We have synthesized N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-cell penetrating peptide Tat conjugates and evaluated their subcellular distribution in A2780 human ovarian carcinoma cells by confocal fluorescence microscopy and subcellular fractionation. Our data indicate the transport of these conjugates by a single Tat molecule to both the cytoplasm and nucleus via a nonendocytotic and concentration independent process. The uptake was observed to occur within 3 min, as confirmed by live cell microscopy. In contrast, HPMA copolymers lacking the Tat peptide were internalized solely by endocytosis. For the first time, Tat-mediated cytoplasmic delivery of a polymer bound anticancer drug, doxorubicin, was also demonstrated. These findings establish the feasibility of overcoming major cellular and subcellular obstacles to intracellular macromolecular delivery and hold great promise for the development of polymer-based systems for the cytoplasmic delivery of therapeutic molecules.

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A novel continuous heterogeneous crystallization process is developed in which the active pharmaceutical ingredient (API) is crystallized directly on the surface of an excipient within the crystallizer. The product is subsequently dried and formed into tablets without the need for complex downstream processing steps, such as milling, sieving, granulation, and blending. The aim is to eliminate many steps of the particle processing in drug product manufacturing. The APIs and excipients systems were selected by investigating heteroepitaxial mechanisms. The effects of various process parameters, such as temperature, residence time, and mode of operation, on drug loading were studied. Three different process designsmixed suspension mixed product removal with a traditional impeller, Viscojet mixing, and a fluidized bed crystallizerwere utilized for direct crystallization of the API on the surface of the crystalline excipient. The excipient selection and process design parameters have a significant impact on drug loading, avoidance of bulk nucleation and crystallization, control of API crystal shape and size, and process control. The maximum drug loading of the excipient with API in this study was 47%. Also, it was demonstrated that increasing the supersaturation ratio and residence time increased the drug loading. The products were collected from the crystallizer and directly compressed into tablet form. The tablet hardness and dissolution profile were also studied. The fully continuous process eliminates the downstream steps, resulting in the production of crystalline compounds and the final form (tablets) in a significantly faster, more efficient, and more economical manner with a smaller footprint. mentioned steps. 6−10 The precise final dosage, content uniformity, composition, mechanical properties, and critical quality attribute of every single tablet, which are highly regulated, 2,11−13 highly depend on the performance of the involved stages, for instance, component segregation, which can be caused by differences in particle size, density, or shape, and segregation in blending, hoppers, transfer lines, or feeders, and results in heterogeneity in tablet compositions. 14−17 Significant academic research and industrial development have been invested to overcome drug product line challenges and enable consistent manufacturing of high-quality tablets. 18−22 These challenges, and subsequent effects, are more problematic in the continuous manufacturing arena, 23,24 where the continuous flow of material, continuous workload of the drug product line, residence time distribution, and validation of "batches" of the final product enter into the design of already complicated processes. 17,20,21,23,24 Recent endeavors in shifting from the traditional batch pharmaceutical processes to the modern and emerging