Formulation of Diacerein Cocrystal Using β-Resorcylic Acid for Improvement of Physicomechanical and Biopharmaceutical Properties

Development and Evaluation of Fluconazole Co-Crystal for Improved Solubility and Mechanical Properties

Background: Fluconazole (FLZ) is a broad-spectrum anti-fungal drug presenting poor flowability, mechanical properties, and limited aqueous solubility. These issues pose challenges for the handling and manufacturing of dosage forms of FLZ. The current research aimed to develop fluconazole co-crystal (CC) for improving its aqueous solubility, flowability, and mechanical properties. (2) Methods: The fluconazole benzoic acid (FLZ-BA) co-crystal was prepared using the solvent evaporation technique. The prepared co-crystal was characterized for drug content, solubility, anti-fungal activity, dissolution, and stability. DSC (Differential Scanning Calorimetry), PXRD (Powder X-Ray Diffraction), SEM (Scanning Electron Microscopy), and FTIR (Fourier Transmission Infrared) spectroscopy were carried out to confirm the co-crystal formation. The co-crystal was further evaluated for their flow characteristics and mechanical properties via CTC (compressibility, tabletability, and compactibility), Heckel, and Kawakita analysis. (3) Results: The CC showed 69.51% drug content and 13-fold greater aqueous solubility than pure FLZ. The DSC thermogram showed a sharp endothermic peak between the parent components, a distinct PXRD pattern was observed, and the SEM analysis revealed a different morphology, confirming the formation of co-crystal (new crystalline form). The CC showed immediate drug release and was found to more stable, and less hygroscopic than FLZ alone. The CC revealed better flowability, tabletability (tensile strength), compressibility, and compactibility. Moreover, Heckel and Kawakita analysis indicated the co-crystal to deform plastically, favoring improved compression. (4) Conclusions: The immediate drug release capabilities, improved hygroscopic stability, solubility, better antifungal activity, and flowability make FLZ-BA co-crystal a suitable candidate for the preparation of an immediate drug release dosage form. The study also revealed the application of co-crystal for improving the flowability and mechanical properties.

A novel cocrystal approach celecoxib with piperine: Simultaneously enhance dissolution rate and compressibility

Celecoxib, a selective COX-2 inhibitor non-steroidal anti-inflammatory drug (NSAID), exhibits analgesic and anti-inflammatory properties similar to piperine, the secondary metabolite of Piper nigrum L. Unfortunately, celecoxib has a low compressibility and low dissolution rate in aqueous medium. This study aimed to prepare a cocrystal of celecoxib and piperine to enhance the dissolution rate and compressibility properties of celecoxib. The cocrystal was synthesized using the seeding method and thoroughly characterized using Powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), infrared spectrophotometry, and single-crystal X-ray diffraction techniques. The complete change in PXRD, decrease in melting point in DSC measurements, and shift in the NH stretching band in the FT-IR spectrum suggested the formation of cocrystals phase. Single-crystal XRD confirmed the formation of an equimolar ratio of cocrystals of celecoxib and piperine. The intrinsic dissolution test was conducted to confirm the impact on the cocrystal to dissolution, and it showed a slight increase compared to intact celecoxib. To assess the physico-mechanical properties, the cocrystal powders were compressed into tablets with varying forces. The results demonstrated a significant improvement in compressibility compared with intact celecoxib owing to the slip plane in the crystal lattice of the cocrystal. In conclusion, our novel celecoxib-piperine cocrystal exhibited distinct physicochemical characteristics compared to intact celecoxib, showing enhanced dissolution rate and compressibility.

The bioavailability enhancement and insight into the action mechanism of poorly soluble natural compounds from co-crystals preparation: Oridonin as an example

BACKGROUND

Natural bioactive molecules are important sources for the development of new drugs. However, most of them were limited in clinical applications due to their low aqueous solubility and bioavailability. Oridonin (ORI) is a powerful anticancer compound with above characteristics.

OBJECTIVE

This study aimed to find an effective method to improve the bioavailability of poorly soluble natural compounds, and explore the action mechanisms of them to promote their application.

RESULTS

In this study, ORI-nicotinamide (NCT) cocrystal was successfully prepared for the first time to overcome the defects of ORI. The solubility and oral bioavailability of cocrystal (COC) increased 1.34 and 1.18 times compared with ORI. Moreover, MTT assay was applied to compare the cytotoxicity of positive control drug sorafenib with ORI and COC. The IC50 values of sorafenib, ORI and COC on HepG2 cells were 7.61, 8.79 and 7.36 nmol·mL-1, which indicated that the cytotoxicity of ORI could be enhanced by cocrystal preparation. The cellular metabolomics was innovatively introduced to gain insight into the difference of cytotoxicity mechanism between ORI and COC. The results showed that there were 78 metabolites with significant differences in content between the two groups, while these differential metabolites were related to 11 metabolic pathways. Among these, glycerophospholipid metabolism and cysteine and methionine metabolism were the significant differential pathways, and the downregulation of PC(14:0/16:1(9z)) and upregulation of homocysteine were the likely main reasons for higher cytotoxicity of COC.

CONCLUSIONS

This study has presented novel approaches for enhancing the bioavailability and drug efficacy of natural compounds, while also offering fresh insights into the underlying action mechanisms of pharmaceutical cocrystals.

Assessment of formulation variables of poor water soluble diacerein for its improved loading and anti-inflammatory activity

Dissolving microneedles have become a popular method for percutaneous administrationof drugs. However, loading poorly soluble drugs into water-based dissolving microneedles remains a challenge. In view of this, we aimed to improve Diacerein (DCN) solubility formulating dissolving microneedles. DCN microsuspension was created by high-speed homogenization with organic solvents or wet milling with Tween 80 as a stabilizer (LD1). They were analyzed for particle size and saturation solubility. Subsequently, the organic solvent-based microneedles were prepared under vacuum, whereas LD1 was mixed with HPMC (8% w/w) and PVP (30% w/w) matrix to concentrate the drug in acral fraction through centrifugation. DCN microsuspension in DMSO had the highest drug solubility with an average particle size of 6 µm, whereas LD1 had a particle size of 3.28 µm showing improved solubility. TD-3 had the highest drug loading and the least amount of drug migration into the blank baseplate. Within 5 min, these microneedles dissolved completely in an agarose-gel block. LD1 was likewise put in the baseplate to generate TD3-B. Within 24 h, 74.39% of the medication was released from TD3-B, with only a small amount remaining in the baseplate. TLC examination indicated the conversion of DCN to Rhein in the skin, whereas DSC and TGA studies revealed amorphous features. DCN microneedles showed no sign of skin irritancy but showed anti-inflammatory response on carrageenan-induced paw edema model. Microneedles remained stable during accelerated stability testing. Wet milling in the presence of a stabilizer can be an effective approach for enhancing DCN solubility for improved drug loading in dissolving microneedles. Improvement in solubility of Diacerein for subsequent loading in Dissolving Microneedle for percutaneous delivery.

RP-HPLC METHOD DEVELOPMENT, VALIDATION, AND ITS PHARMACOKINETIC APPLICABILITY IN PRECLINICAL EVALUATION OF RHEIN TREATED WITH NOVEL DIACEREIN EUTECTICS

The current study represents the bio-analytical method for the estimation of Rhein (Rh, an active metabolite of Diacerein (DIA)) in rats treated with novel DIA eutectics to investigate the pharmacokinetics of DIA. A simple protein precipitation technique was used to extract Rh and internal standard (IS), p-aminobenzoic acid, and injected into a Phenomenex Gemini C18 column. The separation was achieved by gradient elution comprising of ammonium acetate (10 mM; pH 3.0) and acetonitrile in 18 min of run time at a flow rate of 0.8 mL/min with the retention time of 11.8 min (Rh) and 5.9 min (IS). The results revealed that the proposed method was linear over the range of 200-20,000 ng/mL (r² > 0.9988) of Rh and proved to be precise and accurate. The method was fully validated as per the USFDA guideline and the pharmacokinetic study in rats was performed for Rh following oral administration of the pure DIA and newly developed eutectics. Therefore, the present method could be used to estimate DIA to illustrate the comparative pharmacokinetic analysis. This can be also applied to its related multi-component formulations for future study.

Solid-State and Particle Size Control of Pharmaceutical Cocrystals using Atomization-Based Techniques

Poor bioavailability and aqueous solubility represent a major constraint during the development of new API molecules and can influence the impact of new medicines or halt their approval to the market. Cocrystals offer a novel and competitive advantage over other conventional methods with respect towards the substantial improvement in solubility profiles relative to the single-API crystals. Furthermore, the production of such cocrystals through atomization-based methods allow for greater control, with respect to particle size reduction, to further increase the solubility of the API. Such atomization-based methods include supercritical fluid methods, conventional spray drying and electrohydrodynamic atomization/electrospraying. The influence of process parameters such as solution flow rates, pressure and solution concentration, in controlling the solid-state and final particle size are discussed in this review with respect to atomization-based methods. For the last decade, literature has been attempting to catch-up with new regulatory rulings regarding the classification of cocrystals, due in part to data sparsity. In recent years, there has been an increase in cocrystal publications, specifically employing atomization-based methods. This review considers the benefits to employing atomization-based methods for the generation of pharmaceutical cocrystals, examines the most recent regulatory changes regarding cocrystals and provides an outlook towards the future of this field.