Enhanced oral bioavailability of levormeloxifene and raloxifene by nanoemulsion: simultaneous bioanalysis using liquid chromatography-tandem mass spectrometry.

Aim & objective: Levormeloxifene (L-ORM) and raloxifene (RAL) are selective estrogen receptor modulators used in the treatment of postmenopausal osteoporosis and breast cancer. Here, we developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous estimation of both drugs. Materials & methods: A quality-by-design (QbD) approach was used for the optimization of the nanoemulsion, and US FDA guidelines were followed for method validation. Results: Multiple reaction monitoring transitions were used for L-ORM (459.05→98.50), RAL (475.00→112.02) and internal standard (180.10→110.2). Analytes were resolved in a C18 column with 80:20 v/v% acetonitrile (ACN), 0.1% formic acid in triple-distilled water as a mobile phase. The developed method was linear over a concentration range of 1-600 ng/ml. Pharmacokinetic results of free L-ORM-RAL and the L-ORM-RAL nanoemulsion showed Cmax of free L-ORM - 70.65 ± 16.64, free RAL 13.53 ± 2.72, L-ORM nanoemulsion 65.07 ± 14.0 and RAL-nanoemulsion 59.27 ± 17.44 ng/ml. Conclusion: Future findings will contribute to the treatment of postmenopausal osteoporosis and breast cancer using L-ORM and RAL.

[Box: see text].

Effects of raloxifene administration on serum levels of insulin-like growth factor-1 and insulin-like growth factor-binding protein 3 levels: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: To ascertain the clinical magnitude of raloxifene administration on insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-binding protein 3 (IGFBP-3) levels. METHODS: A systematic comprehensive search was performed without language limitation up to 14 December 2020. We included only trials that assessed the effect of raloxifene on IGF-1 and IGFBP-3 in adults. Meta-analysis was performed using the Stata software (Stata Corp. College Station, Texas, USA). RESULTS: Seven arms were included, encompassing postmenopausal women with type 2 diabetes mellitus, postmenopausal women with breast cancer, healthy postmenopausal women, and healthy elderly men. Raloxifene therapy significantly reduced IGF-1 levels (WMD: -2.92 nmol/L, 95% CI: -3.49, -2.35, p < 0.001) compared to placebo. Raloxifene dosage ˃60 mg/day (WMD: -3.29 ng/mL, 95% CI: -3.50 to -3.08, I2 = 0.0%) decreased IGF-1 levels more than 60 mg/day (WMD: -2.29 ng/mL, 95% CI: -2.90 to -1.69, I2 = 16%). Moreover, intervention duration ˃26 weeks (WMD: -3.48 ng/mL, 95% CI: -5.26 to -1.69, I2 = 0.0%) reduced IGF-1 levels more than ˂26 weeks (WMD: -2.55 ng/mL, 95% CI: -3.31 to -1.79, I2 = 92%). In contrast, overall results from the random-effects model did not suggest a significant change in IGFBP-3 levels upon raloxifene therapy. CONCLUSION: Raloxifene therapy significantly reduced serum levels of IGF-1 levels but without changes in IGFPB-3 levels.

Osteoporosis - risk factors, pharmaceutical and non-pharmaceutical treatment.

Osteoporosis is a metabolic disease of the skeletal system which currently affects over 200 million patients worldwide. The WHO criteria define osteoporosis as low bone mineral density, with a T-score ≤ -2.5 found in the spine, the neck of the femur, or during a full hip examination. Osteoporosis considerably reduces a patient's quality of life. QoL should be carefully evaluated before fractures occur to enable the development of an appropriate treatment plan. The progression of osteoporosis may be significantly inhibited by following a proper diet, leading a healthy lifestyle, taking dietary supplements, and receiving appropriate treatment. Education and the prevention of the disease play a major role. Potentially modifiable risk factors for osteoporosis are vitamin D deficiency, smoking, alcohol consumption, low calcium intake, low or excessive phosphorus intake, protein deficiency or a high-protein diet, excessive consumption of coffee, a sedentary lifestyle or lack of mobility, and insufficient exposure to the sun. Pharmaceutical treatment for osteoporosis involves bisphosphonates, calcium and vitamin D3, denosumab, teriparatide, raloxifene, and strontium ranelate. Data indicates that 30%-50% of patients do not take their medication correctly. Other methods of treatment include exercise, kinesitherapy, treatment at a health resort, physical therapy, and diet.

Preventing Breast Cancer Through Identification and Pharmacologic Management of High-Risk Patients.

Breast cancer remains the most common cancer in women in the United States. For certain women at high risk for breast cancer, endocrine therapy (ET) can greatly decrease the risk. Tools such as the Breast Cancer Risk Assessment Tool (or Gail Model) and the International Breast Cancer Intervention Study risk calculator are available to help identify women at increased risk for breast cancer. Physician awareness of family history, reproductive and lifestyle factors, dense breast tissue, and history of benign proliferative breast disease are important when identifying high-risk women. The updated US Preventive Services Task Force and American Society of Clinical Oncology guidelines encourage primary care providers to identify at-risk women and offer risk-reducing medications. Among the various ETs, which include tamoxifen, raloxifene, anastrozole, and exemestane, tamoxifen is the only one available for premenopausal women aged 35 years and older. A shared decision-making process should be used to increase the usage of ET and must be individualized. This individualized approach must account for each woman's medical history and weigh the benefits and risks of ET in combination with the personal values of the patient.

Development of intravaginal rod insert bearing liposomal raloxifene hydrochloride and Leuprolide acetate as a potential carrier for uterine targeting.

OBJECTIVES: This project aimed at the formulation of dual drug entrapped liposomes held as freeze-dried intravaginal rod insert (IVR), to be administered by vaginal route for uterine targeting. METHODS: Liposomes were formulated by dehydration-rehydration method using 3 : 1 molar ratio of1,2-distearoyl-sn-glycero-3-phosphocholine : Cholesterol. Characterization was done for vesicle size, zeta potential, entrapment efficiency, surface morphology and % loading. KEY FINDINGS: Spherical and discrete vesicles of size 354 nm were observed in transmission electron microscopy (TEM) image. The entrapment efficiency of 90.91% and 74.3% w/w was obtained for Raloxifene Hydrochloride (RLX) and Leuprolide acetate (LA) respectively. Drug release was sustained for 6 days. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay results showed that dual drug entrapped liposomal formulation show significant cytotoxicity, as also confirmed by higher apoptosis in cell cycle analysis and apoptosis studies (FACS) analysis. Pharmacodynamic studies in New Zealand white female rabbits revealed that intravaginal administration of RLX-LA entrapped liposomal formulation shows considerable fibroid regression. CONCLUSIONS: Uterine targeting of liposomal RLX-LA suggests its potential to solve the limitations of the presently available therapeutic options.

Bioadhesive polymer/lipid hybrid nanoparticles as oral delivery system of raloxifene with enhancive intestinal retention and bioavailability.

Raloxifene (RLX) is a second-generation selective estrogen receptor modulator used to treat osteoporosis in postmenopausal women. RLX fails to be developed into injectable dosage forms due to poor solubility. Although oral formulations are clinically available, the lower bioavailability (<2%) embarrasses the pharmaceutists. This work reported a bioadhesive nanosystem intended for oral delivery of RLX to enhance its oral bioavailability and address the formulation challenge. The bioadhesive nanosystem refers to polymer-lipid hybrid nanoparticles made up of Carbopol 940, glyceryl distearate, and TGPS. RLX was solidly encapsulated into bioadhesive nanoparticles (bNPs) through a nanoprecipitation technique along with synchronous desalting of RLX·HCl. The resultant RLX-loaded bNPs (RLX-bNPs) were characterized by particle size, ζ potential, morphology, and entrapment efficiency. The in vitro release and in vivo oral bioavailability of RLX-bNPs in rats were comparatively investigated with RLX-loaded common lipid nanoparticles (RLX-cNPs). The preferred formulation possesses a particle size of 150 nm around with a polydispersity index (PDI) of 0.282. RLX-bNPs exhibited slower drug release than RLX-cNPs owing to the presence of an adhesive layer. After oral administration, RLX-bNPs resulted in significant enhancement in the bioavailability of RLX, up to 556.9% relative to RLX suspensions, while it was merely 244.7% for RLX-cNPs. Cellular testing and ex vivo transport imaging demonstrated that bNPs were endowed with excellent intestinal epithelial affinity and absorbability. Our study affords an alternative option for designing a suitable oral delivery system specific to amphiphobic drugs like RLX·HCl.

The effects of alone and combination tamoxifen, raloxifene and estrogen on lipid profile and atherogenic index of ovariectomized type 2 diabetic rats.

INTRODUCTION: The cardiovascular dysfunctions in postmenopausal diabetic women increase relative to premenopausal women. In this study we evaluated protective effects of selective estrogen receptor modulators (SERMs), alone and in combination with estrogen (E2) in diabetic rats with menopausal model. METHODS: Female rats groups are included: Sham-Control (CTL), Diabetes (DM), and ovariectomized rats divided to DM, DM + Vehicle (Veh), DM + Tamoxifen (TAM), DM + Raloxifene (RLX), DM + Veh + Oil, DM + Oil, DM + E2, DM + E2 + Veh, DM + TAM + E2, DM + RLX + E2. DM was induced by high fat diet and followed by a light dose of streptozotocin. SERMs and E2 were administrated for four weeks after establishment of type 2 diabetes mellitus (T2DM). RESULTS: Our results depicts that, T2DM increased triglyceride, total cholesterol, low-density lipoprotein, and fasting blood glucose. Also it decreased high-density lipoprotein, which had exacerbated by ovariectomy. These changes were reversed by using SERMs, E2 and SERMs+E2, although combinatory treatment is more effective than individual treatment. Additionally the cardiovascular indices were also significantly disrupted in ovariectomized diabetic rats, but all therapeutic groups equally improved these disturbances, whereas in TAM + E2 group, the atherogenic index was more decreased than TAM group. CONCLUSION: We concluded that SERMs treatment, individual or in combination with E2 in menopausal model can be efficient substitute for E2 replacement therapy. This study suggests cellular mechanisms of SERMs in future studies.

Nanostructured lipid carrier potentiated oral delivery of raloxifene for breast cancer treatment.

Nanotherapeutics in cancer treatment are dominating global science and research, and have been recognized as the pioneering medical care regimen. Raloxifene (RLN) has been used for its anti-proliferative action on mammary tissue, however, it suffers from poor oral bioavailability. This investigation gives an account of the design and development of RLN-loaded nanostructured lipid carriers (RLN-NLCs) using a simple and scalable ultrasonication method for improved oral efficacy and limited offsite toxicity using Compritol® 888 ATO as a solid lipid and Transcutol® HP as a liquid lipid. In addition, the optimized RLN-NLCs were in the nanometric range (121 nm) with high % entrapment efficiency (%EE) (81%) for RLN, and were further freeze-dried in the presence of mannitol to enhance the stability of RLN-NLCs in the dry state for long-term use. Morphological observation under a transmission electron microscope and scanning electron microscope revealed the spherical smooth surface nanometric size of RLN-NLCs. Powder x-ray diffraction confirmed the encapsulation of RLN into the RLN-NLC's matrix with reduced crystallinity of the drug. The in vitro release study showed a burst release for an initial 4 h, and sustained release for up to 24 h. Furthermore, the RLN-NLCs showed higher cytotoxicity towards MCF-7 cells in vitro in comparison to RLN suspension, and an ex vivo intestinal permeation study demonstrated improved intestinal permeability of RLN-NLCs. Moreover, the in vivo pharmacokinetic study in female Wistar rats showed a 4.79-fold increment in oral bioavailability of RLN from RLN-NLCs compared to RLN suspension. Taken together, our results pave the way for a new nanotherapeutic approach towards breast cancer treatment.

A matrix dispersion based on phospholipid complex system: preparation, lymphatic transport, and pharmacokinetics.

Raloxifene hydrochloride (RH) suffers from low oral bioavailability due to its low water-solubility and first-pass metabolism. Therefore, a novel phospholipid complex of RH (RHPC) and a matrix dispersion based on phospholipid complex (RHPC-MD) were successfully prepared and optimized. Several methods were used to validate the formation of RHPC and RHPC-MD, such as differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, particle size, and zeta potential, meanwhile, their octanol-water partition coefficient, solubility, and dissolution in vitro were also evaluated. To investigate the absorption mechanism of RHPC in vivo, the RHPC was administered to the chylomicron flow blockage rat model. Interestingly, as we expected, a significant reduction in RHPC absorption (67%) (**p< .01) in presence of cycloheximide (CXI) inhibitor was observed, thus confirming the RHPC could be absorbed by lymphatic transport in vivo. Pharmacokinetic studies revealed that the relative oral bioavailability of RHPC as well as RHPC-MD was 223% and 329%, respectively, when comparing with the commercial RH tablets. These outcomes suggested that the current study provided an attractive formulation to enhance the oral bioavailability of RH and stimulated to further research the absorption mechanism of RHPC in vivo.

Efficacy of combined medication of risedronate sodium and selective estrogen receptor modulator on the postmenopausal osteoporosis.

To evaluate the efficacy of combined medication of risedronate sodium and raloxifene, a selective estrogen receptor modulator (SERM) on the postmenopausal osteoporosis (PMOP). PMOP patients underwent the combined medication of risedronate sodium and raloxifene (SERM, Treatment group), or only medication of risedronate sodium (Control group). After medication, more significant increases were observed in the bone densities of the lumber vertebra (L1-4) and the neck of left femur of patients in the treatment group. Simultaneously, the levels of estrogen and progesterone in serum decreased sharply in the treatment group. After treatment, P1NP and ß-CTX levels in serum decreased significantly in two groups in comparison with the levels prior to treatment, with evident elevations in the levels of BAP and BGP; similarly, ameliorations in the treatment group were much more evident than those in the control group. In addition, significant declines were identified in the VAS scores of two groups after treatment when comparing to the scores prior to the treatment, and the decline in the treatment group was more evident than that in the control group. Combined medication of risedronate sodium and SERM (raloxifene) performs better in treatment of osteoporosis than the single use of risedronate sodium, without the deterioration of adverse effect of medication.

In-situ forming chitosan implant-loaded with raloxifene hydrochloride and bioactive glass nanoparticles for treatment of bone injuries: Formulation and biological evaluation in animal model.

In-situ forming implants receive great attention for repairing serious bone injuries. The aim of the present study was to prepare novel chitosan in-situ forming implants (CIFI) loaded with bioactive glass nanoparticles and/or raloxifene hydrochloride (RLX). Incorporating raloxifene hydrochloride (RLX) as a selective estrogen receptor modulator was essential to make use of its anti-resorptive properties. The prepared formulae were tested for their in-vitro gelation time, drug release, injectability, rheological properties, erosion rate and morphological properties. Results revealed that the formulation composed of 1% (w/v) chitosan with 2% (w/v) NaHCO3 and 1% (w/v) bioactive glass nanoparticles (CIFI-BG) possessed the most sustained drug release profile which extended over four months with low burst release effect compared to the same formulation lacking bioactive glass nanoparticles (CIFI). Selected formulations were tested for their ability to enhance bone regeneration in induced puncture in rate tibia. Results declared that these formulations were able to enhance bone regeneration after 12 weeks in comparison to the untreated tibial punctures and that containing bioactive glass could be considered as novel approach for treatment of serious bone injuries which require long term treatment and internal mechanical bone support during healing.

Folic acid-conjugated raloxifene hydrochloride carbon nanotube for targeting breast cancer cells.

Breast cancer is one of the leading causes of mortality specifically for the women. The existing therapy is not sufficient due to the lack of target specificity and drug resistance. Carbon nanotubes (CNTs) are one of the promising formulation approaches that show a promising effect to target specifically the cancer cells, with better cellular internalization. CNTs were prepared based on the modified Staudenmaier process, where temperature and stirring speed were found to be the most influencing factor for particle size and entrapment of the drug raloxifene hydrochloride (RLX). The optimized formulation was produced with drug loading of about 74.2 ± 4.67% and the average particle size of 234.2 ± 1.7 nm. The surface of the CNTs was functionalized by folic acid (FA), which helps to deliver the drug on the site of the cancer cells only in a target-specific manner. in vitro drug-release studies indicated that the drug release was dependent on the pH of the system. Cytotoxicity study clearly indicated the efficacy of the FA physically conjugated CNTs with affectivity induces apoptosis in the cancer cell line with the IC50 value of 43.57305 µg/ml. The fluorescence imagining study showed higher cellular internalization of the RLX compared with the pure drug and the RLX-CNT formulation.

Effects of raloxifene on cognition in postmenopausal women with schizophrenia: a 24-week double-blind, randomized, parallel, placebo-controlled trial.

We assessed the utility of raloxifene (60 mg/day) as an adjuvant treatment for cognitive symptoms in postmenopausal women with schizophrenia in a 24-week, double-blind, randomized, placebo-controlled study. Patients were recruited from the inpatient and outpatient services of Parc Sanitari Sant Joan de Déu, Hospital Universitari Institut Pere Mata, and Corporació Sanitària Parc Taulí. Seventy eight postmenopausal women with schizophrenia were randomized to either adjunctive raloxifene or placebo. Sixty-eight began the clinical trial (37 women on raloxifene adjunct) and 31 on placebo adjunct. The outcome measures were: memory, attention and executive function. Assessment was conducted at baseline and at week 24. Between groups homogeneity was tested with the Student's t test for continuous variables and/or the Mann-Whitney U test for ordinal variables and the χ2 test or Fisher's exact test for categorical variables. The differences between the two groups in neuropsychological test scores were compared using the Student's t test. The sample was homogenous with respect to age, formal education, illness duration and previous pharmacological treatment. The addition of raloxifene to antipsychotic treatment as usual showed no differences in cognitive function. The daily use of 60 mg raloxifene as an adjuvant treatment in postmenopausal women with schizophrenia has no appreciable effect.ClinicalTrials.gov Identifier: NCT01573637.

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 (t1/2  = 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.

Vitamin E TPGS based transferosomes augmented TAT as a promising delivery system for improved transdermal delivery of raloxifene.

Raloxifene is commonly used for breast cancer protection. The low bioavailability of raloxifene (2%) is the result of its low solubility and intestinal glucuronidation. The nano-lipid carriers are characterized by small particle size, biocompatibility, and sustainable properties that improve cellular uptake of the loaded drug. The aim of this study was the improvement of raloxifene bioavailability by enhancing its solubility and cellular penetration through formulation of D-α-tocopheryl polyethylene glycol 1000 succinate based transferosomes and augmenting their effect with the cationic cell-penetrating peptide transactivator of transcription of the human immunodeficiency virus. Particle size, zeta potential, and transmission electron microscope investigation of the formed nanocarriers were carried out. Ex vivo raloxifene permeation through rat skin and cell viability studies was investigated. The results of D-α-tocopheryl polyethylene glycol 1000 succinate- transactivator of transcription of the human immunodeficiency virus transferosomes showed an average vesicle size of 96.05 nm with positively charged vesicles 39.4 mV of zeta potential value. The results revealed significant (p < 0.05) enhancement of raloxifene permeation from raloxifene transferosomes- loaded film when compared with raw raloxifene film. IC50 results showed significant improvement of formulated raloxifene cytotoxicity by 1.42-fold in comparison with raw raloxifene against MCF-7 cell lines. The developed raloxifene-transferosomes are considered promising nano-lipid carriers for the enhancement delivery of raloxifene.

Investigation of in vitro permeability and in vivo pharmacokinetic behavior of bare and functionalized MCM-41 and MCM-48 mesoporous silica nanoparticles: a burst and controlled drug release system for raloxifene.

In the present work, MCM-41 and MCM-48 type of nanoparticles were successfully engineered. Effect of nanosize and amine functionalization on drug release, in vitro intestinal absorption and in vivo pharmacokinetic behavior was investigated in a comprehensive manner. The tailor-made bare and surface decorated MCM-41 and MCM-48 were synthesized and evaluated for their mesoporous skeleton, pore size, particle size, surface area, zeta potential, etc. by nitrogen sorption, DLS, TEM, etc. Incorporation of raloxifene (RLF) was affirmed using optimized immersion-solvent evaporation technique and its success confirmed by DSC, IR, and XRD analysis. TGA analysis revealed higher %grafting of amine groups on the exterior and larger RLF encapsulation into mesoporous derivate. The detailed in vitro release study revealed SGF to be the most compatible media for RLF showing an initial burst release from pristine nanoparticles and a delayed release from surface coated nanoparticles. Furthermore, release kinetics model data demonstrated Weibull and Higuchi as the best fit models for bare and amine-functionalized nanoparticles respectively. Moreover, an in vitro permeability study on Caco-2 cell line revealed higher absorption by engineered nanoparticle as compared to pure RLF and its marketed formulation. The supremacy in the in vivo pharmacokinetic parameters of RLF-41 and RLF-48 was demonstrated with 3.33 and 3.50 times enhancement in the bioavailability of RLF with respect to RLF suspension. To sum up, the results obtained were superior and promising for synthesized nanoparticles and more precisely for MCM-48 amongst them.

In situ misemgel as a multifunctional dual-absorption platform for nasal delivery of raloxifene hydrochloride: formulation, characterization, and in vivo performance.

BACKGROUND: Raloxifene hydrochloride (RLX) is approved by the US Food and Drug Administration for the treatment and prevention of osteoporosis, in addition to reducing the risk of breast cancer in postmenopausal women. RLX has the disadvantages of low aqueous solubility, extensive presystemic intestinal glucuronidation, and first-pass metabolism, resulting in a limited bio-availability of only 2%. The aim of this work was to enhance the bioavailability of RLX via the formulation of an in situ nasal matrix (misemgel) comprising micelles made of vitamin E and D-α-tocopheryl polyethylene glycol 1000 succinate and nanosized self-emulsifying systems (NSEMS). MATERIALS AND METHODS: Optimization of the RLX-loaded NSEMS was performed using a mixture design. The formulations were characterized by particle size and then incorporated into an in situ nasal gel. Transmission electron microscopy, bovine nasal mucosa ex vivo permeation, and visualization using a fluorescence laser microscope were carried out on the RLX in situ misemgel comparing with raw RLX in situ gel. In addition, the in vivo performance was studied in rats. RESULTS: The results revealed improved permeation parameters for RLX misemgel compared with control gel, with an enhancement factor of 2.4. In vivo studies revealed a 4.79- and 13.42-fold increased bioavailability for RLX in situ misemgel compared with control RLX in situ gel and commercially available tablets, respectively. The obtained results highlighted the efficacy of combining two different formulations to enhance drug delivery and the benefits of utilizing different possible paths for drug absorption. CONCLUSION: The developed in situ misemgel matrix could be considered as a promising multifunctional platform for nasal delivery which works based on a dual-absorption mechanism.

Design of a transdermal formulation containing raloxifene nanoparticles for osteoporosis treatment.

PURPOSE: In the clinical setting, raloxifene, a second-generation selective estrogen receptor modulator, is administered orally; however, the bioavailability (BA) is only 2% because of its poor solubility in aqueous fluids and its extensive first-pass metabolism. Therefore, it is expected that the development of a transdermally delivered formulation may reduce the necessary dose without compromising its therapeutic efficacy. In this study, we designed transdermal formulations containing raloxifene nanoparticles and evaluated their usefulness for osteoporosis therapy. METHODS: Raloxifene was crushed with methylcellulose by the bead mill method, and the milled raloxifene was gelled with or without menthol (a permeation enhancer) by Carbopol® 934 (without menthol, Ral-NPs; with menthol, mRal-NPs). The drug release and transdermal penetration were measured using a Franz diffusion cell, and the therapeutic evaluation of osteoporosis was determined in an ovariectomized rat model. RESULTS: The mean particle size of raloxifene in the transdermal formulation (Ral-NPs) was 173.7 nm. Although the raloxifene released from Ral-NPs remained in the nanoparticle state, the skin penetration of raloxifene nanoparticles was prevented by the stratum corneum in rat. On the other hand, inclusion of menthol in the formulation attenuated the barrier function of the stratum corneum and permitted the penetration of raloxifene nanoparticles through the skin. Moreover, macropinocytosis relates to the skin penetration of the formulation including menthol (mRal-NPs), since penetration was inhibited by treatment with 2 µM rottlerin, a macropinocytosis inhibitor. In addition, the application of 0.3% mRal-NPs (once a day) attenuated the decreases in calcium level and stiffness of the bones of ovariectomized rat. CONCLUSION: We prepared raloxifene solid nanoparticles by a bead mill method and designed a novel transdermal formulation containing nanoparticles and permeation enhancers. These trans-dermal formulations overcome the barrier properties of the skin and show high drug penetration through the transdermal route (BA 8.5%). In addition, we found that raloxifene transdermal formulations are useful for the treatment of osteoporosis in ovariectomized rat.

[Effects of raloxifene at two different doses for ovulation induction on endometrial pinopodes in mice during the implantation window].

OBJECTIVE: To compare the expression of pinopodes, the marker of endometrial receptivity, during the implantation window in Kunming mice stimulated with two different doses of raloxifene (RAL). METHODS: Forty-eight 8-week-old female Kunming mice were randomly divided into 4 groups (n=12), namely saline group, clomiphene citrate (CC, 18 mg/kg) group, RAL (33 mg/kg) group and RAL (44 mg/kg group). In each group, the mice received intragastric administration of 1 mL of normal saline containing CC or RAL at the specified doses or saline only as indicated for ovulation induction, once daily for 2 days. The mice received then injection with 5 IU human chorionic gonadotropin (HCG) and mated and on day 4.5 of gestation, the pregnant mice were sacrificed for examination of the uterus with scanning electron microscopy. RESULTS: Abundant and well developed pinopodes were observed in the endometrium of the mice in the 2 RAL groups and in the saline control group. The mice in CC group showed obviously reduced endometrial pinopodes with poor development. CONCLUSIONS: RAL at two different doses does not obviously affect the expression of pinopodes in the uterine epithelium of mice, suggesting the safety of RAL at these two doses for ovulation induction without causing adverse effects on endometrial receptivity.