Pharmaceutical Sciences
Volume:18 Issue: 2, 2012

Digoxin is a drug with very low aqueous solubility, low therapeutic dose and low therapeutic index. Soft gelatin capsule is an ideal dosage form to formulate low soluble drugs that provides faster dissolution, higher bioavailability and higher content uniformity. The purpose of the present study is to enhance digoxin solubility using appropriate vehicles to prepare digoxin soft gelatin capsule core formulation. Solubility of digoxin in different solvents, including water, ethanol, polyethylene glycol 400, propylene glycol, transcutol and binary and/or ternary solvent systems were investigated using shake-flask method. Saturated solutions of these solvents and solvent mixtures were shaken at 25°C for 48 h. After equlibrium, the supernatant layer was withdrawn and passed through 0.45 μm filter. Concentrations of drug in solutions were determined by HPLC and UV method. The mathematical mixture design was used to design the solvent systems. The obtained results indicated that best co-solvent for increasing the solubility of digoxin is ethanol. Digoxin solubility in other co-solvents also was more than its aqueous solubility. Using co-solvency method, the solubility was increased up to 14.5 times more than its aqueous solubility. It is concluded that digoxin solubility could be increased using co-solvency method to achieve appropriate formulations for designing soft gelatin capsules.

Nicotine replacement therapy (NRT) with gradual decreasing of nicotine is one of the smoking cessation methods. Nicotine dosage forms on the market are including gum and skin patches. Muccoadhesive formulations are the novel drug delivery systems that are available in the form of tablets and films, and can be used for NRT. Muccoadhesive nicotine tablets (MNT) when placed in the upper gum, will release its nicotine content in a controlled manner. This will meet the need of the individual to the nicotine, such that the person can decrease his/her dependency on smoking. In the current study, the tablets were prepared using different conventional bioadhesive polymers such as HPMC50cps, NaCMC, and carbapol934 in singular or mixture form; magnesium hydroxide as the pH increasing agent; magnesium stearate as the lubricant; and lactose as the excipiente, of different products of nicotine hydrogen tartrate, which is more stable than the nicotine. Their pharmaceutics characteristics such as the degree of adhesion and the rate of drug release were evaluated. Increasing of HPMC50cps in the formulations decrease speed release of nicotine. The carbapol in formulations beget slow releasing of nicotine. With increasing the percent of lactose, the rate of release in formulations was increased. Formulations which have HPMC 50cps has best adhesiveness. Formulations contains carbapol had not suitable adhesiveness. Formulations contains NaCMC were very fast release and had not suitable adhesiveness. The formulation contains mixture of HPMC50cps and Cp934 with suitable adhesiveness and minimum fluctuation in release, was the best formulation.

Research in the development and application of the porous adsorbents with drug delivery capabilities is receiving great interest by the scientists. Porous adsorbents are able to improve bioavailability and solubility of drugs. They also are capable of controling the drug release for profound long-term implications in the pharmaceutical industry. The porous adsorbents which could be applied for pharmaceutical purposes together with the several methods of drug loading are explained in this review. The applications of the porous adsorbents in the pharmaceutical industry are explained as well. Some of the commonly considered porous adsorbentse.g. SBA15, MCM41, MOFs and porous ceramic are reviewed in the current paper bearing in mind that these carriers could adsorb relatively high amounts of drugs and are able to improve drug release pattern. It is possible to formulate targeted drug delivery systems applying a suitable porous adsorbants.

Spray drying is the most widely used techniqueintended for drying of pharmaceutical products as well as manufacturing of powder with desired characteristics.It is a continuous operation in which almost any pumpable liquid can be converted into a free flowing powder. Considering uniformity of formed particles and well-control on particle size, spray drying is efficiently applicable in the drug delivery systems. This method has found to be a potential way for systematic delivery of therapeutic peptides, proteins and also antibiotics. In this study, the procedures and aplications of spray drying were reviewed and the effect of diffirent affecting parameters was explained. Spray drying is extensively used to dry heat sensitive products like enzymes and proteins with minimum loss on activity and produce drugs with improved solubility as well as drying of nanoparticles, microencapsulation, granulation and coating beyond its well-known background on drying of liquids. Spray drying could be of beneficial in formulation of drug delivery systems with desired physicochemical characteristics.

For many years, various medicinal plants have been used for the treatment of different neuropsychological diseases, like anxiety and depression behaviors. In the present study, the effects of Scrophularia striata extract on anxiety and depression behaviors were investigated in adult male mice. In this study 12 groups (n=7) of adult male mice weighing 25-30g were used. In first protocol 6 groups of mice were received saline and extract of Scrophularia striata (10, 50, 100, 160 and 220 mg/kg) for 14 consecutive days and then tested in elevated plus maze. The second protocol was as the same but at the end of the injections depression was assessed with forced swimming test. Our findings showed that S. striata significantly (p<0.01) reduced anxiety at two doses of 100 and 160 mg/kg as well as attenuated depression at 160 mg/kg (p 0.01) in the EPM and FST tests, respectively. These results indicate that S. striata extract can decrease the anxiety and depression behaviors in rodents dose dependently.

Tonsillectomy is one of the most common surgeries in the world which is accompanied by severe postoperative pain. Recently local drug infiltration is being used for pain control, but the results are controversial. Thus we planned a study to evaluate the effect of infiltration of bupivacaine and clonidine on decreasing posttonsillectomy pain and complications in children. In a double-blind randomized clinical trial, 140 children (3-12 y) scheduled to undergo tonsillectomy in Tabriz Children Hospital were studied. The patients were randomized into two 70-patient groups and received intravenous fentanyl (1μg/kg) (group F) or intravenous fentanyl (1μg/kg) plus infiltration of bupivacaine 0.25% (0.1ml/kg) and clonidine (1μg/kg) (group BC). Post-operative pain was evaluated using Wong-Baker Face Pain Scale (FPS). The pain score was significantly lower in the BC patients in comparison with group F (p<0.001). The need for postoperative analgesics was also lower in BC group (p<0.001). Frequency of subjects with intraoperative bleeding was significantly lower in the BC group compared with F group (1.4% vs. 10%; p=0.031). However, frequency of subjects with intraoperative pain was not significantly different between the two groups (8.5% vs. 11.4%; p=0.573). Based on our results, infiltration of bupivacaine and clonidine in children undergoing tonsillectomy is more efficacious than single IV fentanyl in decreasing post-operative pain. This approach is also safer regarding the intraoperative complications.