Related Experiment Video
Updated: Oct 24, 2025
08:28
Development of an In Vitro Ocular Platform to Test Contact Lenses
Published on: April 6, 2016
10.8K
In vitro dissolution testing models of ocular implants for posterior segment drug delivery
Muhammad Faris Adrianto1,2, Febri Annuryanti1,2, Clive G Wilson3
1School of Pharmacy, Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, UK.
Drug Delivery and Translational Research
|August 12, 2021
Summary
Developing effective ocular implants for long-term drug delivery is challenging. This review examines in vitro dissolution testing models for ocular implants, highlighting challenges in predicting in vivo drug performance.
Area of Science:
- Ophthalmology
- Pharmaceutics
- Biomaterials Science
Background:
- Drug delivery to the posterior eye segment is challenging, necessitating frequent intravitreal injections.
- Intraocular implants offer a promising alternative for sustained drug release, but their development faces hurdles.
- Selecting appropriate in vitro dissolution testing models is crucial for evaluating ocular implant efficacy.
Purpose of the Study:
- To review various in vitro test methods for assessing drug release from ocular implants.
- To discuss the challenges and critical factors in developing and testing ocular implants in vitro.
- To highlight the limitations of in vitro models in predicting in vivo retinal drug exposure.
Main Methods:
- Literature review of in vitro dissolution testing models for ocular implants.
- Analysis of factors influencing drug release from ocular implants.
- Discussion of the correlation between in vitro drug release profiles and in vivo performance.
Main Results:
- Multiple in vitro test models exist for ocular implant drug release analysis.
- In vitro models may not accurately predict in vivo retinal drug exposure due to physiological and metabolic differences.
- Development and testing require careful consideration of specific challenges.
Conclusions:
- In vitro dissolution testing is essential but has limitations in predicting in vivo ocular drug delivery.
- Further research is needed to develop more predictive in vitro models for ocular implants.
- Optimizing in vitro testing is key to advancing long-term ocular drug therapy.
Related Concept Videos
01:09In Vitro Drug Dissolution: Compendial Testing Models II
34
Various dissolution methods are utilized to assess a drug’s dissolution rate, including the flow-through cell, paddle-over-disk, cylinder, and reciprocating disk methods.The flow-through cell apparatus (USP (United States Pharmacopeia) method 4) comprises a reservoir for the dissolution medium and a pump that propels the medium through the cell containing the test sample. This method is crucial for assessing modified-release dosage forms with minimally soluble active ingredients,...
34
01:13In Vitro Drug Dissolution: Compendial Testing Models I
40
Compendial dissolution methods are standardized procedures defined by pharmacopeias to evaluate the rate at which a drug dissolves in a specific medium. These methods ensure batch-to-batch consistency, enable quality control, and support the prediction of drug bioavailability. They are critical for both immediate and modified-release drug products.The apparatuses used for dissolution testing differ in their design and mechanical function, but all aim to simulate the physiological environment of...
40
01:17In Vitro Drug Dissolution: Alternative Methods
37
Alternative drug dissolution methods include the rotating bottle, intrinsic dissolution test, peristalsis, and the Franz diffusion cell method. The rotating bottle method involves meticulously rotating tightly capped controlled-release beads in a temperature-controlled bath. Periodic decanting of samples allows for residue assay, followed by refilling with fresh medium and testing at various pH levels to emulate the gastrointestinal tract conditions.In contrast, the intrinsic dissolution test...
37
01:10In Vitro Drug Release Testing: Overview, Development and Validation
53
In vitro dissolution and drug release tests assess how quickly and how much of a drug is released from its dosage form into an aqueous medium under standardized laboratory conditions. These tests are essential tools in pharmaceutical development and quality assurance, offering insight into the drug's performance before clinical use.During formulation development, dissolution testing identifies incomplete or inconsistent drug release issues. It also supports decisions on selecting the optimal...
53
01:15Theories of Dissolution: Diffusion Layer Model
1.1K
Dissolution, the process by which drug particles dissolve in a solvent, is explained by the diffusion layer model, a theoretical framework that simulates the absorption of oral drugs and allows us to analyze experimental data.
This process starts with a thin layer, saturated with the drug, forming at the interface between the solid and liquid. The solute then diffuses from this layer into the main solution. The Noyes-Whitney equation suggests that the rate of dissolution relies on the diffusion...
This process starts with a thin layer, saturated with the drug, forming at the interface between the solid and liquid. The solute then diffuses from this layer into the main solution. The Noyes-Whitney equation suggests that the rate of dissolution relies on the diffusion...
1.1K
01:23Factors Affecting Dissolution: Particle Size and Effective Surface Area
1.1K
Dissolution kinetics, an essential aspect of oral drug delivery, is significantly influenced by the drug's particle size. According to the Noyes-Whitney dissolution model, the dissolution rate correlates directly with the drug's surface area. The larger the surface area, the higher the drug's solubility in water, leading to a faster drug dissolution rate. Reducing particle size increases the effective surface area, enhancing the dissolution process. Micronization and nanosizing are...
1.1K