The formulation factors relevant to developing immediate and controlled release dosage forms containing poorly soluble drugs dispersed in amorphous systems are poorly understood. While the utility of amorphous solid dispersions is becoming apparent in the pharmaceutical marketplace, literature reports tend to concentrate on the development of solid dispersion particulates, which then must be formulated into a tablet. Amorphous solid dispersions of itraconazole in high molecular weight hydroxypropyl methylcellulose were prepared by KinetiSol® Dispersing and tablets were formulated to immediately disintegrate or control the release of itraconazole.
View Article and Find Full Text PDFDuring formulation development, efficiently integrating in vitro dissolution testing can significantly improve one's ability to estimate in vivo performance and aide in the selection of premier drug candidates. The concept of in vitro-in vivo relationship/correlation has garnered significant attention from pharmaceutical scientists to predict expected bioavailability characteristics for drug substances and products. The present work illustrates a comparative evaluation of in vitro tests to access crystalline carbamazepine and various types of amorphous and crystalline dispersions of carbamazepine and Eudragit L100 produced by spray drying, including a membrane-permeation dissolution methodology and nonsink dissolution.
View Article and Find Full Text PDFThe presented study describes the development of a membrane permeation non-sink dissolution method that can provide analysis of complete drug speciation and emulate the in vivo performance of poorly water-soluble Biopharmaceutical Classification System class II compounds. The designed membrane permeation methodology permits evaluation of free/dissolved/unbound drug from amorphous solid dispersion formulations with the use of a two-cell apparatus, biorelevant dissolution media, and a biomimetic polymer membrane. It offers insight into oral drug dissolution, permeation, and absorption.
View Article and Find Full Text PDFInterest in granulation processes using twin screw extrusion machines is rapidly growing. The primary objectives of this study were to develop a continuous granulation process for direct production of granules using this technique with glyceryl behenate as a binder, evaluate the properties of the resulting granules and develop controlled release tablets containing tramadol HCl. In addition, the granulation mechanism was probed and the polymorphic form of the lipid and drug release rate were evaluated on stability.
View Article and Find Full Text PDFThe objective of this study was to evaluate the use of glyceryl behenate as a plasticizer and release modifier in solid dispersion systems containing itraconazole and carbamazepine. Amorphous solid dispersions of high molecular weight polyvinylpyrrolidone were prepared by hot-melt extrusion, the processing of which was improved by the inclusion of glyceryl behenate. Dispersions were milled and subsequently compressed into tablets.
View Article and Find Full Text PDFWhile the use of amorphous solid dispersions to improve aqueous solubility is well documented, little consideration has traditionally been given to the finished dosage form. The objective of this study was to evaluate the dissolution performance of amorphous solid dispersions containing a dispersed superdisintegrant with binding properties. KinetiSol® dispersing was used to thermally process hypromellose acetate succinate-based compositions containing the drug substance nifedipine (NIF) and a highly compressible grade of low-substituted hydroxypropyl cellulose (New Binder Disintegrants; NBD-grade).
View Article and Find Full Text PDFAcetyl-11-keto-β-boswellic acid (AKBA), a gum resin extract, possesses poor water-solubility that limits bioavailability and a high melting point making it difficult to successfully process into solid dispersions by fusion methods. The purpose of this study was to investigate solvent and thermal processing techniques for the preparation of amorphous solid dispersions (ASDs) exhibiting enhanced solubility, dissolution rates and bioavailability. Solid dispersions were successfully produced by rotary evaporation (RE) and KinetiSol® Dispersing (KSD).
View Article and Find Full Text PDFThe dissolution enhancement advantages inherent to amorphous solid dispersions systems are often not fully realized once they are formulated into a solid dosage form. The objective of this study was to investigate the ability of inorganic salts to improve the dissolution rate of carbamazepine (CBZ) from tablets containing a high loading of a Soluplus®-based solid dispersion. Cloud point and viscometric studies were conducted on Soluplus® solutions to understand the effect of temperature, salt type and salt concentration on the aqueous solubility and gelling tendencies of Soluplus®, properties that can significantly impact dissolution performance.
View Article and Find Full Text PDFThe primary aim of the present study was to investigate the ability of hydroxypropyl and methoxyl substituted cellulose ethers to stabilize supersaturated concentrations of itraconazole (ITZ), a poorly water-soluble weak base, after an acid-to-neutral pH transition. A secondary aim of the study was to evaluate the effect of fusion processes on polymer stability and molecular weight. Polymer screening studies showed that stabilization of ITZ supersaturation was related to the molecular weight of the polymer and levels of hydroxypropyl and methoxyl substitution.
View Article and Find Full Text PDFPoorly water-soluble drug substances that exhibit high melting points are often difficult to successfully process by fusion-based techniques. The purpose of this study was to identify a suitable polymer system for meloxicam (MLX), a high melting point class II BCS compound, and investigate thermal processing techniques for the preparation of chemically stable single phase solid dispersions. Thermal and solution based screening techniques were utilized to screen hydrophilic polymers suitable for immediate release formulations.
View Article and Find Full Text PDFThe development of amorphous solid dispersions containing poorly soluble drug substances has been well-documented; however, little attention has been given to the development of the finished dosage form. The objective of this study was to investigate the use of Ceolus(™) microcrystalline cellulose, a highly compressible excipient, for the production of rapidly disintegrating tablets containing a hydrophilic solid dispersion of a poorly soluble drug, indomethacin. Solid dispersions of indomethacin and Kollidon(®) VA64 were prepared by hot melt extrusion and characterized for amorphous nature.
View Article and Find Full Text PDFIn this study, hot melt extrusion (HME) and KinetiSol Dispersing (KSD) were utilized to prepare dissolution-enhanced solid dispersions of Roche Research Compound A (ROA), a BCS class II drug. Preformulation characterization studies showed that ROA was chemically unstable at elevated temperatures and acidic pH values. Eudragit L100-55 and AQOAT LF (HPMCAS) were evaluated as carrier polymers.
View Article and Find Full Text PDFObjectives: To investigate the ability of KinetiSol Dispersing to prepare amorphous solid dispersions of itraconazole using concentration-enhancing polymers.
Methods: Concentration-enhancing nature of several cellulosic polymers (HPMC, hypromellose acetate succinate) was studied using a modified in vitro dissolution test. Solid dispersions were prepared by KinetiSol Dispersing and characterized for solid-state properties using X-ray diffraction and differential scanning calorimetry.
Many techniques for the production of solid dispersions rely on elevated temperatures and prolonged material residence times, which can result in decomposition of temperature-sensitive components. In this study, hydrocortisone was used as a model temperature-sensitive active ingredient to study the effect of formulation and processing techniques as well as to characterize the benefits of KinetiSol Dispersing for the production of solid dispersions. Preformulation studies were conducted using differential scanning calorimetry and hot stage microscopy to identify optimum carriers for the production of amorphous solid dispersions.
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