The Challenge - Manufacturing Ophthalmic Emulsions
Ophthalmic emulsions and suspensions are sterile formulations that require long shelf lives and high optical transparency. Particle and droplet sizes within the formulations are critical factors which can affect the absorption of active ingredients, the fluidity of the product as well as the users’ comfort level. Size distributions must be tight in addition to submicron to prevent ingredient sedimentation or droplet aggregation. High shear mixing followed by high-pressure homogenization is the traditional method for ophthalmic formulation manufacturing. The challenge is to find a more efficient and cost-effective alternative, with superior results.
To achieve submicron processing of active ingredients, the Quadro® HV-Emulsifier is set up in a recirculation loop - with product feeding through the HV, to a vessel and back. The continuous phase is stabilized first, and then the oil phase is added to the tank and recirculated. To reduce processing time, direct injection of the oil phase through the HV reactor housing ensures 100% has passed through the homogenizer at least once. This reduces the number of tank turnovers while minimizing any chance of a bimodal distribution.
Importance to Ophthalmic Market
Within 20 minutes of recirculation (10 tank turnovers), the droplet size reaches a steady state with 100% of the particles less than 1.2 microns, surpassing the results of traditional methods. The average droplet size was measured to be less than 0.2 microns. If larger droplets are desired, the VFD can be used to decrease the tip speed on the Quadro® HV and limit the size reduction performance while controlling the droplet distribution range.
The HV- Emulsifier is available in three scalable models ranging in capacity from 240 – 13,500 L/hr. All models utilize energy-optimized tooling that enables the equipment to operate at high speeds with the lowest power consumption in the industry.
HV Emulsifier Advantages
- Traditional rotor/stator mixer feeding a valve homogenizer can be replaced with one machine
- An HV is less than 50% of the initial investment cost of a high-pressure homogenizer
- Annual maintenance costs are as low as 10% compared to high-pressure homogenizers
- Precise process scaling is available from lab to production processing
- High capacities save significant process time while using less energy
- Unmatched sterile design and fully drainable
- Improved product quality and shelf-life.