Inclusion Complex of Fexofenadine Hydrochloride with Cyclodextrins

<p>Fexofenadine hydrochloride (FFN), (±)-4-[1-hydroxy-4[4-(hydroxydiphenylmethyl)-1-piperidinyl]-butyl] α,α-dimethylbenzeneacetic acid hydrochloride, is a second-generation antihistamine that is used to treat allergies. The drug is highly hydrophobic and slightly soluble in water. Cyclodextrins are widely used to improve the physicochemical and pharmaceutical properties such as solubility, stability, and bioavailability of poorly soluble drug molecules.Cyclodextrins can molecularly encapsulate various drugs into their hydrophobic cavity without forming any covalent bonds. Cyclodextrin (CDs), especially ß-Cyclodextrin (ß-CD), are widely used in the pharmaceutical field due to its ability to stabilize drug molecules and taste masking purposes.<strong> </strong></p><p>The phase solubility study was performed according to the method of Higuchi and Connors by adding the fexofenadine hydrochloride in excess to different concentrations of cyclodextrin solutions. Phase solubility study records show that the stability constant and complex stoichiometry of FFN-CD complexes increases linearly with CD concentration. Also, an increase in the concentration of β-cyclodextrin leads to an increase in the aqueous solubility of FFN. Complexes were analyzed by UV-VIS spectroscopy using the calibration curve of FFN. Also, UV-VIS spectra indicate a bathochromic shift which proves that complex formation has occurred.</p><p>Solid inclusion complexes of fexofenadine/β-cyclodextrin and its derivatives were prepared at the molar ratios of 1:1 by the physical mixing method. Characterization of the complexes was performed by using infrared spectroscopy. </p>

The Preservation and Enantiomeric Selection of Linalool by Nanoencapsulation Using Cyclodextrins

Linalool, a volatile terpene alcohol, is responsible for a characteristic aroma in food, beverages, and cosmetics. However, linalool’s low aqueous solubility and high volatility limit the applications and shelf life of linalool-containing products. Nanoencapsulation using beta-cyclodextrin (BCD), methyl-beta-cyclodextrin (MBCD) and hydroxypropyl-beta-cyclodextrin (HPBCD) was studied to improve the aqueous solubility and stability of linalool. Linalool has two enantiomers with distinct flavors and odors which affect product quality. The enantiomeric selectivity of the cyclodextrins (CDs) toward racemic linalool standard was evaluated. A computational simulation was performed to predict the conformations and interactions of the inclusion complexes. The 1:1 host-guest ratio from the computer simulation was implemented in the experimental study. Phase solubility study shows an improvement in linalool aqueous solubility after being encapsulated by CDs. The encapsulation efficiencies of linalool/BCD, linalool/MBCD, and linalool/HPBCD inclusion complexes are 66.30%, 51.38% and 32.31%, respectively. Nanoencapsulation by CDs can preserve linalool in the form of inclusion complexes compared to its free form. The amount of remaining linalool in linalool/BCD, linalool/MBCD, and linalool/HPBCD inclusion complexes are 89.57%, 87.07%, and 74.86%, respectively which are considerably larger than that of pure linalool (42.30%). CDs also show the enantiomeric selectivity toward (R)-linalool as evident from (R)-linalool percentage of 54.53% in the inclusion complex.

Dissolution Enhancement of Flurbiprofen by Solid Dispersion Adsorbate Technique

Flurbiprofen solid dispersion Adsorbate (SDA) has been prepared using PEG 4000 and Poloxamer 188 as carrier and Neusilin as adsorbent material. The SDA of Flurbiprofen was prepared by using Fusion method in various drugs to carrier ratios. The phase solubility study concludes that both polymers have ability to improve the aqueous solubility of flurbiprofen. Pure API Flurbiprofen and final formulation samples of SDA are characterized by FTIR, DSC and X-ray diffraction spectroscopy. X-ray powder diffraction and DSC study indicated that the drug was present in amorphous form. FTIR study revealed that the characteristic peaks in spectra of pure Flurbiprofen are also present in spectra of SDA’s. Drug found compatible with the excipients. The highest improvement in solubility and in-vitro drug release were observed in solid dispersion prepared with Poloxamer 188 (F14) by fusion method. The increased dissolution rate of drug from solid dispersion adsorbates may be due to surface tension lowering effect of polymer to the medium and increased wettability and dispersibility of drug. Hence, F14 Solid dispersion adsorbates with the Poloxamer carrier in 1:2 ratio considered as most satisfactory among all solid dispersion adsorbates.

Increased Water-Solubility and Maintained Antioxidant Power of Resveratrol by Its Encapsulation in Vitamin E TPGS Micelles: A Potential Nutritional Supplement for Chronic Liver Disease

Children affected by chronic liver disease exhibit impaired neurocognitive development and growth due to the low absorption and digestion of nutrients. Furthermore, malnutrition is an adverse prognostic factor in liver transplantation as it is associated with an increase in morbidity and mortality. D-α-tocopheryl-polyethylene-glycol-succinate (TPGS) is currently administered per os as a vitamin E source to improve children’s survival and well-being; however, TPGS alone does not reverse spinocerebellar degeneration and lipid peroxidation. To potentiate the effects of TPGS, we loaded micelles with resveratrol (RES), a natural polyphenol, with antioxidant and antiinflammatory activities, which has demonstrated protective action in the liver. Firstly, we investigated the suitability of TPGS to encapsulate RES in micelles by means of a phase-solubility study, then RES-TPGS formulations were prepared via solvent casting and solvent diffusion evaporation methods. RES-TPGS colloidal dispersions showed small mean diameters (12 nm), low polydispersity, and quite neutral Zeta potentials. The formulations showed a sustained drug release and a good drug loading capacity, further confirmed by infrared spectroscopy and differential scanning calorimetry. RES-TPGSs exhibited unaltered antioxidant activity compared to pristine RES via the DPPH assay and a significant reduction in toxicity compared to empty TPGS on HaCaT cells. Thus, RES-TPGS micelles may overcome the challenges of current liver disease therapy by providing more protective effects thanks to the antioxidant activity of RES and by reducing the surfactant toxicity on normal cells.

Design of Experiment Approach to Assess The Effect Of Formulation Variables On Extrusion And Spheronization Of Telmisartan And Cilostazol Loaded Pellets And Its Pharmacokinetic Study

Background: Solubility is an important parameter that affects availability of drug in systemic circulation. Drugs having poor solubility belonging to BCS class II eventually results in lower dissolution and bioavailability. Hence, improvement of solubility is a challenging task. Hence the present work focusses on using solid dispersion and inclusion complex approach for both telmisartan and cilostazol belonging to BCS Class II drugs. Objective: The present study was carried out to improve apparent solubility of telmisartan and cilostazol (BCS-Class II drugs) and optimization as pellets along with its pharmacokinetic study. Methods: Phase solubility study was carried out to screen the excipients such as, PVPK30, PVA, HPMC E5 and β-CD. Solvent evaporation method was adopted to prepare the solid dispersions and inclusion complex of both the drugs. Pellets were optimized by extrusion spheronization method using 32 factorial design and characterized by morphology, drug content, DSC, FTIR, XRD, SEM, in-vitro studies and drug content study Results: Phase solubility study showed improved apparent solubility of telmisartan with HPMC E5 (1:3) by solid dispersion and cilostazol with β-CD (1:3) using inclusion complexation method. Drug characterization did not reveal any incompatibility. Formulation was optimized on the basis of acceptable pellet properties, including acceptable spherical shape and micromeritics properties. The percent friability of all batches was found to be less than 1%. The optimized pellets of both drugs prepared with micro crystalline cellulose provided desirable maximum release with acceptable release profile. Conclusion: The formulated pellets when studied in vivo showed superior pharmacokinetic profile. The drawback associated with apparent solubility and bioavailability of both drugs can thus be alleviated by use of novel pellet formulation.

Synthesis and evaluation of B-cyclodextrin Based Nanosponges of 5- Fluorouracil by Using Ultrasound Assisted Method

CD-nanosponges were prepared by crosslinking B-CD with diphenylcarbonate (DPC) using ultrasound assisted technique. 5-FU was incorporated with NS by freeze drying, and the phase solubility study, complexation efficiency (CE) entrapment efficiency were performed. Also, the particle morphology was studied using SEM and AFM. The in-vitro release of 5-FU from the prepared nanosponges was carried out in 0.1N HCl. 5-FU nanosponges particle size was in the nano size. The optimum formula showed a particle size of (405.46±30) nm, with a polydispersity index (PDI) (0.328±0.002) and a negative zeta potential (-18.75±1.8). Also the drug entrapment efficiency varied with the CD: DPC molar ratio from 15.6 % to 30%. The SEM and AFM showed crystalline and porous nature of the nanosponges. The in vitro drug release study of the selected formula 5-FUNS2 exhibited the fastest dissolution rate which is 56% in the first hr. Different molar ratios of (cyclodextrin to crosslinker) (CD: DPC) has a proficient effect on complexation efficiency (CE), apparent stability constant (Kst) and entrapment efficiency of 5-FU. 5-FUNS2 with (1:4) molar ratio showed the best result of CE, Kst and entrapment efficiency. 5-FUNS2 gave a higher release rate than the 5-FU-BCD inclusion complex and 5-FU solution. Surface morphology of the prepared nanosponges by SEM, AFM indicate that nanosized and highly porous nanosponges was obtained. The overall results suggest that cyclodextrin nanosponges could be a promising 5-FU delivery system utilizing the suitable formula.

Formulation and Evaluation of Supramolecular Food-Grade Piperine HP β CD and TPGS Complex: Dissolution, Physicochemical Characterization, Molecular Docking, In Vitro Antioxidant Activity, and Antimicrobial Assessment

The purpose of the present study was to improve the aqueous solubility, dissolution, and antioxidant activity of the water-insoluble drug piperine (PIP). The study was performed by preparing PIP binary inclusion complex (PIP BIC) and piperine ternary inclusion complex (PIP TIC) by different methods. The effect of a hydrophilic auxiliary substance (TPGS) was assessed with addition to PIP and hydroxypropyl beta cyclodextrin (HP β CD) complex. The phase solubility study was performed to evaluate the complexation efficiency and stability constant. The aqueous solubility, dissolution, physicochemical assessment, antioxidant activity, antimicrobial activity, and molecular docking were further evaluated to check the effect of the complexation of PIP. The stability constant (Ks) value was found to be 238 and 461 M−1 for the binary and ternary inclusion complex. The dissolution study results showed a marked enhancement of release in comparison to pure drug. XRD and SEM studies revealed the presence of more agglomerated and amorphous structures of PIP, which confirmed the formation of complexes. The results of DPPH radical scavenging and antimicrobial activity showed a significant (p < 0.05) enhancement in scavenging activity for PIP TIC (microwave irradiation (MI)). The docking studies have revealed that the binding affinity of TPGS at the PIP-HP β CD complex was −5.2 kcal/mol.

Capsaicin-Cyclodextrin Complex Enhances Mepivacaine Targeting and Improves Local Anesthesia in Inflamed Tissues

Acidic environments, such as in inflamed tissues, favor the charged form of local anesthetics (LA). Hence, these drugs show less cell permeation and diminished potency. Since the analgesic capsaicin (CAP) triggers opening of the TRPV1 receptor pore, its combination with LAs could result in better uptake and improved anesthesia. We tested the above hypothesis and report here for the first time the analgesia effect of a two-drug combination (LA and CAP) on an inflamed tissue. First, CAP solubility increased up to 20 times with hydroxypropyl-beta-cyclodextrin (HP-β-CD), as shown by the phase solubility study. The resulting complex (HP-β-CD-CAP) showed 1:1 stoichiometry and high association constant, according to phase-solubility diagrams and isothermal titration calorimetry data. The inclusion complex formation was also confirmed and characterized by differential scanning calorimetry (DSC), X-ray diffraction, and 1H-NMR. The freeze-dried complex showed physicochemical stability for at least 12 months. To test in vivo performance, we used a pain model based on mouse paw edema. Results showed that 2% mepivacaine injection failed to anesthetize mice inflamed paw, but its combination with complexed CAP resulted in pain control up to 45 min. These promising results encourages deeper research of CAP as an adjuvant for anesthesia in inflamed tissues and cyclodextrin as a solubilizing agent for targeting molecules in drug delivery.

Systematic Development of Bicalutamide Immediate Release Pellets using Aeroperl and Non-MCC Extruder aid

Background: The Microcrystalline Cellulose is called as a gold standard for the manufacture of pellets. The poor disintegration leads to incomplete drug release restricts the use of MCC in the immediate-release formulation. Objective: The present work aims to explore non-MCC extruder aid for pellet formulation and solubility modulation potential of Aeroperl® 300 Pharma. Methods: Bicalutamide (BCL) was selected as a model BCS class-II drug. The solubility of BCL was assessed in different vehicles like polyethylene glycol, propylene glycol, and Tween by carrying out phase solubility study. The suitable vehicle was selected based on the higher solubility of BCL. The vehicle was further adsorbed on newer adsorbent Aeroperl® 300 Pharma to formulate liquisolid granules. The liquisolid granules were further incorporated into the pellet using mannitol and microcrystalline cellulose as an extruder aid. Box-Behnken design was adopted for optimization of formulation considering MCC: mannitol ratio, concentration of HPMC and spheronizer speed as independent factors whereas drug release at 30 min, disintegration time and aspect ratio were selected as dependent variables. The pellets were evaluated for different evaluation parameters. Results: Propylene glycol was selected for the formulation of liquisolid technique based on the results of the phase solubility study. Propylene glycol containing BCL was adsorbed on Aeroperl 300 Pharma. The optimized batch was selected exploring the Design-Expert software by considering limits of different responses. Pellet had excellent flowability. Friability was found to be within the range (<1%). Pellets were found to be spherical and had pores on the surfaces. Conclusion: Liquisolid granules containing newer solubilizer Aeroperl was found to be a promising approach for the improvement in the solubility of the drug. The use of mannitol with MCC has a profound effect on disintegration time, without altering flow property and other parameters. No patents were reported on the combination of Bicalutamide, mannitol and Aeroperl. The critical finding of the present work is to use mannitol as an extruder aid to fasten the disintegration leads to complete drug release within a short period of time. Aeroperl and Mannitol, MCC: mannitol ratio, concentration of HPMC and spheronizer speed was found to be significant and had the potential effect in pellet formulation.

Characterization, in Vitro and in Vivo Evaluation of Naringenin-Hydroxypropyl-β-Cyclodextrin Inclusion for Pulmonary Delivery

Naringenin, a flavonoid compound which exists abundantly in Citrus fruits, is proven to possess excellent antitussive and expectorant effects. However, the clinical applications of naringenin are restricted by its poor solubility and low local concentration by oral administration. The aim of the present study is to prepare a naringenin-hydroxypropyl-β-cyclodextrin (naringenin-HPβCD) inclusion as an inhalation solution for pulmonary delivery. The naringenin-HPβCD inclusion was characterized by phase solubility study, XRD, differential scanning calorimetry (DSC), proton nuclear magnetic resonance (1HNMR), and two-dimensional rotating frame Overhauser effect spectroscopy (2D ROESY). The in vitro permeability of the inclusion was evaluated on Calu-3 cells and the pharmacokinetic profile of pulmonary delivery was investigated in Sprague-Dawley (SD) rats. Based on the linear model of phase solubility study, the relationship between naringenin and HPβCD was identified as AL type with a 1:1 stoichiometry. XRD, DSC, and NMR studies indicated that the entire naringenin molecule is encapsulated into the cavity of HPβCD. HPβCD could increase the concentration of naringenin in the epithelium-lining fluid (ELF) of Calu-3 cells and act as a sustained release system for naringenin. The pharmacokinetic profile of naringenin-HPβCD inclusion showed rapid response and higher local concentration by pulmonary delivery. In conclusion, pulmonary delivery of naringenin-HPβCD inclusion is a promising formulation strategy, which could provide a new possibility for the clinical application of naringenin.