Among all available dosage form, tablet is most widely used because of its stability and patient acceptability. The better aesthetic quality like color, texture, mouth feel, and taste masking depended on film and sugar coatings, so the coating is an important part in the formulation of the tablet. The present work aims to comprehensively review the formulation, characterization, and challenges in the development of Tablet in Tablet dosage form. Film and sugar coatings have the number of disadvantages; most important one is the utilization of aqueous or organic solvent that leads to toxicity. To overcome this problem in the year 1896, Noyes firstly introduced the compression coating or Tablet in Tablet technique. In the development of Tablet in Tablet dosage form, substantial attention among researchers and various research reports and patents inputs can be found in the literature. Also, we focused on the recent advancements in techniques like one-step dry-coating (OSDrC®) for manufacturing Tablet in Tablet dosage form. The current review gathered information on the latest patent, formulation, advantages, and disadvantages of Tablet in Tablet or compression coating. The review also elaborates on the importance of Tablet in Tablet techniques in the development of a modified release system.

中文翻译：

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平板电脑技术回顾

在所有可用的剂型中，片剂因其稳定性和患者可接受性而被最广泛使用。更好的美学品质，如颜色、质地、口感和掩味取决于薄膜和糖衣，因此包衣是片剂配方的重要组成部分。目前的工作旨在全面回顾片剂剂型开发中的制剂、表征和挑战。薄膜和糖衣有许多缺点；最重要的一种是使用导致毒性的水性或有机溶剂。1896年，为了克服这个问题，Noyes首先在片剂技术中引入了压缩包衣或片剂。在片剂剂型的开发中，研究人员的大量关注以及各种研究报告和专利投入可以在文献中找到。此外，我们还重点关注了用于制造片剂剂型片剂的一步干法包衣 (OSDrC®) 等技术的最新进展。目前的审查收集了有关片剂或压缩包衣中片剂的最新专利、配方、优点和缺点的信息。该评论还详细阐述了片剂技术在缓释系统开发中的重要性。