Exploring the drug migration process through ethyl cellulose-based films from infrared-spectral insights

Development of Sinomenine Hydrochloride Sustained-release Pellet With Multiple Release Characteristics

Due to the gastrointestinal side effects, the clinical application of sinomenine hydrochloride (SH) in rheumatoid arthritis is limited. The elderly population constitutes the primary group affected by this disease, and within this demographic, there are significant variations in gastric emptying time. To reduce the influence of individual differences on drug efficacy and concurrently alleviate gastrointestinal side effects, the SH sustained-release pellets with multiple release characteristics were developed, which comprised both regular sustained-release pellets and enteric-coated sustained-release pellets. The drug-loaded layer formulation was optimized by full factorial design. With the optimal formulation, the drug-loaded pellets achieved a yield of 96.05%, an encapsulation efficiency of 83.36% for SH, a relative standard deviation of 3.26% in SH content distribution, an average roundness of 0.971 for the pellets, and the particle size span of 0.808. The pellets with a 4 h SH release profile in an acidic environment and pellets displaying 4 h acid resistance followed by an 8 h SH release behavior in the intestinal environment were individually prepared through in vitro dissolution tests. The results demonstrated stable and compliant dissolution behavior of the formulation, along with excellent stability and physical appearance. This research offers novel insights and references for the innovative formulation of SH.

Pharmaceutical Application of Tablet Film Coating

Tablet film coating is a common but critical process providing various functionalities to tablets, thereby meeting diverse clinical needs and increasing the value of oral solid dosage forms. Tablet film coating is a technology-driven process and the evolution of coated dosage forms relies on advancements in coating technology, equipment, analytical techniques, and coating materials. Although multiple coating techniques are developed for solvent-based or solvent-free coating processes, each method has advantages and disadvantages that may require continuous technical refinement. In the film coating process, intra- and inter-batch coating uniformity of tablets is critical to ensure the quality of the final product, especially for active film coating containing active pharmaceutical ingredients in the coating layer. In addition to experimental evaluation, computational modeling is also actively pursued to predict the influence of operation parameters on the quality of the final product and optimize process variables of tablet film coating. The concerted efforts of experiments and computational modeling can save time and cost in optimizing the tablet coating process. This review provides a brief overview of tablet film coating technology and modeling approaches with a focus on recent advancements in pharmaceutical applications.

Real time MRI to elucidate the functionality of coating films intended for modified release

Polymer films based on mixtures of ethyl cellulose (EC) and hydroxypropyl cellulose (HPC) have been widely used to coat pellets and tablets to modify the release profile of drugs. For three different EC/HPC films we used ¹H and ¹⁹F MRI in combination with a designed release cell to monitor the drug, polymer and water in 5 dimensional (5D) datasets; three spatial, one diffusion or relaxation and a temporal dimension, in real time. We observed that the water inflow through the films correlated with the initiation of the dissolution of the drug in the tablet beneath the film. Leaching of the pore forming HPC further accelerated water penetration and resulted in a drug release onset after a hydrostatic pressure was generated below the film indicated by positional changes of the film. For the more permeable film, both water ingress and drug egress showed a large variability of release over the film surface indicating the heterogeneity of the system. Furthermore, the ¹H diffusion dataset revealed the formation of a gel layer of HPC at the film surface. We conclude that the setup presented provides a significant level of details, which are not achieved with traditional methods.