Influence of spray nozzle aperture during high shear wet granulation on granule properties and its compression attributes

Effect of hydroxy propyl cellulose grade and foam quality on foam granulation of a high drug load formulation

Foam granulation is a relatively newer wet granulation process whereby foamed binder solutions are added to the powders in the mixer to reduce localized over-wetting encountered during the wet granulation. This study is the first to investigate the effect of binder grade and foam quality on foam granulation process and granule properties of a high drug load formulation. Two different HPC grades, HPC LF (two times more viscous) and HPC EXF at an equivalent 7.4%w/w solution concentration, and foam quality of 50%, 90% and binder solution dripped were added to a high drug load (81%w/w) formulation for wet granulation. The granules were evaluated for compactibility and resultant compact strengths. The 50% foam quality of either HPC LF and HPC EXF resulted in lowest impeller power reading and water activity compared to 90% foam quality or dripped HPC solution. Granules prepared with 50% foam quality also exhibited smaller granule size, wider size distribution and higher specific surface area, resulting in higher compactibility. Whilst the granules prepared with different foamed HPC grades were not significantly different in compression behavior, they were higher in compact strengths, suggesting that foam mixing was more efficient in binder distribution compared to binder liquid penetration and distribution.

In-Depth Understanding of Granule Compression Behavior under Variable Raw Material and Processing Conditions

Tablet manufacturing involves the processing of raw materials through several unit operations. Thus, the mitigation of input-induced variability should also consider the downstream processability of intermediary products. The objective of the present work was to study the effect of variable raw materials and processing conditions on the compression properties of granules containing two active pharmaceutical ingredients (APIs) and microcrystalline cellulose. Differences in compressibility and tabletability of granules were highlighted in function of the initial particle size of the first API, granule polydispersity and fragmentation. Moreover, interactions were underlined with the atomizing pressure. Changing the supplier of the second API was efficiently controlled by adapting the binder addition rate and atomizing pressure during granulation, considering the starting crystal size. By fitting mathematical models on the available compression data, the influence of diluent source on granule compactibility and tabletability was identified. These differences resumed to the ease of compaction, tableting capacity and pressure sensitivity index due to variable water binding capacity of microcrystalline cellulose. Building the design space enabled the identification of suitable API types and the appropriate processing conditions (spray rate, atomizing pressure, compression force) required to ensure the desired tableting performance.

Systematic Study of the Effects of High Shear Granulation Parameters on Process Yield, Granule Size, and Shape by Dynamic Image Analysis

The aim of the work was to analyze the influence of process parameters of high shear granulation on the process yield and on the morphology of granules on the basis of dynamic image analysis. The amount of added granulation liquid had a significant effect on all monitored granulometric parameters and caused significant changes in the yield of the process. In regard of the shape, the most spherical granules with the smoothest surface were formed at a liquid to solid ratio of ≈1. The smallest granules were formed at an impeller speed of 700 rpm, but the granules formed at 500 rpm showed both the most desirable shape and the highest process yield. Variation in the shape factors relied not only on the process parameters, but also on the area equivalent diameter of the individual granules in the batch. A linear relationship was found between the amount of granulation liquid and the compressibility of the granules. Using response surface methodology, models for predicting the size of granules and process yield related to the amount of added liquid and the impeller speed were generated, on the basis of which the size of granules and yield can be determined with great accuracy.

Systematic study of paracetamol powder mixtures and granules tabletability: Key role of rheological properties and dynamic image analysis

The aim of this systematic study was to analyze the granulometric and rheological behavior of tableting mixtures in relation to tabletability by single tablet and lab-scale batch compression with an eccentric tablet machine. Three mixtures containing 33, 50, and 66% of the cohesive drug paracetamol were prepared. The high compressibility of the powder mixtures caused problems with overcompaction or lamination in the single tablet compression method; due to jamming of the material during the filling of the die, the lab-scale batch compression was impossible. Using high shear granulation, the flow properties and tabletability were adjusted. A linear relationship between the span of granules and the specific energy measured by FT4 powder rheometer was detected. In parallel, a linear relationship between conditioned bulk density and the tensile strength of the tablets at lab-scale batch tableting was noted. The combination of dynamic image analysis and powder rheometry was useful for predicting the tabletability of pharmaceutical mixtures during the single tablet (design) compression and the lab-scale batch compression.

Process Analytical Technology Tools for Monitoring Pharmaceutical Unit Operations: A Control Strategy for Continuous Process Verification

Various frameworks and methods, such as quality by design (QbD), real time release test (RTRT), and continuous process verification (CPV), have been introduced to improve drug product quality in the pharmaceutical industry. The methods recognize that an appropriate combination of process controls and predefined material attributes and intermediate quality attributes (IQAs) during processing may provide greater assurance of product quality than end-product testing. The efficient analysis method to monitor the relationship between process and quality should be used. Process analytical technology (PAT) was introduced to analyze IQAs during the process of establishing regulatory specifications and facilitating continuous manufacturing improvement. Although PAT was introduced in the pharmaceutical industry in the early 21st century, new PAT tools have been introduced during the last 20 years. In this review, we present the recent pharmaceutical PAT tools and their application in pharmaceutical unit operations. Based on unit operations, the significant IQAs monitored by PAT are presented to establish a control strategy for CPV and real time release testing (RTRT). In addition, the equipment type used in unit operation, PAT tools, multivariate statistical tools, and mathematical preprocessing are introduced, along with relevant literature. This review suggests that various PAT tools are rapidly advancing, and various IQAs are efficiently and precisely monitored in the pharmaceutical industry. Therefore, PAT could be a fundamental tool for the present QbD and CPV to improve drug product quality.

Improved Understanding of the High Shear Wet Granulation Process under the Paradigm of Quality by Design Using Salvia miltiorrhiza Granules

BACKGROUND

High shear wet granulation (HSWG) is a shaping process for granulation that has been enhanced for application in the pharmaceutical industry. However, study of HSWG is complex and challenging due to the relatively poor understanding of HSWG, especially for sticky powder-like herbal extracts.

AIM

In this study, we used Salvia miltiorrhiza granules to investigate the HSWG process across different scales using quality by design (QbD) approaches.

METHODS

A Plackett-Burman experimental design was used to screen nine granulation factors in the HSWG process. Moreover, a quadratic polynomial regression model was established based on a Box-Behnken experimental design to optimize the granulation factors. In addition, the scale-up of HSWG was implemented based on a nucleation regime map approach.

RESULTS

According to the Plackett-Burman experimental design, it was found that three granulation factors, including salvia ratio, binder amount, and chopper speed, significantly affected the granule size (D50) of S. miltiorrhiza in HSWG. Furthermore, the results of the Box-Behnken experimental design and validation experiment showed that the model successfully captured the quadratic polynomial relationship between granule size and the two granulation factors of salvia ratio and binder amount. At the same experiment points, granules at all scales had similar size distribution, surface morphology, and flow properties.

CONCLUSIONS

These results demonstrated that rational design, screening, optimization, and scale-up of HSWG are feasible using QbD approaches. This study provides a better understanding of HSWG process under the paradigm of QbD using S. miltiorrhiza granules.