Systematic DOE Approach for Dry Granulation Study at Early Clinical Stage of Novel Drugs: An Industrial Case.

In order to introduce a cost-effective strategy method for commercial scale dry granulation at the early clinical stage of drug product development, we developed dry granulation process using formulation without API, fitted and optimized the process parameters adopted Design of Experiment (DOE). Then, the process parameters were confirmed using one formulation containing active pharmaceutical ingredient (API). The results showed that the roller pressure had significant effect on particle ratio (retained up to #60 mesh screen), bulk density and tapped density. The roller gap had significant influence on particle ratio and specific energy. The particle ratio was significantly affected by the mill speed (second level). The tabletability of the powder decreased after dry granulation. The effect of magnesium stearate on the tabletability was significant. In the process validation study, the properties of the prepared granules met the requirements for each response studied in the DOE. The prepared tablets showed higher tensile strength, good content uniformity of filled capsules, and the dissolution profiles of which were consistent with that of clinical products. This drug product process development and research strategies could be used as a preliminary experiment for the dry granulation process in the early clinical stage.

Determining the Impact of Roller Compaction Processing Conditions on Granulate and API Properties: Impact of Formulation API Load.

Previous work demonstrated that roller compaction of a 40%w/w theophylline-loaded formulation resulted in granulate consisting of un-compacted fractions which were shown to constitute between 34 and 48%v/v of the granulate dependent on processing conditions. The active pharmaceutical ingredient (API) primary particle size within the un-compacted fraction was also shown to have undergone notable size reduction. The aim of the current work was to test the hypothesis that the observations may be more indicative of the relative compactability of the API due to the formulation being above the percolation threshold. This was done by assessing the impact of varied API loads in the formulation on the non-granulated fraction of the final granulate and the extent of attrition of API particles within the non-granulated fraction. The influence of processing conditions for all formulations was also investigated. The results verify that the observations, both of this study and the previous work, are not a consequence of exceeding the percolation threshold. The volume of un-compacted material within the granulate samples was observed to range between 34.7 and 65.5% depending on the API load and roll pressure, whilst the API attrition was equivalent across all conditions.

Challenges encountered in the transfer of atorvastatin tablet manufacturing - commercial batch-based production as a basis for small-scale continuous tablet manufacturing tests.

As is the case with batch-based tableting processes, continuous tablet manufacturing can be conducted by direct compression or with a granulation step such as dry or wet granulation included in the production procedure. In this work, continuous manufacturing tests were performed with a commercial tablet formulation, while maintaining its original material composition. Challenges were encountered with the feeding performance of the API during initial tests which required designing different powder pre-blend compositions. After the pre-blend optimization phase, granules were prepared with a roller compactor. Tableting was conducted with the granules and an additional brief continuous direct compression run was completed with some ungranulated mixture. The tablets were assessed with off-line tests, applying the quality requirements demanded for the batch-manufactured product. Chemical maps were obtained by Raman mapping and elemental maps by scanning electron microscopy with energy-dispersive X-ray spectroscopy. Large variations in both tablet weights and breaking forces were observed in all tested samples, resulting in significant quality complications. It was suspected that the API tended to adhere to the process equipment, accounting for the low API content in the powder mixture and tablets. These results suggest that this API or the tablet composition was unsuitable for manufacturing in a continuous line; further testing could be continued with different materials and changes in the process.

A tabletability change classification system in supporting the tablet formulation design via the roll compaction and dry granulation process.

In this paper, the material library approach was used to uncover the pattern of tabletability change and related risk for tablet formulation design under the roll compaction and dry granulation (RCDG) process. 31 materials were fully characterized using 18 physical parameters and 9 compression behavior classification system (CBCS) parameters. Then, each material was dry granulated and sieved into small granules (125-250 µm) and large granules (630-850 µm), respectively. The compression behavior of granules was characterized by the CBCS descriptors, and were compared with that of ungranulated powders. The relative change of tabletability (CoTr) index was used to establish the tabletability change classification system (TCCS), and all materials were classified into three types, i.e. loss of tabletability (LoT, Type I), unchanged tabletability (Type II) and increase of tabletability (Type III). Results showed that approximately 65% of materials presented LoT, and as the granules size increased, 84% of the materials exhibited LoT. A risk decision tree was innovatively proposed by joint application of the CBCS tabletability categories and the TCCS tabletability change types. It was found that the LoT posed little risk to the tensile strength of the final tablet, when Category 1 or 2A materials, or Category 2B materials with Type II or Type III change of tabletability were used. Formulation risk happened to Category 2C or 3 materials, or Category 2B materials with Type I change of tabletability, particularly when high proportions of these materials were involved in tablet formulation. In addition, the risk assessment results were verified in the material property design space developed from a latent variable model in prediction of tablet tensile strength. Overall, results suggested that a combinational use of CBCS and TCCS could aid the decision making in selecting materials for tablet formulation design via RCDG.

Developing a Virtual Flowability Sensor for Monitoring a Pharmaceutical Dry Granulation Line.

Current technologies to measure granule flowability involve at-line methods that can take hours to perform. This is problematic for a continuous dry granulation tableting line, where the quality assurance and control of the final tablet products depend on real-time monitoring and control of powder flowability. Hence, a real-time alternative is needed for measuring the flowability of the granular products coming out of the roller compactor, which is the unit operation immediately preceding the tablet press. Since particle analyzers have the potential to take inline measurements of the size and shape of granules, they can potentially serve as real-time flowability sensors, given that the size and shape measurements can be used to reliably predict flowability measurements. This paper reports on the use of Partial Least Squares (PLS) regression to utilize distributions of size and shape measurements in predicting the output of three different types of flowability measurements: rotary drum flow, orifice flow, and tapped density analysis. The prediction performance of PLS had a coefficient of determination ranging from 0.80 to 0.97, which is the best reported performance in the literature. This is attributed to the ability of PLS to handle high collinearity in the datasets and the inclusion of multiple shape characteristics-eccentricity, form factor, and elliptical form factor-into the model. The latter calls for a change in industry perspective, which normally dismisses the importance of shape in favor of size; and the former suggests the use of PLS as a better way to reduce the dimensionality of distribution datasets, instead of the widely used practice of pre-selecting distribution percentiles.

Study of Orally Disintegrating Tablets Using Erythritol as an Excipient Produced by Moisture-Activated Dry Granulation (MADG).

Moisture-activated dry granulation (MADG) is an eco-friendly granulation method that uses a small amount of water and insoluble excipients to absorb moisture. MADG is expected to improve productivity and reduce costs. Erythritol, an excipient used for preparing orally disintegrating tablets (ODTs), has poor tabletability and is difficult to form into tablets by conventional methods, such as high-shear granulation (HSG) and direct compression. In this study, we optimized the manufacturing conditions for ODTs to improve the tabletability of erythritol using MADG. The disintegration time of tablets made using the MADG method was approximately one-tenth that of those made using the HSG method, and the hardness was approximately 1.4 times higher. Moreover, MADG could delay disintegration and improve tabletability. We further attempted to optimize the manufacturing conditions using MADG, particularly in terms of the amount of water used. The disintegration time increased as the amount of added water increased. Moreover, water absorption tests revealed that capillary wetting decreased as the amount of water added increased, but the initial wetting did not change. These results suggested that the disintegration time was prolonged because of the increase in granule density and decrease in capillary wetting with the increase in the amount of added water. The hardness of the tablets increased because of the easy deformation of the granules after the addition of up to 3% water; however, when more than 3% water was added, the hardness decreased because of the aggregation of the granules with the excess water. Finally, two-dimensional maps of the effect of the amount of added water and water activity indicated that tablets with a hardness of ≥80 N and a disintegration time of ≤15 s could be produced by adjusting the amount of added water to within the range of 2.2-3.3% and water activity to 0.3-0.53. These results indicate that MADG can improve the tabletability of erythritol and be used for the granulation of ODTs. Tablets with appropriate hardness and disintegration properties can be produced by adjusting the water content to approximately 2.7% and the water activity to approximately 0.4 when producing ODTs with MADG.

[Prediction of formability of flavonoid extract granules by dry granulation based on design space and RBFNN].

In this paper, a flavonoid extract powder properties-process parameters-granule forming rate prediction model was constructed based on design space and radial basis function neural network(RBFNN) to predict the formability of flavonoid extract gra-nules. Box-Behnken experimental design was employed to explore the mathematical relationships between critical process parameters and quality attributes. The design space of critical process parameters was developed, and the accuracy of the design space was verified by Monte Carlo method(MC). Design Expert 10 was used for Box-Behnken design and mixture design. Scutellariae Radix mixed powder was prepared and its powder properties were measured. The mixed powder was then subjected to dry granulation and the granule forming rate was determined. The correlations between powder properties were analyzed by variance influence factor(VIF), and principal component analysis(PCA) was performed for the factors with strong collinearity. In this way, a prediction model of powder properties-process parameters-granule forming rate was established based on RBFNN, the accuracy of which was evaluated with examples. The results showed that the model had a good predictive effect on the granule forming rate, with the average relative error of 1.04%. The predicted value and the measured value had a high degree of fitting, which indicated that model presented a good prediction ability. The prediction model established in this study can provide reference for the establishment of quality control methods for Chinese medicinal preparations with similar physical properties.

The effect of excipient particle size on the reduction of compactibility after roller compaction.

Developing a robust roller compaction process can be challenging, due to the diversity in process parameters and material properties of the components in a formulation. A major challenge in dry granulation is the reduction of tablet strength as a result of re-compaction of the materials. The aim of this study is to investigate the impact of excipient type and particle size distribution on tablet tensile strength after roller compaction. Lactose monohydrate, anhydrous lactose and microcrystalline cellulose with different particle sizes are roller compacted at varying specific compaction forces. Granules obtained are compressed into tablets to evaluate the reduction in tablet strength upon increasing the specific compaction force. The impact of particle size of the starting material is shown to be vastly different for the three types of excipients investigated, due to the differences in mechanical deformation mechanisms. The presence of rough surfaces and a high degree of fragmentation for anhydrous lactose appears to be beneficial for compaction and re-compaction process. Additionally, the particle size of anhydrous lactose hardly affects the tensile strength of tablets, which can be beneficial for the robustness of a roller compaction process.

Pharmaceutical Development of Film-Coated Mini-Tablets with Losartan Potassium for Epidermolysis Bullosa.

Epidermolysis bullosa is a genetically heterogenous skin fragility disorder with multiorgan involvement appearing already in newborn children. Severe progressive fibrosis follows skin blistering, mucosa lesions, and wound healing, favouring development of highly aggressive squamous cell carcinomas. Losartan potassium (LP) has been described to show positive effects; therefore, it was of clinical interest to develop 2 mm mini-tablets with LP for treatment of the affected children. Several challenges emerged during development: limited flowability and sticking to punches were observed in the first tableting experiments due to a high drug load, and a bitter taste of the LP was reported. Sticking to punches was reduced by using SMCC 50 and a combination of different lubricants; however, direct compression trials on a Korsch XM 12 rotary press were not successful due to compaction phenomena in the hopper. Thus, an intermediate dry granulation was successfully introduced. Two final formulations of the mini-tablets complied with the requirements of the European Pharmacopoeia regarding disintegration times (<15 min) and friability (<1.0%); mean tensile strengths amounted to about 1 MPa as a compromise between manufacturability and sufficient mechanical strength for further coating studies. The subsequent coating step succeeded delaying the initial drug release for more than 2 min. An acceptance value ≤15 was matched for the coated mini-tablets, and stability studies showed a promising shelf life.

Using a Model-based Material Sparing Approach for Formulation and Process Development of a Roller Compacted Drug Product.

The present work details a material sparing approach that combines material profiling with Instron uniaxial die-punch tester and use of a roller compaction mathematical model to guide both formulation and process development of a roller-compacted drug product. True density, compression profiling, and frictional properties of the pre-blend powders are used as inputs for the predictive roller compaction model, while flow properties, particle size distribution, and assay uniformity of roller compaction granules are used to select formulation composition and ribbon solid fraction. Using less than 10 g of a model drug compound for material profiling, roller compacted blend in capsule formulations with appropriate excipient ratios were developed at both 1.4% and 14.4% drug loadings. Subsequently, scale-up batches were successfully manufactured based on the roller compaction process parameters obtained from predictive modeling. The measured solid fractions of roller compaction ribbon samples from the scale-up batches were in good agreement with the target solid fraction of the modeling. This approach demonstrated considerable advantages through savings in both materials and number of batches in the development of a roller-compacted drug product, which is of particular value at early development stages when drug substance is often limited and timelines are aggressive.

Establishment of Feedforward Control Model for Dry Granulation of Polysaccharide Components Based on Quality by Design / 中国实验方剂学杂志

ObjectiveA feedforward control model for dry granulation of polysaccharide components was established to guide the adjustment and optimization of critical process parameters （CPPs） in the design space， so as to reduce the impact of fluctuations in raw materials properties on the quality of medicines. MethodTaking Astragali Radix extract powder as the model drug， the design space of dry granulation CPPs was determined by Box-Behnken design. Astragali Radix mixed powder with different powder properties were prepared by mixture design， the variance inflation factor （VIF） was used to diagnose the multicollinearity of the powder properties， and principal component analysis （PCA） was used to extract the characteristic data of the model. Radial basis function neural network （RBFNN） was used to establish a feedforward control model for reflecting the relationship between the powder properties of polysaccharide components， dry granulation CPPs and one-time molding rate. ResultThe design space for dry granulation CPPs of polysaccharide components was 16-35 Hz for feeding speed， 10-23 Hz for roller speed， and 10-46 kg·cm-2 for roller pressure. The established RBFNN feedforward control model had a good predictive effect on the one-time molding rate of dry granulation of polysaccharide components， which could be used to guide the adjustment and optimization of CPPs in the design space， the relative error was 0.38%-6.73%， and the average relative error was 3.42%. ConclusionThe established feedforward control model can well reflect the relationship between the powder properties of the polysaccharide components， the dry granulation CPPs and the one-time molding rate of the granules， which can be used to guide the adjustment and optimization of CPPs in the design space， reduce the impact of material property fluctuation on product quality， and provide ideas for promoting the quality of traditional Chinese medicine from passive control to active control.

Downstream processing of spray-dried ASD with hypromellose acetate succinate - Roller compaction and subsequent compression into high ASD load tablets.

Despite wide commercial application of hypromellose acetate succinate (HPMCAS) in spray-dried amorphous solid dispersion (ASD) drug products, little information is available in the references on downstream processing of spray-dried dispersions with HPMCAS. Poor flow and high dilution factor are a challenge in formulating spray-dried ASDs into tablets, leaving little space for other excipients facilitating binding and disintegration. Direct compression is not possible due to the poor powder flow of spray-dried ASDs. Moisture has to be avoided due to the plasticizing properties of water on the ASD, resulting in reduced stability of the amorphous state. Thus, dry granulation by roller compaction and subsequent tablet compression is the preferred downstream process. We report the investigation of downstream processing by roller compaction and tablet compression of a high load formulation with 75% of spray-dried amorphous solid dispersion (Nifedipine:HPMCAS 1:2). A head to head comparison of microcrystalline cellulose/croscarmellose (MCC/cl-NaCMC) as binder/disintegrant vs. MCC and low-substituted hydroxypropyl cellulose (L-HPC) as excipient for binding and disintegration showed improved re-workability of the formulation with MCC/L-HPC after roller compaction. Upon transfer to the rotary press, a 45% higher tensile strength of tablets is observed after dry granulation with MCC/L-HPC.

[Exploratory study on preparation of high drug loading granules with traditional Chinese medicine raw powder as carriers].

With Sangtang Yin granule as model drug,and based on the strategy of " unification of medicines and excipients",the feasibility of preparing high drug loading granules with traditional Chinese medicine( TCM) raw powder as carrier was explored. The powder yield,particle size and particle size distribution,fillibility,flowability,hygroscopicity,reconstituability and other key physical properties relating to preparations of 8 herbs( Dioscoreae Rhizoma,Euryales Semen,Atractylodis Macrocephalae Rhizoma,Coicis semen,Poria,Puerariae Lobatae Radix,Puerariae Thomsonii Radix and Coicis Semen by stir-frying with bran) were studied after being smashed,and the feasibility of taking them as excipients of TCM granules was evaluated by co-spray drying,dry granulation and other preparation techniques. According to the results of the physical properties of raw powders,raw powders of Dioscoreae Rhizoma,Euryales Semen and Puerariae Thomsonii Radix had a high powder yield,uniform particle size distribution,good fillibility,poor hygroscopicity and good reconstitutability,with the feature of assisting granule forming. Compared with the prescription of spray dry powder Sangtang Yin without any excipient,the co-sprayed powder had a high yield,good fillibility and compressibility. The yield of dry granules prepared by co-spraying dry powder was increased by more than 10%,and the particles had a uniform color,good fluidity and dissolubility with the drug-loading rate up to 100%. Based on the physical characteristics of TCM raw powder combined with the analysis of the preparation process,Dioscoreae Rhizoma and Puerariae Thomsonii Radix raw powder were selected as the carriers of granule preparations,and Sangtang Yin granule without any excipient was successfully prepared. The findings provide a feasible idea for the preparation of TCM granules with a high drug loading capacity.

Evaluation of Microwave-Assisted Extraction Method for Preparation and Assessment of Thai Herbal Medicine Oral Tablets With Enriched Phytochemical Compounds.

In developing countries, populations have employed herbal medicines for primary health care because they are believed to be more appropriate to the human body and have less side effects than chemically synthesized drugs. The present study aimed to develop and evaluate herbal tablets incorporated with a Thai traditional medicinal extract, U-pa-ri-waat (URW), using microwave-assisted extraction (MAE). The extraction efficiency for URW using MAE and traditional solvent extraction was compared based on the percent yield after spray drying. URW tablets were prepared using the dry granulation method. The optimized products were assessed using standard characterization methods based on the United States and British Pharmacopeias. DPPH and ABTS radical scavenging assays were performed to analyze the antioxidant capacity of the microwave-assisted extracts. The results revealed that the flowability of the dry granule with added maltodextrin was improved compared to a granule without additives, as indicated by an angle of repose of 33.69 ± 2.0°, a compressibility index of 15.38 ± 0.66, and a Hausner's ratio of 1.18 ± 0.06. The resulting formulation produced flat tablets with uniform weight variation, hardness, thickness, friability, and optimum disintegration time. The URW extracts showed antioxidant activity and MAE with maltodextrin carrier displayed the strongest DPPH and ABTS radical activities with IC50 values of 1.60 ± 0.02 µg/mL and 4.02 ± 0.24 µg/mL, respectively. The URW tablet formulation passed the quality control tests. Storage of the formulation tablets for 90 days under accelerated conditions had minimal effects on tablet characteristics.

Manufacturability and Properties of Granules and Tablets Using the Eco-Friendly Granulation Method Green Fluidized Bed Granulation Compared to Direct Compression.

This study aimed to compare the manufacturability and granule and tablet properties of green fluidized bed granulation (GFBG) and of direct compression (DC). Acetaminophen was used as a low compactability model drug. The process time of GFBG to produce final mixtures was comparable to that of DC, and thus GFBG could be considered a simple process. DC could not produce 30% drug load tablets owing to poor granule flowability, whereas no problems were observed in the GFBG tableting process up to 80% of drug load. Tablets prepared with GFBG showed higher tensile strength than those prepared using DC. Compactability evaluation results show that the yield pressure of the granules prepared with GFBG was significantly lower than that of DC, suggesting that the granules prepared with GFBG were easily plastically deformed. Moreover, tablets prepared with GFBG showed fast disintegration, which was faster than that of DC. We conclude that GFBG produces granules with higher drug content and desired physicochemical properties at low cost.

Improved Manufacturability and In Vivo Comparative Pharmacokinetics of Dapagliflozin Cocrystals in Beagle Dogs and Human Volunteers.

Dapagliflozin (DAP), which improves glycemic control in patients with type 2 diabetes mellitus, has poor physical properties against heat and moisture, thus hindering its manufacturing potential. The superior physicochemical properties of a recently developed cocrystal of DAP and citric acid (DAP cocrystal) in comparison with those of DAP and Forxiga®, a patented solvate form with propandiol monohydrate, were identified via structural analysis and moisture sorption isotherm. For the first time, the formulation, manufacturability, and in vivo bioavailability of DAP cocrystals were successfully investigated to develop oral dosage forms that substitute Forxiga®. The intrinsic dissolution rate of DAP cocrystal was controlled by varying particle size distribution. Unlike the direct compression (DC), roller compaction (RC) was more preferable to obtain good flowability of dry granules for a continuous manufacturing system. The cocrystal structure was maintained throughout the stability assessment period. In Vitro dissolution pattern differences of the optimized DAP cocrystal tablet with RC and the reference tablet, Forxiga® 10 mg, were pharmaceutically equivalent within 5% in four different media. Furthermore, comparative pharmacokinetic analysis confirmed that a 10 mg DAP cocrystal tablet with RC was bioequivalent to a 10 mg Forxiga® tablet, as assessed in beagle dogs and human volunteers.

Exploratory study on preparation of high drug loading granules with traditional Chinese medicine raw powder as carriers / 中国中药杂志

With Sangtang Yin granule as model drug,and based on the strategy of " unification of medicines and excipients",the feasibility of preparing high drug loading granules with traditional Chinese medicine( TCM) raw powder as carrier was explored. The powder yield,particle size and particle size distribution,fillibility,flowability,hygroscopicity,reconstituability and other key physical properties relating to preparations of 8 herbs( Dioscoreae Rhizoma,Euryales Semen,Atractylodis Macrocephalae Rhizoma,Coicis semen,Poria,Puerariae Lobatae Radix,Puerariae Thomsonii Radix and Coicis Semen by stir-frying with bran) were studied after being smashed,and the feasibility of taking them as excipients of TCM granules was evaluated by co-spray drying,dry granulation and other preparation techniques. According to the results of the physical properties of raw powders,raw powders of Dioscoreae Rhizoma,Euryales Semen and Puerariae Thomsonii Radix had a high powder yield,uniform particle size distribution,good fillibility,poor hygroscopicity and good reconstitutability,with the feature of assisting granule forming. Compared with the prescription of spray dry powder Sangtang Yin without any excipient,the co-sprayed powder had a high yield,good fillibility and compressibility. The yield of dry granules prepared by co-spraying dry powder was increased by more than 10%,and the particles had a uniform color,good fluidity and dissolubility with the drug-loading rate up to 100%. Based on the physical characteristics of TCM raw powder combined with the analysis of the preparation process,Dioscoreae Rhizoma and Puerariae Thomsonii Radix raw powder were selected as the carriers of granule preparations,and Sangtang Yin granule without any excipient was successfully prepared. The findings provide a feasible idea for the preparation of TCM granules with a high drug loading capacity.

Towards better understanding of the influence of process parameters in roll compaction/dry granulation on throughput, ribbon microhardness and granule failure load.

A key quality attribute for solid oral dosage forms is their hardness and ability to withstand breaking or grinding. If the product is to be manufactured continuously, it can be of interest to monitor the hardness of the material at different stages of manufacturing. Using the controlled process parameters of roll compaction/dry granulation specific compaction force, roll speed and gap width, hardness of the resulting ribbons and granules can be predicted. For the first time, in this study two yield variables (corrected torque of the granulation unit and throughput of material) are used to predict the granules failure load. The increase in granule hardness was monitored in-line when the specific compaction force was increased during the compaction process. This opens the way for in-line control of material hardness, and its use for feedback and feedforward control loops for future continuous manufacturing processes.

Solventless granulation and spheronization of indomethacin crystals using a mechanical powder processor: Effects of mechanically induced amorphization on particle formation.

Our aim was to reveal the effects of mechanically-induced amorphization on the solventless agglomeration and spheronization of drug crystals using a mechanical powder processor. This process can provide spherical particles comprising 100% drug. Indomethacin crystals were mechanically treated using various jacket temperatures and the resulting particles were characterized using particle and crystalline analyses. Also, the adhesive and mechanical properties of amorphous indomethacin were examined. At 20 °C, the indomethacin crystals fragmented and amorphized during processing, indicating that glassy-state indomethacin with no adhesiveness does not contribute to agglomeration or spheronization. At 40 °C, agglomeration occurred due to the transformation of mechanically-induced amorphous phases from non-adhesive glass to an adhesive supercooled liquid at around the glass transition temperature. However, at higher temperatures, the formation of agglomerates was suppressed by recrystallization of the amorphous surface. At 60 °C, the indomethacin crystals compacted and spheronized due to deformation of the particle surface, consistent with results showing that the stiffness of amorphous indomethacin decreased suddenly above 60 °C. The lifespan of the amorphous phase decreased due to enhanced recrystallization as the temperature increased, thereby reducing the degree of spheronization. In conclusion, agglomeration and spheronization are affected by the glass transition temperature and recrystallization of the mechanically-induced amorphous phase.

The effects of screw-to-roll speed ratio on ribbon porosity during roll compaction.

Dry granulation through roll compaction is a technology commonly used in the pharmaceutical industry for producing roll compacted ribbons. The significance of the feed screw speed and roll speed during ribbon production was highlighted in recent publications. However, previous studies focused primarily on the individual effects of either the feed screw speed or roll speed on ribbon porosity, and the synergetic effect of these parameters was rarely examined. The aim of this study therefore was to investigate the effects of the screw-to-roll speed ratio on the porosity of roll compacted ribbons, produced at different roll compaction conditions using the microcrystalline cellulose MCC, Avicel PH-102 feed material. It was observed that ribbon porosity decreased linearly with increasing screw-to-roll speed ratio. Furthermore, an increase in the speed ratio led to an increase in the roll gap and mass throughput while a decrease in the screw constant was observed. Thus, this study demonstrates that the screw-to-roll speed ratio can be treated as one of the critical process parameters for controlling ribbon porosity and can also be used to determine the optimum operating regimes during roll compaction.