Dissolution Chamber for Small Drug Delivery System in the Periodontal Pocket

Leveraging Numerical Simulation Technology to Advance Drug Preparation: A Comprehensive Review of Application Scenarios and Cases

BACKGROUND/OBJECTIVES

Numerical simulation plays an important role in pharmaceutical preparation recently. Mechanistic models, as a type of numerical model, are widely used in the study of pharmaceutical preparations. Mechanistic models are based on a priori knowledge, i.e., laws of physics, chemistry, and biology. However, due to interdisciplinary reasons, pharmacy researchers have greater difficulties in using computer models.

METHODS

In this paper, we highlight the application scenarios and examples of mechanistic modelling in pharmacy research and provide a reference for drug researchers to get started.

RESULTS

By establishing a suitable model and inputting preparation parameters, researchers can analyze the drug preparation process. Therefore, mechanistic models are effective tools to optimize the preparation parameters and predict potential quality problems of the product. With product quality parameters as the ultimate goal, the experiment design is optimized by mechanistic models. This process emphasizes the concept of quality by design.

CONCLUSIONS

The use of numerical simulation saves experimental cost and time, and speeds up the experimental process. In pharmacy experiments, part of the physical information and the change processes are difficult to obtain, such as the mechanical phenomena during tablet compression and the airflow details in the nasal cavity. Therefore, it is necessary to predict the information and guide the formulation with the help of mechanistic models.

Review on Starter Pellets: Inert and Functional Cores

A significant proportion of pharmaceuticals are now considered multiparticulate systems. Modified-release drug delivery formulations can be designed with engineering precision, and patient-centric dosing can be accomplished relatively easily using multi-unit systems. In many cases, Multiple-Unit Pellet Systems (MUPS) are formulated on the basis of a neutral excipient core which may carry the layered drug surrounded also by functional coating. In the present summary, commonly used starter pellets are presented. The manuscript describes the main properties of the various nuclei related to their micro- and macrostructure. In the case of layered pellets formed based on different inert pellet cores, the drug release mechanism can be expected in detail. Finally, the authors would like to prove the industrial significance of inert cores by presenting some of the commercially available formulations.

Modification of Small Dissolution Chamber System for Long-acting Periodontal Drug Product Evaluation

Conventional dissolution testing methods may not be suitable for long-acting periodontal drug products due to the small volume, slow fluid flow rate, and environment in the periodontal pocket. The objective of this study was to evaluate a 3D-printed small volume flow-through dissolution chamber system (modified from a previous study) for biorelevant and dose-discriminating testing. Three periodontal drug products with different dosage forms were tested: Atridox, Arestin, and PerioChip. Modifications were made to suit the specific characteristics of these dosage forms. No significant differences were observed between the % drug release profiles in vitro and in vivo except for Atridox. The differences observed with Atridox could be related to the exposing surface area of the drug product. Similar differences were observed from this effect in COMSOL model simulations. Overall, the drugs show reasonable in vitro-in vivo correlations (R² ≥ 0.91) with linear regression slopes close to unity. For dose discrimination between 75% and full dosing, significant differences were observed in the drug release data at specific time points of the products (p ≤ 0.05). The present results suggest that a small volume dissolution chamber with slow flow rate could potentially provide biologically relevant and dose-discriminating evaluations for periodontal drug products.

Biorelevant and screening dissolution methods for minocycline hydrochloride microspheres intended for periodontal administration

Currently, there is no compendial-level method to assess dissolution of particulate systems administered in the periodontal pocket. This work seeks to develop dissolution methods for extended release poly(lactic-co-glycolic acid) (PLGA) microspheres applied in the periodontal pocket. Arestin®, PLGA microspheres containing minocycline hydrochloride (MIN), is indicated for reduction of pocket depth in adult periodontitis. Utilizing Arestin® as a model product, two dissolution methods were developed: a dialysis set-up using USP apparatus 4 and a novel apparatus fabricated to simulate in vivo environment of the periodontal pocket. In the biorelevant method, the microspheres were dispersed in 250 μL of simulated gingival crevicular fluid (sGCF) which was enclosed in a custom-made dialysis enclosure. sGCF was continuously delivered to the device at a biorelevant flow rate and was collected daily for drug content analysis using UPLC. Both methods could discriminate release characteristics of a panel of MIN-loaded PLGA microspheres that differed in composition and process conditions. A mechanistic model was developed, which satisfactorily explained the release profiles observed using both dissolution methods. The developed methods may have the potential to be used as routine quality control tools to ensure batch-to-batch consistency and to support evaluation of bioequivalence for periodontal microspheres.