Development of hydrophilic gels containing coenzyme Q10-loaded liposomes: characterization,stability and rheology measurements

Objective: The aim of this study was to develop, characterize and evaluate stability of a gel containing coenzyme Q₁₀ (Q₁₀)-loaded liposomes, and enhance the stability of Q₁₀ in the nanocarrier-containing gel compared to the conventional gel.

Methods: Q₁₀-loaded liposome dispersions prepared from unsaturated or saturated lecithin, were characterized for particle size, polydispersity index (PDI), zeta-potential, pH value, oxidation index, Q₁₀-content and morphology, and incorporated into carbomer gel. Liposome gels and liposome-free gel were analyzed for flow properties, pH values, Q₁₀-content, and liposomes size and PDI (liposome gels), 48?h after preparation and in predetermined time intervals during 6?months storage at different temperatures in order to predict their long term stability.

Results: Liposomes were of small particle size, homogeneous, negatively charged, and their incorporation into gel did not significantly change (p?>?.05) their particle size and PDI. All gels revealed non-Newtonian, shear-thinning plastic flow behavior during storage with no marked changes in rheological parameters. Storage of gels did not significantly influence the pH value (p?>?.05), while it significantly decreased Q₁₀-content (p?<?.05). Q₁₀ was significantly more (p?<?.05) stable in liposome gel containing unsaturated lecithin liposomes (G1) than in gel containing saturated lecithin liposomes (G2) and liposome-free gel (G3).

Conclusions: Q₁₀-loaded liposome gel G1 was the optimal formulation, since during storage at different temperatures, it did not show significant increase in liposome size and PDI, it provided significantly higher stability for Q₁₀ than other gels and its pH value was suitable for skin application. Due to limited Q₁₀-stability it should be stored at 4?°C.     

The inactivation of the non-enveloped enterovirus 71 (EV71) by a novel disinfectant gel formulation for topical use

Background: Hand-foot-mouth disease may cause severe central nervous system complications and even death, that is induced mainly by enterovirus 71 (EV71), which is a non-enveloped virus. Inactivation of the EV71 on hands could effectively inhibit the transmission. However, the inactivations of the EV71 by conventional disinfectants including the alcohols are poor, due to the high stability of the EV71. A novel pyridyl imidazolidinone compound (TJAB1099) was designed to specifically inhibit EV71 replication in vitro. It may potentially be developed as formulations applied on hands for EV71 transmission control.

Methods: The stress stability of TJAB1099 was first evaluated after storing in high temperature (60?°C, RH 10%), high humidity (25?°C, RH90%), and the high-intensity photolysis (4500?Lx ± 500?Lx) for 15 days, respectively. A wash-free antimicrobial gel containing the TJAB1099 was developed using the copolymer carrier. The antiviral activity, the acute oral toxicity, and the local irritation of the antimicrobial gel were evaluated accordingly.

Results: The results indicated that the TJAB1099 was stable during the storage in high temperature and humidity. However, a significant change (p?<?.0001) was detected when TJAB1099 stored in the high-intensity photolysis. The antimicrobial gel containing 1?μM TJAB1099 could inhibit EV71 significantly higher than the ethanol (75%) (p?<?.0001) and commercialized disinfectant products (p?<?.0001). The results of acute oral toxicity and the local irritation suggest that the TJAB1099 containing antimicrobial gel was not causing skin irritations and acute oral toxicity symptoms.

Conclusions: The results suggest that the antimicrobial gel containing TJAB1099 was safe and could effectively inhibit EV71 transmission in vitro.     

Oral delivery of the anti-tumor necrosis factor α domain antibody,V565, results in high intestinal and fecal concentrations with minimal systemic exposure in cynomolgus monkeys

Objective: V565 is a novel oral anti-tumor necrosis factor (TNF)-α domain antibody being developed for topical treatment of inflammatory bowel disease (IBD) patients. Protein engineering rendered the molecule resistant to intestinal proteases. Here we investigate the formulation of V565 required to provide gastro-protection and enable optimal delivery to the lower intestinal tract in monkeys.

Methods: Enteric-coated V565 mini-tablets were prepared and dissolution characteristics tested in vitro. Oral dosing of monkeys with enteric-coated mini-tablets containing V565 and methylene blue dye enabled in vivo localization of mini-tablet dissolution. V565 distribution in luminal contents and feces was measured by enzyme-linked immunosorbent assay (ELISA). To mimic transit across the damaged intestinal epithelium seen in IBD patients an intravenous (i.v.) bolus of V565 was given to monkeys and pharmacokinetic parameters of V565 measured in serum and urine by ELISA.

Results: Enteric-coated mini-tablets resisted dissolution in 0.1?M HCl, before dissolving in a sustained release fashion at neutral pH. In orally dosed monkeys methylene blue intestinal staining indicated the jejunum and ileum as sites for mini-tablet dissolution. Measurements of V565 in monkey feces confirmed V565 survival through the intestinal tract. Systemic exposure after oral dosing was very low consistent with limited V565 mucosal penetration in healthy monkeys. The rapid clearance of V565 after i.v. dosing was consistent with renal excretion as the primary route for elimination of any V565 reaching the circulation.

Conclusions: These results suggest that mini-tablets with a 24% Eudragit enteric coating are suitable for targeted release of orally delivered V565 in the intestine for topical treatment of IBD.     

Physicochemical characterization and thermal behavior of hexosomes containing ketoconazole as potential topical antifungal delivery system

Objective: The main purpose of this article is to show the valuable characteristics that liotropic liquid crystal systems possess to be employed as new drug delivery systems.

Significance: Colloidal aqueous dispersions of lyotropic liquid crystal mesophases such as the identified as cubosomes and hexosomes, and so on, have received considerable attention due to their unique nanostructures and their thermodynamic properties, which provide the potential as a sustained drug release matrix. Additionally, their large surface area and similarity with the liquid crystal structures of intercellular lipids of stratum corneum enhances the interaction with the skin and mucous, increasing the potential for topical drug delivery efficiency of biopharmaceutical class II drugs as the antifungal ketoconazole.

Methods: This article presents the results in morphological characteristics, particle size, ζ potential, flow, thermal behavior and drug release studies of hexosomes containing ketoconazole (LHLC-K) obtained with glycerol monooleate, propylene glycol monolaurate, poloxamer, and water mixtures.

Results: This colloidal system exhibits a Newtonian-type flow and a hexagonal nanostructure with a median particle size of 107?±?20?nm and ζ potential of +4.45?±?0.50?mV. Through differential scanning calorimetry studies, the LHLC-K demonstrated physical and chemical stability for more than six months and mesophasic thermal reversibility between 10 and 50?°C. Finally, LHLC-K releases ketoconazole following a kinetics described by the first order model.

Conclusions: Physicochemical properties of the hexosomes containing ketoconazole are important for topical mycosis treatment administration, conditions of storage, and for its incorporation into the formulation of semi-solid dosage forms.     

Dual cross-linked chitosan microspheres formulated with spray-drying technique for the sustained release of levofloxacin

Objective: This study was aimed to develop sustained drug release from levofloxacin (LF)-loaded chitosan (CS) microspheres for treating ophthalmic infections.

Significance: Dual cross-linked CS microspheres developed by the spray-drying technique displays significantly higher level of sustained drug release compared with non-cross-linked CS microspheres.

Methods: LF-loaded CS microspheres were prepared using the spray-drying technique, and then solidified with tripolyphosphate and glutaraldehyde as dual cross-linking agents. The microspheres were characterized by surface morphology, size distribution, zeta potential, encapsulation efficiency, and drug release profiles in vitro. The drug quantification was verified and analyzed by high-performance liquid chromatography (HPLC). The structural interactions of the CS with LF were studied with Fourier transform infrared spectroscopy. The effect of various influencing excipients in the formulation of the dual cross-linked CS microspheres on drug encapsulation efficiency and the drug release profiles were extensively investigated.

Result: The microspheres demonstrated high encapsulation efficiency (72.4?～?98.55%) and were uniformly spherical with wrinkled surface. The mean particle size was between 1020.7?±?101.9 and 2381.2?±?101.6?nm. All microspheres were positively charged (zeta potential ranged from 31.1?±?1.32 to 42.81?±?1.55?mV). The in vitro release profiles showed a sustained release of the drug and it was remarkably influenced by the cross-linking process.

Conclusion: This novel spray-drying technique we have developed is suitable for manufacturing LF-loaded CS microspheres, and thus could serve as a potential platform for sustained drug release for effective therapeutic application in ocular infections.     

Comparative pharmacokinetic evaluation of extended release itopride HCl pellets with once daily tablet formulation in healthy human subjects: a two treatment,four period crossover study in fasted and fed condition

Objective: In this study, pharmacokinetics (PKs) and bioavailability of newly developed extended release (ER) Itopride HCl 150?mg encapsulated ER pellets (test) and 150?mg Ganaton ER once-daily (OD) tablets (reference) were compared and evaluated under fasted and fed conditions.

Methods: Twelve healthy human subjects were enrolled in a single dose, randomized; two treatments, two sequences, four period crossover study. A modified and validated liquid chromatographic method was used for the estimation of Itopride HCl in plasma samples. The data were analyzed through non-compartmental model using PK software Phoenix Winnonlin version 7. The outcome was measured on logarithmically transformed data, where p?>?0.05 was considered as non-significant with 90% CI limit of 0.8–1.25.

Results: The C_max, AUC_0–t, and AUC_0–∞ values of Itopride HCl 150?mg ER pellets versus that of OD 150?mg tablets, in fed and fasted states, were within the limits specified by FDA to establish bioequivalence. The relative bioavailability of Itopride HCl 150?mg ER pellets were 1.019 (fed) and 1.081(fasted). The 90% CIs of AUC values for Itopride HCl 150?mg ER pellets and OD 150?mg tablets in fed versus fast were significantly greater and were not within 80–125% limit.

Conclusion: The test and reference formulations had similar pharmacokinetic parameters in each condition studied. However, an increase in the amount of drug was observed in the fed state.     

A comparison of drug substance predicted chemical stability with ICH compliant stability studies

Objective: The aim of this study is to demonstrate the applicability of predictive stability studies to the degradation of drug substances.

Significance: The use of predicted stability studies during pharmaceutical development and in regulatory submissions is increasing, particularly in early phase to support an initial retest period/shelf life claim in the absence of standard stability data. These studies offer an alternative to standard stability testing and can facilitate clinical trials to be started earlier and medicines to reach patients faster. They involve a short-term stressed stability study, typically designed to degrade a drug substance or product to the specification level of the shelf life limiting attribute. The results are used to predict degradation under long-term storage conditions and enable stability understanding to be gained over a short time frame, using limited amounts of material.

Methods: In this work, Accelerated Stability Assessment Program (ASAP) studies were performed for 10 different drug substances and the predictions obtained for chemical degradation were compared to ICH compliant stability data.

Results: Across the studies good agreement was achieved, with the initial retest period predictions from the ASAP studies being conservative by design. When minimal degradation was observed during an ASAP study, it was demonstrated that at least a 12-month initial retest period could be supported.

Conclusion: This comparison of ASAP predictions and ICH compliant stability data has demonstrated the ability of well-designed ASAP studies to predict the long-term chemical stability of drug substances.     

Influencing factors on gelatin matrix for chlorhexidine delivery

Objective: The objective was to evaluate the influencing factors in the fabrication of gelatin matrix (gelatin chips) for drug delivery. The attributes affecting drug release characteristics of the gelatin products were examined.

Significance: Understanding the attributes that affect drug release from gelatin matrix could provide the knowledge base for the development, manufacturing, and performance evaluation of gelatin-based drug products for sustained drug delivery.

Methods: Chlorhexidine (CHX) was the model drug in the gelatin-product testing. The gelatin products were fabricated by two methods: a single-pot mixing of all the components and a two-step gelatin crosslinking followed by drug loading. Different gelatin types (Type A porcine and Type B bovine), glutaraldehyde (GTA) crosslinking conditions, glycerin concentration, and CHX concentration in drug loading and loading time were used to fabricate the products. The cumulative amounts of CHX release from the gelatin products were determined using in vitro release testing (IVRT).

Results: The attributes affecting CHX release from the gelatin products were gelatin type, GTA crosslinking, and CHX loading concentration. The fabrication methods (two-step method of gelatin crosslinking and drug loading by equilibration vs. direct mixing of the components) also affected CHX release. Other attributes such as glycerin and CHX loading time did not show significant effects on drug release under the conditions studied. In addition, the results in the two IVRT methods employed in this study were comparable.

Conclusion: Gelatin products of qualitative (Q1) and quantitative (Q2) differences could lead to different drug release behaviors. Drug release was also affected by the ingredient mixing steps during gelatin chip fabrication.     

Nanostructured lipid carriers engineered for intranasal delivery of teriflunomide in multiple sclerosis: optimization and in vivo studies

Background: Multiple sclerosis (MS) is one of the most severe autoimmune disorder of the central nervous system (CNS).

Objective: The present research work was aimed to formulate and investigate teriflunomide (TFM)-loaded intranasal (i.n.) nanostructured lipid carriers (NLC) for the treatment of multiple sclerosis (MS).

Methods: The TFM-loaded NLC (TFM-NLC) nanoparticles were prepared by melt emulsification ultrasonication method using biodegradable and biocompatible polymers. The Box–Behnken statistical design was applied to optimize the formulation. The optimized NLC formulation was subjected to evaluate for particle size, entrapment efficiency (%), in vitro and ex vivo permeation. The safety and efficacy of optimized formulations were demonstrated using pharmacodynamic, subacute toxicity and hepatotoxicity data.

Results: Experimental data demonstrated that optimized NLC formulation (F17) showed significant size (99.82?±?1.36?nm), zeta potential (?22.29?±?1.8?mV) and % entrapment efficiency (83.39?±?1.24%). Alternatively, ex vivo permeation of TFM mucoadhesive NLC (TFM-MNLC) and TFM-NLC was observed 830?±?7.6 and 651?±?9.8?µg/cm², respectively. Whereas, TFM-MNLC shows around 2.0-folds more J_ss than the TFM-NLC. Finally, TFM-MNLC (i.n.) formulation produced the rapid remyelination in cuprizone-treated animals and decreases the number of entries in open compartment of EPM when compared with negative control and TFM-NLC (oral) animals. Simultaneously, the nanoformulation did not reflect any gross changes in hepatic biomarkers and subacute toxicity when compared with control.

Conclusions: Hence it can be inferred that the nose-to-brain delivery of TFM-MNLC can be considered as effective and safe delivery for brain disorders.     

Inhalable liposomes of Glycyrrhiza glabra extract for use in tuberculosis: formulation,in vitro characterization,in vivo lung deposition,and in vivo pharmacodynamic studies

Objective: The current study involves the development of liposomal dry powder for inhalation (LDPI) containing licorice extract (LE) for use in tuberculosis.

Significance: The current epidemiology of tuberculosis along with the increasing emergence of resistant forms of tuberculosis necessitates the need for developing alternative efficacious medicines for treatment. Licorice is a medicinal herb with reported activity against Mycobacterium tuberculosis.

Methods: Liposomes with LE were prepared by thin film hydration technique and freeze dried to obtain LDPI. The comprehensive in vitro and in vivo characterization of the LDPI formulation was carried out.

Results: The particle size of liposomes was around 210?nm with drug entrapment of almost 75%. Transmission electron microscopy revealed spherical shape of liposome vesicles. The flow properties of the LDPI were within acceptable limits. Anderson Cascade Impactor studies showed the mean median aerodynamic diameter, geometric standard deviation and fine particle fraction of the LDPI to be 4.29?µm, 1.23, and 54.68%, respectively. In vivo lung deposition studies of LDPI in mice showed that almost 46% of the drug administered reaches the lungs and 16% of administered drug is retained in the lungs after 24?hours of administration. The in vivo pharmacodynamic evaluation of the LDPI showed significant reduction in bacterial counts in lungs as well as spleen of TB-infected mice.

Conclusions: LE LDPI thus has a promising potential to be explored as an effective anti-tubercular medicine or as an adjunct to existing anti-tubercular drugs.     

Proof-of-concept preparation and characterization of dual-drug amorphous nanoparticle complex as fixed-dose combination of poorly soluble drugs

Objectives: To carry out a proof-of-concept study on the development of dual-drug amorphous nanoparticle complex (nanoplex in short) as a potential formulation platform for fixed-dose combination (FDC) of poorly-soluble drugs.

Significance: FDC has been proven effective in improving patient compliance for treatment that requires complex multidrug regimen. Currently, there is growing interest to develop FDC of poorly-soluble drugs due to the increased number of drugs exhibiting poor solubility thus low bioavailability.

Methods: The dual-drug nanoplex was prepared by electrostatically-driven co-complexation of drug molecules with oppositely charged dextran sulfate, using ciprofloxacin (CIP) and itraconazole (ITZ) as the model poorly-soluble drugs.

Results: We first verified that the co-complexation products were dual-drug CIP-ITZ nanoplex, and not binary mixtures of the single-drug CIP and ITZ nanoplexes, by demonstrating their distinct thermal behaviors and dissolution characteristics. Depending on the preparation condition, the dual-drug nanoplex exhibited size and zeta potential of 160–410?nm and ?35–50?mV, respectively. The individual drug payloads were readily manipulated by varying the CIP/ITZ mass ratio in the feed, resulting in CIP and ITZ payloads in the range of 60-30% and 15-45%, respectively. The CIP-ITZ nanoplex, however, exhibited diminished CIP supersaturation generation, thus lower CIP solubility enhancement, compared to the single-drug CIP nanoplex. The CIP-ITZ nanoplex, nonetheless, remained capable of generating high ITZ supersaturation level.

Conclusion: Dual-drug nanoplex was successfully prepared with a high degree of control over its physical characteristics. Nevertheless, whether dual-drug nanoplex always exhibits diminished solubility enhancement compared to its single-drug counterparts needs to be investigated using different poorly-soluble drugs.     

Inhibitory effect of resveratrol on the pharmacokinetic of ibrutinib by UPLC–MS/MS

Objective: To investigate the impact of resveratrol on the metabolism of ibrutinib in vitro and in vivo.

Methods: In vitro, rat liver microsomes (RLM) and human liver microsomes (HLM) were used to study. In vivo, 18 male SD rats were randomly divided into three groups (n?=?6): ibrutinib and the multiple dose of 100?mg/kg resveratrol for consecutive 7 days (Group A), ibrutinib and the single dose of 100?mg/kg resveratrol (Group B), ibrutinib (Group C). Processed samples were analyzed by UPLC–MS/MS.

Results: Resveratrol showed inhibition on RLM and HLM in vitro. The IC₅₀ of resveratrol was 8.745?µM in RLM and 7.789?µM in HLM. Furthermore, Groups A and B both increased the AUC and reduced the CLz/F. The C_max of Group A and the MRT_(0–t) of Group B were significantly improved.

Conclusions: Resveratrol inhibits the pharmacokinetic of ibrutinib in vitro and in vivo. It is necessary to pay more attention to adjust the dose of the drug when resveratrol is used in combination with ibrutinib.     

Effect of semicrystalline copolymers in solid dispersions of pioglitazone hydrochloride: in vitro-in vivo correlation

Objective: The study was aimed to improve the dissolution and bioavailability of developed stable amorphous solid dispersions (SDs) of pioglitazone hydrochloride (PGH), a poorly water-soluble drug.

Significance: Poor aqueous solubility of PGH was overcome by the design of SDs. Level A correlation demonstrated between in vitro release and bioavailability of PGH, suggest its biowaiver potential.

Methods: The effects of semicrystalline copolymers (poloxamer 407 and gelucire 50/13) and methods of preparations on dissolution behavior, in vivo performance, and stability of PGH SDs were investigated. All the SDs were characterized by FTIR, TGA, DSC, XRD, and SEM.

Results: FTIR and TGA showed the compatibility with the polymers. The significant change in melting pattern of the PGH observed in the DSC thermograms supported by XRD patterns & SEM indicated a change from a crystalline to an amorphous state. Gelucire 50/13 was observed to have greater ability to form SDs than poloxamer 407 in solvent evaporation method (SM). Prevention of recrystallization during storage suggested stability of the formulation. Gelucire 50/13 based SD, prepared by SM remarkably increased the dissolution within 15?min (87.27?±?2.25%) and was supported by dissolution parameters (Q₁₅, IDR, RDR, % DE, f₁, f₂). These SDs showed pH-dependent solubility. In vivo test showed significantly (p?<?.05) higher AUC_0–t and C_max, which were about 3.17 and 4.34 times that of the pure drug respectively.

Conclusion: Gelucire 50/13 was found to be a suitable carrier for SM for preparation of SDs of PGH as evident from increased dissolution and bioavailability.     

Natamycin niosomes as a promising ocular nanosized delivery system with ketorolac tromethamine for dual effects for treatment of candida rabbit keratitis; in vitro/in vivo and histopathological studies

Objectives: This study was aimed to develop dual-purpose natamycin (NAT)-loaded niosomes in ketorolac tromethamine (KT) gels topical ocular drug delivery system to improve the clinical efficacy of natamycin through enhancing its penetration through corneal tissue and reducing inflammation associated with Fungal keratitis (FK).

Significance: Nanosized carrier systems, as niosomes would provide great potential for improving NAT ocular bioavailability.NAT niosomal dispersion formulae were prepared and then incorporated in 0.5%KT gels using different mucoadhesive viscosifying polymers.

Methods: Niosomes were prepared using the reverse-phase evaporation technique. In vitro experimental, and in vivo clinical evaluations for these formulations were done for assessment of their safety and efficacy for treatment of Candida Keratitis in Rabbits. In vitro release study was carried out by the dialysis method. In vivo and histopathological studies were performed on albino rabbits.

Results: NAT niosomes exhibited high entrapment efficiency percentage (E.E%) up to96.43% and particle size diameter ranging from 181.75?±?0.64 to 498.95?±?0.64?nm, with negatively charged zeta potential (ZP). NAT niosomal dispersion exhibited prolonged in vitro drug release (40.96–77.49% over 24h). NAT-loaded niosomes/0.5%KT gel formulae revealed retardation in vitro release, compared to marketed-product (NATACYN^®) and NAT-loaded niosomes up to57.32% (F8). In vivo experimental studies showed the superiority for F8 in treatment of candida keratitis and better results on corneal infiltration and hypopyon level. These results were consistent with histopathological examination in comparison with F5 and combined marketed products (NATACYN^® and Ketoroline^®).

Conclusions: This study showed that F8 has the best results from all pharmaceutical in vitro evaluations and a better cure percent in experimental application and enhancing the prolonged delivery of NAT and penetrating the cornea tissues.     

Two placebo-controlled crossover studies in healthy subjects to evaluate gastric acid neutralization by an alginate–antacid formulation (Gaviscon Double Action)

Objective: To investigate the intragastric acid neutralization activity of a combined alginate-antacid formulation.

Significance: Published studies have investigated the reflux-suppressing alginate component of Gaviscon Double Action (Gaviscon DA; RB, UK) but intragastric acid neutralization activity of the antacid component has not been evaluated in vivo.

Methods: Intragastric pH monitoring, using a custom-made 10-electrode catheter, was evaluated in a two-part exploratory study in healthy subjects; Part I (n?=?6) tested suitability of the catheter using antacid tablets (Rennie; Bayer, Germany); Part II (n?=?12) evaluated gastric acid neutralization activity of Gaviscon DA liquid (20?ml) versus placebo in fasted subjects using a randomized, open-label, crossover design. The primary endpoint was the percentage of time that intragastric pH ≥4 was measured during 30?min post-treatment. A confirmatory study of identical design was subsequently conducted (n?=?20).

Results: Monitoring pH using the multielectrode catheter was a viable approach, directly detecting changes in intragastric pH following a single dose of antacid tablets. In the exploratory study, the percentage of time that pH ≥4 during 30?minutes post-treatment was 46.8% with Gaviscon DA liquid versus 4.7% with placebo (p?=?0.0004). These findings were supported by the confirmatory study, where pH ≥4 was recorded 50.8% of the time with Gaviscon DA versus 3.5% with placebo (p?=?0.0051). In this study, Gaviscon DA was safe and well tolerated.

Conclusions: These studies demonstrate the effective acid neutralizing capacity of Gaviscon DA versus placebo in healthy, fasted subjects. This adds to the evidence base for the combination of alginates and antacids.     

Application of scCO2 technology for preparing CoQ10 solid dispersion and SFC-MS/MS for analyzing in vivo bioavailability

Objective: In this study, solid dispersion (SD) for oral delivery of a poorly water-soluble drug, coenzyme Q10 was developed by supercritical fluid technology and characterized in vitro and in vivo.

Methods: Dissolution was used to optimize the formulations of CoQ10-SD. The physicochemical properties of SD were investigated by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). The supercritical fluid chromatography–electrospray ionization tandem mass spectrometry (SFC–ESI-MS/MS) was used for the in vivo study.

Results: The results of DSC and PXRD indicated that the drug in SD was in amorphous state. In vitro drug release, the dissolution of coenzyme Q10 in solid dispersion improved to 78.8% compared with commercial tablets of 0.16%. The area under c–t curve (AUC_0–72h) and mean maximum concentrations (C_max) of CoQ10-SD were 2.43-fold and 3.0-fold, respectively higher than that of commercial tablets in rats, confirming improved bioavailability.

Conclusion: Supercritical fluid technology was successfully used for the preparation and analysis of CoQ10-SD for the first time and significantly improved the dissolution and bioavailability of coenzyme Q10.     

Development and in vitro characterization of chitosan-coated polymeric nanoparticles for oral delivery and sustained release of the immunosuppressant drug mycophenolate mofetil

Objective: To develop an oral sustained release formulation of mycophenolate mofetil (MMF) for once-daily dosing, using chitosan-coated polylactic acid (PLA) or poly(lactic-co-glycolic) acid (PLGA) nanoparticles. The role of polymer molecular weight (MW) and drug to polymer ratio in encapsulation efficiency (EE) and release from the nanoparticles was explored in vitro.

Methods: Nanoparticles were prepared by a single emulsion solvent evaporation method where MMF was encapsulated with PLGA or PLA at various polymer MW and drug: polymer ratios. Subsequently, chitosan was added to create coated cationic particles, also at several chitosan MW grades and drug: polymer ratios. All the formulations were evaluated for mean diameter and polydispersity, EE as well as in vitro drug release. Differential scanning calorimetry (DSC), surface morphology, and in vitro mucin binding of the nanoparticles were performed for further characterization.

Results: Two lead formulations comprise MMF: high MW, PLA: medium MW chitosan 1:7:7 (w/w/w), and MMF: high MW, PLGA: high MW chitosan 1:7:7 (w/w/w), which had high EE (94.34% and 75.44%, respectively) and sustained drug release over 12?h with a minimal burst phase. DSC experiments revealed an amorphous form of MMF in the nanoparticle formulations. The surface morphology of the MMF NP showed spherical nanoparticles with minimal visible porosity. The potential for mucoadhesiveness was assessed by changes in zeta potential after incubation of the nanoparticles in mucin.

Conclusion: Two chitosan-coated nanoparticles formulations of MMF had high EE and a desirable sustained drug release profile in the effort to design a once-daily dosage form for MMF.     

Efficient method for isolation of exosomes from raw bovine milk

Objective: This study aimed to establish a rapid and simple method for isolating exosomes from raw bovine milk and to compare the quality of the isolated exosomes with those isolated by a standard method involving ultracentrifugation (UC).

Methods: To remove caseins, which are major milk proteins consisting more than 80% of milk protein (35% in human breast milk) and hamper isolation and purification of exosomes, hydrochloride (HCl) was added to milk for isoelectric precipitation (IP). The effects of acidification on morphological features, particle size distribution, surface charge, and exosome surface proteins were analyzed by electron microscopy, tunable resistive pulse sensing (TRPS), and Western blot (WB) analysis, respectively.

Results: Electron microscopy showed that some of the exosomes isolated using IP had rough surfaces; most exosomes were successfully isolated without breakage, and their morphological features were similar to those of exosomes isolated by UC. TRPS showed that their surface charge and peaks (mode) for particle size distribution did not significantly differ between both methods. WB analysis using antibodies against the exosome surface marker proteins – milk fat globule-epidermal growth factor 8 (MFG-E8) and CD63 – revealed that the structures of exosome surface proteins were not affected by adding HCl.

Conclusions: IP can be used to remove caseins to reduce operation time. This method will be useful for efficient isolation and purification of bovine milk exosomes and contribute to progression of research on health management of dairy cattle and drug delivery systems in human medicine, which require large amounts of milk exosomes.     

Formulation,optimization, and evaluation of raft-forming formulations containing Nizatidine

Objective: The main objective of this research is to formulate, optimize, and evaluate raft-forming chewable tablets of Nizatidine. Various raft-forming agents were used in preliminary screening. Sodium alginate showed maximum raft strength, so tablets were prepared using sodium alginate as the raft forming agent, along with calcium carbonate (CaCO₃) as antacid and raft strengthening agent, and sodium bicarbonate (NaHCO₃) as a gas generating agent.

Research design and methods: Raft forming chewable tablets containing Nizatidine were prepared by direct compression and wet granulation methods, and evaluated for drug content, acid neutralization capacity, raft strength, and in-vitro drug release in 0.1?N HCl. Box–Behnken design was used for optimization.

Results: Two optimized formulations were predicted from the design space. The first optimized recommended concentrations of the independent variables were predicted to be X₁?=?275.92?mg, X₂?=?28.60?mg, and X₃?=?202.14?mg for direct compression technique and the second optimized recommended concentrations were predicted to be X₁?=?253.62?mg, X₂?=?24.60?mg, and X₃?=?201.77?mg for wet granulation technique. Optimized formulations were stable at accelerated environmental testing for six months at 35?°C and 45?°C with 75% relative humidity. X-Ray showed that the raft floated immediately after ingestion and remained intact for ～3?h.

Conclusion: Raft was successfully formed and optimized. Upon chewing tablets, a raft is formed on stomach content. That results in rapid relief of acid burning symptoms and delivering the drug into systemic circulation with enhanced bioavailability.