Formulation and process development of (recombinant human) deoxyribonuclease I as a powder for inhalation

Construction of intelligent drug delivery system based on polysaccharide-derived polymer micelles: A review

Micelles are nanostructures developed via the spontaneous assembly of amphiphilic polymers in aqueous systems, which possess the advantages of high drug stability or active-ingredient solubilization, targeted transport, controlled release, high bioactivity, and stability. Polysaccharides have excellent water solubility, biocompatibility, and degradability, and can be modified to achieve a hydrophobic core to encapsulate hydrophobic drugs, improve drug biocompatibility, and achieve regulated delivery of the loaded drug. Micelles drug delivery systems based on polysaccharides and their derivatives show great potential in the biomedical field. This review discusses the principles of self-assembly of amphiphilic polymers and the formation of micelles; the preparation of amphiphilic polysaccharides is described in detail, and an overview of common polysaccharides and their modifications is provided. We focus on the review of strategies for encapsulating drugs in polysaccharide-derived polymer micelles (PDPMs) and building intelligent drug delivery systems. This review provides new research directions that will help promote future research and development of PDPMs in the field of drug carriers.

Inulin and Its Application in Drug Delivery

Inulin’s unique and flexible structure, stabilization/protective effects, and organ targeting ability make it an excellent drug delivery carrier compared to other biodegradable polysaccharides. The three hydroxyl groups attached to each fructose unit serve as an anchor for chemical modification. This, in turn, helps in increasing bioavailability, improving cellular uptake, and achieving targeted, sustained, and controlled release of drugs and biomolecules. This review focuses on the various types of inulin drug delivery systems such as hydrogel, conjugates, nanoparticles, microparticles, micelles, liposomes, complexes, prodrugs, and solid dispersion. The preparation and applications of the different inulin drug delivery systems are further discussed. This work highlights the fact that modification of inulin allows the use of this polymer as multifunctional scaffolds for different drug delivery systems.

Inhalation delivery technology for genome-editing of respiratory diseases

The clustered regulatory interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (CRISPR/Cas9) system has significant therapeutic potentials for lung congenital diseases such as cystic fibrosis, as well as other pulmonary disorders like lung cancer and obstructive diseases. Local administration of CRISPR/Cas9 therapeutics through inhalation can achieve high drug concentration and minimise systemic exposure. While the field is advancing with better understanding on the biological functions achieved by CRISPR/Cas9 systems, the lack of progress in inhalation formulation and delivery of the molecule may impede their clinical translation efficiently. This forward-looking review discussed the current status of formulations and delivery for inhalation of relevant biologics such as genes (plasmids and mRNAs) and proteins, emphasising on their design strategies and preparation methods. By adapting and optimising formulation strategies used for genes and proteins, we envisage that development of inhalable CRISPR/Cas9 liquid or powder formulations for inhalation administration can potentially be fast-tracked in near future.

Mechanism and efficacy of virus inactivation by a microplasma UV lamp generating monochromatic UV irradiation at 222 nm

This study evaluated the potential of a microplasma UV lamp as an alternative UV source to the current mercury-based (Hg-based) UV lamp for water disinfection. We developed a set of PCR-based molecular assays (long-range qPCR, DNase, and binding assay) to quantify the adenovirus genome, capsid, and fiber damage with a wide detection range (10^0.5-10^6.5 PFU/mL). We used these molecular assays to characterize adenovirus (AdV) inactivation kinetics by microplasma UV that produced monochromatic UV at 222 nm. We found that the inactivation rate constant (0.142 cm²/mJ) due to microplasma UV was 4.4 times higher than that of low-pressure Hg UV (0.032 cm²/mJ). This high efficacy was attributed to monochromatic UV wavelength at 222 nm damaging the AdV capsid protein. The results of these molecular assays also proved that microplasma UV and medium-pressure Hg UV with a bandpass filter at 223 nm (MPUV_223nm) have a similar influence on AdV (p>0.05). We then estimated the relative energy efficiency of MPUV and microplasma UV to LPUV for 4 log reduction of the viruses. We found that the microplasma UV resulted in higher inactivation rate constants for viruses than the current Hg-based UV. Consequently, microplasma UV could be more energy efficient than low-pressure Hg UV for water disinfection if the wall-plug efficiency of the microplasma UV lamp improved to 8.4% (currently 1.5%). Therefore, the microplasma UV lamp is a promising option for water disinfection.

The physiological functions and pharmaceutical applications of inulin: A review

Inulin (IN), a fructan-type plant polysaccharide, is widely found in nature. The major plant sources of IN include chicory, Jerusalem artichoke, dahlia etc. Studies have found that IN possessed a wide array of biological activities, e.g. as a prebiotic to improve the intestinal microbe environment, regulating blood sugar, regulating blood lipids, antioxidant, anticancer, immune regulation and so on. Currently, IN is widely used in the food and pharmaceutical industries. IN can be used as thickener, fat replacer, sweetener and water retaining agent in the food industry. IN also can be applied in the pharmaceutics as stabilizer, drug carrier, and auxiliary therapeutic agent for certain diseases such as constipation and diabetes. This paper reviews the physiological functions of IN and its applications in the field of pharmaceutics, analyzes its present research status and future research direction. This review will serve as a one-in-all resource for the researchers who are interested to work on IN.

Comparison between Colistin Sulfate Dry Powder and Solution for Pulmonary Delivery

To assess the difference in the fate of the antibiotic colistin (COLI) after its pulmonary delivery as a powder or a solution, we developed a COLI powder and evaluated the COLI pharmacokinetic properties in rats after pulmonary administration of the powder or the solution. The amorphous COLI powder prepared by spray drying was characterized by a mass median aerodynamic diameter and fine particle fraction of 2.68 ± 0.07 µm and 59.5 ± 5.4%, respectively, when emitted from a Handihaler^®. After intratracheal administration, the average pulmonary epithelial lining fluid (ELF): plasma area under the concentration versus time curves (AUC) ratios were 570 and 95 for the COLI solution and powder, respectively. However, the same COLI plasma concentration profiles were obtained with the two formulations. According to our pharmacokinetic model, this difference in ELF COLI concentration could be due to faster systemic absorption of COLI after the powder inhalation than for the solution. In addition, the COLI apparent permeability (P_app) across a Calu-3 epithelium model increased 10-fold when its concentration changed from 100 to 4000 mg/L. Based on this last result, we propose that the difference observed in vivo between the COLI solution and powder could be due to a high local ELF COLI concentration being obtained at the site where the dry particles impact the lung. This high local COLI concentration can lead to a local increase in COLI P_app, which is associated with a high concentration gradient and could produce a high local transfer of COLI across the epithelium and a consequent increase in the overall absorption rate of COLI.

Preparation and Characterization of Oxidized Inulin Hydrogel for Controlled Drug Delivery

Inulin-based hydrogels are useful carriers for the delivery of drugs in the colon-targeted system and in other biomedical applications. In this project, inulin hydrogels were fabricated by crosslinking oxidized inulin with adipic acid dihydrazide (AAD) without the use of a catalyst or initiator. The physicochemical properties of the obtained hydrogels were further characterized using different techniques, such as swelling experiments, in vitro drug release, degradation, and biocompatibility tests. The crosslinking was confirmed with Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC). In vitro releases of 5-fluorouracil (5FU) from the various inulin hydrogels was enhanced in acidic conditions (pH 5) compared with physiological pH (pH 7.4). In addition, blank gels did not show any appreciable cytotoxicity, whereas 5FU-loaded hydrogels demonstrated efficacy against HCT116 colon cancer cells, which further confirms the potential use of these delivery platforms for direct targeting of 5-FU to the colon.

Characterization and Formulation of Isoniazid for High-Dose Dry Powder Inhalation

Tuberculosis is a major health problem and remains one of the main causes of mortality. In recent years, there has been an increased interest in the pulmonary delivery of antibiotics to treat tuberculosis. Isoniazid is one of these antibiotics. In this study, we aimed to characterize isoniazid and formulate it into a dry powder for pulmonary administration with little or no excipient, and for use in the disposable Twincer^® inhaler. Isoniazid was jet milled and spray dried with and without the excipient l-leucine. Physiochemical characterization showed that isoniazid has a low Tg of −3.99 ± 0.18 °C and starts to sublimate around 80 °C. Milling isoniazid with and without excipients did not result in a suitable formulation, as it resulted in a low and highly variable fine particle fraction. Spray drying pure isoniazid resulted in particles too large for pulmonary administration. The addition of 5% l-leucine resulted in a fraction <5 µm = 89.61% ± 1.77% from spray drying, which dispersed well from the Twincer^®. However, storage stability was poor at higher relative humidity, which likely results from dissolution-crystallization. Therefore, follow up research is needed to further optimize this spray dried formulation.

Ovalbumin-containing core-shell implants suitable to obtain a delayed IgG1 antibody response in support of a biphasic pulsatile release profile in mice

A single-injection vaccine formulation that provides for both a prime and a boost immunization would have various advantages over a multiple-injection regime. For such a vaccine formulation, it is essential that the booster dose is released after a certain, preferably adjustable, lag time. In this study we investigated whether a core-shell based implant, containing ovalbumin as core material and poly(DL-lactic-co-glycolic acid) of various monomer ratios as shell material can be used to obtain such a booster release. An in vitro release study showed that the lag time after which the ovalbumin was released from the core-shell implant increased with increasing lactic to glycolic acid ratio of the polymer and ranged from 3-6 weeks. Fluorescence spectroscopy showed minimal differences between native ovalbumin and ovalbumin from core-shell implants that were incubated until just before the observed in vitro release. In addition, mice immunized with a subcutaneous inserted core-shell implant containing ovalbumin showed an ovalbumin-specific IgG1 antibody response after a lag time of 4 or 6-8 weeks. Moreover, delayed release of ovalbumin caused higher IgG1 antibody titers than conventional subcutaneous vaccination with ovalbumin dissolved in PBS. Collectively, these findings could contribute to the further development of a single-injection vaccine, making multiple injections of the vaccine superfluous.

Inhalable siRNA-loaded nano-embedded microparticles engineered using microfluidics and spray drying

Medicines based on small interfering RNA (siRNA) are promising for the treatment of a number of lung diseases. However, efficient delivery systems and design of stable dosage forms are required for inhalation therapy, as well as cost-effective methods for manufacturing of the final product. In this study, a 3D-printed micromixer was used for preparation of siRNA-dendrimer nanocomplexes, which were subsequently processed into microparticle-based dry powders for inhalation using spray drying. By applying the disposable micromixer, nanocomplexes were prepared of an average hydrodynamic diameter comparable to that of nanocomplexes prepared by manual mixing, but with narrower size distribution and low batch-to-batch variation. The nanocomplexes were processed into nanoembedded microparticles using different saccharide excipients. Data showed that siRNA integrity and bioactivity are retained after processing, and nanocomplexes could be reconstituted from the dry powders. The amorphous saccharide excipients trehalose and inulin provided better stabilization than crystalline mannitol, and they enabled full reconstitution of the nanocomplexes. In particular, a binary mixture of trehalose and inulin showed optimal stabilization, and enhanced cellular uptake and gene silencing efficiency. This study demonstrates that inexpensive and scalable micromixers can be used to optimize the production of siRNA-dendrimer nanocomplexes, and they can be applied in combination with spray drying for the engineering of dry powder formulations suitable for delivery of siRNA to the therapeutic target site.

Pharmaceutical spray freeze drying

Pharmaceutical spray-freeze drying (SFD) includes a heterogeneous set of technologies with primary applications in apparent solubility enhancement, pulmonary drug delivery, intradermal ballistic administration and delivery of vaccines to the nasal mucosa. The methods comprise of three steps: droplet generation, freezing and sublimation drying, which can be matched to the requirements given by the dosage form and route of administration. The objectives, various methods and physicochemical and pharmacological outcomes have been reviewed with a scope including related fields of science and technology.

Unraveling protein stabilization mechanisms: vitrification and water replacement in a glass transition temperature controlled system

The aim of this study was to elucidate the role of the two main mechanisms used to explain the stabilization of proteins by sugar glasses during drying and subsequent storage: the vitrification and the water replacement theory. Although in literature protein stability is often attributed to either vitrification or water replacement, both mechanisms could play a role and they should be considered simultaneously. A model protein, alkaline phosphatase, was incorporated in either inulin or trehalose by spray drying. To study the storage stability at different glass transition temperatures, a buffer which acts as a plasticizer, ammediol, was incorporated in the sugar glasses. At low glass transition temperatures (<50°C), the enzymatic activity of the protein strongly decreased during storage at 60°C. Protein stability increased when the glass transition temperature was raised considerably above the storage temperature. This increased stability could be attributed to vitrification. A further increase of the glass transition temperature did not further improve stability. In conclusion, vitrification plays a dominant role in stabilization at glass transition temperatures up to 10 to 20°C above storage temperature, depending on whether trehalose or inulin is used. On the other hand, the water replacement mechanism predominantly determines stability at higher glass transition temperatures.