Preparation of hydrophobic drugs cyclodextrin complex by lyophilization monophase solution

Enhancing the Drug-Like Profile of a Potent Peptide PACE4 Inhibitor by the Formation of a Host-Guest Inclusion Complex with β-Cyclodextrin

The enzyme PACE4 has been validated as a promising therapeutic target to expand the range of prostate cancer (PCa) treatments. In recent years, we have developed a potent peptidomimetic inhibitor, namely, compound C23 (Ac-(DLeu)LLLRVK-4-amidinobenzylamide). Like many peptides, C23 suffers from an unfavorable drug-like profile which, despite our efforts, has not yet benefited from the usual SAR studies. Hence, we turned our attention toward a novel formulation strategy, i.e., the use of cyclodextrins (CDs). CDs can benefit compounds through the formation of "host-guest" complexes, shielding the guest from degradation and enhancing biological survival. In this study, a series of βCD-C23 complexes have been generated and their properties evaluated, including potency toward the enzyme in vitro, a cell-based proliferation assay, and stability in plasma. As a result, a new βCD-formulated lead compound has been identified, which, in addition to being more soluble and more potent, also showed an improved stability profile.

A supramolecular thermosensitive gel of ketoconazole for ocular applications: In silico, in vitro, and ex vivo studies

The incidence of corneal fungal infections continues to be a growing concern worldwide. Ocular delivery of anti-fungal drugs is challenging due to the anatomical and physiological barriers of the eye. The ocular bioavailability of ketoconazole (KTZ), a widely prescribed antifungal agent, is hampered by its limited aqueous solubility and permeation. In the study, the physicochemical properties of KTZ were improved by complexation with sulfobutylether-β-cyclodextrin (SBE-β-CD).KTZ-SBE-β-CD complex was studied in silico with docking and dynamics simulations, followed by wet-lab experiments.The optimized KTZ-SBE-β-CD complex was loaded into a thermosensitivein situ gel to increase corneal bioavailability. The supramolecular complex increased the solubility of KTZ by 5-folds and exhibited a 10-fold increment in drug release compared to the pure KTZ. Owing to the diffusion, thein situ gel exhibited a more sustained drug release profile. Theex vivocorneal permeation studies showed higher permeation from KTZ-SBE-β-CD in situ gel (flux of ∼19.11 µg/cm²/h) than KTZin situ gel (flux of ∼1.17 µg/cm²/h). The cytotoxicity assays and the hen's egg chorioallantoic membrane assay (HET-CAM) confirmed the formulations' safety and non-irritancy. In silico guided design of KTZ-SBE-β-CD inclusion complexes successfully modified the physicochemical properties of KTZ. In addition, the loading of the KTZ-SBE-β-CD complex into an in situ gel significantly increased the precorneal retention and permeation of KTZ, indicating that the developed formulation is a viable modality to treat fungal keratitis.

Cyclodextrin Diethyldithiocarbamate Copper II Inclusion Complexes: A Promising Chemotherapeutic Delivery System against Chemoresistant Triple Negative Breast Cancer Cell Lines

Diethyldithiocarbamate Copper II (DDC-Cu) has shown potent anticancer activity against a wide range of cancer cells, but further investigations are hindered by its practical insolubility in water. In this study, inclusion complexes of DDC-Cu with hydroxypropyl beta-cyclodextrin (HP) or sulfobutyl ether beta-cyclodextrin (SBE) were prepared and investigated as an approach to enhance the apparent solubility of DDC-Cu. Formulations were prepared by simple mixing of DDC-Cu with both cyclodextrin (CDs) at room temperature. Phase solubility assessments of the resulting solutions were performed. DDC-Cu CD solutions were freeze-dried for further characterisations by DSC, thermogravimetric analysis (TGA) and FT-IR. Stability and cytotoxicity studies were also performed to investigate the maintenance of DDC-Cu anticancer activity. The phase solubility profile deviated positively from the linearity (Ap type) showing significant solubility enhancement of the DDC-Cu in both CD solutions (approximately 4 mg/mL at 20% w/w CD solutions). The DSC and TGA analysis confirmed the solid solution status of DDC-Cu in CD. The resulting solutions of DDC-Cu were stable for 28 days and conveyed the anticancer activity of DDC-Cu on chemoresistant triple negative breast cancer cell lines, with IC₅₀ values less than 200 nM. Overall, cyclodextrin DDC-Cu complexes offer a great potential for anticancer applications, as evidenced by their very positive effects against chemoresistant triple negative breast cancer cells.

Formulation and evaluation of carvedilol microcapsules using Eudragit NE30D and sodium alginate

Inclusion complexes of carvedilol(CR) with hydroxyl propyl beta-cyclodextrin (HPBCD) was prepared using co-grinding technique. Then, the inclusion complex was microencapsulated using combinations of Eudragit NE30D (EU) and sodium alginate (SA) utilizing orifice gelation technique. The formulations were analysed by using Scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), Differential scanning Calorimetry (DSC) and X-ray diffractometer (XRD) and also evaluated for particle size, encapsulation efficiency, production yield, swelling capacity, mucoadhesive properties, zeta potential and drug release. The microcapsules were smooth and showed no visible cracks and extended drug release of 55.2006% up to 12 hours in phosphate buffer of pH 6.8, showing particle size within the range of 264.5-358.5 µm, and encapsulation efficiency of 99.337±0.0100-66.2753±0.0014%.The in vitro release data of optimized batch of microcapsules were plotted in various kinetic equations to understand the mechanisms and kinetics of drug release, which followed first order kinetics, value of "n" is calculated to be 0.459 and drug release was diffusion controlled. The mice were fed with diet for inducing high blood pressure and the in vivo antihypertensive activity of formulations was carried out administering the optimized formulations and pure drug separately by oral feeding and measured by B.P Monwin IITC Life Science instrument and the results indicated that the bioavailability of carvedilol was increased both in vitro and in vivo with the mucoadhesive polymers showing primary role in retarding the drug release.

Kinetic solubility and dissolution velocity of rutin nanocrystals

Lyophilized rutin nanocrystals were intensively evaluated regarding their physicochemical properties with respect to particle size analyses, crystallinity, kinetic solubility and dissolution behavior. The particle size was determined by photon correlation spectroscopy (PCS) and laser diffraction (LD). DSC and X-ray diffraction were used to study the crystalline state of rutin nanocrystals. In a period of 1 week, the kinetic solubility was determined using a shaker at 25 degrees C. DSC and X-ray diffraction analyses showed that lyophilized rutin nanocrystals prepared by high pressure homogenization remained in crystalline state. Lyophilized rutin nanocrystals could be re-dispersed completely in water and the kinetic solubility in water increased to 133 microg/ml.. Lyophilized rutin nanocrystals were almost completely dissolved within 15 min in water, buffer of pH 1.2 and buffer of pH 6.8. In contrast, only 70% of rutin raw material (rutin microcrystals) was dissolved within 15 min. The superior physicochemical properties of rutin nanocrystals should overcome the absorption problem in the gastrointestinal tract and increase the bioavailability.