Dry Powder and Budesonide Inhalation Suspension Deposition Rates in Asthmatic Airway-Obstruction Regions

Steroid inhalation is the standard bronchial asthma therapy and it includes powdered metered doses, dry powder, and nebulizer suspension. However, particle sizes vary widely. The research goal was to demonstrate that different budesonide administration forms and devices have various deposition rates in the airway obstruction region. Here, we compared relative inhalation therapy efficacies and identified therapies that delivered the highest drug doses to the airway obstruction region. Weibel’s anatomy data were used to identify the airway obstruction region in asthma. Based on European Standardization Committee data, we investigated the diameters of the drug particles being deposited there and evaluated the average particle size and distribution of the budesonide dosage forms and application devices. Drug dose depositions were measured by HPLC at each stage of a Cascade Impactor. Weibel’s anatomy data indicated that the 1st–4th bronchial generations comprised the airway obstruction region and corresponded to the tracheobronchial area. According to the European Standardization, particles 2–6 µm in diameter were readily deposited there. The proportions of particles in this size range were 33.0%, 32.0%, 59.0%, and 78.0% for Turbuhaler, Symbicort, mesh-type NE-U22 suspension, and jet-type NE-C28 suspension, respectively. We localized the airway obstruction regions of bronchial asthma and identified the optimal inhalation therapy particle size. An electric nebulizer was more efficacious for budesonide administration than dry powder delivery. The NE-C28 treatment deposited 2.36x more budesonide in the airway obstruction region than dry powder delivery systems.

Advanced Lipid Technologies® (ALT®): A Proven Formulation Platform to Enhance the Bioavailability of Lipophilic Compounds

Despite recent advances, the drug development process continues to face significant challenges to efficiently improve the poor solubility of active pharmaceutical ingredients (API) in aqueous media or to improve the bioavailability of lipid-based formulations. The inherent high intra- and interindividual variability of absorption of oral lipophilic drug leads to inconsistent and unpredictable bioavailability and magnitude of the therapeutic effect. For this reason, the development of lipid-based drugs remains a challenging endeavour with a high risk of failure. Therefore, effective strategies to assure a predictable, consistent, and reproducible bioavailability and therapeutic effect for lipid-based medications are needed. Different solutions to address this problem have been broadly studied, including the approaches of particle size reduction, prodrugs, salt forms, cocrystals, solid amorphous forms, cyclodextrin clathrates, and lipid-based drug delivery systems such as self-emulsifying systems and liposomes. Here, we provide a brief description of the current strategies commonly employed to increase the bioavailability of lipophilic drugs and present Advanced Lipid Technologies® (ALT®), a combination of different surfactants that has been demonstrated to improve the absorption of omega-3 fatty acids under various physiological and pathological states.

Rate of Drug Coating Dissolution Determines In-Tissue Drug Retention and Durability of Biological Efficacy

Two different drug-coated balloons (DCBs) possessing different coating formulations were compared for rate of coating dissolution in vitro, in addition to tissue drug concentration and histological responses of treated vascular tissue in vivo, to determine if the rate of drug bioavailability to vascular tissue can impact the degree and duration of the observed pharmacological response to locally delivered drug. In vitro dissolution comparison demonstrated that a urea/paclitaxel-based coating formulation (IN.PACT™ Admiral™) released drug from solid to soluble phase at a slower and constant rate, yielding approximately 7% solubilized drug in 24 h. In contrast, a coating formulated from polysorbate/sorbitol/paclitaxel (Lutonix™) released 51% of solid phase drug to soluble phase in 1 h of dissolution with the remainder solubilizing in 24 h. In vivo evaluation of tissue drug concentration of both products showed significantly different tissue pharmacokinetic profile, with a higher concentration of paclitaxel in tissue at 90 days with a urea-based formulation excipient. Histological comparison of smooth muscle cell loss in response to drug exposure revealed contrasting trends of smooth muscle cell loss from 28 to 90 days with significantly higher response to drug observed at 90 days with the urea-based formulation. Rapid dissolution of drug from the polysorbate/sorbitol coating formulation was associated with an early increase in local cellular response to drug which diminished over 90 days with clearance of local drug from tissue. Sustained long-term drug-in-tissue concentration associated with the urea-based formulation demonstrated sustained pharmacological activity at 90 days, suggesting that slow coating dissolution provides a sustainable long-term tissue response.

Alkyl Length Effects on the DNA Transport Properties of Cu (II) and Zn(II) Metallovesicles: An In Vitro and In Vivo Study

Cationic liposomes with DNA-transportation properties have attracted considerable attention for their ability to deliver medicinal oligonucleotides to mammalian cells. Amongst these are metalloliposomes that use transition metal ions to confer the lipid molecules cationic charge and unique advantages such as redox- and ligand-exchange triggered DNA-release properties. In this study, lipophilic copper (II) and zinc (II) complexes of 1-alkyl-1,4,7-triazacyclononane were prepared to investigate their ability to bind and transfect double stranded DNA with mammalian cells in vitro and in vivo. The copper(II)-surfactant complexes Cu(TACN-C8)2 (1), Cu(TACN-C10)2 (2), Cu(TACN-C12)2 (3), Cu(TACN-C14)2 (4), Cu(TACN-C16)2 (5), and Cu(TACN-C18)2 (6) that comprise ligands that vary in the length of the alkyl group and the zinc (II)-surfactant complex of Zn(TACN-C12)2 (7) were synthesized. The critical micelle concentration (CMC) for 1-7 was measured using fluorescence spectroscopy and an evaluation of the transfection efficiency of the complexes was assessed using the pEGFP-N1 plasmid and HEK 293-T cells. An inverse relationship between DNA transfection efficiency and CMC of the Cu(II) metallosurfactants was observed. The highest transfection efficiency of 38% was observed for Cu(TACN-C12)2 corresponding to the surfactant with dodecyl alkyl chain having a CMC of 50 μM. Further, an in vivo experiment using mice models was conducted to test the Cu(TACN-C12)2 (3) and Zn(TACN-C12)2 (7) metallosurfactants delivering a DNA vaccine designed for protection against leishmaniasis disease and the study revealed that the Cu-lipoplex elicited the production of significantly more T cells than the Zn-lipoplex and the control group in vivo.

Potential of Cocoa Pod Husk Pectin-Based Modified Release Capsules as a Carrier for Chronodelivery of Hydrocortisone in Sprague-Dawley Rats

The potential of cocoa pod husk (CPH) pectin-based modified release (MR) capsules as a carrier for chronodelivery of hydrocortisone in Sprague-Dawley rats was assessed. Extemporaneously formulated CPH pectin-based hydrocortisone (10 mg) capsules crosslinked with calcium chloride (Formulation A) or zinc (Formulation B) and a commercial immediate release hydrocortisone formulation were administered orally to Sprague-Dawley rats and the pharmacokinetic parameters were evaluated using noncompartmental analysis. Formulation A had a 2 h lag phase followed by an increase in serum drug concentration in the treated rats. Peak concentrations (Cmax) of 21.799 ± 1.993 ng/ml and 20.844 ± 2.661 ng/ml were achieved after 6 ± 0.23 h and 6 ± 0.35 h (Tmax), respectively, for capsules A and B. The immediate release formulation had a peak concentration of 15.322 ± 0.313 ng/ml within 1 ± 0.2 h. The relative bioavailability of the CPH pectin-based capsules A and B was 213% and 274%, respectively. Formulations A and B had half-lives more than three times that of the immediate release formulation. The MR capsules exhibited a higher exposure, greater bioavailability, and versatility in release of cortisol than the commercial immediate release formulation. Additionally, the MR capsules exhibited an extended drug release with overnight cortisol rise and early morning cortisol peak and hold promise in the management of adrenal insufficiency.

Volatile Acid-Solvent Evaporation (VASE): Molecularly Homogeneous Distribution of Acyclovir in a Bioerodable Polymer Matrix for Long-Term Treatment of Herpes Simplex Virus-1 Infections

Treatment for herpes simplex virus-1 and -2 (HSV-1 and -2) patients who suffer from recurrent outbreaks consists of multiple daily doses of the antiviral drugs acyclovir (ACV), penciclovir, or their more orally bioavailable derivatives valacyclovir or famciclovir. Drug troughs caused by missed doses may result in viral replication, which can generate drug-resistant mutants along with clinical sequelae. We developed a molecularly homogeneous mixture of ACV with the bioerodable polymer polycaprolactone. Through scanning electron microscopy, infrared spectroscopy, gel permeation chromatography, 1H NMR, and differential scanning calorimetry, our method of combining drug and polymer, termed Volatile Acid-Solvent Evaporation (VASE), does not compromise the integrity of polymer or drug. Furthermore, VASE creates materials that deliver therapeutic amounts of drug consistently for approximately two months. Devices with high enough drug loads diminish primary infection of HSV-1 in Vero cells to the same level as seen with a single dose of ACV. Our data will lead to further experiments in animal models, demonstrating efficacy in preventing reactivation of these viruses with a single intervention, and with other antiviral drugs amenable to such manipulation. Additionally, this type of treatment would leave no trace after its useful lifetime, as drug is released and polymer matrix is degraded in vivo.

Development and Characterization of Solid Lipid Nanoparticles Containing Herbal Extract: In Vivo Antidepressant Activity

In alternate systems of medicine like Ayurveda and traditional Chinese medicine, Hibiscus rosa sinensis and its extracts have been traditionally prescribed for their antidepressant activity. Crude extracts and rudimentary formulations approaches are good for proof-of-concept studies; however, these formulations are fraught with problems like poor oral bioavailability and high variability between subjects. Systematic drug delivery approaches could prove effective in addressing some of these problems. In this study, we report the development of Hibiscus rosa sinensis extract loaded solid lipid nanoparticles (HSLNs) using glycerol monostearate or beeswax as lipids. The HSLNs were evaluated for their size, surface charge, and morphology. The optimized HSLNs were tested for antidepressant activity in male Swiss albino mice. It was found that, with the optimized procedure, HSLNs of ~175 nm, carrying negative charge and nearly spherical shape, could be obtained. The in vivo test results suggested that there were marked differences in the immobility times of the test animals. Moreover, with HSLNs, it was found that at doses several times lower than the native crude extract dose, similar pharmacological effect could be obtained. These initial findings suggest that encapsulating phytopharmaceuticals into advanced delivery systems like solid lipid nanoparticles can be an effective strategy in improving their in vivo performance.

Emphasized Mechanistic Antimicrobial Study of Biofunctionalized Silver Nanoparticles on Model Proteus mirabilis

Antimicrobial study of biofunctionalized silver nanoparticles has been done with the emphasis on its mechanism on both gram positive and negative bacteria. The biofunctionalized silver nanoparticles are employed considering their importance in green chemistry with respect to easy synthesis, usefulness, and economic synthetic procedure involved. The stability of these nanoparticles was determined by zeta potential analyzer. The probable mechanism of antibacterial activity was performed on Proteus mirabilis by field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDAX) study which does not show the presence of silver. The free radicals generated by silver nanoparticles were responsible for lethal antibacterial activity by rupturing the cell surface which causes improper nutrient and signal supply. Free radical scavenging efficacy of silver nanoparticles was confirmed by 1,1-Diphenyl-2-picrylhydrazyl (DPPH) method. AgNP enhanced the membrane leakage of reducing sugars by destroying the proteins existing on the cell wall. These nanoparticles are found to be toxic against human pathogens and are highly effective on Staphylococcus aureus. The effect of silver nanoparticles is concentration dependent and independent of the type of strains used.

Intestinal Permeability of Artesunate-Loaded Solid Lipid Nanoparticles Using the Everted Gut Method

Background. Artesunate is one of the most potent, rapidly acting and therapeutically versatile antimalarial drugs. Its efficacy is hampered by poor aqueous solubility and stability resulting in low oral bioavailability. Recent efforts to nanoformulate artesunate have shown great potential of improving its dissolution profile and bioavailability. However, no study has yet been done to investigate the intestinal permeability of these nanoformulations, which is a critical determinant of systemic absorption. Objective of the Study. The main aim of the study was to determine the intestinal permeability of artesunate-loaded solid lipid nanoparticles (SLN). Method. The microemulsion dilution technique was used to fabricate artesunate-loaded solid lipid nanoparticles. In vitro drug release studies were performed at pH 1.2 and 6.8 using the dialysis membrane method. The everted gut sac method was used to assess the intestinal permeability of the prepared nanoparticles. Results. The average particle size was 1109 nm and the polydispersity index (PDI) was 0.082. The zeta potential was found to be −20.7 mV. The encapsulation efficiency of the solid lipid nanoparticles obtained was 51.7%. At both pH 1.2 and 6.8, pure artesunate was rapidly released within the first 30 mins while the SLN showed a biphasic release pattern with an initial burst release during the first hour followed by a prolonged release over time. The rate of drug release increased with increasing pH. The apparent permeability (Papp) of SLN was found to be greater (0.169 mg/cm2) as compared to that of pure artesunate (0.117 mg/cm2) at the end of the experiment. Conclusion. The results obtained in this study showed that the microemulsion dilution technique can be used to formulate artesunate solid lipid nanoparticles. The formulation exhibited a sustained drug release profile. The intestinal permeability of artesunate could be enhanced by the nanoformulation.