The G-protein-coupled estrogen receptor, a gene co-expressed with ERα in breast tumors, is regulated by estrogen-ERα signalling in ERα positive breast cancer cells.

GPER is a seven transmembrane G-protein-coupled estrogen receptor that mediates rapid estrogen actions. Large volumes of data have revealed its association with clinicopathological variables in breast tumors, role in epidermal growth factor (EGF)-like effects of estrogen, potential as a therapeutic target or a prognostic marker, and involvement in endocrine resistance in the face of tamoxifen agonism. GPER cross-talks with estrogen receptor alpha (ERα) in cell culture models implicating its role in the physiology of normal or transformed mammary epithelial cells. However, discrepancies in the literature have obfuscated the nature of their relationship, its significance, and the underlying mechanism. The purpose of this study was to assess the relationship between GPER, and ERα in breast tumors, to understand the mechanistic basis, and to gauge its clinical significance. We mined The Cancer Genome Atlas (TCGA)-BRCA data to examine the relationship between GPER and ERα expression. GPER mRNA, and protein expression were analyzed in ERα-positive or -negative breast tumors from two independent cohorts using immunohistochemistry, western blotting, or RT-qPCR. The Kaplan-Meier Plotter (KM) was employed for survival analysis. The influence of estrogen in vivo was studied by examining GPER expression levels in estrus or diestrus mouse mammary tissues, and the impact of 17ß-estradiol (E2) administration in juvenile or adult mice. The effect of E2, or propylpyrazoletriol (PPT, an ERα agonist) stimulation on GPER expression was studied in MCF-7 and T47D cells, with or without tamoxifen or ERα knockdown. ERα-binding to the GPER locus was explored by analysing ChIP-seq data (ERP000380), in silico prediction of estrogen response elements, and chromatin immunoprecipitation (ChIP) assay. Clinical data revealed significant positive association between GPER and ERα expression in breast tumors. The median GPER expression in ERα-positive tumors was significantly higher than ERα-negative tumors. High GPER expression was significantly associated with longer overall survival (OS) of patients with ERα-positive tumors. In vivo experiments showed a positive effect of E2 on GPER expression. E2 induced GPER expression in MCF-7 and T47D cells; an effect mimicked by PPT. Tamoxifen or ERα-knockdown blocked the induction of GPER. Estrogen-mediated induction was associated with increased ERα occupancy in the upstream region of GPER. Furthermore, treatment with 17ß-estradiol or PPT significantly reduced the IC50 of the GPER agonist (G1)-mediated loss of MCF-7 or T47D cell viability. In conclusion, GPER is positively associated with ERα in breast tumors, and induced by estrogen-ERα signalling axis. Estrogen-mediated induction of GPER makes the cells more responsive to GPER ligands. More in-depth studies are warranted to establish the significance of GPER-ERα co-expression, and their interplay in breast tumor development, progression, and treatment.

Preparation, Characterization and Pharmacodynamic Evaluation of Fused Dispersions of Simvastatin using PEO-PPO Block Copolymer.

The solubility enhancement of poorly soluble compounds is an important task in pharmaceutical technology as it leads to better bioavailability and a more efficient application. Fused dispersions (FDs) of simvastatin (SIM) using PEO-PPO block copolymer were prepared which paved the way for the formation of an amorphous product with enhanced dissolution and bioavailability. The accumulative solubility of simvastatin (SIM) from PEO-PPO block copolymer (Lutrol NF 127 prill surfactant) was found to be superior to the drug alone which may be due to the increased oxyethylene content that played the major role in solubility enhancement. A 3(2) full factorial approach was used for optimization wherein the temperature to which the melt-drug mixture cooled (X1) and the drug-to-polymer ratio (X2) were selected as the independent variables and the time required for 90% drug dissolution (t90%) was selected as the dependent variable. A low level of X1 and a high level of X2 were suitable for obtaining higher dissolution of SIM from SIM FDs. On increasing melt to cool drug temperature, t90% increased thus improving dissolution rate of FD2 batch with the maximum drug release (99.63%) in 120 min. The optimized FDs were characterized by saturation solubility study, drug content, in-vitro dissolution, fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, x-ray diffraction, (1)HNMR spectroscopy and pharmacodynamic evaluation. Capsules containing optimized FDs were prepared and compared with marketed brand (SIMVOTIN®). Finally, it can be concluded that the optimized FDs of SIM ameliorate the solubility and dissolution of drug with improved pharmacodynamic activity.

Chronopharmaceuticals: hype or future of pharmaceutics.

Drugs for several diseases are still given without regard to the time of the day. Variation in dosing time is generally related with the effectiveness and toxicity of many drugs. On the other hand, several drugs affect the circadian clock. The knowledge of interactions between the circadian clock and drugs is valuable in clinical practice. The pharmacodynamics and pharmacokinetics of the medication influence the chronopharmacological phenomena and recent advances in it have made the traditional goal of pharmaceutics rather outdated. Enhanced progress in chronopharmacotherapy can be achieved if an identification of a rhythmic marker for selecting dosing time is done. However, technology involved in development of drug delivery systems (DDS) that match the circadian rhythm, and the unraveling of the relationship between circardian clock and pathology may be the hindrance in its prosperity for now. The Chronopharmaceutical Drug Delivery System (CDDS) has emerged during the last decade as a possible drug delivery system against several diseases, which may lead to the creation of a sub-disciple of pharmaceutics to be explored called 'chronopharmaceutics'. The review addresses the approaches to this sub-discipline, call attention to potential disease-targets, identifies existing technologies, hurdles and future of chropharmaceuticals. Chronopharmaceuticals coupled with nanotechnology could be the future of DDS, and lead to safer and more efficient disease therapy in the future.

In Situ Phase-Transited Asymmetric Membrane Capsules: A Means for Achieving Delayed and Osmotic Release for pH Solubility-Dependant Drugs.

In the present study, an in situ nondisintegrating polymeric capsular system in achieving delayed as well as improved osmotic flow for the model drug cefadroxil was developed. In situ formed asymmetric membrane capsule was prepared by precipitation of the asymmetric membrane (AM) on the walls of conventional hard gelatin capsules in fabricated glass holders via a dry phase inversion process. The effect of different formulation variables were studied based on a 2(3) factorial design as one variable changed from one level to another, namely, the level of osmogen, ethylcellulose, and pore former, apart from studying the effect of varying osmotic pressure and agitation intensity on drug release. Scanning electron microscopy showed an outer, dense, non-porous region and an inner, lighter, porous region for the prepared AM inside, and a gelatin layer outside. Statistical testing (Dunnett multiple comparison test) was applied for in vitro drug release (n = 6) at P < 0.05. The best formulation in the design closely corresponded to the extra design checkpoint formulation by a similarity (f(2)) value of 96.18. The drug release was independent of the agitation intensity but dependent on the osmotic pressure of the dissolution media. The release kinetics followed the Higuchi model, and the mechanism of release was Fickian diffusion. LAY ABSTRACT: The asymmetric membrane capsule (AMC) is a unique drug delivery system that looks like a conventional hard gelatin capsule but has significant advantages over it. In the present study, a system was made that had an outer disintegrating hard gelatin capsule and an inner nondisintegrating polymeric capsular system for delivering a model drug cefadroxil. The inner nondisintegrating polymeric capsular system was the AMC, which was prepared by precipitation of the asymmetric membrane (AM) on the walls of conventional hard gelatin capsules in fabricated glass holders via a dry phase inversion process. The effect of different formulation variables that might affect the drug release were studied based on a 2(3) factorial design. The formulation variables were level of osmogen, ethylcellulose, and pore former. The effect of varying osmotic pressure and agitation intensity on drug release was also studied. Scanning electron microscopy showed an outer, dense, nonporous region and an inner, lighter, porous region for the prepared AM inside, and a gelatin layer outside. Statistical testing was applied for in vitro drug release. Results showed the drug release to be independent of the agitation intensity but dependent on the osmotic pressure of the dissolution media. The release kinetics followed the Higuchi model, and the mechanism of release was Fickian diffusion.

Phase transited and vapor-induced dual capsular system (DCS) for achieving delayed and osmotic release of cefadroxil.

In the present study, an intestinal pH, disintegrating and non-disintegrating dual capsular system using formaldehyde vapor and phase transition technique, respectively, was developed to achieve delayed as well as improved osmotic flow for the model drug cefadroxil. Formaldehyde vapor was used to attain gastric resistance to the outer gelatin capsule, which disintegrated at the intestinal pH to give a non-disintegrating asymmetric membrane capsule (AMC). The AMC was prepared via dry phase inversion process. The effects of different formulation variables were studied based on 2³ factorial design, namely, level of osmogen, ethylcellulose, and pore former, apart from studying the effects of varying osmotic pressure, agitation intensity, and intentional defect on drug release. Scanning electron microscopy showed an outer dense non-porous and an inner lighter porous region for the prepared asymmetric membrane. Statistical test was applied for in-vitro drug release at P > 0.05. The best formulation in the design closely corresponded to the extra design checkpoint formulation by a similarity (f2) value of 95.28. The drug release was independent of the agitation intensity and intentional defect of the film but dependent on the osmotic pressure of the dissolution medium. The release kinetics followed zero-order, and mechanism of release was Fickian diffusion.

High-efficiency loading and controlled release of highly water-soluble drug, pravastatin sodium by use of cross-linked ß-cyclodextrin.

AIM: The aim of the project was to develop cross-linked b-cyclodextrin (CL ß-CD) microparticles for controlled delivery of a highly water-soluble drug. MATERIALS AND METHODS: CL ß-CD microparticles were prepared by emulsification phase separation technique using epichlorohydrin as a cross-linking reagent. The developed microparticles were compared with ß-CD for their pharmacotechnical properties. A highly water-soluble model drug, pravastatin sodium (PS) was loaded within these hydrophobic microparticles by active drug loading method using nonionic surfactant Tween 80 as the loading facilitator. RESULTS: Maximal drug fixation (216.8 mg/g beads) was observed in pH 4 at 20°C. In vitro release studies of PS-loaded CL ß-CD microparticles in simulated gastric fluid and simulated intestinal fluid resulted in modified dissolution profiles. Modeling of release profiles confirmed controlled release (r(2) = 0.9910) of PS from the cross-linked system. CONCLUSION: Controlled release CL ß-CD microparticles PS that have the potential to enhance its therapeutic properties by offering the advantage of less frequent dosing and decreased fluctuations in the blood levels during the dosing interval were successfully developed.

Phase Transited Asymmetric Membrane Capsule: A Means for Achieving Delayed and Controlled Osmotic Flow.

In the present study, a phase transited nondisintegrating polymeric capsular system in achieving delayed as well as improved osmotic flow for the model drug cefadroxil was developed. Asymmetric membrane capsule (AMC) was prepared by precipitation of asymmetric membrane (AM) on the fabricated glass mold pins via wet phase inversion process. Effect of different formulation variables were studied based on 23 factorial design, namely, level of osmogen, ethylcellulose, pore former, apart from studying the effect of varying osmotic pressure on drug release. Scanning electron microscopy showed an outer dense non-porous region and an inner lighter porous region for the prepared AMC. Statistical test (Dunnett multiple comparison test) was applied for in vitro drug release (n=6) at P < 0.05. The best formulation in the design closely corresponded to the extra design checkpoint formulation by a similarity factor (f2) of 98.91, and a difference factor (f1) of 2.17. The drug release was independent of agitation intensity but dependent on the osmotic pressure of the dissolution medium. The release kinetics followed Higuchi model, and mechanism of release was Fickian diffusion.

Colon targeted drug delivery systems: a review on primary and novel approaches.

The colon is a site where both local and systemic delivery of drugs can take place. Local delivery allows topical treatment of inflammatory bowel disease. However, treatment can be made effective if the drugs can be targeted directly into the colon, thereby reducing the systemic side effects. This review, mainly compares the primary approaches for CDDS (Colon Specific Drug Delivery) namely prodrugs, pH and time dependent systems, and microbially triggered systems, which achieved limited success and had limitations as compared with newer CDDS namely pressure controlled colonic delivery capsules, CODESTM, and osmotic controlled drug delivery which are unique in terms of achieving in vivo site specificity, and feasibility of manufacturing process.

Effect of auxiliary substances on complexation efficiency and intrinsic dissolution rate of gemfibrozil-beta-CD complexes.

The studies reported in this work are aimed to elucidate the ternary inclusion complex formation of gemfibrozil (GFZ), a poorly water-soluble drug, with beta-cyclodextrin (beta-CD) with the aid of auxiliary substances like different grades of povidone(s) (viz. PVP K-29/32, PVP K-40, Plasdone S-630, and Polyplasdone XL), organic base (viz. triethanolamine), and metal ion (viz. MgCl(2).6H(2)O), by investigating their interactions in solution and solid state. Phase solubility studies were carried out to evaluate the solubilizing power of beta-cyclodextrin, in association with various auxiliary substances, to determine the apparent stability constant (K (C)) and complexation efficiency (CE) of complexes. Improvement in K (C) values for ternary complexes clearly proves the benefit of the addition of auxiliary substances to promote CE. Of all the approaches used, the use of polymer Plasdone S-630 was found to be the most promising approach in terms of optimum CE and K (C). GFZ-beta-CD (1:1) binary and ternary systems were prepared by kneading and lyophilization methods. The ternary systems clearly signified superiority over binary systems in terms of CE, solubility, K (C), and reduction in the formulation bulk. Optimized ternary system of GFZ-beta-CD-Plasdone S-630 prepared by using lyophilization method indicated a significant improvement in intrinsic dissolution rate when compared with ternary kneaded system. Differential scanning calorimetry, X-ray diffraction, Fourier transform infrared, scanning electron microscopy, and proton nuclear magnetic resonance were carried out to characterize the binary and optimized ternary complex. The results suggested the formation of new solid phases, eliciting strong evidences of ternary inclusion complex formation between GFZ, beta-CD, and Plasdone S-630, particularly for lyophilized products.

Preformulative assessment of preformed complexes of gemfibrozil, with cyclodextrins.

The aim of this study is to carry out preformulative investigations on preformed inclusion complexes of the poorly water-soluble, lipid-lowering agent gemfibrozil and naturally occurring cyclodextrins (CDs). Phase solubility studies showed a linear AL- type diagram with alpha, beta, and y cyclodextrins, indicating the formation of inclusion complexes in a 1:1 molar ratio with all the three CDs. beta-CD-gemfibrozil complex having a maximum stability constant of 148.88 M(-1) was selected for preparation of preformed inclusion complex by kneading, co-precipitation, co-evaporation, and freeze-drying and compared with the physical mixture. The kneaded product was subjected to microwave-drying, with this mode of drying studied as an alternative method for preparation of the complex. The prepared complexes were assessed by equilibrium solubility analysis and intrinsic dissolution rate studies. Further characterization was done by differential scanning calorimetry, X-ray powder diffractometry, Fourier transform infrared spectroscopy, and scanning electron microscopy. The freeze-dried product was identified as the inclusion complex having the maximum intrinsic dissolution rate and hence was assessed for changes in permeability characteristics. pH partition studies and partial in vivo permeability studies showed no changes in the permeability of the freeze-dried product when compared to the pure drug.