Frequently asked questions

What is the difference between a 503A pharmacy and a 503B outsourcing facility?

A 503A pharmacy compounds for an identified patient against a valid prescription and is regulated primarily by its state board of pharmacy. A 503B outsourcing facility registers with the FDA, may compound in batches without patient-specific prescriptions, and operates under cGMP with direct FDA inspection. The practical differences for a practice are how the preparation is ordered, whether office stock is possible, and the quality framework behind it.

Why is a diluent specified rather than left to the practice to choose?

The diluent affects both stability and whether a vial can be entered more than once. Preserved diluents permit repeated entry; unpreserved ones do not. Some formulations are also not compatible with an electrolyte solution. Because those properties are formulation-specific, the dispensing pharmacy specifies the diluent and that instruction governs.

Does a leftover volume in the vial mean it can be used again?

No. Repeat use is determined by whether the diluent contains a preservative and by the beyond-use date the pharmacy assigned, not by how much solution remains. A partially used vial reconstituted with unpreserved fluid is still a single-use vial.

What is the difference between an expiration date and a beyond-use date?

An expiration date comes from a manufacturer's stability testing on an unopened product in its original container. A beyond-use date is assigned by the compounding pharmacy to a preparation it made or altered, and it reflects both chemical stability and the microbiological risk of the compounding process. Once a vial is reconstituted, the BUD supersedes the printed expiry.

Can a reconstituted vial be frozen to extend its life?

No. Freezing concentrates solutes, shifts pH, and creates ice interfaces that drive aggregation and denaturation, and freeze-thaw cycling compounds the damage. A solution that was frozen inadvertently should be quarantined and referred back to the dispensing pharmacy rather than thawed and used.

How should a temperature-controlled shipment be handled on arrival?

Open it promptly, since a validated shipper only holds temperature for a defined window. Check the coolant, read any temperature indicator or data logger before discarding packaging, inspect the vials for damage, reconcile against the packing list, move product into correct storage immediately, and log the receipt with date, time, condition, and who checked it.

What should be done with a shipment that arrives warm or damaged?

Quarantine it — clearly separated and labeled not for use — and contact the dispensing pharmacy before anything is shelved into working stock. A quarantined vial can be released later once the excursion is assessed; product already mixed into general stock cannot be untangled.

What information has to be written on a reconstituted vial?

At minimum the date and time of reconstitution, the diluent used and whether it was preserved, the volume added, the resulting concentration, the assigned beyond-use date, and the initials of the person who prepared it. The diluent volume is essential because it is the only way anyone else can reconstruct the concentration.

Why does shaking a vial matter if the powder dissolves faster?

Vigorous agitation creates an air-liquid interface across which many molecules, peptides in particular, denature or aggregate, and the resulting foam traps drug substance and makes accurate measurement difficult. Gentle swirling or rolling achieves the same dissolution without the mechanical stress.

What is coring and how is it avoided?

Coring is when a needle punches a fragment out of the rubber stopper and carries it into the vial as particulate. It is avoided by entering through the centre of the stopper with the bevel facing up, applying slight rotational pressure so the needle cuts rather than punches, using the smallest workable gauge, and varying the puncture site across repeated entries.

How many units is a given volume on an insulin syringe?

It depends on the barrel calibration. On a U-100 syringe 1 mL is 100 units, on U-50 it is 50 units, and on U-40 it is 40 units. The same unit count is therefore a different volume on different barrels, so a figure stated in units is ambiguous unless the calibration is stated with it.

Can milligrams be converted to international units?

Not generically. An IU is a measure of biological activity defined separately for each substance against a reference standard, so there is no universal conversion factor. Where a preparation is labeled in IU, the conversion must come from that product's own labeling or the dispensing pharmacy.

When should a preparation be taken out of service?

If the solution is cloudy, discoloured, or contains particulates; if material will not dissolve after reasonable gentle mixing; if the beyond-use date has passed; if there was a storage excursion such as freezing or an unknown period at room temperature; if the container or stopper is compromised; if labeling is missing or illegible; or if there is any doubt about sterility.

Does a smaller syringe barrel improve measurement accuracy?

Yes, when the intended volume fits within it. A smaller-capacity barrel spreads graduations further apart and often carries half-unit markings, so the same volume is easier to read precisely. Aim for a draw that lands in the middle of the barrel's range rather than at the very bottom, where dead space and plunger seal effects have the most proportional influence.

What is a certificate of analysis and when should one be requested?

A CoA records the analytical results for a specific lot — identity, purity, potency, and contaminant testing. Practices commonly request one when qualifying a new supplier, when documenting quality for their own records, or when investigating a suspected product issue. Requests go through the dispensing pharmacy.

Who assigns the storage requirements a practice has to follow?

The dispensing pharmacy, through the product labeling. General guidance of the kind published here explains the reasoning behind common requirements, but where the label and any general guidance differ, the label governs.

How does ordering through VitaRelay work?

Practices order through their VitaRelay portal against a valid prescription; the order is routed to a licensed 503A or 503B pharmacy in the network, which reviews, dispenses, and ships directly. VitaRelay operates the technology and logistics layer and is not a pharmacy, prescriber, or distributor.

Is availability the same in every state?

No. Provider availability, permissible compounding categories, and product options vary by jurisdiction, and services are only offered where permitted by law. Current details are published on our service availability page.

Still have a question?

Technique and terminology are covered across the resources library, including the reconstitution guide and the syringe measurement guide. Anything specific to a preparation you have been dispensed should go to that pharmacy directly.