ASD Formation Prior to Material Characterization as Key Parameter for Accurate Measurements and Subsequent Process Simulation for Hot-Melt Extrusion

Modeling Shear-Thinning Flow in Twin-Screw Extrusion Processes

Background/Objective: Hot-melt extrusion has been established as a formulation strategy for various pharmaceutical applications. However, tailoring the screw configuration is a major challenge where 1D modeling is utilized. This usually requires specific screw parameters, which are rarely noted in the literature, especially when dealing with shear-thinning formulations. Methods: Therefore, a custom-made test rig was used to assess the behavior of various conveying and kneading elements using Newtonian silicon oil and shear-thinning silicon rubber. The pressure and the power were measured as a function of volume flow. A model was proposed characterizing the screw element behavior by six individual parameters A1, A2, A3, B1, B2, B3. Results: The experimental results regarding the behavior with respect to Newtonian fluids were in good agreement with the literature and were modeled in accordance with the Pawlowski approach. In terms of shear-thinning fluids, the influence of screw speed on pressure and power was quantified. An evaluation framework was proposed to assess this effect using two additional parameters. Based on a high number of repetitive measurements, a confidence interval for the individual screw parameters was determined that is suitable to highlight the differences between element types. Conclusions: Finally, geometrical screw parameters for Newtonian and shear-thinning flow were assessed and modeled, with three conveying and three kneading elements characterized.

Exploring Orodispersible Films Containing the Proteolysis Targeting Chimera ARV-110 in Hot Melt Extrusion and Solvent Casting Using Polyvinyl Alcohol

BACKGROUND/OBJECTIVES

This project aims to provide valuable insights into the formulation of orodispersible films (ODFs) for the delivery of PROTAC ARV-110. The primary objective of this drug delivery formulation is to enhance the solubility of PROTAC ARV-110, which faces significant challenges due to the low solubility of this active pharmaceutical ingredient, as it belongs to a molecular class that is considered to exceed the "Rule of Five".

METHODS

We employed the concept of developing a rapidly disintegrating ODF to enhance the solubility of PROTAC ARV-110, utilizing polyvinyl alcohol as the polymer of choice. Given the high thermal stability of ARV-110, the PROTAC was subjected to two primary ODF manufacturing techniques: Hot melt extrusion (HME) and solvent casting. To establish the HME method, pre-screening through vacuum compression molding was performed. The films were characterized based on their disintegration in artificial saliva, drug release in a physiological environment, and mechanical strength.

RESULTS

All formulations demonstrated enhanced solubility of ARV-110, achieving exceptional results in terms of disintegration times and resistance to applied stress.

CONCLUSIONS

The findings from the experiments outlined herein establish a solid foundation for the successful production of orodispersible films for the delivery of PROTACs.

Evaluation of Printability of PVA-Based Tablets from Powder and Assessment of Critical Rheological Parameters

Fused deposition modeling (FDM) is a rather new technology in the production of personalized dosage forms. The melting and printing of polymer-active pharmaceutical ingredient (API)-mixtures can be used to produce oral dosage forms with different dosage as well as release behavior. This process is utilized to increase the bioavailability of pharmaceutically relevant active ingredients that are poorly soluble in physiological medium by transforming them into solid amorphous dispersions (ASD). The release from such ASDs is expected to be faster and higher compared to the raw materials and thus enhance bioavailability. Printing directly from powder while forming ASDs from loperamide in Polyvinylalcohol was realized. Different techniques such as a change in infill and the incorporation of sorbitol as a plastisizer to change release patterns as well as a non-destructive way for the determination of API distribution were shown. By measuring the melt viscosities of the mixtures printed, a rheological model for the printer used is proposed.

An isocratic RP-HPLC-UV method for simultaneous quantification of tizanidine and lidocaine: application to in vitro release studies of a subcutaneous implant

Implantable devices have been widely investigated to improve the treatment of multiple diseases. Even with low drug loadings, these devices can achieve effective delivery and increase patient compliance by minimizing potential side effects, consequently enhancing the quality of life of the patients. Moreover, multi-drug products are emerging in the pharmaceutical field, capable of treating more than one ailment concurrently. Therefore, a simple analytical method is essential for detecting and quantifying different analytes used in formulation development and evaluation. Here, we present, for the first time, an isocratic method for tizanidine hydrochloride (TZ) and lidocaine (LD) loaded into a subcutaneous implant, utilizing reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with a UV detector. These implants have the potential to treat muscular spasticity while providing pain relief for several days after implantation. Chromatographic separation of the two drugs was accomplished using a C18 column, with a mobile phase consisting of 0.1% TFA in water and MeOH in a 58 : 42 ratio, flowing at 0.7 ml min-1. The method exhibited specificity and robustness, providing accurate and precise results. It displayed linearity within the range of 0.79 to 100 μg ml-1, with an R2 value of 1 for the simultaneous analysis of TZ and LD. The developed method demonstrated selectivity, offering limits of detection and quantification of 0.16 and 0.49 μg ml-1 for TZ, and 0.30 and 0.93 μg ml-1 for LD, respectively. Furthermore, the solution containing both TZ and LD proved stable under various storage conditions. While this study applied the method to assess an implant device, it has broader applicability for analysing and quantifying the in vitro drug release of TZ and LD from diverse dosage forms in preclinical settings.

Amorphous solid dispersions: Stability mechanism, design strategy and key production technique of hot melt extrusion

Solid dispersion (SD) system has been used as an effective formulation strategy to increase in vitro and in vivo performances of poorly water-soluble drugs, such as solubility/dissolution, stability and bioavailability. This review provides a comprehensive SD classification and identifies the most popular amorphous solid dispersions (ASDs). Meanwhile, this review further puts forward the systematic design strategy of satisfactory ASDs in terms of drug properties, carrier selection, preparation methods and stabilization mechanisms. In addition, hot melt extrusion (HME) as the continuous manufacturing technique is described including the principle and structure of HME instrument, key process parameters and production application, in order to guide the scale-up of ASDs and develop more ASD products to the market in pharmaceutical industry.