In Vitro-In Vivo Predictive Dissolution-Permeation-Absorption Dynamics of Highly Permeable Drug Extended-Release Tablets via Drug Dissolution/Absorption Simulating System and pH Alteration

Impact of sink conditions on drug release behavior of controlled-release formulations

Developing a controlled release (CR) formulations is a complex and iterative process, often requiring preclinical or clinical studies to establish in vitro-in vivo correlations. This can be particularly challenging for poorly soluble drugs due to the non-sink conditions encountered in vitro. Although compendial dissolution methods (e.g., USP II, IV) have historically been used to understand the dissolution performance of CR formulations, there is increasing interest in more physiologically relevant experimental techniques to improve the predictive ability. In this study, traditional USP apparatus as well as the biorelevant absorptive dissolution apparatus were employed to understand the impact of apparatus type and sink condition on the release mechanisms of CR formulations and in turn evaluate the application of absorptive dissolution apparatus for dissolution testing of CR formulations. Release mechanisms were further analyzed using the Peppas equations, providing additional mechanistic insights. The release behavior showed a strong dependence on sink conditions for drugs with low intrinsic solubility, while highly soluble drugs were unaffected by dissolution conditions. Interestingly, the dissolution mechanism was found to be independent of the apparatus type. The study clearly underscores the importance of considering the sink conditions in developing more predictive and biorelevant dissolution testing methods for CR formulations. Furthermore, the study highlights the potential impact on the sink and resultant differences in the drug release mechanisms as a function of the dose.

Self Nanoelmusifying Drug Delivery System of Rosuvastatin: Bioavailability Evaluation and In vitro - In vivo Correlation

BACKGROUND

Rosuvastatin, most commonly used in the form of calcium salt, belongs to the statin groups of synthetic antihyperlipidemic agents. Rosuvastatin possesses high permeability, however, its aqueous solubility is poor, causing a slow dissolution rate in water. Consequently, this dissolution rate has a decisive role in the release and absorption of rosuvastatin in the gastrointestinal tube.

OBJECTIVE

The aims of this study were to evaluate the absorption of the drug from the self-nano emulsifying drug delivery system of rosuvastatin (Ros SNEDDS) compared to rosuvastatin substance and to develop a level-A in vitro-in vivo correlation (IVIVC) for Ros SNEDDS.

METHODS

An in-house developed LC-MS/MS method was used to determine the concentrations of rosuvastatin in dog plasma. Six beagle dogs received an intravenous dose, Ros SNEDDS, rosuvastatin substance. In vitro dissolution of the Ros SNEDDS was carried out with different conditions. Correlation models were developed from the dissolution and absorption results of Ros SNEDDS.

RESULTS

The results showed a 1.7-fold enhanced oral bioavailability and 2.1-time increase of rosuvastatin Cmax in Ros SNEDDS form, compared to the rosuvastatin substance. A 900 ml dissolution medium of pH of 6.6 has demonstrated its suitability, the in vitro dissolution model was studied and supported by the Weibull equation with a weighting factor of 1/y2 as it presented the lowest values of AIC.

CONCLUSION

Ros SNEDDS demonstrated higher bioavailability of rosuvastatin in comparison to rosuvastatin substance and established a level A IVIVC used in future bioequivalence trials.

Role of Permeability on the Biopredictive Dissolution of Amorphous Solid Dispersions

An ideal dissolution test for amorphous solid dispersions (ASDs) should reflect physicochemical, physiological, and hydrodynamic conditions which accurately represent in vivo dissolution. However, this is confounded by the evolution of different molecular and colloidal species during dissolution, generating a supersaturated state of the drug. The supersaturated state of a drug is thermodynamically unstable which drives the process of precipitation resulting in a loss of solubility advantage. Maintaining a supersaturated state of the drug with the help of precipitation inhibiting excipients is a key component in the design of ASDs. Therefore, a biopredictive dissolution test is critical for proper risk assessment during the development of an optimal ASD formulation. One of the overlooked components of biopredictive dissolution is the role of drug permeability. The kinetic changes in the phase behavior of a drug during dissolution of ASDs are influenced by drug permeability across a membrane. Conventionally, drug dissolution and permeation are analyzed separately although they occur simultaneously in vivo. The kinetic phase changes occurring during dissolution of ASDs can influence the thermodynamic activity and membrane flux of a drug. The present review evaluates the feasibility, predictability, and practicability of permeability/dissolution for the optimal development and risk assessment of ASD formulations.

Portable and automated analyzer for rapid and high precision in vitro dissolution of drugs

We developed a novel portable and automated dissolution test analyzer for rapid and high precision in vitro dissolution testing of drugs. The analyzer consists of a flow-through-cell drug dissolution system, an automated sequential sampling system, a high-speed capillary electrophoresis (HSCE) system, and a data acquisition system. Combining the high-temporal resolution flow-gating sampling approach with HSCE, which has outstanding advantages of efficient separation and resolution, the analyzer can achieve rapid analysis and exhibits the ability in miniaturization for on-site assessment of different active pharmaceutical ingredients. To integrate the flow-through-cell dissolution system with HSCE, a specially designed flow-gating-injection (FGI) interface was employed. The performance of the analyzer was investigated by analyzing the dissolution of immediate-release drugs including single dose (amoxicillin dispersible tablets) and fixed dose combination (amoxicillin and clavulanate potassium) drug tablets with the high-temporal resolutions of 12 s and 20 s, respectively. The dissolution profiles of different active pharmaceutical ingredients could be simultaneously and automatically monitored with high repeatability and accuracy. The analyzer was successfully utilized for the pharmaceutical quality control and bio-relevant dissolution testing, as well as in vivo-in vitro correlation analysis. Our portable analyzer is miniaturized, convenient and of low-cost, and will provide a valuable tool for dissolution testing in pharmaceutical research and development.

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Portable automated analyzer for rapid and high precision dissolution of drugs.

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Miniaturized, low-cost and battery-powered with high repeatability and accuracy.

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Successful applications in QC, bio-relevant dissolution and IVIVC analysis of drugs.

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Universal applicability for both immediate-release and fixed dose combination drugs.

A differential equation based modelling approach to predict supersaturation and in vivo absorption from in vitro dissolution-absorption system (idas2) data

In vitro dissolution tests are widely used to monitor the quality and consistency of oral solid dosage forms, but to increase the physiological relevance of in vitro dissolution tests, newer systems combine dissolution and permeation measurements. Some of these use artificial membranes while others (e.g., in the in vitro dissolution absorption system 2; IDAS2), utilize cell monolayers to assess drug permeation. We determined the effect of the precipitation inhibitor Hypromellose Acetate Succinate (HPMCAS) on the supersaturation/permeation of Ketoconazole and Dipyridamole in IDAS2 and its effect on their absorption in rats. Thus the main objectives of this study were to determine: (1) whether dissolution and permeation data from IDAS2 could be used to predict rat plasma concentration using an absorption model and (2) whether the effect of the precipitation inhibitor HPMCAS on supersaturation and permeation in IDAS2 was correlated with its effect on systemic absorption in the rat. Predicted drug concentrations in rat plasma, generated using parameters estimated from IDAS2 dissolution/permeation data and a mathematical absorption model, showed good agreement with measured concentrations. While in IDAS2, the prolongation of Ketoconazole's supersaturation caused by HPMCAS led to higher permeation, which paralleled the higher systemic absorption in rats, Dipyridamole showed no supersaturation and, thus, no effect of HPMCAS in dissolution or permeation in IDAS2 and no effect on Dipyridamole absorption in rats. The ability of IDAS2 to detect supersaturation following a pH-shift supports the potential value of this system for studying approaches to enhance intestinal absorption through supersaturation and the accuracy of plasma concentration predictions in rats suggest the possibility of combining IDAS2 with absorption models to predict plasma concentration in different species.

Determination of the Dissociation Constants of 16 Active Ingredients in Medicinal Herbs Using a Liquid–Liquid Equilibrium Method

The dissociation constant is an important physicochemical property of drug molecules that affects the pharmacokinetic and pharmacodynamic properties of drugs. In this study, the distribution coefficients of 16 active ingredients extracted from herbal materials were determined at different pH values in liquid–liquid equilibrium systems; the active ingredients were sinomenine, aescin A, aescin B, aescin C, aescin D, chlorogenic acid, neochlorogenic acid, cryptochlorogenic acid, isochlorogenic acid A, isochlorogenic acid B, isochlorogenic acid C, baicalin, wogonoside, calycosin-7-glucoside, astraisoflavan-7-O-β-D-glucoside, and isomucronulatol 7-O-glucoside. The dissociation constants of these active ingredients were calibrated and compared with reported values. The dissociation constants obtained were close to those reported in other studies, which means that the results of this work are reliable.

In silico prediction of bioequivalence of Isosorbide Mononitrate tablets with different dissolution profiles using PBPK modeling and simulation

AIM

The waiver of bioequivalence (BE) studies is well accepted for Biopharmaceutics Classification System (BCS) class I drugs in form of immediate-release solid oral products. This study aimed to assess whether the rapid dissolution profiles (≥85% in 30 min) was crucial to guarantee bioequivalence of isosorbide mononitrate (ISMN) and then established a clinically relevant dissolution specification (CRDS) for screening BE or non-BE batches.

METHOD

A physiologically based pharmacokinetic (PBPK) model was constructed by integrating clinical and non-clinical data by B²O simulator. The model was verified by an actual clinical study (NMPA registration number: CTR20191360) with 28 healthy Chinese subjects. Then a virtual BE study was simulated to evaluate the bioequivalence of 7 virtual batches of ISMN tablets with different dissolution profiles, and the CRDS was established by integrating the results.

RESULT

The simulated PK behavior of ISMN was comparable to the observed. Even though the batches with slower dissolution were not equivalent to a rapid dissolution profile (≥85% in 30 min), it was demonstrated these batches would exhibit the similar in vivo performance. Meanwhile, the in vitro dissolution specification time point and the percentage of drug release (75% in 45 min) proved to have clinical relevance.

CONCLUSION

The virtual BE simulation by integrating in vitro dissolution profiles into the PBPK model provided a powerful tool for screening formulations, contributing to gaining time and reducing costs in BE evaluations.

Simultaneous Evaluation of Dissolution and Permeation of Oral Drug Solid Formulations for Predicting Absorption Rate-Limiting Factors and In Vitro-In Vivo Correlations: Case Study Using a Poorly Soluble Weakly Basic Drug

Combined dissolution and permeation systems are designed to simultaneously assess the dissolution of a pharmaceutical dosage form and the permeation of dissolved drugs therefrom. However, there were still some limitations on predicting the possible absorption rate-limiting steps and improving the in vitro-in vivo correlation (IVIVC) of a complete dosage form. In this study, the modified biorelevant media with some solubilizers and pH modifiers were integrated into the drug dissolution/absorption simulating system (DDASS). Indapamide, a poorly soluble compound (pKa = 8.8), was selected to validate the applicability of the modified biorelevant media. The elution and permeation dynamics of indapamide were investigated by using appropriate solubilizing agents in the DDASS. The absorption behaviors were analyzed after oral administration of indapamide in beagle dogs. The absorption rate-limiting steps and IVIVCs were predicted from the dissolution-permeation-absorption dynamic parameters. As a result, the absorption fraction of indapamide in the FaSSIF_mod of DDASS was estimated to be approximately 100%, in accordance with its high permeability. The ratios of permeation rate to elution rate were 2.55 and 3.34 for the immediate- and sustained-release tablets of indapamide, respectively, suggesting a dissolution rate-limiting absorption for indapamine. In addition, point-to-point correlations were established between in vitro elution and in vivo absorption by the nonlinear and linear regression analysis ways (r > 0.85). The findings indicate that DDASS is a promising technique to develop improved IVIVCs of a complete dosage form, and the FaSSIF_mod is suitable to predict the possible absorption rate-limiting steps of poorly soluble drugs in DDASS.