Microneedles are gaining popularity as a new paradigm in the area of transdermal drug delivery for biomedical and healthcare applications. Efficient drug delivery with minimal invasion is the prime advantage of microneedles. The concept of the microneedle array provides an extensive surface area for efficient drug delivery. Various types of inorganics (silicon, ceramic, metal, etc.) and polymeric materials are used for the fabrication of microneedles. The polymeric microneedles have various advantages over other microneedles fabricated using inorganic material, such as biocompatibility, biodegradation, and non-toxicity. The wide variety of polymers used in microneedle fabrication can provide a broad scope for drug delivery and other biomedical applications. Multiple metallic and polymeric microneedles can be functionalized by polymer coatings for various biomedical applications. The fabrication of polymeric microneedles is shifting from conventional to advanced 3D and 4D printing technology. The multifaceted biomedical applications of polymeric microneedles include drug delivery, vaccine delivery, biosensing, and diagnostic applications. Here, we provide the overview of the current and advanced information on polymers used for fabrication, the selection criteria for polymers, biomedical applications, and the regulatory perspective of polymer-based and polymer-coated microneedles, along with a patent scenario.

Bu araştırma kapsamında, etodolak ko-kristallerinin sentezi ve farklı koformerlerin yapılarının aydınlatılması ile Hansen çözünürlük paratmetrelerinin tayini çalışılmıştır. Etodolak’ın çözünürlüğünün arttırılması ve dissolüsyon özelliğinin iyileştirilmesi amacıyla hazırlanan etodolak ko-kristallerinin farklı koformerleri izlenmiştir. Ko-Kristallerin yapısı; Fourier dönüşümlü infrared spektroskopisi (FTIR), diferansiyal taramalı kalorimetri (DSC) tayini, X-ışını kırınım (PXRD) tayini ile aydınlatılmış, ayrıca çözünürlük ve çözelti doygunluğu çalışmaları, in vitro dissolüsyon ve stabilite çalışmaları yapılmıştır. Çalışma sonucunda etodolak’ın, p-amino benzoik asit, ferrulik asit ve salisilik asit ile kokristalleri hazırlandığında çözünürlüğünün arttığı tespit edilmiştir. Etodolak:Salisilik ait 1:1M kokristalinin hızlı ilaç salımı için formüle edilen tablet içeriğinde kullanılması öngörülmüştür. Etodolak kokristallerinin yeterli farmasötik stabiliteye sahip oldukları ve etodolak’ın çözünürlük ve dissolüsyon özelliğini arttırdıkları sonucuna ulaşılmıştır.

In the current study, we attempted to improve the physicochemical properties of antiviral drug efavirenz through the cocrystal synthesis. The neat grinding performed to study the effect of coformer-fumaric acid (FA) on solubility and dissolution of efavirenz, which can serve as the green cocrystal synthesis approach. The prepared cocrystals were characterized for characteristics like powder flow properties, aqueous saturation solubility, in vitro powder dissolution study. The synthesized cocrystals were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, powder X-ray diffraction. The formation of a cocrystal of efavirenz and caffeine was confirmed by the characterization techniques which suggests the interactions between efavirenz and coformer-fumaric acid leads to cocrystal formation. The powder flow properties, solubility, and dissolution profile of efavirenz are significantly improved by its cocrystallization.

Rosuvastatin calcium is a promising lipid-lowering agent and the drug of choice in hyperlipidemia. Conventional solid oral delivery of rosuvastatin is limited by its poor solubility and ultimately poor bioavailability. An attempt was made to fabricate the cocrystals of RSC for enhancing solubility and bioavailability. Cocrystals were prepared by a microwave synthesiser-assisted solvent evaporation technique with multiple cocrystal formers. Rosuvastatin-Ascorbic acid (RSC-AA) cocrystals showed the highest solubility (~5-fold increased) amongst all twenty drug-coformer combination (DCC). RSC-AA cocrystals (1:1 ratio) were further characterized by various analytical techniques like FTIR, DSC and XRD to confirm the formation of cocrystals. RSC-AA cocrystals also showed improved flow properties and compressibility in comparison with pure drug, and it was demonstrated using the SeDeM diagram. RSC-AA cocrystals were further formulated into an immediate-release tablet by implementing experimental optimization. Comparative dissolution study of the cocrystal and pure drug tablet revealed improved dissolution after cocrystallization. RSC-AA cocrystal tablet showed the % drug release of 95.61 ± 3.94 while RSC pure drug showed the drug release of 67.83 ± 3.29. In vivo pharmacokinetic analysis showed significant improvement in systemic availability and cumulative absorption of the drug. The peak plasma concentration (Cmax) for RSC pure drug was 13.924 ± 0.477 μg/mL, while RSC-AA cocrystals showed a peak plasma concentration of 22.464 ± 0.484 μg/mL. Area Under Curve (AUC) of RSC-AA cocrystal was also significantly greater compared to the pure drug. In the stability study analysis, the shelf life was calculated from a graphical method and was found to be around 34.58 months for RSC-AA cocrystal tablets and 19.87 months for RSC pure drug tablets, which indicates improved stability with cocrystallization. Overall, the cocrystallization resulted in significant improvement in dissolution and solubility of RSC.

Physicochemical characteristics of active pharmaceutical compounds, including solubility and flow properties, are crucial in the development of drug formulation. The physical form of compound and formulation has potential effect on biopharmaceutical parameters of the drug. The crystal engineering approach can be employed for modification of physicochemical properties of the active pharmaceutical ingredients whilst maintaining the intrinsic activity of the drug molecule. This article covers the advantages of co-crystals over salts, solvates (hydrates), solid dispersions and polymorphs, mechanism of formation of co-crystals, methods of preparation of co-crystals and application of co-crystals to modify physicochemical characteristics of active pharmaceutical ingredients along with case studies.