not for the small quantities stocked by most local pharmacies, hospitals or clinics.
POCs: CDR Michelle Hupp or Mrs. Mindy Scruggs
301-619-4161/8886
Updated: 1 Oct 2009
