Risks of Powder Flow Obstruction in Hopper and Bin Discharge in Solid Dosage Form Manufacture should be Predicted Under The Active Stress State.

Discharge of powder from a hopper or bin is a common operation in solid dosage form manufacture. Powder flow obstruction during hopper/bin discharge, such as arching or ratholing, remains an outstanding risk and cannot be reliably diagnosed using the existing flow function coefficient-based method. In this study, we showed that the major principal stress (σ1) at the bin outlet is required for an accurate prediction of powder flow obstruction risks. We noted that powder is susceptible to flow obstruction when the unconfined yield strength exceeds the stress facilitating powder failure. We presented a complete model to calculate the stress conditions and subsequently predict flow obstruction risks in hopper/bin discharge based on this criterion. The method was experimentally verified by hopper/bin discharge experiments encompassing 10 powder blends and 2 equipment systems. Importantly, we showed that the active stress state assumption should be employed for the powder flow obstruction prediction because σ1 is high and powder is more susceptible to flow obstruction. Prediction under the passive stress state can lead to significant under-estimation of flow obstruction risks. Therefore, the hopper design protocol, which assumes the passive stress state in arching prediction, should not be indiscriminately used toward pharmaceutical powder flow applications.

An implementation evaluation of the physical activity counseling for in-patients with major depressive disorder (PACINPAT) intervention: a randomized controlled trial.

BACKGROUND: The physical activity counseling for in-patients with major depression (PACINPAT) randomized controlled trial was launched to tackle physical inactivity for in-patients with major depressive disorder. Evidence shows that despite potential treatment effects, physical inactivity is prevalent in this population. To contribute to the assessment of how this in-person and remote, theory-based, individually tailored intervention was designed, received and effected behavior, the aim of this study was to evaluate its implementation. METHODS: This implementation evaluation was conducted within a multi-center randomized controlled trial according to the Process Evaluation Framework by the Medical Research Council including the analysis of reach, dose, fidelity and adaptation. Data were collected from the implementers and the participants randomized to the intervention group of the trial. RESULTS: The study sample comprised 95 physically inactive in-patients (mean age: 42 years, 53% women) with diagnosed major depressive disorder. The intervention reached the intended population (N = 95 in-patients enrolled in the study). The intervention dose varied between early dropouts (counseling sessions, M = 1.67) and study completers with some participants receiving a low dose (counseling sessions, M = 10.05) and high dose (counseling sessions, M = 25.37). Differences in the attendance groups were recognizable in the first two counseling sessions (duration of counseling session about 45 min in early dropouts versus 60 min for study completers). Fidelity of the in-person counseling content was partly achieved and adapted, whereas that of the remote counseling content was well achieved. Participants (86% at follow up) reported satisfaction with the implementers of the intervention. Adaptations were made to content, delivery mode and dose. CONCLUSION: The PACINPAT trial was implemented in the intended population, in varying doses and with adaptations made to in-person counseling content and remote counseling dose. These findings are key to understanding outcome analyses within the PACINPAT trial, further developing interventions and contributing to implementation research among in-patients with depressive disorders. TRIAL REGISTRATION: ISRCTN, ISRCTN10469580 , registered on 3rd September 2018.

Theoretical and Experimental Evaluation of Flow Pattern of Pharmaceutical Powder Blends Discharged From Intermediate Bulk Containers (IBCs).

The purpose of this study is to assess the prevalence of funnel flow pattern for common pharmaceutical powder blends, upon discharging from modern intermediate bulk containers (IBCs) in drug product manufacturing. The estimation was built upon Jenike's original radial stress field theory. It was modified to account for the stress-dependence of wall friction angle commonly observed in pharmaceutical powders. A total of 260 flow pattern estimations, based on 20 real-life IBCs and 13 investigational powder blends, were made. The estimated results showed that the mass flow pattern is present in less than 5% of all cases. Funnel flow pattern is clearly prevalent among pharmaceutical powder blends. The prevalence of funnel flow stems from several factors: 1) relatively shallow hopper section shared by all IBCs, 2) the common transition-type geometry, leading to even shallower hopper inclination at the edge of the hopper section, and 3) relatively high wall friction angles resulting from low wall normal stresses. This conclusion was verified through at-scale experiments, by discharging multiple pharmaceutical powder blends from a representative IBC. In general, our study suggests that, unless the powder wall friction can be substantially reduced, pharmaceutical powders are likely to discharge under funnel flow from modern IBCs.

Feeding of particle-based materials in continuous solid dosage manufacturing: a material science perspective.

The pharmaceutical industry today is experiencing a paradigm shift from batch to continuous manufacturing, which promises greater flexibility to target diverse populations, as well as more-consistent product quality to ensure best efficacy. However, shifting to continuous processing means that even basic process steps, such as feeding, can become unexpected but are crucially important. In this review, we will present the fundamental differences between dispensing (batch) and feeding (continuous) and how they impact the formulation design space. We will further outline our rational development approach, applicable to continuous unit operations in general, which includes standardized material and process characterization, as well as predictive modeling based on advanced, multidomain simulation tools.

Formulating Amorphous Solid Dispersions: Impact of Inorganic Salts on Drug Release from Tablets Containing Itraconazole-HPMC Extrudate.

Amorphous solid dispersions (ASD) are increasingly used to improve the oral bioavailability of poorly water-soluble compounds. However, hydrophilic polymers in ASD have high water-binding properties and, upon water contact, they often form a gel on the surface of the tablet, impacting the rate and extent of drug release. Most inorganic salts decrease water solubility of organic solutes, changing the gel properties of hydrophilic polymers. In this study, the effect of inorganic salts on drug release from a tablet formulation containing an itraconazole (ITZ)-hydroxypropyl methyl cellulose (HPMC) extrudate was investigated. The cloud point of a 1% HPMC solution with and without inorganic salts (KCl, KH2PO4, KHCO3, and potassium iodate (KI)) was determined to classify the salts according to their salting-out or salting-in effect. A kosmotropic effect on HPMC was observed for KCl, KH2PO4, and KHCO3, whereas KI exhibited a chaotropic effect. To prove the effect of these salts on drug release, tablets containing 66% of ITZ-HPMC extrudate (20:80 w/w %), 4% croscarmellose sodium, 30% microcrystalline cellulose, and different types and amounts of KHCO3, KH2PO4, KCl, and KI were compressed (same solid fraction of 0.83-0.85). Tablets without salts showed a slow release and low peak concentrations during dissolution in simulated gastric fluids. By adding the kosmotropic salts to the tablets, the rate and extent of drug release were increased, whereas the chaotropic anion iodide had no effect. The effect was pronounced even with the addition of as little as 2% of inorganic salts and tended to increase with the increasing amount of salt in the formulation. Tablets without salt stored under either dry or humid conditions exhibited a large difference in dissolution profiles, whereas little variation was observed for tablets with kosmotropic salts. In conclusion, the effect of inorganic salts was mechanistically clarified on ASD containing commonly used HPMC. This approach can be beneficial to successfully develop robust formulations containing ASD.

A Miniaturized Extruder to Prototype Amorphous Solid Dispersions: Selection of Plasticizers for Hot Melt Extrusion.

Hot-melt extrusion is an option to fabricate amorphous solid dispersions and to enhance oral bioavailability of poorly soluble compounds. The selection of suitable polymer carriers and processing aids determines the dissolution, homogeneity and stability performance of this solid dosage form. A miniaturized extrusion device (MinEx) was developed and Hypromellose acetate succinate type L (HPMCAS-L) based extrudates containing the model drugs neurokinin-1 (NK1) and cholesterylester transfer protein (CETP) were manufactured, plasticizers were added and their impact on dissolution and solid-state properties were assessed. Similar mixtures were manufactured with a lab-scale extruder, for face to face comparison. The properties of MinEx extrudates widely translated to those manufactured with a lab-scale extruder. Plasticizers, Polyethyleneglycol 4000 (PEG4000) and Poloxamer 188, were homogenously distributed but decreased the storage stability of the extrudates. Stearic acid was found condensed in ultrathin nanoplatelets which did not impact the storage stability of the system. Depending on their distribution and physicochemical properties, plasticizers can modulate storage stability and dissolution performance of extrudates. MinEx is a valuable prototyping-screening method and enables rational selection of plasticizers in a time and material sparing manner. In eight out of eight cases the properties of the extrudates translated to products manufactured in lab-scale extrusion trials.