This study aimed to develop and optimize a self-nanoemulsifying drug delivery system (SNEDDS) of bosentan (BOS) to solve its poor oral bioavailability due to low water solubility. A pseudo-ternary phase diagram was created based on the solubility and emulsification studies. The major components of the formulation were selected as glyceryl monolinoleate (lipid), polyoxyl 40 hydrogenated castor oil (surfactant), and caprylocaproyl polyoxyl-8 glycerides (co-surfactant). The composition of BOS-SNEDDS was optimized using the Box-Behnken design (BBD) and then was characterized for various physicochemical properties. The in vitro dissolution, in vitro lipolysis, and ex-vivo permeability studies were performed and compared to SNEDDS and reference tablets. The fasted and fed state bioavailability of BOS-loaded SNEDDS was evaluated in Wistar rats (n = 6) compared to the reference. The prepared SNEDDS were thermodynamically stable with a droplet size of 17.11 nm, a polydispersity index of 0.180, and an emulsification time of <1 min. The BOS-loaded SNEDDS showed 3.0, 7.97, 4.23, and 4.94-fold increases in the percentages of cumulative dissolution compared to reference tablets in FaSSIF, FeSSIF, FaSSIF-V2, and FeSSIF-V2, respectively. The permeation study showed that the SNEDDS increased the drug permeation by 3.36, 19.2, 16.4, and 16.6-fold in FaSSIF, FeSSIF, FaSSIF-V2, and FeSSIF-V2, respectively. The enhancement of in vitro dissolution, in vitro lipolysis, and ex-vivo permeability was found significant (p < 0.05). SNEDDS was increased the C_max and AUC 1.67 and 2.12-fold and 5.15 and 1.84-fold in fasted and fed state compared to the reference, respectively. The in vitro-in vivo relationship has been successfully performed for SNEDDS. These results indicated that the SNEDDS formulation could be a promising delivery system that enhances the absorption and oral bioavailability of BOS.

In transdermal applications of nonsteroidal anti-inflammatory drugs, the rheological and mechanical properties of the dosage form affect the performance of the drug. The aim of this study to develop emulgel and nanostructured lipid carrier NLC-based gel formulations containing ibuprofen, evaluate their mechanical properties, bioadhesive value and ex-vivo rabbit skin permeability. All formulations showed non-Newtonian pseudoplastic behavior and their viscosity values are suitable for topical application. The particle size of the nanostructured lipid carrier system was found to be 468 ± 21 nm, and the encapsulation efficiency was 95.58 ± 0.41%. According to the index of viscosity, consistency, firmness, and cohesiveness values obtained as a result of the back extrusion study, E2 formulation was found to be more suitable for transdermal application. The firmness and work of shear values of the E2 formulation, which has the highest viscosity value, were also found to be the highest and it was chosen as the most suitable formulation in terms of the spreadability test. The work of bioadhesion values of NLC-based gel and IBU-loaded NLC-based gel were found as 0.226 ± 0.028 and 0.181 ± 0.006 mJ/cm2 respectively. The percentages of IBU that penetrated through rabbit skin from the Ibuactive-Cream and the E2 were 87.4 ± 2.11% and 93.4 ± 2.72% after 24 h, respectively. When the penetration of ibuprofen through the skin was evaluated, it was found that the E2 formulation increased penetration due to its lipid and nanoparticle structure. As a result of these findings, it can be said that the NLC-based gel formulation will increase the therapeutic efficacy and will be a good alternative transdermal formulation. Graphical Abstract

The aim of this study was to develop and optimize a simple, cost-effective, and robust high-performance liquid chromatography (HPLC) method by taking an experimental design approach to the assay and dissolution analysis of amlodipine besylate and enalapril maleate from a fixed-dose combination tablet. The chromatographic analysis was performed on a C18 column (4.6x250 mm id., particle size of 5 μm). The injection volume was 5 μL, and the detection wavelength was 215 nm. A Box-Behnken design was used to test the robustness of the method. The flow rate (1, 1.2, and 1.4 mL/min), column temperature (25°C, 30°C, and 35°C), methanol ratio of the mobile phase (5, 10, and 15%), and pH of the mobile phase (2.8, 3, and 3.2) were selected as independent variables. The method was validated according to International Conference on Harmonization guidelines. Dissolution of the tablets was performed by using USP apparatus 2 and analyzed using the optimized HPLC method. Multivariate linear regression analysis and ANOVA were used in the statistical evaluation. Linear models were fitted for all variables. The flow rate was the most significant factor affecting the APIs' concentrations. The optimized method included the following parameters: Column temperature of 25°C, 10% methanol as the mobile phase, pH of 2.95, and flow rate of 1.205 mL/min. Retention times were 3.8 min and 7.9 min for enalapril and amlodipine, respectively. The method was found to be linear in the range of 0.8-24 μg/mL (R2 >0.999) and 1.6-48 μg/mL (R2 >0.999) for amlodipine and enalapril, respectively. Both APIs were dissolved more than 85% within 10 min. The experimental design was proved as a useful tool for the determination and separation of enalapril maleate and amlodipine besylate in dosage forms. The optimized method can be used for in vitro performance and quality control tests of fixed-dose tablet combinations containing enalapril maleate and amlodipine besylate.

This study was planned to determine the effects of carob use on puberty because of the observation of early puberty or pubertal variants due to the long-term use of carob in our clinic. Forty-eight Wistar albino rats, on postnatal day 21, were assigned into two groups female (n=24) and male (n=24). Groups were divided into four groups Control, and Carob-150, Carob-300, and Carob-600. Ceratonia siliqua L. extract was given to rats in a 0.5% carboxymethylcellulose (CMC) solution. CMC (0.5%) was given to the control, Ceratonia siliqua L. extract was given 150 mg/kg/day to the Carob-150, 300 mg/kg/day to the Carob-300, 600 mg/kg/day to the Carob-600 by oral gavage. The treatments were performed once daily until the first sign of puberty. Serum follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, total testosterone, leptin, glutathione, glutathione peroxidase (GPx), and malondialdehyde were measured by commercial rat-specific ELISA kits. Testis, uterus and ovarian tissue were examined histologically. The median time of preputial separation in male rats was ^38th, 31^st, 31^st, and 31^st days in the Control, Carob-150, Carob-300, and Carob-600 groups, respectively (p=0.004). The median day of vaginal opening day was the 39^th, 31^st, 34^th, and 31^st days in the Control, Carob-150, Carob-300, and Carob-600 groups, respectively (p=0.059). FSH, LH, testosterone (male), estradiol (female) and leptin levels of the groups were similar. However, GPx levels were higher in male and female animals given C. siliqua extract compared to the Control (male p=0.001 and female p=0.008). Testicular and ovarian tissues were concordant with the pubertal period in all groups. As the dose of Ceratonia siliqua extract increased, it induced spermatogenesis and spermiogenesis, causing abnormal changes, such as ondulation in the basement membrane, capillary dilatation, and increased congestion in males. In females, edema in the medulla gradually increased with increased dosage, and granulosa cell connections were separated in Carob-300 and Carob-600 groups. This study demonstrated that C. siliqua caused early puberty and increased spermiogenesis and folliculogenesis. Antioxidant mechanisms were impaired with increasing dose, possibly leading to tissue damage at high doses.