Ophthalmic Suspensions

Ophthalmic suspensions are used to deliver poorly soluble compounds and are sterile liquid preparations containing solid particles dispersed in a liquid carrier. Such suspensions must contain the drug in micronized form to prevent irritation and/or scratching cornea. CD Formulation's team are leading experts in all aspects of pharmaceutical dosage form development and dosage form optimization, and we can design suspension dosage forms based on the properties of the API and the client's development goals. CD Formulation can be your one stop shop for your suspension dosage form needs.

Our Services

The services provided by CD Formulation are:

• Establish a predictive, discriminative and robust in vitro dissolution test method to analyze the correlation between in vitro dissolution rate and ocular bioavailability.
• Evaluation of suspension properties (particle size, polymorphism, viscosity, pH and buffering capacity), etc.

Our CD Formulation team is a leading expert in all aspects of pharmaceutical formulation development and dosage form optimization, and can design formulations for suspensions based on API properties and customer development objectives.

Formulation Considerations for Ophthalmic Suspensions

Most formulation considerations for ophthalmic dosage forms are similar to those described for general drug solutions, and the main considerations for suspensions are as follows:

• Physical Properties of Dispersed Therapeutics
  The physical properties of the therapeutic agent are an important design feature of ophthalmic suspensions, and indeed in all types of suspension dosage forms. Due to the relationship between particle size and eye irritation, the particle size used for ocular suspensions is the most important.
• Solution pH / Buffer Included
  Ideally, the pH of the ophthalmic solution should be controlled at 7.4, as this is the pH of the tear fluid.
• Good Chemical Stability
• Viscosity Modifier

Ideally, viscosity modifiers should have the following properties:
- Easy to Filter: All eye drops are filtered during the manufacturing process.
- Ease of Sterilization: Sterilization of eye drops is usually performed by filtration (see above) or by heating.
- Compatibility with Other Ingredients: Pharmaceutical scientists must ensure that there is no or only limited interaction between the therapeutic agent and the viscosity modifier.

Advantages of Ophthalmic Suspensions

1. Direct application of the therapeutic agent to the site of action ensures that the therapeutic agent is available at a higher concentration than may be achieved after oral administration.

2. Topical application of therapeutic agents ensures that the incidence of side effects is minimized.

If you have a requirement about our services, please contact us by phone or email, our colleagues will reply to you within three working days.

References

1. Vo, A. , et al. Analyzing Ophthalmic Suspension Particle Size Distributions Using Laser Diffraction: Placebo Background Subtraction Method. International Journal of Pharmaceutics, 2021, 598(3):120401.
2. Vo, A. , et al. In Vitro Physicochemical Characterization and Dissolution of Brinzolamide Ophthalmic Suspensions with Similar Composition. International Journal of Pharmaceutics, 2020, 588:119761.