Raloxifene and Bazedoxifene Could Be Promising Candidates for Preventing the COVID-19 Related Cytokine Storm, ARDS and Mortality

The FDA-approved drugs raloxifene and bazedoxifene could be among the best candidates to prevent mortality in severe COVID-19 patients. Raloxifene and bazedoxifene inhibit IL-6 signaling at therapeutic doses, suggesting they have the potential to prevent the cytokine storm, ARDS and mortality in severe COVID-19 patients, as is being shown with humanized antibodies blocking IL-6 signaling. In addition, raloxifene and bazedoxifene are selective estrogen receptor modulators with strong antiviral activity.

A Non-Lipolysis Nanoemulsion Improved Oral Bioavailability by Reducing the First-Pass Metabolism of Raloxifene, and Related Absorption Mechanisms Being Studied

Objective

A non-lipolysis nanoemulsion (NNE) was designed to reduce the first-pass metabolism of raloxifene (RAL) by intestinal UDP-glucuronosyltransferases (UGTs) for increasing the oral absorption of RAL, coupled with in vitro and in vivo studies.

Methods

In vitro stability of NNE was evaluated by lipolysis and the UGT metabolism system. The oral bioavailability of NNE was studied in rats and pigs. Finally, the absorption mechanisms of NNE were investigated by in situ single-pass intestinal perfusion (SPIP) in rats, Madin-Darby canine kidney (MDCK) cells model, and lymphatic blocking model.

Results

The pre-NNE consisted of isopropyl palmitate, linoleic acid, Cremophor RH40, and ethanol in a weight ratio of 3.33:1.67:3:2. Compared to lipolysis nanoemulsion of RAL (RAL-LNE), the RAL-NNE was more stable in in vitro gastrointestinal buffers, lipolysis, and UGT metabolism system (p < 0.05). The oral bioavailability was significantly improved by the NNE (203.30%) and the LNE (205.89%) relative to the suspension group in rats. However, 541.28% relative bioavailability was achieved in pigs after oral NNE intake compared to the suspension and had two-fold greater bioavailability than the LNE (p < 0.05). The RAL-NNE was mainly absorbed in the jejunum and had high permeability at the intestine of rats. The results of both SPIP and MDCK cell models demonstrated that the RAL-NNE was absorbed via endocytosis mediated by caveolin and clathrin. The other absorption route, the lymphatic transport (cycloheximide as blocking agent), was significantly improved by the NNE compared with the LNE (p < 0.05).

Conclusion

A NNE was successfully developed to reduce the first-pass metabolism of RAL in the intestine and enhance its lymphatic transport, thereby improving the oral bioavailability. Altogether, NNE is a promising carrier for the oral delivery of drugs with significant first-pass metabolism.

A Combination Treatment of Raloxifene and Vitamin D Enhances Bone-to-Tendon Healing of the Rotator Cuff in a Rat Model

BACKGROUND

Tearing and degeneration of the rotator cuff at the tendon-to-bone junction are common in adults aged ≥50 years. Few studies have reported on the relationship between estrogen and the rotator cuff enthesis. In addition to preventing bone loss, selective estrogen receptor modulators have been shown to improve tendon and muscle quality.

PURPOSE

To evaluate the effects of raloxifene (RLX) and vitamin D on rotator cuff tendon-to-bone healing in a rat model.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 29 female rats (58 shoulders) were assigned to 4 groups: (1) control group, (2) ovariectomy (OVX)-only group, (3) no RLX group (OVX and rotator cuff repair [RCR]), and (4) RLX group (OVX, RCR, and RLX). Rats that did not undergo rotator cuff tear (RCT) surgery were divided into the control and OVX-only groups according to OVX surgery. Rats that underwent RCT surgery and RCR were divided into the no RLX and RLX groups according to RLX and vitamin D administration. An estrogen-deficient state was induced by OVX at 12 weeks of age. Bone mineral density (BMD) and trabecular bone characteristics were measured by micro-computed tomography, and healing of the tendon-to-bone junction was evaluated by biomechanical testing, histomorphometry, and micro-magnetic resonance imaging (MRI).

RESULTS

The mean final body weight (BW; 461.6 ± 47.3 g) of the OVX-only group was significantly higher and BMD (0.25 ± 0.07 g/cm³) was significantly lower (P < .001) than the mean final BW (338.5 ± 35.1 g) and BMD (0.48 ± 0.05 g/cm³) of the control group. In contrast, the RLX group showed that the BW (369.6 ± 35.8 g) and BMD (0.41 ± 0.08 g/cm³) were not significantly different from the control group. The RLX group had a significantly higher histomorphometric total score (8.50 ± 1.05) than the no RLX group (4.83 ± 2.48). On biomechanical testing, the RLX group (29.7 ± 9.1 N) showed a significantly higher load to failure than the no RLX group (19.4 ± 8.8 N). On micro-MRI, the RLX group had a more homogeneous low signal and tendon continuity than the no RLX group.

CONCLUSION

The combination treatment of RLX and vitamin D prevented a decrease in local BMD (greater tuberosity of the proximal humerus) and enhanced tendon-to-bone healing of the rotator cuff in a rat model.

CLINICAL RELEVANCE

This study induced an estrogen-deficient state similar to the human postmenopausal state and used drugs that are actually being prescribed in a clinical situation.

Review of Pharmacological Strategies with Repurposed Drugs for Hereditary Hemorrhagic Telangiectasia Related Bleeding

The diagnosis of hereditary hemorrhagic telangiectasia (HHT) is based on the Curaçao criteria: epistaxis, telangiectases, arteriovenous malformations in internal organs, and family history. Genetically speaking, more than 90% of HHT patients show mutations in ENG or ACVRL1/ALK1 genes, both belonging to the TGF-β/BMP9 signaling pathway. Despite clear knowledge of the symptoms and genes of the disease, we still lack a definite cure for HHT, having just palliative measures and pharmacological trials. Among the former, two strategies are: intervention at "ground zero" to minimize by iron and blood transfusions in order to counteract anemia. Among the later, along the last 15 years, three different strategies have been tested: (1) To favor coagulation with antifibrinolytic agents (tranexamic acid); (2) to increase transcription of ENG and ALK1 with specific estrogen-receptor modulators (bazedoxifene or raloxifene), antioxidants (N-acetylcysteine, resveratrol), or immunosuppressants (tacrolimus); and (3) to impair the abnormal angiogenic process with antibodies (bevacizumab) or blocking drugs like etamsylate, and propranolol. This manuscript reviews the main strategies and sums up the clinical trials developed with drugs alleviating HHT.

Oral Bioavailability Enhancement of Raloxifene with Nanostructured Lipid Carriers

Raloxifene hydrochloride (RLX) shows poor bioavailability (<2%), high inter-patient variability and extensive gut metabolism (>90%). The objective of this study was to develop nanostructured lipid carriers (NLCs) for RLX to enhance its bioavailability. The NLC formulations were produced with glyceryl tribehenate and oleic acid. The particle characteristics, entrapment efficiency (EE), differential scanning calorimetry (DSC), in vitro drug release, oral bioavailability (in rats) and stability studies were performed. The optimized nanoparticles were 120 ± 3 nm in size with positive zeta potential (14.4 ± 0.5 mV); % EE was over 90% with the drug loading of 5%. The RLX exists in an amorphous form in the lipid matrix. The optimized RLX-NLC formulation showed sustained release in vitro. The RLX-NLC significantly (p < 0.05) enhanced oral bioavailability 3.19-fold as compared to RLX-free suspension in female Wistar rats. The RLX-NLC can potentially enhance the oral bioavailability of RLX. It can also improve the storage stability.

Raloxifene improves TNF-α-induced osteogenic differentiation inhibition of bone marrow mesenchymal stem cells and alleviates osteoporosis

Effect of raloxifene (RLF) on the improvement of inhibited osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) resulted from tumor necrosis factor-α (TNF-α) induction, thus alleviating the progression of osteoporosis (OP), was investigated. An in vivo OP rat model was constructed by performing the procedures of ovariectomy (OVX). Rats were randomly divided into sham group, OVX group and RLF+OVX group. BMSCs were extracted from healthy rats, and randomly divided into control group, TNF-α group, RLF group and TNF-α+RLF group. Viability and cellular calcification ability in each group were detected. The relative levels of osteocalcin (OCN), Runx2 and NF-κB in cells with different treatments were determined. The body weight of rats in the OVX group and RLF+OVX group gradually increased compared with that in the sham group on the 8th week. No significant difference in body weight was observed between the rats of the OVX group and RLF+OVX group. Bone metabolism index (BMD) in the rats of the RLF+OVX group was higher than that of the OVX group, and lower compared with that of the sham group. Compared with the sham group, the elastic/max radial degree and elastic/max load of femora were reduced in the OVX group and RLF+OVX group, especially in the OVX group. The relative levels of OCN and Runx2, as well as the ALP activity and calcification ability, were decreased in the OVX group compared with the sham group, and the effect was partially reversed by the RLF treatment. After osteogenic differentiation of BMSCs, the viability and calcification ability were markedly reduced in TNF-α group, which was reversed by RLF treatment. Moreover, TNF-α induction downregulated the relative levels of OCN and Runx2, and RLF treatment could enhance their levels. The upregulated NF-κB protein level, induced by TNF-α, was reduced after RLF treatment. TNF-α induction inhibits osteogenic differentiation of BMSCs, which could be remarkably alleviated by RLF. It is suggested that RLF contributes to the alleviation of OP progression.

Beyond estrogen: advances in tissue selective estrogen complexes and selective estrogen receptor modulators

Selective estrogen receptor modulators (SERMs) are synthetic non-steroidal agents which have variable estrogen agonist and antagonist activities in different target tissues. Tamoxifen is an anti-estrogen in the breast used for treatment and prevention of breast cancer, with estrogen agonist activity in the uterus. Raloxifene prevents and treats osteoporosis and prevents breast cancer, and can be safely combined with vaginal but not systemic estrogen. The tissue selective estrogen complex combines conjugated equine estrogens (CEE) with the SERM bazedoxifene (BZA). The five Selective Estrogen Menopause and Response to Therapy studies, with up to 2 years of data, demonstrated that CEE/BZA 0.45 mg/BZA 20 mg improved vasomotor symptoms and vulvovaginal atrophy, prevented bone loss, and was neutral on breast tenderness, breast density, with breast cancer incidence similar to placebo. Protection against estrogen-induced endometrial hyperplasia and cancer was found, with similar amenorrhea rates to placebo. Ospemifene is approved to treat dyspareunia, with potential benefits on bone and the breast, while lasofoxifene is being developed to treat resistant estrogen receptor-positive breast cancer in women. Estetrol is an estrogen synthesized exclusively during pregnancy by the human fetal liver and initially considered a weak estrogen, but it appears to have dual weak estrogenic/anti-estrogenic features.

Distinct Approaches of Raloxifene: Its Far-Reaching Beneficial Effects Implicating the HO-System

Selective estrogen receptor modulators (SERMs) were discovered in the mid-1900s in connection with estrogen-related pathological conditions. They were developed to antagonize the adverse effects of estrogen and have been shown to be effective against postmenopausal disorders manifested by estrogen deficiency. Raloxifene (RAL), one of the most widely used SERMs, expresses estrogen-like effects on bones, while it is found to be an antagonist on breast and uterus. RAL has multiple beneficial effects throughout the body, including antioxidant and anti-inflammatory properties, because of which it gains particular attention. Additionally, previous studies have revealed that RAL is an efficient modulator of heme-oxygenase (HO) expression. HO, through its general activity, participates in comprehensive cell defense processes, thus the induction of HO by RAL administration indicates a major role in its therapeutic efficacy. In this review, we compile the current knowledge about the overall metabolic, neurocognitive, and cardiovascular effects of RAL involving the cytoprotective HO-system.

Pulmonary delivery alters the disposition of raloxifene in rats

OBJECTIVE

Pulmonary delivery is an effective way to improve the bioavailability of drugs with extensive metabolism. This research was designed to study the different pharmacokinetic behaviours of small molecule drug after pulmonary delivery and intragastric (i.g) administration.

METHODS

Raloxifene, a selective estrogen receptor modulator with low oral bioavailability (~2%), was chosen as the model drug. Studies were conducted systematically in rats, including plasma pharmacokinetics, excretion, tissue distribution and metabolism.

KEY FINDINGS

Results showed that raloxifene solution dosed by intratracheal (i.t) administration exhibited relatively quick plasma elimination (t_1/2  = 1.78 ± 0.14 h) and undetected absorption process, which was similar with intravenous injection. Compared with i.g administration, the bioavailability increased by 58 times, but the major route of excretion remained faecal excretion. Drug concentration on the bone and the target efficiency were improved by 49.6 times and five times, respectively. Benefited from quick elimination in the lung, chronic toxicity might be ignored.

CONCLUSIONS

Pulmonary administration improved the bioavailability of raloxifene and further increased the distribution on the target organ (bone), with no obvious impact on its excretory pattern.

Systemic lupus erythematosus and menopause

Estrogen has been known for a long time to be a trigger on auto-immunity and may influence the course of lupus. Women experiencing systemic lupus are at high risk for premature ovarian insufficiency if using cyclophosphamide, of osteoporosis, arterial ischemic diseases and venous thrombosis at young age. In about 30% of them, an antiphospholipid/anticoagulant antibody can occur which is associated with very high risk of thrombosis. However, the severity of the disease may vary and some women with lupus could benefit from a menopausal hormone therapy (MHT). As a consequence, management of menopause symptoms needs to evaluate carefully the condition of the patient, her lupus history and cardiovascular risk. We will describe the effect of lupus on menopause, of menopause on lupus and report in detail the literature available on MHT and the risk of lupus or the risk of flares in women with lupus. Some other options than MHT for the management of climacteric symptoms will be discussed.

Raloxifene alleviates amyloid-β-induced cytotoxicity in HT22 neuronal cells via inhibiting oligomeric and fibrillar species formation

Raloxifene, a selective estrogen receptor modulator, displays benefits for Alzheimer's disease (AD) prevention in postmenopausal women as hormonal changes during menopause have the potential to influence AD pathogenesis, but the underlying mechanism of its neuroprotection is not entirely clear. In this study, the effects of raloxifene on amyloid-β (Aβ) amyloidogenesis were evaluated. The results demonstrated that raloxifene inhibits Aβ₄₂ aggregation and destabilizes preformed Aβ₄₂ fibrils through directly interacting with the N-terminus and middle domains of Aβ₄₂ peptides. Consequently, raloxifene not only reduces direct toxicity of Aβ₄₂ in HT22 neuronal cells, but also suppresses expressions of tumor necrosis factor-α and transforming growth factor-β induced by Aβ₄₂ peptides, and then alleviates microglia-mediated indirect toxicity of Aβ₄₂ to HT22 neuronal cells. Our results suggested an alternative possible explanation for the neuroprotective activity of raloxifene in AD prevention.

Is there any potential anticancer effect of raloxifene and fluoxetine on DMBA-induced rat breast cancer?

Breast cancer is the most common cancer among women in the world and the incidence is increasing alarmingly. It was aimed to determine the effect of raloxifene (RAL) and fluoxetine (FLX) on selected parameters in 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinoma. Thirty-two female Wistar albino rats were assorted into four groups: DMBA (group I), DMBA+RAL (group II), DMBA+FLX (group III), and DMBA+RAL+FLX (group IV). Mammary tissue vascular endothelial growth factor (VEGF), macrophage colony-stimulating factor (M-CSF), matrix metalloproteinase-9 (MMP-9), and tissue inhibitors of matrix metalloproteinase-1 (TIMP-1) levels were determined by the enzyme-linked immunosorbent assay method. The tissue VEGF levels were lower in group IV compared with DMBA group. Decreased M-CSF levels were observed in all therapeutic groups rather than the DMBA group, but the most effective decrease was found in group IV. Compared with the DMBA group, MMP-9 levels were statistically significantly decreased in group II and group IV. However, TIMP-1 levels were higher in the whole therapeutic groups rather than the DMBA group and the most effective increase was observed in group IV. Results of the present study suggest that combined therapy of RAL with FLX might lead to a better outcome targeting breast tumor.

The use of selective estrogen receptor modulators on bone health in men

Selective estrogen receptor modulators (SERMs) represent a class of drugs that act as agonist or antagonist for estrogen receptor in a tissue-specific manner. The SERMs drugs are initially used for the prevention and treatment of osteoporosis in postmenopausal women. Bone health in prostate cancer patients has become a significant concern, whereby patients undergo androgen deprivation therapy is often associated with deleterious effects on bone. Previous preclinical and epidemiological findings showed that estrogens play a dominant role in improving bone health as compared to testosterone in men. Therefore, this evidence-based review aims to assess the available evidence derived from animal and human studies on the effects of SERMs on the male skeletal system. The effects of SERMs on bone mineral density (BMD)/content (BMC), bone histomorphometry, bone turnover, bone strength and fracture risk have been summarized in this review.

Estrogen Modulates Cartilage and Subchondral Bone Remodeling in an Ovariectomized Rat Model of Postmenopausal Osteoarthritis

BACKGROUND Estrogen levels regulate changes in osteoarthritis (OA) by inhibiting degradation of the extracellular matrix. Recent in vitro studies have also shown the role of microRNA-140-5p (miR-140-5p). This study aimed to investigate the role of estrogen deficiency, selective modulation of expression of the estrogen receptor (ER), and expression of miR-140-5p in cartilage and subchondral bone remodeling in an ovariectomized rat model of postmenopausal OA. MATERIAL AND METHODS Female Sprague-Dawley rats included two model groups, ovariectomized (OVX) rats and rats with destabilization of the medial meniscus (DMM) rats. Two months after surgery, estrogen levels were measured by the enzyme-linked immunosorbent assay (ELISA). Three-dimensional (3D) micro-computed tomography (micro-CT) was used to image the knee joints. Rats were treated with subcutaneous injection of estrogen (E2) or the selective estrogen receptor modulator (SERM), raloxifene (RAL), for one month. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect miR-140-5p in serum, and histology of the knee joint cartilage and bone was performed. RESULTS In the ovariectomized rat model of OA, estrogen therapy reduced the degree of cartilaginous degeneration, while treatment with raloxifene showed no significant effect. Expression levels of miR-140-5p in the OA model group were significantly lower than the control group. Micro-CT showed that in the model group, anterior cruciate ligament dislocation and subchondral bone density were significantly reduced. CONCLUSIONS In an ovariectomized rat model of postmenopausal OA, estrogen deficiency resulted in resorption of subchondral bone and degeneration of articular cartilage.

Raloxifene decreases cell viability and migratory potential in prostate cancer cells (LNCaP) with GPR30/GPER1 involvement

OBJECTIVES

This study evaluated raloxifene (ral) effects on LNCaP prostate tumour cells modulating the activity of GPER1/GPR30 receptors.

METHODS

LNCaP cells were submitted for 40/120 min and 12 h to the following treatments: C: RPMI + DMSO; R: RPMI + Ral; G: RPMI + Ral + G15 (GPER1 antagonist). Trypan blue staining measured cell viability. Migratory potential (12 h) was measured by transwell migration test in translucent inserts, which were then stained with DAPI and analysed under a fluorescence microscope for quantification. Cells from 40- and 120-min treatments were subjected to protein extraction to the study of AKT, pAKT, ERK, pERK, ERβ and SIRT1.

KEY FINDINGS

There is a reduction in cellular viability in R compared to C at all evaluated times, and an increased cell viability in G when compared to R; cell viability was similar in C and G in all times studied. The migration assay demonstrated a significant decrease in migration potential of tumour cells in R compared to C and G. Ral treatment reduced pERK expression and increased pAKT in the treated groups after 40 min, pointing out to an antiproliferative and apoptotic effect in the GPER1-controlled rapid-effect pathways.

CONCLUSIONS

Raloxifene was able to modulate GPER1 in LNCaP prostate tumour cells, decreasing cell viability and their migratory potential.

Raloxifene nano-micelles effect on triple-negative breast cancer is mediated through estrogen receptor-β and epidermal growth factor receptor

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer that differs in progression, recurrence, and prognosis from other forms of breast cancer. The heterogeneity of TNBC has remained a challenge as no targeted therapy is currently available. Previously, we and others have demonstrated that raloxifene, a selective oestrogen receptor modulator, was also acting independently of the oestrogen receptor-α. However, raloxifene is characterised by a low bioavailability in vivo. Thus, we encapsulated raloxifene into a styrene-maleic acid (SMA) micelle to improve its pharmacokinetics. The micellar raloxifene had higher cytotoxicity when compared to the free formulation, promoted a higher cellular uptake and affected critical signalling pathways. Furthermore, SMA-raloxifene reduced TNBC tumour growth more efficiently than free raloxifene. Finally, we showed that this effect was partially mediated through oestrogen receptor-β. In conclusion, we have provided new insight into the role of raloxifene nanoformulation in improving the management of TNBC.

Bone repair with raloxifene and bioglass nanoceramic composite in animal experiment

OBJECTIVE

This study proposes to evaluate, by means of microtomographic analysis, the topical potential of raloxifene combined with BioGran® through the sonochemical method in the repair of critical bone defects in the calvaria of rats. The hypothesis was that the homogenization of Raloxifene to Biogran at the 20% concentration would improve the bone repair at the grafted site.

MATERIALS AND METHODS

A 5-mm calvaria bone defect was induced in three groups: CTR (100% BioGran®); RAL10 (90% BioGran® and 10% raloxifene), and RAL20 (80% BioGran® and 20% raloxifene). The animals were euthanized after 30 days and the microCT analysis was then performed to evaluate the parameters bone volume (BV), bone volume percentage (BV/TV), trabecular bone thickness (Tb.Th), and the separation and number of trabeculae (Tb.Sp and Tb.N). The obtained results were compared using ANOVA and Tukey test (p < 0.05).

RESULTS

The best results were found for the CTR and RAL20 groups, in which the BV, BV/TV, Tb.Sp, and Tb.N parameters were statistically significant in comparison with RAL10 (p < 0.05).

CONCLUSIONS

In view of the results obtained in this experiment, we can conclude that BioGran® alone or in an 80/20 mass concentration with raloxifene can lead to favorable bone formation.

SERMs Promote Anti-Inflammatory Signaling and Phenotype of CD14+ Cells

Signaling via estrogen receptors (ER) is recognized as an essential part of the immune regulation, and ER-mediated signaling is involved in autoimmune reactions. Especially ERα activation in immune cells has been suggested to skew cytokine production toward Th2/M2-type mediators, which can have protective effect on inflammatory diseases and reduce Th1 and Th17 responses. These effects are caused by increased alternative activation of macrophages and changes in the activation of different T cell populations. In humans, hormonal status has been shown to have a major impact on several inflammatory diseases. Selective estrogen receptor modulators (SERMs) are ER ligands that regulate ER actions in a tissue-specific manner mostly lacking the adverse effects of steroid hormones. The impact of SERMs on the immune system is less studied, but it is suggested that certain SERMs may also produce immunoprotective effects. Here, we show that two novel SERMs and raloxifene affect immune cells by promoting M2 macrophage phenotype, alleviating NFκB activity, inhibiting T cell proliferation, and stimulating the production of anti-inflammatory compounds such as IL10 and IL1 receptor antagonist. Thus, these compounds have high potency as drug candidates against autoimmune diseases.

Effects of 17β-estradioland raloxifene on endothelial OPG and RANKL secretion

OBJECTIVES

This study aims to asses the effects of estradiol vs. raloxifene on the levels of osteoprotegerin and soluble Receptor Activator of Nuclear Factor kB Ligand (sRANKL) in Human Umbilical Vein Endothelial Cells (HUVEC) culture in standard and calcifying medium.

MATERIAL AND METHODS

Human Umbilical Vein Endothelial Cells were isolated from human umbilical vein by standard method. The supernatant concentrations of osteoprotegerin (OPG) and sRANKL (ELISA) were determined after incubation with glicerophosphate, estradiol , raloxifene, glicerophoshate and estradiol, glicerophosphate and raloxifene in comparison with control group at four designated time points (0, 1, 2 and 4 days of incubation).

RESULTS

Incubation of estradiol with HUVEC colony lowered the OPG level significantly after day 2 and 4. Meantime, the level of sRANKL was stable. Raloxifene added to standard growth medium also significantly lowered OPG concentration after day 4 only, with no impact on sRANKL concentration. When added to calcifying medium, both estradiol and raloxifene significantly changed OPG level during the experiment. In all treated groups OPG levels were lower than in groups exposed to calcifying medium only. Neither estradiol, nor raloxifene changed sRANKL levels during the experiment.

CONCLUSIONS

Estradiol and raloxifene affect OPG secretion from endothelial cells in vitro which may suggest their modifying role in pathogenesis of vascular calcification in postmenopausal women.

Development and Evaluation of Raloxifene-Hydrochloride-Loaded Supersaturatable SMEDDS Containing an Acidifier

Raloxifene hydrochloride (RLH) was formulated into a pH-modified supersaturatable self-microemulsifying drug delivery system (S-SMEDDS) to increase drug solubility and dissolution rate. Optimal formulations of pH-modified S-SMEDDSs were developed by incorporating hydroxypropyl-cellulose-L as a precipitation inhibitor and phosphoric acid as a pH modifier (an acidifier). RLH was dissolved to greater extents by all pH-modified S-SMEDDSs compared with non-pH-modified S-SMEDDSs. In particular, phosphoric acid afforded greater drug dissolution than did the other acidifiers tested, perhaps because phosphoric acid better controlled the pH. More than 50% of the RLH was released from the pH-modified S-SMEDDS at pH 2.5 compared with only ~5% of the drug into aqueous buffer (pH 1.2 or 6.8) after dissolution of a conventional tablet. pH-modified S-SMEDDSs with a hydrophilic polymer and phosphoric acid improved the dissolution behavior of a drug exhibiting poor aqueous solubility.

Raloxifene/SBE-β-CD Inclusion Complexes Formulated into Nanoparticles with Chitosan to Overcome the Absorption Barrier for Bioavailability Enhancement

Raloxifene (RXF) is a hormone-like medication used for treating postmenopausal osteoporosis and estrogen-dependent breast cancer, yet associated with bad low bioavailability due to poor solubility. This study was intended to develop cyclodextrin/chitosan nanoparticles (ccNPs) for oral delivery of RXF in order to enhance the oral bioavailability. RXF-loaded ccNPs (RXF-ccNPs) were prepared by cyclodextrin inclusion followed by complexation with chitosan. RXF-ccNPs were fully characterized by particle size, morphology and in vitro drug release. The oral delivery efficacy and transepithelial transport potential were evaluated by pharmacokinetics, in situ single-pass intestinal perfusion, cellular uptake and ex vivo imaging. The resulting RXF-ccNPs were around 165 nm in particle size with a narrow distribution. The oral bioavailability of RXF was enhanced by 2.6 folds through ccNPs compared to RXF suspensions in rats. It was shown that RXF-ccNPs could improve the intestinal permeability of RXF, increase the cellular uptake of RXF and facilitate its transport across the absorptive epithelia. The results indicate that our developed ccNPs based on sulfobutylether-β-cyclodextrin and oligochitosan are a promising vehicle to orally deliver poorly water-soluble drugs over and above RXF.

Use of raloxifene and tamoxifen by breast cancer risk level in a Medicare-eligible cohort

BACKGROUND

Raloxifene and tamoxifen are Food and Drug Administration-approved for breast cancer risk reduction; in 2013, the US Preventive Services Task Force recommended these drugs for breast cancer risk reduction in high-risk women. Information on the use of raloxifene and tamoxifen for breast cancer risk reduction in the general population indicates that the risk is believed to be low; however, there is little literature.

OBJECTIVE

The purpose of this study was to assess the use of breast cancer risk reduction medications by breast cancer risk level in an older cohort of women.

STUDY DESIGN

Women who were enrolled in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial were assessed for the use of raloxifene, tamoxifen, and other medications. The data sources for use of the drugs were a mailed medication use questionnaire in 2013 and linked Medicare Part D claims files from 2010-2014. Estimated breast cancer risk within 5 years was assessed with the use of the modified Gail model and self-reported breast cancer risk factors; comorbidities were assessed through a questionnaire.

RESULTS

A total of 22,235 women completed the medication use questionnaire; of these, 13,640 women (61%) had linked Part D data. In 2013, 45% of the women were 65-74 years old, and 55% of the women were 75-84 years old. From the medication use questionnaire, raloxifene use (past month) was 1.8%, 2.5%, and 4.0% for women with breast cancer risk within 5 years of <1.66%, 1.66-3.0%, and ≥3%, respectively (probability value trend, <.0001). From Part D, for any use during the period among women with coverage, raloxifene rates were 3.3%, 4.0%, and 6.6% for the 3 categories for breast cancer risk within 5 years (probability value trend, <.0001); use was 7.4% and 3.3% in women with and without osteoporosis, respectively. Raloxifene use significantly decreased from 2010-2014, and specifically from 2012-2014, both for all women and for women with breast cancer risk within 5 years of ≥3%. Tamoxifen use from Part D was 0.36%, 0.45%, and 0.85% for the 3 categories for breast cancer risk within 5 years (probability value trend, .009).

CONCLUSION

Raloxifene use was low overall but increased modestly with breast cancer risk, and usage decreased from 2010-2014. Tamoxifen use was very low.