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Controlled release, on the contrary traditional treatment, means the gradual release of a substance from a system in order to maintain its concentration in a medium over a period of time. In drug release systems, the controlled release of the drug to the diseased area has importance in terms of treatment and toxicity. Especially drugs with high toxic properties such as 5-Fluorouracil (5-FU) have an important place in controlled drug release technology. In order to complete the treatment successfully, it is important to develop controlled drug release systems to eliminate the possible side effects of anticancer drugs such as 5-FU and to increase the therapeutic effect. The aim of this study is to develop a unique biodegradable and biocompatible bionanocomposite film for the controlled release of 5-FU. For this purpose, bentonite loaded chitosan hydroxypropyl methylcellulose bionanocomposite films were synthesized using solution casting and solvent evaporation techniques. The chemical bond structure of the bionanocomposite films and the effect of bentonite addition on the amine and hydroxyl groups in the structure were determined by Fourier transform infrared. Morphological properties and compatibility of polymers and bentonite were characterized by using scanning electron microscopy. The degree of sorption of the bionanocomposite films was evaluated by swelling tests. As the bentonite content in the nanocomposite film increased from 5% to 25%, the sorption degree of film increased from 2.99% to 65.05%. In addition, the effects of bentonite addition of the synthesized bionanocomposite films and pH of medium on the 5-FU loading and encapsulation efficiency were investigated. Controlled release studies were carried out by using 5-FU loaded nanocomposite films. The obtained results showed that the usage of bentonite in nanocomposite drug carrier films were improved the release properties. After four days, a release value was obtained as 40.12% at pH=7.4 in the 5 wt. % bentonite loaded films. [ABSTRACT FROM AUTHOR]

Objetive: The aim of the study was to develop thymol thermosensitive in situ gels based on poloxamers in order to prolong dental contact time, control drug release, and enhance dental bioavailability. Materials and Methods: Poloxamer 188 (P188) and poloxamer 407 (P407) were used in varying amounts to designed the in situ gels. Mucoadhesive excipient, like hydroxypropyl methylcellulose (HPMC), was transferred to the in situ gels to improve the formulation's ability to adhere to biological surfaces. For the created formulations, in vitro drug release, pH, clarity, and sol-gel transition temperature were all evaluated. Results: The all of in situ gels gelation temperatures of the developed formulations range from 33 to 37°C, pH values are around 7, and syringeability is defined as the amount of force necessary to discharge each formulation from a syringe fitted with a 20-gauge needle. The quantities of P407 and HPMC with the preparations, decreasing in vitro burst release while also increasing the viscosity but every in situ gel formulation releases for six hours. Conclusion:The results show that in situ gels containing P407 and P188 show promise for thymol dental application. [ABSTRACT FROM AUTHOR]

Objectives: The aim of the present study was to prepare pectin-hydroxypropyl methylcellulose-coated floating beads for pulsatile release of piroxicam in the treatment of early morning inflammation. Materials and Methods: Piroxicam-loaded beads were prepared from sodium alginate and hydroxypropyl methylcellulose (HPMC) in different concentrations of calcium carbonate using the ionotropic gelation method. In order to avoid drug release in the upper part of the gastrointestinal tract, the beads were coated with a pectin-HPMC layer using the dip coating method. Size analysis and encapsulation efficiency, drug loading, in vitro release, swelling behavior, and surface morphology studies of the beads were carried out. Results: The in vitro release study revealed that the pectin-HPMC coating of the beads prevented the release of the drug in an acidic medium and provided pulsed release of the drug after a lag time. Formulation CF4 (containing calcium carbonate in the ratio 3:4 with respect to sodium alginate) exhibited pulsed release of 95.55% at the end of 7 h in phosphate buffer, which was after the desired lag time of 6 h. Conclusion: The study revealed that optimized floating pulsatile beads coated with pectin-HPMC can efficiently retain piroxicam in an acidic medium and that there is pulsed release in an alkaline medium after a lag time. It also showed that the beads prepared can potentially be used for chronotherapeutic treatment of the disease associated with early morning inflammation. [ABSTRACT FROM AUTHOR]