Development of an oil suspension containing granisetron hydrochloride as a sustained-release parenteral formulation for enhancement of pharmacokinetic properties

Recent advances in lipid-based long-acting injectable depot formulations

Long-acting injectable (LAIs) delivery systems sustain the drug therapeutic action in the body, resulting in reduced dosage regimen, toxicity, and improved patient compliance. Lipid-based depots are biocompatible, provide extended drug release, and improve drug stability, making them suitable for systemic and localized treatment of various chronic ailments, including psychosis, diabetes, hormonal disorders, arthritis, ocular diseases, and cancer. These depots include oil solutions, suspensions, oleogels, liquid crystalline systems, liposomes, solid lipid nanoparticles, nanostructured lipid carriers, phospholipid phase separation gel, vesicular phospholipid gel etc. This review summarizes recent advancements in lipid-based LAIs for delivering small and macromolecules, and their potential in managing chronic diseases. It also provides an overview of the lipid depots available in market or clinical phase, as well as patents for lipid-based LAIs. Furthermore, this review critically discusses the current scenario of using in vitro release methods to establish IVIVC and highlights the challenges involved in developing lipid-based LAIs.

Evaluation of Drug Sorption on Laboratory Materials with Abraham Solvation Parameters of Drugs and its Prevention

PURPOSE

Undesired drug sorption on laboratory material surfaces reduces the performance of analytical methods and results in the generation of unreliable data. Hence, we characterized the sorption of drugs and evaluated the sorption extent using a linear free energy relationship (LFER) model with Abraham solvation parameters of drugs. Furthermore, to prevent sorption, the effects of additives, such as organic solvents and salts, were evaluated.

METHODS

The sorption of fifteen model drugs (concentration: 2 μM), with various physicochemical properties, on materials in 0.2% dimethyl sulfoxide aqueous solutions was evaluated. Drug sorption extent on the materials was determined using high-performance liquid chromatography. The obtained results were analyzed using an LFER model with Abraham solvation parameters of the drugs. The effect of additives on the sorption of itraconazole, one of the most hydrophobic drugs among those tested in this study, was investigated.

RESULTS

Sorption was dependent on the physicochemical properties of drugs, rather than the type of materials used, and additives altered the rate of drug sorption. Equations were developed to evaluate the sorption extent (nmol) of drugs to glass and polypropylene using the Abraham solvation parameters of the drugs.

CONCLUSIONS

LFER modeling with Abraham solvation parameters of drugs enabled us to evaluate drug sorption on materials. All the additives altered the rate of drug sorption, and some organic solvents effectively prevented sorption. The developed LFER model would be useful for assessment of the sorption properties of compounds in in vitro evaluations in drug discovery research and various other biochemical fields.

Development and Validation of a Bioanalytical LC-MS/MS Method for Simultaneous Determination of Sirolimus in Porcine Whole Blood and Lung Tissue and Pharmacokinetic Application with Coronary Stents

Sirolimus is a hydrophobic macrolide compound that has been used for long-term immunosuppressive therapy, prevention of restenosis, and treatment of lymphangioleiomyomatosis. In this study, a simple and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated for the simultaneous determination of sirolimus in both porcine whole blood and lung tissue. Blood and lung tissue homogenates were deproteinized with acetonitrile and injected into the LC-MS/MS system for analysis using the positive electrospray ionization mode. The drug was separated on a C18 reversed phase column with a gradient mobile phase (ammonium formate buffer (5 mM) with 0.1% formic acid and acetonitrile) at 0.2 mL/min. The selected reaction monitoring transitions of m/z 931.5 → 864.4 and m/z 809.5 → 756.5 were applied for sirolimus and ascomycin (the internal standard, IS), respectively. The method was selective and linear over a concentration range of 0.5–50 ng/mL. The method was validated for sensitivity, accuracy, precision, extraction recovery, matrix effect, and stability in porcine whole blood and lung tissue homogenates, and all values were within acceptable ranges. The method was applied to a pharmacokinetic study to quantitate sirolimus levels in porcine blood and its distribution in lung tissue following the application of stents in the porcine coronary arteries. It enabled the quantification of sirolimus concentration until 2 and 14 days in blood and in lung tissue, respectively. This method would be appropriate for both routine porcine pharmacokinetic and bio-distribution studies of sirolimus formulations.

Determination of KD025 (SLx-2119), a Selective ROCK2 Inhibitor, in Rat Plasma by High-Performance Liquid Chromatography-Tandem Mass Spectrometry and its Pharmacokinetic Application

KD025 (SLx-2119), the first specific Rho-associated protein kinase 2 (ROCK2) inhibitor, is a potential new drug candidate currently undergoing several phase 2 clinical trials for psoriasis, idiopathic pulmonary fibrosis, chronic graft-versus-host disease, and systemic sclerosis. In this study, a bio-analytical method was developed and fully validated for the quantification of KD025 in rat plasma and for application in pharmacokinetic studies. KD025 and GSK429286A (the internal standard) in rat plasma samples were analyzed by high-performance liquid chromatography-tandem mass spectrometry with m/z transition values of 453.10 → 366.10 and 433.00 → 178.00, respectively. The method was fully validated according to the United State Food and Drug Administration guidelines in terms of selectivity, linearity, accuracy, precision, sensitivity, matrix effects, extraction recovery, and stability. The method enabled the quantification of KD025 levels in rat plasma following oral administration of 5 mg/kg KD025 and intravenous administration of 2 mg/kg KD025 to rats, respectively. Our findings suggest that the developed method is practical and reliable for pharmacokinetic studies of KD025 in preclinical animals.

Pharmacokinetics and relative bioavailability of meloxicam oil suspension in pigs after intramuscular administration

This study aimed to develop one novel meloxicam (MEL) oil suspension for sustained-release and compare the pharmacokinetic characteristics of it with MEL conventional formulation in pigs after a single intramuscular administration. Six healthy pigs were used for the study by a crossover design in two periods with a withdrawal interval of 14 days. Plasma concentrations of MEL were measured by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Pharmacokinetic parameters were calculated by noncompartmental methods. The difference was statistically significant (p < .05) between MEL oil suspension and MEL conventional formulation in pharmacokinetic parameters of mean residence time (6.16 ± 4.04) hr versus (2.66 ± 0.55) hr, peak plasma concentration (C_max ) (0.82 ± 0.12) µg/ml versus (1.12 ± 0.22) µg/ml, time needed to reach C_max (T_max ) (2.33 ± 0.82) hr versus (0.59 ± 0.18) hr, and terminal elimination half-life (t_1/2λz ) (3.74 ± 2.66) hr versus (1.55 ± 0.37) hr. The mean area under the concentration-time curve (AUC_0-∝ ) of MEL oil suspension and MEL conventional formulation was 5.35 and 3.43 hr µg/ml, respectively, with a relative bioavailability of 155.98%. Results of the present study demonstrated that the MEL oil suspension could prolong the effective time of drugs in blood, thereby reducing the frequency of administration on a course of treatment. Therefore, the novel MEL oil suspension seems to be of great value in veterinary clinical application.