Determination of buprenorphine in raw material and pharmaceutical products using ion-pair formation

A simple and sensitive extractive spectrophotometric method has been described for the determination of buprenorphine either in raw material or in pharmaceutical formulations. The developed method is based on the formation of a colored ion-pair complex (1 : 1 drug/dye) of buprenorphine and bromocresol green (BCG) in buffer pH 3 and extracting in chloroform. The extracted complex shows absorbance maxima at 415 nm. Beer's law is obeyed in the concentration range of 1.32-100.81 μg mL−1 . The proposed method has been applied successfully for the determination of drug in commercial sublingual tablets and injectable dosage form. No significant interference was observed from the excipients commonly used as pharmaceutical aids with the assay procedure

Benzylidene Barbituric Acid Derivatives Shown Anticonvulsant Activity on Pentylenetetrazole-Induced Seizures in Mice: Involvement of Nitric Oxide Pathway

ABSTRACT Background: Barbituric acid derivatives have long been used as central nervous system (CNS) suppressants, such as sedatives, hypnotics and anticonvulsants. In addition, previous studies have implicated the involvement of nitric oxide (NO) in the anticonvulsive effects of barbiturates in CNS. Therefore, the purpose of this study was to figure out the effects of a novel class of barbituric acid derivatives on pentylenetetrazole (PTZ)-induced seizures in male mice. Methods: Thirteen synthesized barbituric acid derivatives (a-m) and phenobarbital were administered intraperitoneally (i.p.) 30 min before induction of seizures by PTZ administration. The mechanisms of PTZ-induced seizures in the mice was evaluated using a non-selective nitric oxide synthase (NOS) inhibitor, selective inducible NOS (iNOS) inhibitor, a selective neuronal NOS (nNOS) inhibitor, and NO substrate. Results: Administration of most of the above mentioned derivatives significantly increased the seizures threshold (P<0.001). The most potent derivative (compound a), was chosen in order to investigate the mechanism of action involving in anticonvulsant activity. Administration of a non-selective NOS inhibitor, NG-nitro-L-arginine methyl ester (L-NAME) and a selective nNOS inhibitor, 7-nitroindazole (7-NI) reversed anticonvulsant activity of compound a. However, injection of the nitric oxide precursor, L-arginine (L-Arg) and a selective iNOS inhibitor, aminoguanidine (AG), did not change anticonvulsant activity of the mentioned compound. Conclusion: These results indicated that the NO system, specifically nNOS may contribute to the anticonvulsant activity of benzylidene barbituric acid derivative a. Therefore, this compound is a good candidate in order to designing new anticonvulsant medication

Mesoporous silica nanoparticles functionalized with folic acid/methionine for active targeted delivery of docetaxel

Abstract: Mesoporous silica nanoparticles (MSNs) are known as carriers with high loading capacity and large functionalizable surface area for target-directed delivery. In this study, a series of docetaxel-loaded folic acid- or methionine-functionalized mesoporous silica nanoparticles (DTX/MSN-FA or DTX/MSN-Met) with large pores and amine groups at inner pore surface properties were prepared. The results showed that the MSNs were successfully synthesized, having good pay load and pH-sensitive drug release kinetics. The cellular investigation on MCF-7 cells showed better performance of cytotoxicity and cell apoptosis and an increase in cellular uptake of targeted nanoparticles. In vivo fluorescent imaging on healthy BALB/c mice proved that bare MSN-NH2 are mostly accumulated in the liver but MSN-FA or MSN-Met are more concentrated in the kidney. Importantly, ex vivo fluorescent images of tumor-induced BALB/c mice organs revealed the ability of MSN-FA to reach the tumor tissues. In conclusion, DTX/MSNs exhibited a good anticancer activity and enhanced the possibility of targeted drug delivery for breast cancer

Effect of Dexamethasone on Striatal Neurotransmissions in the Rats Subjected to Parkinson’s Disease Animal Model

Objective(s)The aim of this study was to evaluate the effects of dexamethasone on striatal dopaminergic, glutamatergic and gamma amino butyric acid (GABA) ergic neurotransmission in normal and parkinsonian rats.Materials and MethodsDexamethasone (0.15, 0.30, 0.60 and 0.8 mg/kg) was administered to normal or parkinsonian rats (i.p.) followed by the analysis of the striatal neurotransmitters concentrations. Additionally, the effect of dexamethasone on the damaged Substantia nigra pars compata (SNc) neurons has been investigated. ResultsDexamethasone resulted in decreased level of striatum glutamatergic-GABAergic and enhanced dopaminergic neurotransmission in normal and parkinsonian rats. In addition, acute treatment with dexamethasone did not improve the lesion at all. ConclusionThese findings suggest the new therapeutic mechanism of action for dexamethasone in Parkinson’s disease animal model

Spectrophotometric Determination of Tropicamide in Bulk and Pharmaceutical Formulations: Determination of tropicamide

Asimple and sensitive extractive spectrophotometric method is described fordetermination of tropicamide. The method is based on the reaction of tropicamideand bromocresol green. The ion-paired colored complex was extracted withchloroform at pH 3. The extracted complex showed maximum absorbance at 423nm. The complex was stable up to 2 days and obeyed Beer's law over theconcentration ranges of 1.32-100.81 μg/ml. No significant interference was observedfrom the excipients, coloring and flavoring agents commonly used in the tropicamidepharmaceutical preparations. The proposed method was applied successfully fordetermination of tropicamide in commercial eye drop dosage forms

The interaction of several herbal extracts with α-synuclein: Fibril formation and surface plasmon resonance analysis.

Proteins from their native conformation convert into highly ordered fibrillar aggregation under particular conditions; that are described as amyloid fibrils. α-Synuclein (α-Syn) is a small natively unfolded protein that its fibrillation is the causative factor of Parkinson's disease. One important approach in the development of therapeutic agents is the use of small molecules (such as flavonoids) that could specifically and efficiently inhibit the aggregation process. In this study the effect of few herbal extract (Berberis, Quercus robur, Zizyphus vulgaris, Salix aegyptica) containing flavonoids were investigated on fibril formation of α-syn by using conventional methods such as ThT fluorescence, circular dichroism (CD) spectroscopy and transmission electron microscopy (TEM). The interaction of extracts were also analysed by surface plasmon resonance (SPR). Among extracts, Salix aegyptica revealed the highest inhibitory effect on fibril formation. As expected, Salix aegyptica extract also exhibited the highest affinity toward α-syn. Cell viability using MTT assay revealed that fibrils alone were more toxic than those containing the extract. Overall, we demonstrated that the affinity of compounds used in this study corresponds to their ability to arrest fibrillation and reduce cellular toxicity of α-syn fibrils

Development and Validation of a Rapid Derivative Spectrophotometric Method for Determination of Tropicamide in Eye Drops: Determination of tropicamide in eye drops

Tropicamide is an antimuscarinic agent used as eye drops for refractive examinations. The aim of this study was to develop a simple and suitable analytical method for determination of tropicamide in eye drops in the presence of excipients. A zero-crossing third and fourth derivative spectrophotometric method was described for determination of tropicamide in eye drops. The measurements were carried outat wavelengths of 263.8 and 255.4 nm for third- and fourth-derivative, respectively. The method was found to be linear (r2&gt; 0.999) in the range of 10-100 µg/ml for tropicamide in the presence of excipients. The limit of determination was 10 mg/ml for tropicamide. The method was successfully applied for determination of tropicamide in eye drops without any interference from excipients or need to prior separation before analysis

Theoretical investigation of cyclooxygenase inhibition property of several non-steroidal anti-inflammatory drugs by density functional theory calculations and molecular docking studies

Understanding the geometry and electronic properties of non-steroidal anti-inflammatory drugs (NSAIDs) and the nature of their interactions with human cyclooxygenase-2 (COX-2) is important in the development and design of novel NSAIDs. In this paper, B3LYP/6-311++G (d,p) level of theory was applied to assess the acidity of NSAIDs in the gas phase. Subsequently, the role of intramolecular hydrogen bond on acidity of these compounds was confirmed by means of natural bond orbital (NBO) and quantum theory of atoms in molecules analyses (QTAIM). Furthermore, by applying the polarized continuum model (PCM) at the B3LYP/6-311++G(d,p) level, the pKa value of NSAIDs in aqueous solution was calculated. The maximum error was found to be less than 0.1 pKa unit in comparison with the experimental value. This protocol can be used as a tool to predict pKa values of NSAIDs in future studies. In the last step, attempts have been made to generate a functional model of the structure of human COX-2 enzyme by means of homology modeling to gain more insight into the nature of interactions between NSAIDs and the active site of this COX-2 enzyme by docking studies. In addition, a mean binding energy for each drug was estimated based on its ionization ratio

Comparison of the Efficacy of Topical Triamcinolone in Orabase and Curcumin in Orabase in Oral Graft-versus-Host Disease

Objectives: Graft-versus-host disease (GVHD) is among the most frequent complications of allogeneic hematopoietic stem cell transplantation (HSCT). GVHD has several clinical manifestations in the oral cavity, including painful desquamative erythema, ulcerative mucosal lesions, and lichenoid lesions. The patients presenting with oral GVHD complain of oral sensitivity, pain, dysgeusia, and xerostomia. The treatment of oral GVHD includes a proper systemic therapy combined with a good oral hygiene and the use of local and topical steroids. Corticosteroids and immunosuppressants are used for the treatment of chronic oral GVHD; however, they are associated with different complications. Evidence shows that curcumin has anti-inflammatory and antioxidative properties. The treatment of lichen planus and oral mucositis with curcumin has been successful. This study aimed to compare the efficacy of topical curcumin in Orabase and triamcinolone in Orabase in the patients affected by oral GVHD. Materials and Methods: Twenty-six patients presenting with oral GVHD were randomly divided into two groups of 13 using block randomization. The control group used triamcinolone in Orabase, and the case group received curcumin in Orabase. Results: The two groups were not significantly different in terms of the alleviated severity of the lesions at the end of the treatment (P=0.052). The comparison of the pain score via the visual analog scale (VAS) at the onset of the treatment and at days 14 and 28 (completion of the treatment) showed no significant difference between the two groups (P>0.05). Conclusions: Curcumin has comparable efficacy to that of triamcinolone and may be prescribed for the patients presenting with oral GVHD