No abstract

Mucoadhesive buccal dosage forms are becoming more popular and patient acceptable dosage forms. By this route advantages are many as the dose can be reduced, avoidance of first pass metabolism and liver toxicity, etc. The Tizanidine has first pass metabolism because of this the patient has to take more dose and two to three times in a day. To overcome this problem mucoadhesive patches of tizanidine are prepared and evaluated. Tizanidine is a non-selective, α-two adrenergic agonist receptor and used as muscle relaxant. The oral bioavailability of Tizanidine is 40%, because of first pass metabolism. The polymers used are polyvinyl alcohol and polyvinyl pyrolidine. FTIR and UV spectroscopic methods reveal that there is no interaction between tizanidine and polymers. The patches evaluated for various parameters and results are satisfied. In vitro release studies in phosphate buffer (pH, 6.6) exhibited drug release in the range of 71.68 to 97.27% in 90 min. The release of tizanidine from the patches followed first order, Higuchi's model and mechanism diffusion rate limited. In vivo buccal absorption studies in rabbits showed 68.85% of drug releases from polyvinyl alcohol patch while it 67.52 to 88.31% within 90 min in human volunteers. Good correlation among in-vitro release and in-vivo studies observed.

The main objective of developing any new dosage form is reduce the side effects and increase the therapeutic effect of drug in existing dose of dosage form. Mucoadhesive drug delivery system is oral dosage form, where the tablet, gel or patch is attached to the buccal region for direct absorption of drug into blood circulation. This route can prevent the metabolism of drug in G.I tract or liver and side effects of metabolites avoided. In this study, the attempt was made to prepare mucoadhesive buccal tablets of Terbutaline sulphate with natural polymer sodium alginate with one side absorption by backing layer with ethyl cellulose. The buccal tablets of Terbutaline sulphate studied in detail. I R Spectroscopy did the compatible study between polymers and Terbutaline sulphate and No interaction was found between drug and polymers. Different formulations of oral Mucoadhesive buccal tablets of Terbutaline Sulphate (TS) were prepared using polymer sodium alginate, in different concentrations by direct compression. Post compressed evaluation studies, hardness, thickness, friability; weight variation and drug content, mucoadhesive strength of tablets were studied. The in-vitro release of TS was studied in buffer pH 6.8 at 37 0 C. All parameters of TS buccal tablets are passed the standard of mucoadhesive buccal tablets. It was found that mucoadhesive natural polymers exhibited better adhesiveness and mucoadhesiveness. The in vitro study of TS exhibited greater drug release profile with release of in the range of 79.25 to 99.85%.

Objective: The main objective of the present study was to design and evaluate a time-controlled single unit oral pulsatile drug delivery system containing salbutamol sulfate for the prevention of nocturnal asthma attacks.Methods: Drug containing core tablets (C1-C10) with different composition of superdisintegrants such as sodium starch glycolate, croscarmellose sodium, and crospovidone were prepared by direct compression technique. The fast disintegrating core tablet formulation was selected, and press-coated tablets (P1-P11) were prepared with different compositions of hydrophobic and hydrophilic polymers: Ethylcellulose-20 (EC-20), hydroxypropyl methylcellulose K4M, and low substituted hydroxypropyl cellulose (L-HPC LH11). The coating polymers were selected and quantified based on in vitro lag time and drug release profile in simulated gastric and intestinal fluids.Results: Formulation C10 with 7.5% crospovidone showed least disintegrating time, i.e., 0.31 min and was selected as the best immediate release core tablet. The press-coated tablet formulation P11 having 360 mg barrier layer of EC-20 and L-HPC LH11 in ratio 14:1 over the core tablet C10 showed rapid and complete drug release nearly after 6 h lag time. Accelerated stability studies of the optimized formulation P11 indicated no significant difference in release profile after a period of 6 months.Conclusion: The in vitro dissolution study showed that lag time before drug release was highly affected by the coating level and nature of coating polymer used. Time-controlled pulsatile release tablets can be prepared using press-coating techniques.

The aim of the present study was to develop and evaluate sustained release floating tablets of Diltiazem hydro-chloride, an antihypertensive agent. The sustained release floating tablets were prepared by direct compression method and formulated using different polymer combinations, formulations such as F1 to F9. Natural polymer Sodium alginate and synthetic polymer HPMC K4M were used. Developed formulations were evaluated for the pre compression parameters i.e., drug- excipients compatibility by FTIR, bulk density, compressibility, and angle of repose etc. Post compression parameters i.e. weight variation; full factorial design was applied to optimize the developed formulation. SA and HPMC K4M were selected as independent variable at three different concentrations. The in-vitro drug release study revealed that formulation F8 combination of both synthetic (HPMC) and natural polymers (sodium alginate) was the most successful formulation of the study, all tablets but one exhibited gradual and near complete sustained release for diltiazem HCl (90-100%) that extended the drug release up to 8 hours, with satisfactory drug release in the initial hours, and the total release pattern was close to the theoretical release profile.  Model equations of zero and first order, Higuchi, Hixson-Crowell and Peppas, intended to elucidate the drug release mechanism, and were fitted to the release data. Mathematical modelling of in-vitro dissolution data indicated the best-fit release kinetics was achieved with Higuchi model with r2 vales of 0.994 in its semi log plot. The ‘n’ value in Higuchi model was >0.89 which indicated, Super Case-II transport of drug from polymer sustained, i.e., diffusion with relaxation of polymeric chain. In conclusion, the results indicated that the prepared sustained-release tablets of Diltiazem hydrochloride could perform therapeutically better than conventional tablets with improved efficacy and better patient compliance.