Issue link: https://www.e-digitaleditions.com/i/1373953
Pharmaceutical Technology BIOLOGICS AND STERILE DRUG MANUFACTURING EBOOK 2021 21 profiles, future vaccine development may consider aseptic spray drying to enhance thermo stabilization. Aseptic spray-drying basics Aseptic spray drying, which enables the drying of a liquid formulation into a dry powder (Figure 1), can produce drug substance with room-temperature sta- bility or prolonged stability at 2–8 °C storage. Spray drying has been established in the pharmaceutical industry for many years, particularly for API and antibiotics manufacture. While pharma spray dry- ing is carried out in a low-bioburden manufacturing environment, aseptic spray drying is done under cur- rent good manufacturing practice sterile conditions, making the process an option for injectable-grade parenteral products. Some pharmaceutical companies have been reluc- tant to adopt novel technologies like aseptic spray dry- ing as opposed to lyophilization, the more established method of drying drug substances (Table II). The suc- cessful application of aseptic spray drying to several products including vaccines in recent years has gained the attention of pharmaceutical companies. The first aseptically spray-dried pharmaceutical product, Rap- lixa, was approved by FDA and European Medicines Agency in 2015. There are currently no commercially available vaccines that are spray dried; however, phar- maceutical companies and contract development and manufacturing organizations are evaluating the suit- ability of vaccines to this technology. Thermostable spray-dried powder can be incorpo- rated into ready-to-inject technologies to create user- friendly, error-free delivery methods. The Vitrified Ready to Inject Suspension (VitRIS) technology from Nova Laboratories uses the particle-engineering ca- pability of spray drying to generate spherical powder particles with a narrow particle density to allow the vaccine product to be suspended in a non-aqueous solution by matching the density of the powder to the solution. VitRIS technology eliminates the need to reconstitute the vaccine at the time of administra- tion (3). Other technologies using aseptic spray drying to stabilize and deliver vaccines are ImplaVax solid dose formulation technology from Enesi Pharma and XeriJect formulation technology from Xeris Pharma. Applications for vaccine manufacture A common misconception about spray drying is that temperatures can affect the product during process- ing. In processing, the product is not exposed to high Table II. Comparison of spray drying and lyophilization processes. Characteristics Spray drying Lyophilization Compatibility with biologics Yes Yes Mode of processing • Continuous • Able to manufacture large quantities • Batch • Limited by the freeze-dryer size Product suitability • Sensitive biopharmaceuticals • Sensitive biopharmaceuticals Particle engineering • Control over particle and morphology • Enhance bioavailability • Improved mixing and dissolution • Porous lyo cake • Issues with dissolution Product filling • Versatile • Not limited by the type of container • Highly flowable powder • Compatability issues • Limited by the type of containers • Less favorable powder Process scalability • Capable • Difficult Capital, running, and support costs • Low • High