Cocrystal of phloretin with isoniazid: preparation, characterization, and evaluation

Pharmaceutical cocrystals: a rising star in drug delivery applications

Pharmaceutical cocrystals, owing to their manifold applications, are acting as bridge between drug discovery and pharmaceutical product development. The ability to scale up pharmaceutical cocrystals through continuous manufacturing approaches offers superior and economic pharmaceutical products. Moreover, cocrystals can be an aid for the nanoparticulate systems to solve the issues related to scale-up and cost. Cocrystals grabbed attention of academic researchers and pharmaceutical scientist due to their potential to target various diseases like cancer. The present review is mainly focussed on the diverse and comprehensive applications of pharmaceutical cocrystals in drug delivery including solubility and dissolution enhancement, improvement of bioavailability of drug, mechanical and flow properties of active pharmaceutical ingredients, controlled/sustained release and colour tuning of API. Besides, phytochemical based cocrystals, multi-drug cocrystals and cocrystals for tumour therapy have been discussed in this review. Additionally, recent progress pertinent to pharmaceutical cocrystals is also included, which may provide future directions to manufacturing and scale-up of cocrystals.

Multi-component forms of the 2nd generation H1 receptor antagonist drug, Bilastine and its enhanced physicochemical characteristics

Bilastine (BIL) is a novel 2nd generation antihistamine medication is used to treat symptoms of chronic urticaria and allergic rhinitis. However, its poor solubility limits its therapeutic efficacy. In order to enhance the physicochemical characteristics of BIL, various molecular adducts of BIL (Salt, hydrate and co-crystal) were discovered in this study using two distinct salt-formers: Terephthalic acid (TA), 2,4-Dihydroxybenzoic acid (2,4-DHBA), and three nutraceuticals (Vanillic Acid (VA), Hydroquinone (HQN) and Hippuric acid (HA)). Various analytical methods were used to examine the synthesised adducts, including Powder X-Ray Diffraction (PXRD), Single Crystal X-ray Diffraction (SCXRD), and thermal analysis (Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC)). Single-crystal X-ray diffraction (SCXRD) studies avowed that the architectures of the molecular adducts are maintained in the solid state by an array of strong (N+H⋯O-, NH⋯O, OH⋯O) and weak (CH⋯O) hydrogen bonds. Additionally, a solubility test was performed to establish the in vitro release characteristics of newly synthesised BIL adducts and it observed that most of the molecular adducts exhibit higher rates of dissolution in comparison to pure BIL; in particular, BIL.TA.HYD showed the highest solubility and the fastest rate of dissolution. Moreover, experiments on flux permeability and diffusion demonstrated that the BIL.TA.HYD and BIL.VA salts had strong permeability and a high diffusion rate. In addition, the synthesized adduct's stability was assessed at 25 °C and 90 % ± 5 % relative humidity, and it was found that all the molecular salts were stable and did not undergo any phase changes or dissociation. The foregoing result leads us to believe that the newly synthesized molecular adducts' increased permeability and solubility will be advantageous for the creation of novel BIL formulations.

Pharmaceutical Properties of the Phloretin-4,4'-Bipyridine Cocrystal: Structure Analysis, Drug Release Profile, and Antioxidant Activity Research

To improve the water solubility of phloretin, we synthesized the Phl-4B cocrystal using the solvent evaporation method. Various analytical techniques including powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), 1HNMR, and single-crystal X-ray diffraction (SCXRD) were employed to evaluate the crystal thermodynamics and structure. The results of PXRD and SCXRD showed that it was a new cocrystal crystallized in the P-1 space group of the triclinic system. Thermal analysis confirmed the purity of the Phl-4B cocrystal. The equilibrium solubility of the Phl-4B cocrystal in pH 1.2 was improved. In vitro simulated digestion experiments indicated that the release of the Phl-4B cocrystal followed Fick diffusion. The stability activity of phloretin after pharmaceutical cocrystallization was improved. The antioxidant of the Phl-4B cocrystal was better than that of pure Phl.

Study of the preparation, characterization, and solubility of lidocaine complexed with 5-sulfosalicylic acid dihydrate

OBJECTIVE

This study was to prepare solid dispersions of lidocaine (Lid) with 5-sulfosalicylic acid dihydrate (SSA) by freeze-drying (freeze-dried [FD] Lid/SSA = 1/1) and to evaluate their physical properties.

METHODS

Here, we evaluated the physicochemical properties and solubility of solid dispersions of Lid and SSA prepared by freeze-drying (freeze-dried [FD] Lid/SSA = 1/1).

RESULTS

Differential scanning calorimetry measurements showed that after freeze-drying, the endothermic peak due to Lid melting, the dehydration peak, and the endothermic peak due to SSA melting disappeared. Powder X-ray diffraction results showed that the characteristic Lid and SSA peaks disappeared after freeze-drying, indicating a halo pattern. The near-infrared spectroscopy results suggested that Lid-derived -NH and -CH groups and the Lid-derived -OH and -CH groups from the SSA peak shifted and broadened after freeze-drying, suggesting their involvement in complex formation through Lid/SSA intermolecular interactions. Nuclear Overhauser effect spectroscopy-nuclear magnetic resonance (NMR) measurements showed a cross-peak due to the interaction between the Lid-derived -CH group and the SSA-derived -OH group, suggesting hydrogen bonding. Diffusion-ordered spectroscopy NMR measurements showed that the diffusion coefficients of Lid and SSA aggregated in FD Lid/SSA, suggesting a change in Lid dispersibility in the solvent owing to the formation of a complex with SSA. The solubility of FD Lid/SSA was approximately 88 mg/mL (∼20-fold higher than that of Lid).

CONCLUSIONS

These findings suggest that complex formation occurred in FD Lid/SSA; this enhanced the solubility of this dispersion.

Formulation, characterization, pharmacokinetics and antioxidant activity of phloretin oral granules

Phloretin (PHL), a flavonoid of the dihydrogen chalcone class, is reported to have low oral bioavailability due to its poor solubility and absorption. A common approach to enhance the solubility of such flavonoids is solubilization in a polymeric or lipidic matrix which would help in enhance dissolution rate and solubility. Accordingly, in the current study PHL was dissolved in Gelucire® 44/14 by melt-fusion technique and the viscous semisolid melt was adsorbed on a solid carrier to obtain free flowing granules. SeDeM-SLA (Solid-Liquid Adsorption) expert system was employed to select the most suitable carrier. This study achieved positive outcomes through the successful development of formulated oral PHL granules. The granules exhibited good stability, and favourable pharmacokinetic properties. In addition, the selected carrier effectively retained the antioxidant properties of PHL.