Kollidon® SR: Formulation techniques and drug delivery applications

Kollidon® SR is one of the recent versatile coprocessed excipients in the formulation of modified-release dosage forms. It is prepared by co-spray drying aqueous dispersions of polyvinylacetate and polyvinylpyrrolidone. This article gives a critical review of the physicochemical attributes and technological properties of Kollidon® SR. The current review discusses various technological approaches used in the formulation with Kollidon® SR, from conventional ones like direct compaction and wet granulation to more advanced methodologies such as 3D printing, electrospinning and hot-melt extrusion. The review further elaborates on the influence of the major factors on drug release kinetics from Kollidon® SR-based formulations. Furthermore, this review unravels the potential of Kollidon® SR in the development of site-targeted oral drug delivery systems and focuses on its adaptability to other routes of administration. Further, the review deals with the considerations to be made regarding stability to make sure the formulations based on Kollidon® SR are reliable.

Cocrystals of Apixaban with Improved Solubility and Permeability: Formulation, Physicochemical Characterization, Pharmacokinetic Evaluation, and Computational Studies

The objective of the current study was to develop new cocrystals of Apixaban (APX) to improve its solubility and permeability. The molecular interaction between APX and caffeine (CFFN) was further studied by Raman spectroscopy. The results of all eight studied conformers revealed that the synthesized APX-CFFN cocrystals had the highest solubility and permeability. The water solubility and permeability of APX in the cocrystal were simultaneously enhanced as compared with pure APX in the physiological pH environment (pH 6.8 and pH 7.4). The X-ray diffraction analysis revealed that the cocrystal has a component molar ratio of 1:1. This was dominated by a three-dimensional hydrogen bonding supramolecular structure. The in vivo pharmacokinetic (PK) study indicated that the mean area under curve (AUC) of APX from the synthesized cocrystal was enhanced more than three-folds than the pure APX. Tablets of APX and APX-CFFN cocrystals were prepared using direct compression method and evaluated for in vitro dissolution profile in phosphate buffers (pH 6.8 and pH 7.4). Computational investigations with molecular dynamics simulations also supported the formation of stable cocrystals. The drug release of APX from the tablets was considerably increased when compared with the pure APX in both pH conditions and it was found to increase with an increase in media pH. The present investigation represents an alternative approach for optimizing physicochemical and PK properties of Biopharmaceutical Classification System class-III drugs without changing its molecular structure and intrinsic bioactivities.

Sustained Release Bilayer Tablet of Ibuprofen and Phenylephrine Hydrochloride: Preparation and Pharmacokinetics in Beagle Dogs

Cold is a global common infectious disease accompanied by symptoms such as headache and stuffy nose. Ibuprofen (IBU) and phenylephrine hydrochloride (PE) were commonly used for common cold due to their different effects in relieving fever and the main symptoms such as nasal congestion and high sinus pressure. However, the commercial tablets of IBU and PE have to be administered 2 to 3 times per day due to their short half-life, with inconvenience for patient and fluctuations of plasma concentration. Bilayer tablet technology was utilized to design the IBU-PE sustained release tablets because of the significantly different solubility of IBU and PE in release media. The formulations of IBU layer and PE layer contain different viscosity grades of hydroxypropyl methylcellulose (HPMC) as sustained-release matrix, hydrophilic diluent, and traditional glidant and lubricant. The sustained release bilayer tablet exhibited satisfying sustained release performance with the mechanisms of diffusion and matrix erosion. Compared with the conventional tablets, the IBU-PE sustained release bilayer tablet expressed significantly sustained-release behavior with decreased C_max and prolonged T_max in fasted conditions for IBU and PE. Though IBU of IBU-PE sustained release bilayer tablet was bioequivalent to the commercial IBU tablet, the relative bioavailability of PE from the bilayer tablets was 87.49 ± 20.00% (90% confidence interval was 72.3 to 102.5%), indicating bioinequivalence probably due to the "first pass" effect.