Evaluation of different in vitro dissolution tests based on level A in vitro–in vivo correlations for fenofibrate self-emulsifying lipid-based formulations

An Intravenous Pharmacokinetic Study of Cannabidiol Solutions in Piglets through the Application of a Validated Ultra-High-Pressure Liquid Chromatography Coupled to Tandem Mass Spectrometry Method for the Simultaneous Quantification of CBD and Its Carboxylated Metabolite in Plasma

Cannabidiol (CBD) has multiple therapeutic benefits that need to be maximized by optimizing its bioavailability. Numerous formulations are therefore being developed and their pharmacokinetics need to be studied, requiring analytical methods and data from intravenous administration. As CBD is susceptible to hepatic metabolism, the requirement of any method is to quantify metabolites such as 7-COOH-CBD. We demonstrated that CBD and 7-COOH-CBD could be simultaneously and correctly quantified in piglet plasma by using an UHPLC-MS/MS technique. The validated method allowed for an accurate bioanalysis of an intravenously injected solution consisting of CBD-HPβCD complexes. The experimental pharmacokinetic profile of CBD showed multi-exponential decay characterized by a fast apparent distribution half-life (0.25 h) and an elimination half-life of two hours. The profile of 7-COOH-CBD was not linked with the first-pass metabolism, since 80% of the maximum metabolite concentration was reached at the first sampling time point, without any decrease during the period of study. A two-compartment model was optimal to describe the experimental CBD profile. This model allowed us to calculate macro-micro constants and volumes of distribution (Vss = 3260.35 ± 2286.66 mL) and clearance (1514.5 ± 261.16 mL·h-1), showing that CBD is rapidly distributed to peripheral tissues once injected and slowly released into the bloodstream.

Design and Characterization of HY-038 Solid Dispersions via Spray Drying Technology: In Vitro and In Vivo Evaluations

The aim of this study was to prepare HY-038 solid dispersions (SDs) with single carrier at high drug loading and then forming a tablet to enhance solubility, dissolution, and bioavailability via spray drying technology. At the same time, we hope to develop a more convenient in vitro method to predict the absorption behavior of different formulations in vivo. Different solid dispersions, varying in drug/polymer ratios, were prepared. Infrared spectroscopy, differential scanning calorimetry, scanning electron microscope, and X-ray diffraction were used to perform solid-state characterizations of the pure drug and SDs. Contact angle of water, dissolution in pH = 6.8 phosphate buffer, and in vivo absorption in dogs were studied. As a result, solid-state characterization demonstrated the transformation of the crystalline HY-038 to an amorphous state in the solid dispersions, and the in vivo exposure followed with the trend of the dissolution curve combined with contact angle. Compared with the prototype formulation, the C_max and AUC_0-∞ of optimized formulation SD2 (HY-038-HPMCAS 3:1) increased by about 5 ~ 9 times at the same dose. More importantly, the SD2 formulation showed approximately linear increases in C_max and AUC_0-∞ as the dose increased from 50 to 100 mg, while the prototype formulation reached absorption saturation at 50 mg. SD2 (HY-038-HPMCAS 3:1) was selected as the best formulation for the downstream development.

In vivo dissolution of poorly water-soluble drugs: Proof of concept based on fluorescence bioimaging

In vitro‒in vivo correlation (IVIVC) of solid dosage forms should be established basically between in vitro and in vivo dissolution of active pharmaceutical ingredients. Nevertheless, in vivo dissolution profiles have never been accurately portrayed. The current practice of IVIVC has to resort to in vivo absorption fractions (F_a). In this proof-of-concept study, in vivo dissolution of a model poorly water-soluble drug fenofibrate (FNB) was investigated by fluorescence bioimaging. FNB crystals were first labeled by near-infrared fluorophores with aggregation-caused quenching properties. The dyes illuminated FNB crystals but quenched immediately and absolutely once been released into aqueous media, enabling accurate monitoring of residual drug crystals. The linearity established between fluorescence and crystal concentration justified reliable quantification of FNB crystals. In vitro dissolution was first measured following pharmacopoeia monograph protocols with well-documented IVIVC. The synchronicity between fluorescence and in vitro dissolution of FNB supported using fluorescence as a measure for determination of dissolution. In vitro dissolution correlated well with in vivo dissolution, acquired by either live or ex vivo imaging. The newly established IVIVC was further validated by correlating both in vitro and in vivo dissolution with F_a obtained from pharmacokinetic data.

Shared IVIVR for Five Commercial Enabling Formulations Using the BiPHa+ Biphasic Dissolution Assay

The present study intended to confirm the in vivo relevance of the BiPHa+ biphasic dissolution assay using a single set of assay parameters. Herein, we evaluated five commercial drug products formulated by various enabling formulation principles under fasted conditions using the BiPHa+ assay. The in vitro partitioning profiles in the organic phase were compared with human pharmacokinetic data obtained from literature. In the first part, a meaningful in vitro dose of the formulations was assessed by determining the maximum drug concentration in the artificial absorption sink during dissolution (organic 1-decanol layer, C_dec,max). Then, the maximum concentration of the partitioned drug in the organic layer was correlated with the in vivo fraction absorbed, which was derived from published human pharmacokinetic data. Fraction absorbed represents the percentage, which is absorbed from the intestine without considering first pass. It was found that the maximum drug concentration in the organic phase obtained from an in vitro dose of ten milligrams, which is equivalent to 15–25 µmol of the respective drug, led to the highest congruency with the fraction absorbed in vivo. In the second part, the in vivo relevance of the BiPHa+ dissolution data was verified by establishing a shared in vitro/in vivo relationship including all formulations. Based on the in vitro kinetics of the BiPHa+ experiments human in vivo plasma profiles were predicted using convolutional modelling approach. Subsequently, the calculated pharmacokinetic profiles were compared with in vivo performance of the studied drug products to assess the predictive power of the BiPHa+ assay. The BiPHa+ assay demonstrated biorelevance for the investigated in vitro partitioning profiles using a single set of assay parameters, which was verified based on human pharmacokinetic data of the five drug products.

Self-Nanoemulsifying Drug Delivery Systems (SNEDDS) Containing Rice Bran Oil for Enhanced Fenofibrate Oral Delivery: In Vitro Digestion, Ex Vivo Permeability, and In Vivo Bioavailability Studies

Lipid-based drug delivery systems (LbDDS), such as self-nanoemulsifying drug delivery systems (SNEDDS), constitute a prominent formulation approach for enhancing the aqueous solubility and oral bioavailability of poorly water-soluble compounds. Utilization of biorefinery wastes, such as oil from rice bran, may prove advantageous to both improving drug solubilization and absorption and to achieving sustainable agri-food waste valorization. Here, we assessed the effect of four SNEDDS compositions differing in the oil (rice bran oil and corn oil) and surfactant type (Kolliphor RH40 and EL) on the oral bioavailability of fenofibrate, a BCS class II compound. Prior to the in vivo oral administration of the SNEDDS in rats, drug solubilization was tested in vitro using the static digestion model, followed by the ex vivo permeability study of the predigested SNEDDS using the non-everted gut sac model. No significant variation was observed in the solubilization capacity within the different SNEDDS formulations. On the other hand, the ex vivo permeability data of the predigested SNEDDS correlated well with the in vivo bioavailability data designating the superiority of rice bran oil with Kolliphor EL as the surfactant, to enhance the oral absorption of fenofibrate. Results indicated that valorization of agro-industrial waste such as rice bran oil may prove useful in enhancing the oral performance of LbDDS in the case of fenofibrate, while at the same time maximizing the use of agricultural by-products via the creation of new sustainable value chains in the pharmaceutical field.

Biphasic Dissolution as an Exploratory Method During Early Drug Product Development

Dissolution testing is a major tool used to assess a drug product's performance and as a quality control test for solid oral dosage forms. However, compendial equipment and methods may lack discriminatory power and the ability to simulate aspects of in vivo dissolution. Using low buffer capacity media combined with an absorptive phase (biphasic dissolution) increases the physiologic relevance of in vitro testing. The purpose of this study was to use non-compendial and compendial dissolution test conditions to evaluate the in vitro performance of different formulations. The United States Pharmacopeia (USP)-recommended dissolution method greatly lacked discriminatory power, whereas low buffer capacity media discriminated between manufacturing methods. The use of an absorptive phase in the biphasic dissolution test assisted in controlling the medium pH due to the drug removal from the aqueous medium. Hence, the applied non-compendial methods were more discriminative to drug formulation differences and manufacturing methods than conventional dissolution conditions. In this study, it was demonstrated how biphasic dissolution and a low buffer capacity can be used to assess in vitro drug product performance differences. This can be a valuable approach during the early stages of drug product development for investigating in vitro drug release with improved physiological relevance.

A Rational Design of a Biphasic DissolutionSetup-Modelling of Biorelevant Kinetics for a Ritonavir Hot-Melt Extruded Amorphous Solid Dispersion

Biphasic dissolution systems achieved good predictability for the in vivo performance of several formulations of poorly water-soluble drugs by characterizing dissolution, precipitation, re-dissolution, and absorption. To achieve a high degree of predictive performance, acceptor media, aqueous phase composition, and the apparatus type have to be carefully selected. Hence, a combination of 1-decanol and an optimized buffer system are proposed as a new, one-vessel biphasic dissolution method (BiPHa+). The BiPHa+ was developed to combine the advantages of the well-described biorelevance of the United States Pharmacopeia (USP) apparatus II coupled with USP apparatus IV and a small-scale, one-vessel method. The BiPHa+ was designed for automated medium addition and pH control of the aqueous phase. In combination with the diode array UV-spectrophotometer, the system was able to determine the aqueous and the organic medium simultaneously, even if scattering or overlapping of spectra occurred. At controlled hydrodynamic conditions, the relative absorption area, the ratio between the organic and aqueous phase, and the selected drug concentrations were identified to be the discriminating factors. The performance of a hot-melt extruded ritonavir-containing amorphous solid dispersion (ritonavir-ASD) was compared in fasted-state dissolution media leading to different dissolution-partitioning profiles depending on the content of bile salts. An advanced kinetic model for ASD-based well described all phenomena from dispersing of the ASD to the partitioning of the dissolved ritonavir into the organic phase.

Evaluating supersaturation in vitro and predicting its performance in vivo with Biphasic gastrointestinal Simulator: A case study of a BCS IIB drug

This study aimed to develop an evaluation approach for supersaturation by employing an in vitro bio-mimicking apparatus designed to predict in vivo performance. The Biphasic Gastrointestinal Simulator (BGIS) is composed of three chambers with absorption phases that represent the stomach, duodenum, and jejunum, respectively. The concentration of apatinib in each chamber was detected by fiber optical probes in situ. The dissolution data and the pharmacokinetic data were correlated by Gastroplus^TM. The precipitates were characterized by polarizing microscope, Scanning Electron Microscopy, Powder X-ray diffraction and Differential scanning calorimetry. According to the results, Vinylpyrrolidone-vinyl acetate copolymer (CoPVP) prolonged supersaturation by improving solubility and inhibiting crystallization, while Hydroxypropyl methylcellulose (HPMC) prolonged supersaturation by inhibiting crystallization alone. Furthermore, a predictive in vitro-in vivo correlation was established, which confirmed the anti-precipitation effect of CoPVP and HPMC on in vitro performance and in vivo behavior. In conclusion, CoPVP and HPMC increased and prolonged the supersaturation of apatinib, and then improved its bioavailability. Moreover, BGIS was demonstrated to be a significant approach for simulating in vivo conditions for in vitro-in vivo correlation in a supersaturation study. This study presents a promising approach for evaluating supersaturation, screening precipitation inhibitors in vitro, and predicting their performances in vivo.

Critical In Vitro Characterization Methods of Lipid-Based Formulations for Oral Delivery: a Comprehensive Review

Lipids have been extensively used in formulations to enhance dissolution and bioavailability of poorly water-soluble as well as water-soluble drug molecules. The digestion of lipid-based formulations, in the presence of bile salts, phospholipids, and cholesterol, changes the lipid composition in vivo, resulting in the formation of different colloidal phases in the intestine. Therefore, in vitro characterization and evaluation of such formulations are critical in developing a successful formulation. This review covers comprehensive discussion on in vitro characterization techniques such as solubility, drug entrapment, thermal characterization, dissolution, and digestion of lipid-based formulations.

Studies on Core-Shell Nanocapsules of Felodipine: In Vitro-In Vivo Evaluations

The present study aimed for in vitro-in vivo-in silico simulation studies of experimentally designed (3²-factorial) Capmul PG-8-cored, Eudragit RSPO-Lutrol F 127 nanocapsules to ferry felodipine using GastroPlus™. The in silico parameter sensitivity analysis for pharmacokinetic parameters was initially assessed to justify the preparation of felodipine-loaded nanocapsules (FLNs) with enhanced solubility to overcome the bioavailability issues of felodipine. The overall integrated desirability ranged between 0.8187 and 0.9488 for three optimized FLNs when analyzed for mean particle size, zeta potential, encapsulation efficiency, and in vitro dissolution parameters. The morphological evaluation (SEM, TEM, and AFM) demonstrated spherical nanoparticles (200-300 nm). Validated LC-MS/MS analysis demonstrated enhanced relative bioavailability (13.37-fold) of optimized FLN as compared to suspension. The simulated regional absorption of the FLN presented significant absorption from the cecum (26.3%) and ascending colon (20.1%) with overall absorption of 67.4% from the GIT tract. Furthermore, in vitro-in vivo correlation demonstrated the Wagner-Nelson method as the preferred model as compared to mechanistic and numerical deconvolution on the basis of least mean absolute prediction error, least standard error of prediction, least mean absolute error, and maximum correlation coefficient (r ² = 0.920). The study demonstrated enhanced oral absorption of felodipine-loaded nanocapsules, and GastroPlus™ was found to be an efficient simulation tool for in vitro-in vivo-in silico simulations.

Developing Quantitative In Vitro-In Vivo Correlation for Fenofibrate Immediate-Release Formulations With the Biphasic Dissolution-Partition Test Method

This study is to evaluate 3 fenofibrate (FEN) formulations including Fournier® 200 mg capsule, Lipidil® 145 mg tablet, and a clinical HME 160 mg tablet by an in vitro biphasic method. Key experimental parameters were evaluated including the selection of biorelevant media, the United States Pharmacopeia IV flow rate, and the United States Pharmacopeia paddle speed. Varying the hydrodynamic condition resulted in a significant impact on FEN concentration time profiles in both aqueous and octanol phases for these formulations. In vivo pharmacokinetic profiles of the HME tablet, the Lipidil tablet, and Fournier capsule under the fasting and low-fat fed states are reported. Their corresponding absorption-time profiles were obtained through deconvolution by the Wagner-Nelson method. When fed state simulated intestinal fluid version 2 was used, the partitioned FEN amount-time profiles in octanol from the 3 formulations under an appropriate hydrodynamic condition exhibited a good agreement with their in vivo absorbed amount-time profiles, permitting a quantitative in vitro-in vivo correlation. When fasted state simulated intestinal fluid version 2 was used, partitioned FEN amounts into octanol from these formulations are significantly lower than those from in vivo data. Although no food effect was observed for both HME and Lipidil tablets, the positive food effect of the Fournier capsules significantly overestimated by the biphasic test.