by Melissa Merrell Rhoads, PharmD, PCCA Director of Formulations

An anhydrous suspension vehicle for use in oral suspension formulations, SuspendIt Anhydrous is ideal for active pharmaceutical ingredients (APIs) that are unstable in water or have incompatibilities in some aqueous vehicles. It offers improved taste, broader application and prolonged default beyond-use dates (BUDs). 
When preparing formulations: 

• Shake the vehicle bottle well before using in your compound. 
• Use of wetting agents often depends on the API. Some agents that could be used with SuspendIt Anhydrous are Glycerin USP or Medium Chain Triglycerides NF; however, the majority of the PCCA formulas use the base itself as the wetting agent. 
• All PCCA formulas recommend mixing in an electronic mortar and pestle (EMP) for two (2) minutes on a medium setting, then transferring to an appropriately sized dispensing container. Due to the viscosity of the base, using the EMP mixing method showed consistent, optimal content uniformity across all PCCA formulas.

1. However, we recently conducted testing that showed good results when mixing with a mortar and pestle: Triturate the API with a portion of the base and mix well. Continue to add additional base with thorough mixing and triturating in the mortar until you have reached approximately 60% of the final volume. Transfer the preparation into the dispensing bottle (choosing a bottle size that allows for some head space) and shake vigorously until obtaining a uniform preparation.

• Because of the viscosity of SuspendIt Anhydrous, approximately 10% (100 mg/mL) is the max powder load. To date, formulations with a powder load over 10% have not been tested. Should you have a need to make such a formulation, we recommend you engage in appropriate testing of the formulation. 
• Oil flavors may be used at a concentration of 0.1-1%. 
• Many PCCA formulas did not require any additional sweeteners. For extremely bitter APIs, Acesulfame Potassium and Steviol Glycosides 95% may be added at a concentration level of up to 0.4% each. 
• Allow some head space in the dispensing bottle to provide adequate room for the patient to be able to thoroughly shake the preparation prior to administration. 
• Recommended dispensing devices: 

1. Bottle, Prescription Oval Amber Plastic (PCCA #35-2303 [2 oz]), PCCA #35-1975 [4 oz]).

2. SealSafe™ 24 mm Self-Sealing Dosing Adapter (PCCA #35-4262). We advise dispensing with the self-sealing adapter due to the viscosity of formulas. Using these adapters prevents buildup of suspension in the neck of the dispensing container and reduces the potential loss of dosages. 

3. Use oral syringes for measuring dose. 

• Shipping or exposing the formulation to high temperatures may affect the stability of the API and/or the base itself at temperatures above 35°C (90°F) for extended periods of time. We suggest shipping on ice during the summer months.

For additional information on SuspendIt Anhydrous, please view our Product Catalog. PCCA offers a growing list of SuspendIt Anhydrous formulas to our members. Members with Clinical Services may also contact our Clinical Services team for help with formulas and other compounding concerns.
     
A version of this article originally appeared entirely in PCCA’s members-only magazine, the Apothagram.