The influence of direct compression powder blend transfer method from the container to the tablet press on product critical quality attributes: a case study.

OBJECTIVE: The aim of this article is to compare the gravitational powder blend loading method to the tablet press and manual loading in terms of their influence on tablets' critical quality attributes (CQA). SIGNIFICANCE: The results of the study can be of practical relevance to the pharmaceutical industry in the area of direct compression of low-dose formulations, which could be prone to content uniformity (CU) issues. METHODS: In the preliminary study, particle size distribution (PSD) and surface energy of raw materials were determined using laser diffraction method and inverse gas chromatography, respectively. For trials purpose, a formulation containing two pharmaceutical ingredients (APIs) was used. Tablet samples were collected during the compression progress to analyze their CQAs, namely assay and CU. RESULTS: Results obtained during trials indicate that tested direct compression powder blend is sensitive to applied powder handling method. Mild increase in both APIs content was observed during manual scooping. Gravitational approach (based on discharge into the drum) resulted in a decrease in CU, which is connected to a more pronounced assay increase at the end of tableting than in the case of manual loading. CONCLUSIONS: The correct design of blend transfer over single unit processes is an important issue and should be investigated during the development phase since it may influence the final product CQAs. The manual scooping method, although simplistic, can be a temporary solution to improve the results of API's content and uniformity when compared to industrial gravitational transfer.

Evaluation of drug-carrier interactions in quaternary powder mixtures containing perindopril tert-butylamine and indapamide.

Interactions occurring between components in the quaternary powder mixtures consisting of perindopril tert-butylamine, indapamide (active pharmaceutical ingredients), carrier substance and hydrophobic colloidal silica were examined. Two grades of lactose monohydrate: Spherolac(®) 100 and Granulac(®) 200 and two types of microcrystalline cellulose: M101D+ and Vivapur(®) 102 were used as carriers. We determined the size distribution (laser diffraction method), morphology (scanning electron microscopy) and a specific surface area of the powder particles (by nitrogen adsorption-desorption). For the determination of the surface energy of powder mixtures the method of inverse gas chromatography was applied. Investigated mixtures were characterized by surface parameters (dispersive component of surface energy, specific interactions parameters, specific surface area), work of adhesion and cohesion as well as Flory-Huggins parameter χ23('). Results obtained for all quaternary powder mixtures indicate existence of interactions between components. The strongest interactions occur for both blends with different types of microcrystalline cellulose (PM-1 and PM-4) while much weaker ones for powder mixtures with various types of lactose (PM-2 and PM-3).

Preparation of hybrid materials for controlled drug release.

Authors obtained hybrid organic-inorganic materials applied in sustained drug delivery. The materials are ibuprofen as a model drug, hydroxyapatite and three different polymers as supports. Influence of the type of employed polymer, an inorganic carrier, on the properties and drug release profiles was estimated. Flory-Huggins interaction parameters, the dispersive component of surface free energy and acid-base characteristic of the surface were used to assess the behavior of the composites in terms of drug release. The experiments were carried out with the use of inverse gas chromatography (IGC), Fourier transform infrared (FTIR) and ultraviolet (UV) techniques. FTIR and ATR-FTIR spectra were collected. The values of [Formula: see text] parameter obtained for all investigated materials (excluding poly(L-lactide) (PLA2)) indicate low or medium activity. The strongest interactions (the lowest values of the Flory-Huggins [Formula: see text] parameter) are observed for PLA2 composition, while the weakest interactions for systems with polyethylene glycol (PEG). Finally, drug release profiles are shown. For materials prepared with Eudragit® (EUD) and PLA, the release of drug was much smaller, which corresponds to lower values of Flory-Huggins parameter. The executed experiments allowed the estimation of the properties of prepared composites. Prepared materials present properties required in sustained drug release and may be successfully applied as drug delivery systems.

Relationship between surface properties determined by inverse gas chromatography and ibuprofen release from hybrid materials based on fumed silica.

The ability of organic-inorganic hybrid materials to act as drug release-modifying agents was examined. In this study, ibuprofen, a non-steroidal anti-inflammatory drug was used as a model active pharmaceutical ingredient. The physicochemical properties of individual components of the hybrids, as well as these for two- and three-component systems were examined by inverse gas chromatography. The dispersive component of the free surface energy (γ(S)(D)), K(A) and K(D) parameters describing acidity and basicity of hybrid materials, respectively, as well as Flory-Huggins parameters were determined. χ(12)(∞) and [Formula: see text] parameters characterize the interactions between the hybrids and a test solute, or interactions between the drug and inorganic-organic materials, respectively. Additionally, Brunauer-Emmett-Teller (BET) method was used to characterize adsorption activity of the studied materials. The prepared hybrid materials were also characterized by Fourier transform infra-red (FTIR) spectroscopy. The release profiles of ibuprofen for the created hybrid materials were determined. Relationship between the physicochemical activity of hybrid materials and ibuprofen release was presented and discussed.

Inverse gas chromatography as a source of physiochemical data.

Inverse gas chromatography (IGC) is presented as a useful method for the examination of physicochemical properties of various materials. The advantages of IGC are presented. However, the uncertainties and sources of possible errors are also indicated and discussed.

Characterization of the interactions in polymer-filler systems by inverse gas chromatography.

Inverse gas chromatography (IGC) has been applied to observe the interactions in filled polymer-organic solvent as well as modified filler-polymer systems under conditions approaching infinite dilution of the volatile component. We investigated polyether-urethane-modified silica systems containing different kinds of modified silicas (filler) at 10% w/w loading. The fillers were modified with N-2-aminoethyl-3-aminopropyltrimethoxysilane (B2), 3-aminopropyltriethoxysilane (B3), 3-mercaptopropyl-trimethoxysilane (B4), n-octyltriethoxysilane (B5). The values of Flory-Huggins parameter chi(12)infinity calculated from the retention volumes indicate that interactions between filled polymer and solvent probe varied with type of the modifier and temperature. Authors propose to express the magnitude of modified filler-polymer interactions by Flory-Huggins chi(23)' parameter. The influence of conditions of IGC experiment (temperature, the type of filler, the nature of test solute) on the evaluated parameters is presented and discussed.