Distribution is the process by which procured anti-TB drugs are received at the port of entry, cleared through customs, and transported from the central warehouse(s) to depots and health facilities where they are stored and dispensed to patients. In this process, attention is given to drug orders from the time they arrive in the country until they are distributed to TB treatment facilities. The process begins with rapid clearance through customs to avoid deterioration of the drugs while sitting in the port of entry or in inappropriate storage conditions.
Before the drugs can be distributed from the receiving warehouse, they must be inspected for quantity and quality. At least a visual inspection of random samples of each shipment should be done to check the labelling (language, dosage strengths, dosage form, and acceptable shelf-life or expiry date), quantities received, and condition of the drugs against the required specifications of the contract. Random samples should undergo laboratory testing, as should all suspect products e.g. those that appear damaged or are inappropriately labelled; this should include an identification test to determine the content of the active ingredient, and a dissolution test (see section 4.3).
Once the drug shipment has passed quality inspections and testing, the drugs can then be stored under normal storage conditions and distributed to local warehouses and TB treatment facilities. In order to provide TB drugs and supplies on time, there needs to be a steady flow of information from health facilities concerning their current stocks of drugs and orders for additional drugs based on the notified (or estimated) number of TB cases. Atransportation schedule needs to be established for timely delivery of orders, both for normal and emergency needs.
Accepted inventory control procedures must be used at all levels of the programme to avoid stock-outs and provide reliable data for estimating drug needs at the next procurement. See Box 7 for examples of good stock procedures. Supply managers may use a minimum (Smin) and maximum (Smax) stock level formula to know when to place an order and the quantity (Qo). This is based on the following parameters:
• CA: Average monthly consumption, adjusted for stock-outs;
• CT: Total consumption during review period, in basic units e.g. tablets;
• DOS: Number of days an item was out of stock during the review period;
• RM: Review period in months (number of months of data reviewed for forecasting);
• LT: Supplier lead time in months;
• PP: Procurement period (months) - time until the next order will be placed;
• SS: Buffer (reserve or safety stock);
• S1: Stock on hand in inventory; and
• So: Stock on order but not yet arrived.
Box 7: Good stock management
• Record the receipt and distribution of all shipments of FDCs and drugs to TB depots and health facilities
• Record the receipt and dispensing of all FDCs and drugs to inpatients and outpatients on a regular basis
• Store drugs in an appropriate way (no direct sunlight, dry environment, access security, easy to find)
• Rotate stocks, putting shortest expiry date in the front, to avoid loss due to expiry and possible dispensing of a deteriorated drug to a patient - the first-expired first-out (FEFO) and then the first-in first-out (FIFO) principles should apply
• Review the stock level for an item every time an issue is made. If the stock level is at, or has fallen below the set minimum, order enough stock to bring the level up to the maximum (see Box 8 for how to calculate stock levels)
• Maintain adequate buffer or reserve stocks at all levels of TB care facilities
Box 8: Maximum and minimum stock level formula and quantity to order
• CA = CT ÷ [RM - (DOS ÷ 30.4)]
• Smin = (LT x CA) + SS
• Smax = Smin + (PP x CA)
• Quantity to order (Qo) = Smax - (So + S1)