Enhanced dissolution and oral bioavailability of praziquantel by emulsification with human serum albumin followed by spray drying

The Use of Systemically Absorbed Drugs to Explore An In Vitro Bioequivalence Approach For Comparing Non-Systemically Absorbed Active Pharmaceutical Ingredients in Drug Products For Use in Dogs

PURPOSE

Currently, for veterinary oral formulations containing one or more active pharmaceutical ingredient (API) that are not systemically absorbed and act locally within the gastrointestinal (GI) tract, the use of terminal clinical endpoint bioequivalence (BE) studies is the only option for evaluating product BE. This investigation explored the use of a totality of evidence approach as an alternative to these terminal studies.

METHODS

Three formulations of tablets containing ivermectin plus praziquantel were manufactured to exhibit distinctly different in vitro release characteristics. Because these APIs are highly permeable, plasma drug concentrations served as a biomarker of in vivo dissolution. Tablets were administered to 27 healthy Beagle dogs (3-way crossover) and the rate and extent of exposure of each API for each formulation was compared in a pairwise manner. These results were compared to product relative in vitro dissolution profiles in 3 media. In vivo and in vitro BE predictions were compared.

RESULTS

In vivo/in vitro inconsistencies in product relative performance were observed with both compounds when considering product performance across the 3 dissolution media. Formulation comparisons flagged major differences that could explain this outcome.

CONCLUSIONS

The finding of an inconsistent in vivo/in vitro relationship confirmed that in vitro dissolution alone cannot assure product BE for veterinary locally acting GI products. However, when combined with a comparison of product composition and manufacturing method, this totality of evidence approach can successfully alert scientists to potential therapeutic inequivalence, thereby supporting FDA's efforts to Replace, Reduce, and/or Refine terminal animal studies.

Mechanochemical Synthesis of New Praziquantel Cocrystals: Solid-State Characterization and Solubility

New cocrystals of praziquantel with suberic, 3-hydroxybenzoic, benzene-1,2,4,5-tetracarboxylic, trimesic, and 5-hydroxyisophthalic acids were obtained through ball milling experiments. The optimal conditions for the milling process were chosen by changing the solvent volume and the mechanical action time. Supramolecular interactions in the new cocrystals are detailed based on single-crystal X-ray diffraction analysis, confirming the expected formation of hydrogen bonds between the praziquantel carbonyl group and the carboxyl (or hydroxyl) moieties of the coformers. Different structural characterization techniques were performed for all samples, but the praziquantel:suberic acid cocrystal includes a wider range of investigations such as thermal analysis, infrared and X-ray photoelectron spectroscopies, and SEM microscopy. The stability for up to five months was established by keeping it under extreme conditions of temperature and humidity. Solubility studies were carried out for all the new forms disclosed herein and compared with the promising cocrystals previously reported with salicylic, 4-aminosalicylic, vanillic, and oxalic acids. HPLC analyses revealed a higher solubility for most of the new cocrystal forms, as compared to pure praziquantel.

Protein-based Nanoparticles: From Drug Delivery to Imaging, Nanocatalysis and Protein Therapy

Proteins and enzymes are versatile biomaterials for a wide range of medical applications due to their high specificity for receptors and substrates, high degradability, low toxicity, and overall good biocompatibility. Protein nanoparticles are formed by the arrangement of several native or modified proteins into nanometer-sized assemblies. In this review, we will focus on artificial nanoparticle systems, where proteins are the main structural element and not just an encapsulated payload. While under natural conditions, only certain proteins form defined aggregates and nanoparticles, chemical modifications or a change in the physical environment can further extend the pool of available building blocks. This allows the assembly of many globular proteins and even enzymes. These advances in preparation methods led to the emergence of new generations of nanosystems that extend beyond transport vehicles to diverse applications, from multifunctional drug delivery to imaging, nanocatalysis and protein therapy.

Superparamagnetic Iron-Oxide Nanoparticles Synthesized via Green Chemistry for the Potential Treatment of Breast Cancer

In the emerging field of nanomedicine, nanoparticles have been widely considered as drug carriers and are now used in various clinically approved products. Therefore, in this study, we synthesized superparamagnetic iron-oxide nanoparticles (SPIONs) via green chemistry, and the SPIONs were further coated with tamoxifen-conjugated bovine serum albumin (BSA-SPIONs-TMX). The BSA-SPIONs-TMX were within the nanometric hydrodynamic size (117 ± 4 nm), with a small poly dispersity index (0.28 ± 0.02) and zeta potential of -30.2 ± 0.09 mV. FTIR, DSC, X-RD, and elemental analysis confirmed that BSA-SPIONs-TMX were successfully prepared. The saturation magnetization (M_s) of BSA-SPIONs-TMX was found to be ~8.31 emu/g, indicating that BSA-SPIONs-TMX possess superparamagnetic properties for theragnostic applications. In addition, BSA-SPIONs-TMX were efficiently internalized into breast cancer cell lines (MCF-7 and T47D) and were effective in reducing cell proliferation of breast cancer cells, with IC₅₀ values of 4.97 ± 0.42 μM and 6.29 ± 0.21 μM in MCF-7 and T47D cells, respectively. Furthermore, an acute toxicity study on rats confirmed that these BSA-SPIONs-TMX are safe for use in drug delivery systems. In conclusion, green synthesized superparamagnetic iron-oxide nanoparticles have the potential to be used as drug delivery carriers and may also have diagnostic applications.

Recent Advances in Improving the Bioavailability of Hydrophobic/Lipophilic Drugs and Their Delivery via Self-Emulsifying Formulations

Formulations based on emulsions for enhancing hydrophobic and lipophilic drug delivery and its bioavailability have attracted a lot of interest. As potential therapeutic agents, they are integrated with inert oils, emulsions, surfactant solubility, liposomes, etc.; drug delivering systems that use emulsion formations have emerged as a unique and commercially achievable accession to override the issue of less oral bioavailability in connection with hydrophobic and lipophilic drugs. As an ideal isotropic oil mixture of surfactants and co-solvents, it self-emulsifies and forms fine oil in water emulsions when acquainted with aqueous material. As droplets rapidly pass through the stomach, fine oil promotes the vast spread of the drug all over the GI (gastrointestinal tract) and conquers the slow disintegration commonly seen in solid drug forms. The current status of advancement in technologies for drug carrying has promulgated the expansion of innovative drug carriers for the controlled release of self-emulsifying pellets, tablets, capsules, microspheres, etc., which got a boost for drug delivery usage with self-emulsification. The present review article includes various kinds of formulations based on the size of particles and excipients utilized in emulsion formation for drug delivery mechanisms and the increase in the bioavailability of lipophilic/hydrophobic drugs in the present time.

Increase in Dissolution Rate of Zotepine via Nanomilling Process - Impact of Dried Nanocrystalline Suspensions on Bioavailability

Zotepine is an atypical antipsychotic drug used in the treatment of schizophrenia. However, its poor dissolution properties limit its therapeutic efficacy. In this investigation, a series of nanosuspension-containing zotepine were prepared employing media milling method with an aim to improve its dissolution properties and oral bioavailability. Briefly, Box-Behnken design was applied to investigate the influence of various independent variables such as X₁- amount of stabilizer, X₂- amount of milling agent, and X₃- milling time on the performance of the formulation. Dissolution studies revealed enhancement of dissolution rate as compared to pure drug. Solid state characterization (DSC, PXRD, and SEM) studies demonstrated no polymorphic changes in drug after lyophilization of media-milled nanosuspension. In vivo pharmacokinetic studies of lyophilized nanosuspension was carried out in rat and the results exhibited significant improvement in C_max and AUC_0-t, about 450.0 and 287.45%, respectively, suggesting amelioration in oral bioavailability by 2.87-fold higher as compared to pure drug. Accelerated stability studies of the optimized lyophilized formulation at 40°C and 75% RH suggested stability of the nanocrystals for at least a 6-month period. The obtained nanocrystals successfully showed dissolution enhancement and improved oral bioavailability of poorly water-soluble drug, zotepine.

Preparation and In Vitro/In Vivo Evaluation of Orally Disintegrating/Modified-Release Praziquantel Tablets

This study was designed to develop orally disintegrating/sustained-release praziquantel (PZQ) tablets using the hot-melt extrusion (HME) technique and direct compression, and subsequently evaluate their release in in vitro and in vivo pharmacokinetics. For the extrusion process, hypromellose acetate succinate (HPMCAS)-LG was the carrier of pure PZQ, with a standard screw configuration used at an extrusion temperature of 140 °C and a screw rotation speed of 100 rpm. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD) and Fourier-transform infrared spectroscopy (FTIR) were performed to characterize the extrudate. Orally disintegrating/sustained-release praziquantel tablets (PZQ ODSRTs) were prepared by direct compression after appropriate excipients were blended with the extrudate. The release amount was 5.10% in pH 1.0 hydrochloric acid at 2 h and over 90% in phosphoric acid buffer at 45 min, indicating the enteric-coating character of PZQ ODSRTs. Compared with the pharmacokinetics of marketed PZQ tablets (Aipuruike^®) in dogs, the times to peak (T_max), elimination half-life (t_1/2λ) and mean residence time (MRT) were extended in PZQ ODSRTs, and the relative bioavailability of PZQ ODSRTs was up to 184.48% of that of Aipuruike^®. This study suggested that PZQ ODSRTs may have potential for the clinical treatment of parasitosis.

When Albumin Meets Liposomes: A Feasible Drug Carrier for Biomedical Applications

Albumin, the most abundant protein in plasma, possesses some inherent beneficial structural and physiological characteristics that make it suitable for use as a drug delivery agent, such as an extraordinary drug-binding capacity and long blood retention, with a high biocompatibility. The use of these characteristics as a nanoparticle drug delivery system (DDS) offers several advantages, including a longer circulation time, lower toxicity, and more significant drug loading. To date, many innovative liposome preparations have been developed in which albumin is involved as a DDS. These novel albumin-containing liposome preparations show superior deliverability for genes, hydrophilic/hydrophobic substances and proteins/peptides to the targeting area compared to original liposomes by virtue of their high biocompatibility, stability, effective loading content, and the capacity for targeting. This review summarizes the current status of albumin applications in liposome-based DDS, focusing on albumin-coated liposomes and albumin-encapsulated liposomes as a DDS carrier for potential medical applications.