Towards personalized drug delivery via semi-solid extrusion: Exploring poly(vinyl alcohol-co-vinyl acetate) copolymers for hydrochlorothiazide-loaded films

A simplified method to interpret the mechanism of drug release from thin polymeric films by drug diffusivity measurements

Drug-polymer interactions and their respective affinities provide vital information for developing any polymer-containing drug delivery system, such as oral films. This paper offers a simplified method to estimate the effects of interactions between the drug and polymers in corresponding film formulations using a recently developed Fickian diffusion-based methodology. Poly(vinyl alcohol-co-vinyl acetate) (PVA/PVAc) copolymers were used as film matrix formers. To systematically vary the hydrophilicity of the polymer and drug, PVA/PVAc copolymers (monomer ratios 35:65, 50:50, 74:26, 88:12, 98:2) and model drugs, hydrochlorothiazide and caffeine (with a factor 1:30 in solubility) were used. Drug diffusivities determined in a polymer solution (5 % w/v) were compared to classical in vitro drug release from the films. The drug release rate from films containing copolymers with a lower VA/VAc ratio (35:65, 50:50, and 74:26) was significantly different for the two drugs in the first 30 min. It was found that this diffusivity method provided valuable guidance in assessing drug-polymer affinity, described as the average theoretical partition constant Km/w between the polymer solution and pure aqueous media. This partition constant could be correlated to the drug release rate and serve as a simple, easy, and inexpensive screening method to provide deeper mechanistic insight into drug release mechanisms. This would allow enhanced sustainability and accelerate the formulation development process by reducing resources needed for the development of film formulations.

From conception to consumption: Applications of semi-solid extrusion 3D printing in oral drug delivery

Semi-Solid Extrusion 3D printing (SSE 3DP) has emerged as a promising technology for fabricating oral drug formulations, offering significant opportunities for personalized medicine and tailored therapeutic outcomes. SSE 3DP is particularly advantageous for producing soft and chewable drug products and is well-suited for formulations containing thermosensitive drugs due to its low-temperature printing process. Among various 3D printing techniques, SSE 3DP holds considerable potential for point-of-care applications, enabling the on-demand production of patient-specific dosage forms. Despite these advantages, SSE 3DP faces certain limitations that affect its overall development and widespread adoption. This review provides a comprehensive overview of SSE 3DP's fundamental principles, current applications, and future prospects in oral drug delivery. It also addresses the challenges and limitations associated with SSE 3DP and examines the current outlook of this technique in oral drug delivery applications. An example of such a challenge is the lack of a harmonized method for evaluating rheological properties. To address this issue, the review describes a methodology for obtaining information related to extrudability and shape fidelity from rheological properties. Overall, this review aims to highlight the transformative potential of SSE 3DP in the pharmaceutical landscape, paving the way for tailored, and patient-centric therapies.

Exploring Hydrogel Nanoparticle Systems for Enhanced Ocular Drug Delivery

Drug delivery to the ocular system is affected by anatomical factors like the corneal epithelium, blinking reflex, aqueous blood barrier, and retinal blood barrier, which lead to quick removal from the site and inefficient drug delivery. Developing a drug delivery mechanism that targets specific eye tissue is a major hurdle for researchers. Our study examines the challenges of drug absorption in these pathways. Hydrogels have been researched as a suitable delivery method to overcome some obstacles. These are developed alone or in conjunction with other technologies, such as nanoparticles. Many polymer hydrogel nanoparticle systems utilizing both natural and synthetic polymers have been created and investigated; each has pros and cons. The complex release mechanism of encapsulated agents from hydrogel nanoparticles depends on three key factors: hydrogel matrix swelling, drug-matrix chemical interactions, and drug diffusion. This mechanism exists regardless of the type of polymer. This study provides an overview of the classification of hydrogels, release mechanisms, and the role of controlled release systems in pharmaceutical applications. Additionally, it highlights the integration of nanotechnology in ocular disease therapy, focusing on different types of nanoparticles, including nanosuspensions, nanoemulsions, and pharmaceutical nanoparticles. Finally, the review discusses current commercial formulations for ocular drug delivery and recent advancements in non-invasive techniques. The objective is to present a comprehensive overview of the possibilities for enhancing ocular medication delivery through hydrogel nanoparticle systems.