by Matt Martin, PharmD, BCSCP, PCCA Director of Clinical Services

Although SuspendIt® and SuspendIt® Anhydrous share similar names and some characteristics, the two oral suspending vehicles are very different. Each product offers distinct benefits to compounders and patients. Most notably, SuspendIt is an aqueous (containing water) base and SuspendIt Anhydrous is a nonaqueous (anhydrous) base.

Water Activity

In the revisions to USP 795, effective November 1, 2023, a distinction is made between aqueous and nonaqueous preparations based on their water activity (a_w).

Water activity is not a measure of water content, but rather the water in a substance that is unbound and freely available to participate in reactions such as hydrolysis that may cause drug degradation or in the proliferation of microbes, causing microbial growth or contamination. A water activity equal to or greater than 0.6 defines a preparation as aqueous, while a water activity below 0.6 defines a nonaqueous preparation. Compounders are not expected to test for water activity, but rather to consider the dosage form they are making against a lengthy table in the revisions to 795.

Aqueous preparations are offered shorter BUDs compared to nonaqueous preparations unless the appropriate data exists to support longer BUDs. PCCA has created a number of formulations with this stability data and designates these as FormulaPlus^TM formulations.

SuspendIt

SuspendIt (PCCA #30-4825) is our “all in one” aqueous (a_w > 0.6) oral suspension vehicle. SuspendIt contains a unique synergistic polymer complex, which allows rapid redispersion of APIs with agitation and minimizes sedimentation. It is made with an all-natural sweetener derived from monk fruit, making SuspendIt an ideal choice for patients requiring formulations without sugar, casein, gluten or any condition that requires an oral suspension formula. SuspendIt is compatible with all feeding tubes.

SuspendIt is a preserved aqueous oral suspension vehicle that uses sodium benzoate as the preservative. The revisions to USP 795 offers BUDs of up to 35 days for an aqueous preserved preparation. Please note that in felines, sodium benzoate can be a potential toxin when chronically administered and use should be limited to two weeks.

PCCA has created many formulations for SuspendIt including FormulaPlus^TM formulations supported by a stability indicating assay and USP 51 antimicrobial effectiveness testing.

SuspendIt Anhydrous

SuspendIt Anhydrous (PCCA #30-5176) is our patent-pending anhydrous oral suspension vehicle. As an anhydrous vehicle, its water activity is less than 0.6, which meets the definition of nonaqueous in the revisions to USP 795. The revised 795 provides up to a 90-day BUD for nonaqueous oral preparations.

We combined surfactants within our anhydrous vehicle to make SuspendIt Anhydrous water miscible. The self-emulsifying properties of SuspendIt Anhydrous may also improve the solubility, dispersibility and possibly enhance bioavailability of APIs with poor water-solubility.

SuspendIt Anhydrous is compatible with hydrophilic or lipophilic drugs. Naturally sweetened with monk fruit, it offers improved palatability and mixes easily with water, juice or breast milk. Its ability to mix with fluids may make patient compliance to medication adherence easier.

SuspendIt Anhydrous is also compatible with polyurethane nasogastric (feeding) tubes. It is preservative free and free of many allergens.

For veterinary compounding, please note that in animals with pancreatitis, the use of any anhydrous vehicle that contains a high concentration of oils is not recommended. Caution must also be exercised in certain species, such as birds or herbivorous animals.

Access to SuspendIt (aqueous) and SuspendIt Anhydrous provides opportunities for compounders to serve the needs of their patients as is appropriate between aqueous and nonaqueous preparations and BUDs that work for prescribers, patients and compounding pharmacists.

We are happy discuss these innovative bases with you and the value of PCCA Membership. Members with clinical services can call our Clinical Services team at 800.331.2498 to discuss use of these and other PCCA bases, or any additional compounding concerns.

At-a-Glance Reference