Mucoadhesion

  The objective of the present investigation was to develop and evaluate microemulsion based gel for the vaginal delivery of Sertaconazole. The solubility of Sertaconazole in various oils, surfactants and co-surfactants were checked to identify components of the microemulsion. The ternary diagrams were plotted to identify the area of microemulsion existence. Various gelling agents were evaluated for their potential to gel the Sertaconazole microemulsion without affecting its structure. Carbopol 940 was selected for the formulation of microemulsion based gel. The prepared formulations of Sertaconazole Microemulsion based gel was evaluated by checking its pH, spreadability, rheological studies, mucoadhesive strength, in-vitro drug release studies and ex-vivo retention studies. The Sertaconazole Microemulsion based gel showed good in vitro bioadhesion and anti-fungal activity. The Sertaconazole Microemulsion based gel has potential be successfully used for the topical treatment of vaginal candidiasis.

The study aim was concerned with formulation and in vitro evaluation of mucoadhesive buccal patch of carvedilol, which is extensively metabolized by liver. During last few years mucoadhesive dosage forms have promoted an area of drug delivery system that renders the treatment more effective and safe, not only for topical disorders but also for systemic problems. Therefore the present investigation is concerned with the development of the bucco-mucoadhesive patches, which were designed to prolong the buccal residence time, to increase penetration through buccal mucosa and thus increase the bioavailability. Various formulations were developed by using release rate controlling patches forming polymers like HPMC (K15, K4), HPC-L, Sodium alginate, PVP K30& Carbopol 934P in  alone & various combinations by solvent casting technique using plasticizer glycerol. For unidirectional release, backing layer prepared using ethyl cellulose 2.5%w/v dissolve in isopropyl alcohol and acetone. Glycerol used as a plasticizer was casted on the patches. The patches were evaluated for their thickness uniformity, folding endurance, weight uniformity, content uniformity, swelling behaviour, tensile strength, and surface pH, In vitro release studies, in vitro residence time, in vitro diffusion study. Patches exhibited drug release (diffusion) in the range of 75.69% to 96.53%. Kinetic models i.e. Higuchi, Korsemeyer-peppas, zero order were applied on data of diffusion release to explain release. The optimized formulation (F1) shows the zero order release.

  Drug development technologies constituting innovations at the formulation end in the pharmaceutical industry has received a lot of attention in past two decades. Drug delivery as an opportunity to extend product life cycles has indeed proved its place in the market with significant advantages of therapeutic gains as well as commercial success. Carrier technology offers an intelligent approach for drug delivery by coupling the drug to a carrier particle such as microspheres, nanoparticles, liposomes, etc. which modulates the release and absorption characteristics of the drug. Mucoadhesion is a topic of current interest in the design of drug delivery systems. Mucoadhesive microspheres exhibit a prolonged residence time at the site of application or absorption and facilitate an intimate contact with the underlying absorption surface and thus contribute to improved and/or better therapeutic performance of drugs. Hence, uptake and consequently bioavailability of the drug is increased and frequency of dosing reduced with the result that patient compliance is improved. In recent years such Mucoadhesive microspheres have been developed for oral, buccal, nasal, ocular, rectal and vaginal for either systemic or local effects. This review article aims to provide various aspects of mucoadhesion, theories of mucoadhesion and the polymers which will shows the excellent mucoadhesive properties. It also contains a number of available methods of preparation of microspheres and its evaluation including in vitro-wash off test for to determine the mucoadhesive property of prepared microspheres.

  A novel mucoadhesive, thermoresponsive vaginal gel for microbicide was developed with gelation temperature 24-35 °C. Poloxamer 407 (P407) or: and poloxamer 188 (P188) were used to confer the temperature-sensitive gelation property. The mixtures of P407 (15%) and P188 (15–20%) existed as a liquid at room temperature, but gelled at 30–36°C. To modulate the gel strength and the bioadhesive force of Ciclopirox olamine gel, mucoadhesive polymer such as polyox WSR N-60K was used. Among bioadhesive polymers, polyox polymer enhanced gel strength most efficiently. These polymers reinforced the bioadhesive forces 4-7 fold compared to P407/P188 (15:15) alone and 3-6 fold compared to P407/P188 (15:20) alone. Differential scanning calorimetry (DSC) was employed to investigate the effect of poloxamer gel on the conformational changes of rat vaginal membrane. The in-situ gelling liquid with polyox polymer inserted into the vagina of women without difficulty and leakage and retained in the vagina at least 6-8 h. These results suggest that in situ-gelling and mucoadhesive vaginal microbicide gel for women can be further developed as a more convenient and effective vaginal dosage form for treating sexually transmitted disease.   Key-words: Mucoadhesion, Vaginal drug delivery, Polyox polymers, Microbicide, Sexually transmitted disease, Conformational change