The role of a polymer as coformer is not a well-explored area for pharmaceutical co-crystals. To investigate this class of materials, a series of seven co-crystals, which are composed of dapsone and polyethylene glycol are reported. A promising strategy for fine-tuning physicochemical properties namely, crystallinity, thermal stability, hygroscopicity, and solubility was discussed via an in-depth structural understanding. Molecular insights into drug–polymer interactions and co-crystal formation are elaborated from the single crystal X-ray structure determination, Fourier transform infrared spectroscopy, differential scanning calorimetry, and hot-stage microscopy studies.

Dye-sensitized solar cells based on biopolymer gel electrolyte systems deal with the perspective of good power conversion efficiency with low-cost fabrication. In this work, we synthesized an electron-rich triphenylamine core as an organic additive for hydroxyethyl cellulose (HEC) polymer gel electrolytes with a redox couple (I − /I 3 − ), which is efficient for DSSCs. The presence of a more conjugated system and heteroatoms in additives paved the way for the whole mobility transport and quasi-Fermi level shift, which reduces the recombination reaction between the TiO 2 surface and I 3 − ion, enhancing the organic photovoltaic properties. The electrochemical and photovoltaic properties of HEC gel electrolytes without additives (bare HEC) and with an additive ( 4-(di(1H-pyrrol-2-yl)methyl)-N,Ndiphenylaniline (DPMDA), (1H-phenanthro[9,10-d]imidazol-2-yl)-N,N-diphenylaniline (PIDA), 4-(di(1H-pyrrol-2-yl)methyl)-N-(4-(di(1H-pyrrol-2-yl)methyl)phenyl)-N-phenylaniline (DPMPPA), N-(4-(1H-phenanthro[9,10-d]imidazol-2-yl)phenyl)-4-(1H-phenanthro[9,10-d]imidazol-2-yl)-N-phenylaniline (DPIPA), tris(4-(di-(1H-pyrrol-2-yl)methyl)phenyl)amine (TDPMPA), and tris(4-(1H-phenanthro[9,10-d]imidazol-2-yl)phenyl)amine (TPIPA)) were studied, respectively; one of the organic additive tris(4-(1H-phenanthro[9,10-d]imidazol-2-yl)phenyl)amine [TPIPA]-based polymer gel electrolytes (A6: TiO 2 /N3 dye/HEC/I − /I 3− /TPIPA/Pt) showed good electrochemical properties, longer electron lifetime, and hence an improved photoconversion efficiency of 5.72% with better stability under light illumination of 100 mW/cm 2 .

Apalutamide (APA), a second-generation nonsteroidal antiandrogen BCS Class II drug with poor solubility and high permeability. A novel 1:1 cocrystal of Apalutamide (APA) with methylparaben (MP) was identified by cooling crystallization during the cocrystal screening and characterized by various solid-state techniques, such as PXRD, DSC, TGA, FT-IR, and 13C solid-state CP-MAS NMR spectroscopy. The crystal structures of APA and its cocrystal (APA-MP) were determined by the SC-XRD technique. The crystal structure analysis of the APA-MP cocrystal revealed that the APA and MP molecules are connected through strong O–H···O hydrogen bonds. The novel cocrystal improves the solubility and dissolution rate in different physiological conditions compared to poorly soluble APA due to strong hydrogen bond between the drug and the coformer. The cocrystal is stable (physically and chemically) under stress conditions, such as exposure to the relative humidity, mechanical grinding, open exposure to atmosphere at cRT (critical room temperature) and compression pressure of 10 tons. In addition, the compatibility of the cocrystal with excipients used in the drug product of APA (ERLEADA) was also investigated, and no disproportionation of cocrystal was observed.

Please cite this article as: kommavarapu P, Maruthapillai A, Palanisamy K, Sunkara M, Preparation and characterization of rilpivirine solid dispersions with the application of enhanced solubility and dissolution rate, ABSTRACT Rilpivirine (RPV) is a pharmaceutical drug used for the treatment of HIV infection. The drug is characterized with poor aqueous solubility and dissolution rate leading to low bioavailability of the drug. Hence, there is a need for the improvement of the solubility and dissolution of such drugs. In this exertion, enhancement of the solubility and dissolution of the practically water insoluble drug rilpivirine was achieved by solid dispersion (SD) preparation using solvent evaporation method which eventually leads to bioavailability enhancement. SD's were formed using Kollidon VA 64 which is a water-soluble copolymer and varying copolymer ratio to Avicel PH-101, Gelucire 50/13 and lecithin soya. Solubility studies were carried out to establish the solubility-enhancing property of the SD's. To support solubility analysis results, powder dissolution studies were carried out. The SD's were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray powder diffraction studies, scanning electron microscopy. It was found that the SD's formed showed the absence of crystalline nature of the drug and its conversion to amorphous state. The solubility and dissolution of the rilpivirine SD's were enhanced. There is a 14.9 fold increase in solubility for Drug: Kollidan VA 64: Gelucire 50/13 (1:4:1). For Drug: Kollidan VA 64 (1:5), Drug: Kollidan VA 64: Lecithin soya (1:4:1) and Drug:Kollidan VA 64 :Avicel PH-101 (1:4:1) it was 5.9, 5.4 and 4.2 respectively. In-vitro drug release kinetics was investigated. This study demonstrates the use of solvent evaporation method for the preparation of SD'S in solubility and dissolution enhancement.