An Artificial Gut/Absorption Simulator: Understanding the Impact of Absorption on In Vitro Dissolution, Speciation, and Precipitation of Amorphous Solid Dispersions.

Upon dissolution, amorphous solid dispersions (ASDs) of poorly water-soluble compounds can generate supersaturated solutions consisting of bound and free drug species that are in dynamic equilibrium with each other. Only free drug is available for absorption. Drug species bound to bile micelles, polymer excipients, and amorphous and crystalline precipitate can reduce the drug solute's activity to permeate, but they can also serve as reservoirs to replenish free drug in solution lost to absorption. However, with multiple processes of dissolution, absorption, and speciation occurring simultaneously, it may become challenging to understand which processes lead to an increase or decrease in drug solution concentration. Closed, nonsink dissolution testing methods used routinely, in the absence of drug removal, allow only for static equilibrium to exist and obscure the impact of each drug species on absorption. An artificial gut simulator (AGS) introduced recently consists of a hollow fiber-based absorption module and allows mass transfer of the drug from the dissolution media at a physiological rate after tuning the operating parameters. In the present work, ASDs of varying drug loadings were prepared with a BCS-II model compound, ketoconazole (KTZ), and hypromellose acetate succinate (HPMCAS) polymer. Simultaneous dissolution and absorption testing of the ASDs was conducted with the AGS, and simple analytical techniques were utilized to elucidate the impact of bound drug species on absorption. In all cases, a lower amount of crystalline precipitate was formed in the presence of absorption relative to the nonsink dissolution "control". However, formation of HPMCAS-bound drug species and crystalline precipitate significantly reduced KTZ absorption. Moreover, at high drug loading, inclusion of an absorption module was shown to enhance ASD dissolution. The rank ordering of the ASDs with respect to dissolution was significantly different when nonsink dissolution versus AGS was used, and this discrepancy could be mechanistically elucidated by understanding drug dissolution and speciation in the presence of absorption.

Accelerated and Biopredictive In Vitro Release Testing Strategy for Single Agent and Combination Long-Acting Injectables.

The purpose of this study was to develop an in vitro release testing (IVRT) strategy to predict the pre-clinical performance of single agent and combination long acting injectable (LAI) suspension products. Two accelerated IVRT methods were developed using USP apparatus 2 to characterize initial, intermediate, and terminal phases of drug release. Initial and intermediate phases were captured using a suspension cup with moderate agitation to ensure a constant, low surface area exposure of the LAI suspension to the release media. The terminal phase was obtained by exposing the LAI suspension to a high initial paddle speed. This resulted in smaller suspension particulates with high cumulative surface area that were dispersed throughout the release media, enabling rapid drug release. The in vitro release profiles obtained with these two methods in 48 h or less were independently time scaled to reflect the in vivo time scale of approximately 1800 h. Level-A in vitro in vivo correlations (IVIVCs) were separately developed for each method and active pharmaceutical ingredient (API) using in vivo absorption profiles obtained by deconvolution of rat plasma concentration-time profiles. The IVIVCs were successfully validated for each API. This work provides a framework for evaluating individual phases of drug release of complex LAIs to ultimately predict their in vivo performance.

Predetermination of burst times of elastoplastic osmotic capsules.

"Pulsed drug release" for dosing drugs such as vaccines, hormones etc. that require multiple, predetermined release events can be obtained by using capsules that exploit the principle of osmosis to achieve a delayed burst release of their payload. An objective of this study was to precisely determine the lag time before burst which occurs when the hydrostatic pressure developed due to water influx expands the capsule shell to rupture. A novel 'dip coating' technique was used to encapsulate osmotic agent solution or solid within biodegradable poly(lactic acid-co-glycolic) (PLGA) spherical capsule shells. As a prelude to determine the hydrostatic pressure to burst, first, elastoplastic and failure characterization of PLGA was conducted by a novel "beach ball inflation" technique. The lag time before burst of various capsule configurations was predetermined by modeling the rate of water uptake by the capsule core as a function of capsule shell thickness, radius of the sphere, core osmotic pressure, and the membrane's hydraulic permeability and tensile properties. In vitro release was studied with capsules of different configurations to determine their actual time to burst. The time to rupture predetermined from the mathematical model corroborated with the in vitro results and was found to increase with increases in capsule radius and shell thickness and decrease in osmotic pressure. Pulsatile drug delivery can be achieved by using a multitude of these osmotic capsules consolidated in a single system, each programmed to release the drug payload after a pre-determined time lag.

Knowledge, Awareness, and Understanding of Pediatric Triage Among Nursing Officers in India: A Multicenter Study.

INTRODUCTION:  Triage is crucial in patient screening within emergency departments (EDs) worldwide. It is one of the essential and standard medical practices in many developed countries. However, in India, there is a need for improvement in triage utilization, as it is predominantly performed by resident doctors or medical officers, leading to an uneven distribution of clinical skills among healthcare providers (HCPs). A comprehensive analysis incorporating literature review and data collection revealed that while mandatory screening is conducted in most Indian EDs, the formal implementation of standardized triage protocols remains limited. Like in developed countries, registered nurses or nursing officers (NOs) can be effectively trained and directed to play the role of dedicated triage personnel in EDs of most of the healthcare facilities in India. METHOD AND MATERIALS:  This study aimed to examine the current state of triage utilization and its impact on the distribution of responsibilities among HCPs in Indian EDs. Through this online survey, the investigators assessed the knowledge and practical understanding of clinical triaging among NOs, working at various hospitals nationwide. RESULTS:  The participants included 5,029 NOs working in various parts of India, predominantly nursing graduates (82.52%), the majority being employed in government healthcare settings (84.01%) and most having over five years of cumulative working experience in the ED (70.77%). Nurses showed inadequate knowledge and awareness about the Pediatric Assessment Triangle (PAT) used for quick initial evaluation (62.18% among all participants). Concerning the complete triage process applicable, especially in pediatric ED settings, they had even less satisfactory knowledge and understanding, e.g., identifying primary (28.27%) and secondary (22.69%) survey components via focused history and examination, properly using temperature assessment (23.32%) and instant blood glucose level assessment (22.95%) in triage, and knowing various types of internationally accepted triage systems for ED-based health facilities such as the Emergency Severity Index (ESI), Canadian Triage and Acuity Scale (CTAS), and Australasian Triage Scale (ATS) (15.87%). ANOVA and post hoc analysis revealed that the intergroup performance of the study participants with maximum correct responses to the knowledge-determining specified subset of the questionnaire depicts the significantly higher role of graduate nursing degree over diploma such as General Nursing and Midwifery (GNM)/Auxiliary Nursing and Midwifery (ANM) qualification, working in government hospital versus private setup, and ED working experience of >5 years over that of <5 years. CONCLUSIONS:  Of the participants in the study, 50% were not evaluated for cognitive or psychomotor domains during their assessment examinations. The research illuminated a significant disparity in knowledge and proficiency levels among Indian nurses concerning pediatric triage, especially with the ability to effectively apply the PAT for initial patient evaluations, discern components of primary and secondary surveys, and comprehend various triage systems. This study underscores the importance of comprehensive reform in the Indian healthcare system and teaching curriculum by emphasizing clinical triage training and interprofessional collaboration, and establishing guidelines and regulations to ensure consistent and standardized triage practices across all EDs.

An Artificial Gut/Absorption Simulator: Simultaneous Evaluation of Desupersaturation and Absorption from Ketoconazole Supersaturated Solutions.

For supersaturating formulations of BCS-II compounds, which by definition have high intestinal permeability, a closed USP apparatus does not provide the necessary absorptive conditions during dissolution. To address this, an artificial gut simulator (AGS) has been constructed consisting of a 2.5 mL donor compartment in which a hollow fiber-based absorption module is suspended. Drug from donor diffuses across the hollow fiber membrane to be absorbed by the continuously flowing intraluminal receiver fluid. The membrane surface area and intraluminal fluid flow rate are tuned to obtain the physiologically observed absorption rate constant for a weakly basic, poorly water-soluble model compound, ketoconazole (KTZ). Supersaturated solutions of KTZ were generated in the donor in pH 6.5 phosphate buffer by the pH-shift method in the absence (closed system, control) and presence (open system, biorelevant) of an optimally or suboptimally tuned absorption module. Drug concentrations in the donor and intraluminal fluids were determined by in-line UV spectroscopy. The presence of an absorptive sink reduced the supersaturated solution's crystallization propensity, more so in the case of the optimally tuned AGS. This study demonstrates the significance of simulating absorption of drug at a physiological rate during dissolution studies, especially to predict the performance of formulations of BCS-II drugs.

An Artificial Gut/Absorption Simulator: Description, Modeling, and Validation Using Caffeine.

The purpose of this study was to develop and validate a simultaneous dissolution and absorption testing tool, the "artificial gut simulator" (AGS), for oral drug formulations. The AGS was constructed using hollow fibers and housed in a 3-mL UV spectrophotometric cuvette that provided a large surface area-to-volume ratio to simulate absorption at a physiological rate. A quasi-steady-state model describing absorption was developed and validated using a high aqueous solubility, BCS-I model compound, caffeine. This model was used to optimize the AGS operating parameters to simulate physiological gastric emptying and caffeine absorption, which was further input into a one-compartment pharmacokinetic (PK) model. The in vivo caffeine plasma concentration-time profiles matched those predicted by the PK model with in vitro input from the AGS. This work provides a framework for establishing an in vitro/in vivo correlation with high-permeability, BCS-II supersaturating drug formulations, which will be explored in the future studies.