Comparative evaluation of the powder properties and compression behaviour of a new cellulose-based direct compression excipient and Avicel PH-102

Preparation and optimization of multi-functional directly compressible excipient: an integrated approach of principal component analysis and design of experiments

Developing a new excipient and obtaining its market approval is an expensive, time-consuming, and complex process. The application of a multivariate analytical approach - principal component analysis (PCA) - in combination with the design of experiments (DoE) approach can make the process of developing co-processed excipient cost-effective and rapid. The present investigation was aimed to demonstrate the applicability of the DoE approach and PCA in developing a co-processed excipient by using the spray drying technique. The preliminary studies suggested a significant effect of inlet air temperature (X ₁) and polymer ratio [chitosan chlorhydrate (CC): mannitol - X ₂) on critical product characteristics so they were selected as independent variables in 3² full factorial design. The result of regression analysis suggested a significant effect of both independent variables on all response variables. The PCA of practically obtained value suggested a strong effect of all the selected response variables on the model. The prepared co-processed excipient had better tableting properties compared to the physical mixture of excipients and was able to accommodate more than 80% drug without compromising the flow property and compressibility. The present investigation successfully proved the applicability PCA and DoE approach as an effective and rapid tool for optimizing process parameters and formulation composition for preparing a directly compressible co-processed excipient.

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.

Assessment of processing and polymorphic form effect on the powder and tableting properties of microcrystalline celluloses I and II

Microcrystalline cellulose I (MCCI) is an excipient used as a diluent, disintegrant, glidant and binder for the production of pharmaceutical tablets. In this work, microcrystalline cellulose II (MCCII) was obtained from cotton fibers by basic treatment with 7.5 N NaOH followed by an acid hydrolysis. MCCI and MCCII materials were processed by wet granulation, dry granulation and spray drying. Either the polymorphic form or processing had no effects on the particle morphology or particle size. However, MCCII powders had a higher porosity, less packing tendency, degree of crystallinity, degree of polymerization and density, but a faster disintegration than MCCI. The tensile strength of MCCI was highly affected by the wet and dry granulation processes. Most of the resulting powder and tableting properties were dependent on the polymorphic form of cellulose, rather than on the processing employed.

Comparative evaluation of powder and tableting properties of low and high degree of polymerization cellulose I and cellulose II excipients

Low and high degree of polymerization (DP) cellulose II powders have been prepared from Avicel PH-102 and Solka Floc 40NF (low and high DP cellulose I powders, respectively), respectively, by treatment with sodium hydroxide (5N) for 24h and their powder and tableting properties investigated. Cellulose II powders, compared to the respective cellulose I counterpart, exhibited lower crystallinity, true density, and specific surface area. They were denser and showed higher moisture uptake. The Heckel analyses revealed both low and high DP cellulose II powders to be less ductile than the low DP cellulose I powder and more ductile compared to the high DP cellulose I powder. The crushing strengths of low and high DP cellulose II powders were comparable to that of the high DP cellulose I powder but lower than the low DP cellulose I powder. When compressed to comparable crushing strengths, the low and high DP cellulose II compacts disintegrated faster in comparison to the corresponding cellulose I compacts. Low DP cellulose I and II powders, compared to the high DP cellulose I counterparts were more sensitive to magnesium stearate. Magnesium stearate decreased the disintegration times of low DP cellulose I compacts but had no effect on the low and high DP cellulose II and high DP cellulose I compacts. In conclusion, low and high DP cellulose II powders, despite their different powder properties, show similar tableting properties, leading to the formation of rapidly disintegrating compacts. The low and high DP cellulose I excipients, in contrast, differ in their powder properties as well as tableting characteristics.

Modified Cellulose II Powder: Preparation, Characterization, and Tableting Properties

The reaction of UICEL-A/102, a cellulose II powder recently prepared from Avicel(R) PH-102 by treatment with an aqueous sodium hydroxide solution, with glutaraldehyde in 0.01 N HCl has been investigated to improve its binder properties, without adversely affecting the rapid disintegration characteristic. The results showed that UICEL-A/102 and glutaraldehyde when reacted in a 1:0.6 weight ratio at 100 degrees C for 8.5 h produces a product, (hereinafter referred to as UICEL-XL), that, compared to UICEL-A/102, had a lower degree of polymerization, higher crystallinity, lower bulk density, lower tapped density, and higher porosity. Further, it showed lower yield pressure and higher crushing strength, and tensile strength values, indicating that UICEL-XL is more compressible and compactable than the starting material, UICEL-A/102. A comparison of "in-die" and "out-of-die" Heckel data indicated UICEL-XL to be less elastic than UICEL-A/102. Both UICEL-XL and UICEL-A/102 showed similar moisture sorption isotherms, and their compacts disintegrated rapidly in water. In conclusion, the glutaraldehyde-treated cellulose II powder not only serves as good a disintegrant as the untreated cellulose powder but also possesses superior binder properties.

Evaluation of cellulose II powders as a potential multifunctional excipient in tablet formulations

The use of UICEL-A/102 and UICEL-XL, the cellulose II powders, as a multifunctional direct compression excipient in the design of tablets containing hydrochlorothiazide (HCTZ) or ibuprofen (IBU), the model low and high dose drugs, respectively, has been reported. Commercial Oretic and Advil tablets containing HCTZ and IBU, respectively, and tablets made using Avicel PH-102 - the most commonly and widely used commercial direct compression excipient, were used in the study for comparison purposes. Tablets were made by first blending drug with the excipient and then with stearic acid, a lubricant, in a V-blender, followed by compressing into a tablet on a hydraulic press using 105 MPa of compression pressure and a dwell time of 30 s. The crushing strengths of HCTZ tablets decreased in the order Avicel PH-102>UICEL-XL, UICEL-A/102>Oretic and of IBU tablets in the order Avicel PH-102 > or = UICEL-XL approximately UICEL-A/102>Advil. The friability values for all tablets were well below the maximum 1% USP tolerance limit. UICEL-A/102 and UICEL-XL tablets containing HCTZ disintegrated rapidly (<25 s). Oretic tablets disintegrated in about 60 s, while Avicel PH-102 tablets remained intact during 1 h test period. The IBU tablets made using UICEL-A/102 disintegrated the fastest, UICEL-XL and Advil tablets the next, and Avicel PH-102 tablets remained intact. All tablets, except for those of Avicel PH-102, conformed to the USP drug release requirements. These results conclusively show that UICEL-A/102 and UICEL-XL have the potential to be used as filler, binder, and disintegrant, all-in-one, in the design of tablets containing either a low dose or high dose drug by the direct compression method.