Antibiotics are typically more effective against replicating rather than nonreplicating bacteria. However, a major need in global health is to eradicate persistent or nonreplicating subpopulations of bacteria such as Mycobacterium tuberculosis (Mtb). Hence, identifying chemical inhibitors that selectively kill bacteria that are not replicating is of practical importance. To address this, we screened for inhibitors of dihydrolipoamide acyltransferase (DlaT), an enzyme required by Mtb to cause tuberculosis in guinea pigs and used by the bacterium to resist nitric oxide-derived reactive nitrogen intermediates, a stress encountered in the host. Chemical screening for inhibitors of Mtb DlaT identified select rhodanines as compounds that almost exclusively kill nonreplicating mycobacteria in synergy with products of host immunity, such as nitric oxide and hypoxia, and are effective on bacteria within macrophages, a cellular reservoir for latent Mtb. Compounds that kill nonreplicating pathogens in cooperation with host immunity could complement the conventional chemotherapy of infectious disease.

Purpose. Drying of nanosuspensions can cause destabilization of the particles, leading to irreversible aggregation. In order to prepare an effective solid dosage form for a nanosuspension, it is imperative that the spray-dried nanoparticles should go back to their original particle size when reconstituted in an aqueous system. This case study examines impact of various formulation and processing parameters on redispersibility of the spray dried nanoparticles. Methods. Nanosuspensions were prepared using the microprecipitation-homogenization process. Spray drying of nanosuspensions was achieved using a lab-scale Buchi spray dryer.Results. Formulation components appeared to have the most significant impact on redispersibility of spray dried particles. Absence of surface charge led to particles that could not be redispersed. On the other hand, charged particles stabilized with an appropriate sugar led to spray dried powders that were flowable and easily redispersible. Dissolution testing showed the presence of two phases-a lag phase that represented dispersion of the loose aggregates, and dissolution of the dispersed nanoparticles. Conclusions. Nanosuspensions of a poorly soluble drug could be spray dried to obtain flowable powders that could be easily redispersed. These optimized powders also showed significantly improved dissolution rates as compared to the micronized drug, or unoptimized nanosuspensions.

Dextran sulphate can significantly increase AG incorporation into the chitosan nanoparticles. The concentration of each component was critical in preparing AG-loaded chitosan nanoparticles. The chitosan nanoparticles designed in this study may provide a promising oral drug delivery formulation for AG which usually, in tuberculosis treatment, is administrated as an injectible preparation.

The aim of this study is to develop an orally disintegrating film (ODF) containing a microparticulate measles vaccine formulation for buccal delivery. The measles vaccine microparticles were made with biocompatible and biodegradable bovine serum albumin (BSA) and processed by spray drying. These vaccine microparticles were incorporated in the ODF, consisting of Lycoat RS720®, Neosorb P60W® and Tween 80. The yield of the microparticles was approximately 85-95%, w/w. The mean size of the vaccine microparticles was 3.65 ± 1.89 μm and had a slightly negative surface charge of 32.65 ± 2.4 mV. The vaccine particles were nontoxic to normal cells at high concentrations (500 μg/2.5 × 10 cells) of vaccine particles. There was a significant induction of innate immune response by vaccine microparticles which was observed in vitro when compared to blank microparticles (P < 0.05). The vaccine microparticles also significantly increased the antigen presentation and co-stimulatory molecules expression on antigen presenting cells, which is a prerequisite for Th1 and Th2 immune responses. When the ODF vaccine formulation was dosed in juvenile pigs, significantly higher antibody titers were observed after week 2, with a significant increase at week 4 and plateauing through week 6 comparative to naïve predose titers. The results suggest that the ODF measles vaccine formulation is a viable dosage form alternative to noninvasive immunization that may increase patient compliance and commercial distribution.

Abstract. The objective of this research was to investigate physicochemical properties of an active pharmaceutical ingredient (API) that influence cyclodextrin complexation through experimental and computational studies. Native β-cyclodextrin (B-CD) and two hydroxypropyl derivatives were first evaluated by conventional phase solubility experiments for their ability to complex four poorly watersoluble nonsteroidal anti-inflammatory drugs (NSAIDs). Differential scanning calorimetry was used to confirm complexation. Secondly, molecular modeling was used to estimate Log P and aqueous solubility (S o ) of the NSAIDs. Molecular dynamics simulations (MDS) were used to investigate the thermodynamics and geometry of drug-CD cavity docking. NSAID solubility increased linearly with increasing CD concentration for the two CD derivatives (displaying an A L profile), whereas increases in drug solubility were low and plateaued in the B-CD solutions (type B profile). The calculated Log P and S o of the NSAIDs were in good concordance with experimental values reported in the literature. Side chain substitutions on the B-CD moiety did not significantly influence complexation. Explicitly, complexation and the associated solubility increase were mainly dependent on the chemical structure of the NSAID. MDS indicated that each NSAID-CD complex had a distinct geometry. Moreover, complexing energy had a large, stabilizing, and fairly constant hydrophobic component for a given CD across the NSAIDs, while electrostatic and solvation interaction complex energies were quite variable but smaller in magnitude.

Abstract. The objective of this project was to investigate the potential of Kleptose Linecaps DE17 (KLD) in masking the unpleasant/bitter taste of therapeutic agents by hot melt extrusion (HME). Griseofulvin (GRI) and caffeine anhydrous (CA) were used as a bitter active pharmaceutical ingredient (API) model drugs. Thermogravimetric studies confirmed the stability of GRI, CA, and KLD at the employed extrusion temperatures. The differential scanning calorimetry (DSC) studies revealed a characteristic melting endotherm of GRI at 218-220°C and CA at 230-232°C in the physical mixtures as well as in all extrudates over the period of study, indicating the crystalline nature of drug. HME of KLD was achieved only in the presence of plasticizer. Among the several plasticizers investigated, xylitol showed improved processability of KLD at 15% w/w concentration. Dissolution studies of HME extrudates using simulated salivary medium exhibited ∼threefold less release compared to physical mixture at the end of 5 min (the lesser drug release, better the taste masking efficiency). Furthermore, the results from the sensory evaluation of products in human panel demonstrated strong bitter taste in the case of physical mixture compared to the HME formulation, suggesting the potential of Kleptose Linecaps DE17 as taste masking polymer in melt extruded form.

The following research study focuses on improving the solubility of zaleplon (BCS class II drug) via micronization technique in order to enhance its oral delivery in orodispersible formulations. Zaleplon along with a surfactant solution was micronized by ultrasonication. The micronization process reduced the particle size of the crystalline drug about six-fold from its original size of 155.5 μm. The micronized zalepon dispersion was lyophilized to allow for a change in the state of matter (to a powder). The superior dissolution parameters (Q, Q, IDR, MDR, MDT, DE, and RDR) of zaleplon in microcrystalline form over the original crystalline form in in vitro dissolution studies had unraveled that micronization technique is an efficient tool in enhancing drug solubility. The micronized zaleplon solid dispersion (after lyophilization) was loaded into orodispersible tablet (ODT) and orodispersible film (ODF) formulations. The positive quality of ODT with adequate hardness and smooth texture was attributing to the presence of Pearlitol Flash® as a ready to use ODT platform. On the other hand, the ODF loaded with micronized zaleplon and prepared with Lycoat® RS 720 (as a film former) ensured adequate tensile strength. The disintegration time of ODT and ODF was 30 ± 5 and 35 ± 5 s, respectively. Thus, the orodispersible formulations containing micronized zaleplon have a strong potential for rapid disintegration following superior absorption in solution state through oral cavity into the blood stream, envisaging better oral delivery.

We elucidate grapevine evolution and domestication histories with 3525 cultivated and wild accessions worldwide. In the Pleistocene, harsh climate drove the separation of wild grape ecotypes caused by continuous habitat fragmentation. Then, domestication occurred concurrently about 11,000 years ago in Western Asia and the Caucasus to yield table and wine grapevines. The Western Asia domesticates dispersed into Europe with early farmers, introgressed with ancient wild western ecotypes, and subsequently diversified along human migration trails into muscat and unique western wine grape ancestries by the late Neolithic. Analyses of domestication traits also reveal new insights into selection for berry palatability, hermaphroditism, muscat flavor, and berry skin color. These data demonstrate the role of the grapevines in the early inception of agriculture across Eurasia.