Evaluation of mechanical and mucoadhesive properties of clomiphene citrate gel formulations containing carbomers and their thiolated derivatives.

The aim of our study was to prepare clomiphene citrate gel formulations that possess appropriate mechanical properties, stay on the vaginal mucosa for a long period of time, and provide sustained drug release for the local treatment of human papilloma virus infections. In this respect, 1% CLM gels including polyacrylic acid (PAA) polymers such as Carbopol 934P (C934P), Carbopol 971P (C971P), Carbopol 974P (C974P) in various concentrations, and their conjugates containing thiol groups were prepared. Polyacrylic acid-cysteine (PAA-Cys) conjugates were synthesized in laboratory conditions. Mechanical properties of the gels such as hardness, compressibility, elasticity, adhesiveness, and cohesiveness were measured by TA-XTPlus texture analyzer and the vaginal mucoadhesion of formulations was investigated by mucoadhesion test. Based on obtained data, gel formulations containing C934P and its conjugate had appropriate hardness and compressibility to be applied to the vaginal mucosa and highest elasticity to show good spreadability and highest cohesion to prevent the disintegration of gel in the vagina. The mucoadhesion of the gels changed significantly depending on the polymer type and concentration (p < 0.05). The addition of conjugates containing thiol groups caused an increase in mucoadhesion (p < 0.05). The gels containing C934P-Cys showed highest adhesiveness and mucoadhesion due to the highest amount of thiol groups. A significant decrease was observed in the drug release of gel formulations as the polymer concentration increased (p < 0.05). The increase in the drug release related to the conjugate addition was not statistically significant (p > 0.05). A change in the amount of CLM was not observed in all formulations at the end of the stability test.

The preparation of ciprofloxacin hydrochloride-loaded chitosan and pectin microspheres: their evaluation in an animal osteomyelitis model.

Ciprofloxacin hydrochloride-loaded microspheres were prepared by a spray-drying method using pectin and chitosan. The effects of different polymers and drug ratios were investigated. The most appropriate carriers were selected by in vitro testing. A rat methicillin-resistant Staphylococcus aureus osteomyelitis model was used to evaluate the effects of the loaded microspheres. The drug was released rapidly from the pectin carrier but this was more sustained in the chitosan formulation.Chitosan microspheres loaded with ciprofloxacin hydrochloride were more effective for the treatment of osteomyelitis than equivalent intramuscular antibiotics.

Effect of vehicles and penetration enhancers on the in vitro percutaneous absorption of celecoxib through human skin.

The aim of this study was the comparison of three different formulations (gel, o/w emulsion, oleagenous cream) and two penetration enhancers (oleic acid and menthol) as vehicle systems for celecoxib in respect of release and penetration through excised human skin in vitro. The influence of the vehicle on the release rate was studied in vitro using a cellulose acetate membrane. The release rate could be increased by up to 6.5 and 2.5 times with gel and o/w emulsion compared to oleagenous cream respectively. Further in vitro penetration measurements using human skin on Franz diffusion cells were performed with and without oleic acid and menthol as enhancers. It was shown that the penetration rate is strongly dependent upon the enhancer type and concentration but not on the vehicle itself and could be increased by 48% when 5% oleic acid was used in oleagenous cream. In all formulations tested, celecoxib was released and penetrated into human skin more quickly and to a greater extent from the gel formulations. There is no topical formulation available of celecoxib and its penetration properties through human skin have not been investigated. Since celecoxib creates some gastrointestinal disturbances, topical formulations of celecoxib preferably in gel form including 5% oleic acid could be suggested as an alternative.

Investigations on mefenamic acid sustained release tablets with water-insoluble gel.

Mefenamic acid (MA) has analgesic, anti-inflammatory and antipyretic properties. Available conventional dosage forms are capsules and film-coated tablets. No commercial sustained release preparation of MA exists in the market. The usual oral dose is 250 or 500 mg and reported half-life is 2 h. Sodium alginate (NaAL) is the sodium salt of alginic acid, a natural polysaccharide extracted from marine brown algae. It has the ability to form a water-insoluble gel with a bivalent metal ions as calcium. Therefore, NaAL has been studied for preparing sustained release formulations in pharmaceutical technology. In this study, tablet formulations containing different ratios of NaAL and calcium gluconate (CaGL) were prepared by direct compression method. In vitro release studies were carried out using USP 23 basket method and release data were kinetically evaluated. According to release studies, it can be emphasized that NaAL and CaGL can be used for design of sustained release preparation of MA.