Critical elements in tissue engineering of craniofacial malformations.

Abnormal craniofacial bone fusion can lead to the generation of several congenital malformations such as cleft palate, craniosynostosis and craniofacial skeletal hypoplasia, which physically and mentally affect patients. Conventional approaches for the treatment of craniofacial malformations such as the transplantation of autologous bone grafts are not completely efficient and usually, patients suffer from various complications. In line with these statements, the advent of novel therapeutic approaches in human medicine is mandatory. Regarding the extent, size and severity of the bone malformation, supplementation and release of oxygen molecules into the affected sites are critical issues for successful osteogenesis. Here, tissue engineering modalities associated with oxygen supplementation and novel approaches associated with hydrogel synthesis were highlighted in terms of craniofacial malformations.

Craniofacial anomalies are a group of conditions that can affect a person's head and facial tissue, mostly bones. These abnormalities can be categorized from mild to severe and commonly include the separation in the lip and the palate (cleft palate), the early joining of the baby's skull bone (craniosynostosis) and problems with the lower jawbone (mandibular defects). Several surgical methods are available to treat these abnormalities, which are invasive and have many disadvantages. In this review, we discuss new treatments in regenerative medicine as well as the importance factors of such as oxygen delivery in these methods. The provision of oxygen plays a key role in the growth of new blood vessels, cellular growth and bone tissue reconstruction.

Long-Lasting In Situ Forming Implant Loaded with Bupivacaine: Investigation on Polymeric and Non-Polymeric Carrier and Solvent Effect.

INTRODUCTION: Typically, in situ forming implants utilize Poly (lactide- co- glycolide) (PLGA) as carrier and N-methyl-2-pyrrolidone (NMP) as solvent. However, it is essential to develop different carriers to release various drugs in a controlled and sustained manner with economic and safety considerations. OBJECTIVE: The present study aims to evaluate the in-vitro release of Bupivacaine HCl from in situ forming systems as post-operative local anesthesia. METHODS: We used Sucrose acetate isobutyrate (SAIB), PLGA 50:50, and a mixture of them as carriers to compare the release behavior. Besides, the effect of PLGA molecular weight (RG 502H, RG 503H, and RG 504H), solvent type, and solvent concentration on the drug release profile has been evaluated. The formulations were characterized by investigating their in-vitro drug release, rheological properties, solubility, and DSC, in addition to their morphological properties. Furthermore, the Korsmeyer-Peppas and Weibull models were applied to the experimental data. Results revealed that using a mixture of SAIB and PLGA compared to using them solely can extend the Bupivacaine HCl release from 3 days to two weeks. RESULTS: The DSC results demonstrated the compatibility of the mixture by showing a single Tg. The formulation with NMP exhibited a higher burst release and final release in comparison with other solvents by 30% and 96%, respectively. Increasing the solvent concentration from 12% to 32% raised the drug release significantly, which confirmed the larger porosity in the morphology results. From the Korsmeyer-Peppas model, the mechanism of drug release has been predicted to be non-Fickian diffusion.

Preparation, optimization, and evaluation of midazolam nanosuspension: enhanced bioavailability for buccal administration.

Midazolam is considered as one of the best first-line drugs in managing status epilepticus in children who require emergency drug treatment. Due to poor water solubility, oral bioavailability of midazolam is relatively low. To improve its dissolution and absorption, midazolam nano-suspensions were formulated with different stabilizers using the ultrasonic technique. A combination of Tween 80 and Poloxamer (TP) was considered as one stabilizer and 3-methyl chitosan (TMC) as another stabilizer. The ratio of the stabilizers was selected as an independent variable, and their effects on the particle size and the zeta potential were evaluated by the simplex lattice mixture method. The freeze-dried optimized midazolam nano-suspension powder was characterized by particle-size analysis, SEM, the stability test, and the dissolution test. The optimized midazolam nano-suspension (containing 76% TMC and 24% TP) had a mean particle size of 197 ± 7 nm and a zeta potential of 31 ± 4 (mV). The stability test showed that the midazolam nano-suspension is stable for 12 months. In the in vitro dissolution test, the midazolam nano-suspension showed a marked increase in the drug dissolution percentage versus coarse midazolam. In the in vivo evaluation, the midazolam nano-suspension exhibited a significant increase in the Cmax and the AUC0-5, and a major decrease in Tmax. The overall results indicate the nano-suspension of midazolam is a promising candidate for managing status epilepticus in children in emergency situation.

Enhancement of The Stability of Human Growth Hormone by Using Tris(hydroxymethyl)aminomethane: Molecular Docking and Experimental Analysis.

OBJECTIVE: It is so difficult to formulate human growth hormone (hGH) in a solution with high stability and new drug delivery system (NDDs) due to physiochemical instability. The purpose of this study was to investigate the possibility of using Tris as a hGH stabilizer. MATERIALS AND METHODS: In this experimental study, the role of tris(hydroxymethyl)aminomethane (Tris) was evaluated as a hGH stabilizing agent in phosphate buffer, as a practical aqueous solution and a media to release NDDs. Highperformance liquid chromatography (HPLC) and enzyme-linked immune sorbent assay (ELISA) were applied to investigate the stability of hGH in solutions and dynamic light scattering (DLS) was used to measure the effect of Tris on the hydrodynamic size of hGH in aqueous solutions. Ultra violet (UV) spectrophotometry was used to check the hGH spectrum. In computational study, formation of ligand-protein complex of the Tris-hGH, and the intermolecular interactions between Tris and hGH were studied by molecular docking modeling. RESULTS: The results demonstrated that Tris at the optimum concentration, increases hGH stability in aqueous solutions. Also, molecular docking modeling confirmed that amino acid residues such as tyrosine (Tyr), proline (Pro), glutamic acid (Glu), aspartic acid (Asp), leucine (Leu), and phenylalanine (Phe) in hGH structure, were linked with Tris as a ligand. CONCLUSION: It seems that interactions between hGH and Tris are the most important reason for increment of the physicochemical stability of hGH in aqueous solutions containing Tris.

ADCs, as Novel Revolutionary Weapons for Providing a Step Forward in Targeted Therapy of Malignancies.

Antibody drug conjugates (ADCs), as potent pharmaceutical trojan horses for cancer treatment, provide superior efficacy and specific targeting along with low risk of adverse reactions compared to traditional chemotherapeutics. In fact, the development of these agents combines the selective targeting capability of monoclonal antibody (mAb) with high cytotoxicity of chemotherapeutics for controlling the neoplastic mass growth. Different ADCs (more than 60 ADCs) in preclinical and clinical trials were introduced in this novel pharmaceutical field. Various design-based factors must be taken into account for improving the functionality of ADC technology, including selection of appropriate target antigen and high binding affinity of fragment (miniaturized ADCs) or full mAbs (preferentially use of humanized or fully human antibodies compared to murine and chimeric ones), use of bispecific antibodies for dual targeting effect, linker engineering and conjugation method efficacy to obtain more controlled drug to antibody ratio (DAR). Challenging issues affecting therapeutic efficacy and safety of ADCs, including bystander effect, on- and off-target toxicities, multi drug resistance (MDR) are also addressed. 4 FDA-approved ADCs in the market, including ADCETRIS ®, MYLOTARG®, BESPONSA ®, KADCYLA®. The goal of the current review is to evaluate the key parameters affecting ADCs development.

Development of a simvastatin loaded injectable porous scaffold in situ formed by phase inversion method for bone tissue regeneration.

INTRODUCTION:: The use of injectable scaffolds as a minimally invasive method is a good choice in tissue engineering applications. A critical parameter for the tissue engineering scaffolds is a suitable morphology with interconnected pores. We present the development of a simvastatin loaded scaffold that forms in situ and provides the porous structure with interconnected pores. METHODS:: The formulation of these scaffolds includes a polymeric solution of poly lactic-co-glycolic acid (25 wt%) in N-methyl-2-pyrrolidone containing 6 wt% deionized water and porogen (mannitol, four times the weight of the polymer). We have grafted simvastatin to poly lactic-co-glycolic acid by the esterification reactions. Simvastatin or simvastatin-grafted poly lactic-co-glycolic acid in different levels was added to polymer solution and finally the solution was injected into phosphate buffered saline. The simvastatin-grafted poly lactic-co-glycolic acid was characterized by attenuated total reflection Fourier-transform infra-red and 1H-nuclear magnetic resonance spectroscopy. The morphology, porosity, and biocompatibility of the scaffolds were evaluated. The in vitro simvastatin release from the various formulations was studied. Osteogenic differentiation of the adipose-derived stem cells was investigated using alkaline phosphatase activity assay and cell mineralization was evaluated using Alizarin red staining. RESULTS:: The morphology results showed the resultant scaffold was porous with the interconnected pores. The scaffolds presented 91% porosity. Non-toxic doses of simvastatin in the scaffolds were determined by methyl-thiazolyl diphenyl-tetrazolium bromide assay. The released simvastatin from the scaffolds continues over 80 days. Alkaline phosphatase activity and Alizarin red results indicated that cell osteogenic differentiation is promoted. CONCLUSION:: The results demonstrated that release of simvastatin from the injectable scaffolds can have positive effects on osteogenic differentiation of the adipose-derived stem cells.

Development and Evaluation of an Anti-Epileptic Oral Fast-Dissolving Film with Enhanced Dissolution and In vivo Permeation.

OBJECTIVES: The main objective of this novel study was to develop midazolam hydrochloride fast dissolving oral films (FDFs) using solvent casting method and to evaluate the characteristics of the optimum formulation through in vitro and in vivo analysis. The FDFs are new favorable solid dosage forms that deliver drugs rapidly to the blood circulation system and have great advantages in the emergent control of severe neuropathic attacks in children. METHODS: Midazolam nanosuspensions were prepared using the ultrasonic method and then incorporated in the hydroxypropyl methyl cellulose (HPMC)/pullulan polymeric matrix with other excipients like glycerol and cellulose nanofiber as a softener and a compatibilizer, respectively. The prepared films were evaluated for mechanical properties, morphology study, disintegration time, and dissolution time. RESULTS: SEM images of FDFs showed the uniform distribution of spherical nanoparticles in the polymeric matrix. A film with 36% HPMC, 64% pullulan, and 21% glycerin was selected as the optimum formulation by the Design Expert 7 software. The optimum film was stable for three months. CONCLUSION: The pharmacokinetic parameters of midazolam oral film in comparison to coarse midazolam suspension exhibited significant increase in AUC, Cmax, and a good decrease in Tmax. The overall results showed the enhanced in vivo orotransmucosal absorption of poorly water-soluble drugs via the insertion of drugs nanosuspension in buccal films.

The Effects of Transdermal Estrogen Delivery on Bone Mineral Density in Postmenopausal Women: A Meta-analysis.

Due to its minimal systematic adverse effects, transdermal estrogen is widely used for the prevention of osteoporosis in postmenopausal women. The present meta-analysis aimed to clarify the effects of transdermal estrogen on bone mineral density (BMD) of postmenopausal women. Studies were identified by searching electronic databases including Cochrane Library, MEDLINE, Embase , and CINAHL databases, and also the Sciences Citation Index. Systematic review of articles was published between January 1989 to February 2016.Reference lists of the included articles were also evaluated and consultations were made with relevant experts. While 132 studies included the desired keywords, only nine clinical trials met the inclusion criteria and were finally reviewed. The pooled percent change in BMD was statistically significant in favor of transdermal estrogen. According to resulting pooled estimate, lumbar spine BMD one and two years after transdermal estrogen therapy was respectively 3.4% (95% CI: 1.7-5.1) and 3.7% (95% CI: 1.7-5.7) higher than the baseline values. The test for heterogeneity was not statistically significant based on the I2 heterogeneity index. One-two years of transdermal estrogen delivery can effectively increase BMD and protect the bone structure in postmenopausal women.

Leuprolide Acetate Release Study from γ-Irradiated PLGA-based In Situ Forming System.

BACKGROUND: It is well known that the properties of polymers can be altered by exposure to γ- ray. γ-irradiation has been used as a sterilization method for polymeric drug delivery devices, and its drug release profile must not be significantly changed. In this study, the effect of γ-irradiation on the release profile of leuprolide acetate from PLGA-based in situ forming system was investigated. METHODS: Poly(lactide-co-glycolide) (PLGA) was dissolved in N-methylpyrrolidinone (NMP) and irradiated with a total dose of 8 kGy γ-ray emitted by a 60Co source. Then, leuprolide acetate was added to the polymer solution. PLGA-based in situ forming systems were prepared by injecting some specific amount of prepared solution into a buffer phosphate pH 7.4 at 37 °C. The effects of γ-ray on drug release profiles, morphology of matrices and thermal properties as well as stability of polymer were evaluated. RESULTS: The results showed that γ-irradiation causes a decrease in glass transition temperature (Tg) of PLGA from 43.4 to 38.1°C. A reduction in molecular weight of PLGA by about 17.8 % was found as consequence of radiolytic degradation. The morphological studies of PLGA matrices confirmed that the irradiated sample had higher porosity than the non-irradiated sample. It is found that the amount of released leuprolide acetate from irradiated matrix was increased by about 1.6 times after 33 days compared to the nonirradiated ones. In vitro drug release experimental data were fitted using the Gallagher- Corrigan model which indicated that diffusion and degradation were the predominant mechanisms of drug release. CONCLUSION: Accordingly, leuprolide acetate was released faster from the irradiated matrix compared to the non- irradiated matrix.

Hops for Menopausal Vasomotor Symptoms: Mechanisms of Action.

Menopause is a critical stage of women's life associated with various complaints and distresses. Vasomotor symptoms (VMS), such as hot flushes, night sweats, sleep disturbances, and fatigue, are the most common menopause symptoms affecting about 50% to 80% of middle-aged women. Obviously, these symptoms, resulting from estrogen deficiency during menopause, can exert negative effects on women's health and quality of life and thus require to be managed through approaches such as hormone replacement therapy (HRT). Many herbal treatments for menopause symptoms contain and its components such as 8-prenylnaringenin, 6-PN, isoxanthohumol and xanthohumol. Recent in-vivo studies have highlighted the ability of 8-prenylnaringenin to reduce serum-luteinizing hormone (LH) and follicle-stimulating hormone (FSH), to increase serum prolactin levels and uterine weight, and to induce vaginal hyperplastic epithelium. Previous research has shown that hops extract can strongly bind to both estrogen receptors, stimulate alkaline phosphatase activity in Ishikawa cells, and upregulate presenelin-2 and progesterone receptor mRNA in Ishikawa cells. Numerous clinical trials have documented significant reductions in the frequency of hot flushes following the administration of hop-containing preparations. Nevertheless, further clinical trials with larger sample size and longer follow-up are warranted to confirm such benefits.

In situ-forming PLGA implants loaded with leuprolide acetate/ß-cyclodextrin complexes: mathematical modelling and degradation.

Drug release mechanism of in situ-forming implants (ISIs) based on poly(lactic acid-co-glycolic acid) (PLGA) loaded with leuprolide acetate/ß-cyclodextrin (LA/ß-CD) complexes via fitting with four diffusion-based semi-empirical models were studied. The release rate constants and release exponent of ISIs were calculated. The main drug release mechanism was Fickian diffusion. The LA diffusion coefficient and release constant were decreased via increasing the portion of ß-CD in complexes. The release curve was parabolic, with a higher initial slope and then consistent with the exponential. All ISIs containing LA/ß-CD complexes better fitted with the Korsmeyer-Peppas, Weibull and Peppas-Sahlin models rather than first-order model. Furthermore, the effect of LA/ß-CD complexation on the degradation of ISIs was studied through scanning electron microscopy (SEM). Results showed that hydrophilic nature of ß-CD facilitated the surface erosion of PLGA chains, however after 18 d, ISI-1/10 had still a proper structural strength, due to no hydrolytic degradation of ß-CD in this implant.

Hormone Therapy for Relieving Postmenopausal Vasomotor Symptoms: A Systematic Review.

BACKGROUND: Menopause is a critical phenomenon in women's life. After cardiac diseases, menopause is the second major cause of living with a disability in 45-60 year old women. The majority of women will experience bothersome vasomotor symptoms (VMS). Menopausal hormone therapy (MHT) is the most effective treatment for these symptoms. The objective of this review is to focus on hormone therapy for relieving postmenopausal vasomotor symptoms. METHODS: For this systematic review, we primarily explored 125 papers published about hormone therapy for VMS from 2001 to 2015 by searching with combinations of the keywords in various databases. Among those, 59 papers met the initial search criteria and among them, 9 papers were potentially retrievable and reviewed. All included studies used estrogen formulations in the management of VMS. RESULTS: Nine studies met all inclusion criteria. All studies assessed the effects of hormone replacement therapy on VSM. The results showed that low-dose oral and transdermal estrogen in all dose ranges were more likely than placebo to decrease the frequency of VMS. Indeed, the nanostructured formulation was safe and effective in relieving the symptoms of menopause. The mean daily decrease in the number of hot flashes from baseline was found in the studies. CONCLUSION: MHT has a complex pattern. Understanding the natural history of VMS, and the risks and benefits of both hormonal therapies, helps to individualize management plans. Low-dose estrogen-based therapies can be the most effective regimens to relieve VMS. These medications can be used by different administration routes and formulations.

A stability-indicating HPLC method for simultaneous determination of morphine and naltrexone.

This study developed a stability-indicating reversed-phase HPLC method for the simultaneous determination of morphine sulfate and naltrexone hydrochloride content in bulk, Solid dosage forms and in-vitro dissolution samples to support product development and quality control efforts. Chromatographic separation of the pharmaceutical compound was achieved on a perfectSil™ MZ C18 column (250×4.6mm, 5µm) with an isocratic mobile phase composed of a mixture of acetate buffer (10mM, pH 4, containing 0.1% of 1-heptanesulfonic acid sodium salt) and acetonitrile with 80/20 at a flow rate of 1.5mlmin(-1). Both analytes were quantified using a photodiode array detector set at a wavelength of 280nm and column temperature was set to 30°C. naltrexone, morphine and a mixture of the two were subjected to thermal, peroxide, acid, base and photolytic degradation and their peak homogeneity was obtained using a photodiode array detector, demonstrating the specificity of method. These pharmaceuticals were spiked in biological fluid to examine method selectivity. The method was validated for system suitability, linearity, accuracy, precision, detection and quantification limits and robustness and was found it is acceptable in range of 2-250µgml(-1) for morphine and 4-100µgml(-1) for naltrexone.

Aqueous stability of leuprolide acetate: effect of temperature, dissolved oxygen, pH and complexation with ß-cyclodextrin.

In the present research, the aqueous stability of leuprolide acetate (LA) in phosphate buffered saline (PBS) medium was studied (pH = 2.0-7.4). For this purpose, the effect of temperature, dissolved oxygen and pH on the stability of LA during 35 days was investigated. Results showed that the aqueous stability of LA was higher at low temperatures. Degassing of the PBS medium partially increased the stability of LA at 4 °C, while did not change at 37 °C. The degradation of LA was accelerated at lower pH values. In addition, complexes of LA with different portions of ß-cyclodextrin (ß-CD) were prepared through freeze-drying procedure and characterized by Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC) analyses. Studying their aqueous stability at various pH values (2.0-7.4) showed LA/ß-CD complexes exhibited higher stability when compared with LA at all pH values. The stability of complexes was also improved by increasing the portion of LA/ß-CD up to 1/10.

Investigation of aqueous stability of taxol in different release media.

In the present study, the aqueous stability of taxol in different aqueous media and immiscible aqueous/organic systems at 37 °C was investigated. The aqueous media included phosphate buffered saline (PBS) and PBS containing 10% methanol, 10% ethanol, 10% hydroxypropyl ß-cyclodextrin (HP-ßCD), 1% sodium citrate and 1% Tween 80. The immiscible systems consisted of PBS/octanol, PBS/dichloromethane, PBS/chloroform and PBS/ethyl acetate. The concentrations of taxol and related derivatives in each of the media were determined through the high-performance liquid chromatography assay. Results showed that hydrolysis and epimerization were two major types of degradation for taxol in the aqueous media starting from the initial hours of contact (6 hours). Addition of Tween 80 to PBS moderately increased the aqueous stability of taxol. As well, using PBS containing 10% HP-ßCD inhibited the taxol hydrolysis, while epimerization still in process. In the case of immiscible systems, except for PBS/ethyl acetate system, no evidences of taxol hydrolysis were observed. Meanwhile, epimerization of taxol in PBS/dichloromethane and PBS/chloroform systems underwent due to the ability of C-Cl bonds to form hydrogen bonding with the hydroxyl group of C7 of taxol.

In-vitro/In-vivo comparison of leuprolide acetate release from an in-situ forming plga system.

A poly (lactide-co-glycolide) (PLGA) implant was used to control the release profile of leuprolide acetate (LA) drug. The system is an in-situ polymeric precipitation system. And the formulation consisted of PLGA polymer, LA drug and N-methyl-2-pyrrolidon solvent with no additives. First, the formulation was injected into PBS solution for in-vitro studies and then it was administered to the animal models (female rats) for in-vivo release studies. The release profiles of leuprolide acetate were measured by UV spectrophotometry for a period of 28 days. The initial burst release of LA was 14% in in-vitro whereas it was 7% in in-vivo. In-vitro and in-vivo release profiles of LA had similar trends after 72 hours. However, the rate of LA release was slower in-vivo. This might be attributed to the limited diffusion process of solvent and the drug molecules. This could be due to presence of an additional pressure caused by the surrounding tissue and also the presence of small amount of water between cells in the subcutaneous site. Cross-section and surface of the implants were studied via scanning electron microscopy. Morphology of both in-vitro and in-vivo implants confirmed the release behaviours. No toxicity effects were reported in the histopathological assay. Furthermore, the pharmacological analysis showed more inactive ovaries due to release of LA.

Influence of poly (lactide-co-glycolide) type and gamma irradiation on the betamethasone acetate release from the in situ forming systems.

In situ forming biodegradable polymeric systems were prepared from Poly (DL-lactide-co-glycolide), RG504H (50:50, lactide:glycolide), RG756 (75:25) and mixture of them. They were dissolved in N-methyl-2-pyrrolidone (33% w/w) and mixed with betamethasone acetate (BTMA, 5 and 10% w/w) and ethyl heptanoate (5% w/w, as an additive). The effects of gamma irradiation, drug loading, type of polymers and solvent removal were evaluated on release profiles. Scanning electron microscopy (SEM) of RG756 samples loaded by BTMA did not show any degradation until two weeks. Differential scanning calorimeter (DSC) experiments confirmed insignificant decrease in T(g), and consequently release rate. Declining T(g) of RG504H and RG756 after gamma irradiation was about 0.4 and 1.46 degrees C, respectively. High performance liquid chromatography (HPLC) revealed that BTMA release is more rapid from the formulations prepared using the RG504H with lower molecular weight. The formulations prepared by RG756 had lower burst release (2.5-41%) than the samples based on RG504H (60-67%) and mixture of them (30-33%). Regarding this research three different kinds of steriled in situ forming systems were developed which can release BTMA for 24, 90 and 60 days.

Changes in morphology of in situ forming PLGA implant prepared by different polymer molecular weight and its effect on release behavior.

The effects of polymer molecular weight on drug release behavior would be more complicated from in situ forming implants (ISFIs) that change gradually from liquid to semi-solid or solid after injection. To investigate this phenomenon, three commercially available D,L-lactic acid-co-glycolic acid (PLGA) polymers with molecular weights of 12, 34, and 48 kDa were used to prepare ISFIs containing leuprolide acetate (LA) as a model peptide. The influence of polymer molecular weight on the membrane formation, morphology, and also on their in vitro drug release behavior over a period of 28 days was investigated. Results showed that the amount of drug released over the first 24 h (36% +/- 0.34%) (burst release), for formulation prepared with polymer RG 503H (medium molecular weight, M(w) 34 kDa), was significantly higher than others (p < 0.05). Surface and cross-section morphology of ISFI prepared with medium molecular weight polymer to cellular and spongy-like structure which was in good agreement with the release behavior of LA from it.

Simultaneous determination of levodopa and carbidopa in levodopa-carbidopa tablets by ATR-FTIR spectrometry.

A novel analytical procedure has been developed for quantitative determination of levodopa and carbidopa in aqueous binary solutions acidified by HCl and without any other sample pretreatment. The method is based partially on least squares treatment of data obtained by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectrometry in 1211-1315 cm(-1) and 1488-1550 cm(-1) spectral regions. The simple, rapid, and accurate proposed method was applied to determine levodopa and carbidopa in Levodopa-C tablets. The statistical parameters, such as R2, RSD, SEE, SECV, LOD, and recovery were evaluated. Number of factors, scans, and resolution were optimized. In this method R2 and RSD for levodopa and carbidopa were (0.9965, 1.209) and (0.9537, 0.813), respectively.