Guar gum is derived from the seeds of Cyamopsis tetragonolobus. Guar has certain drawbacks such as uncontrolled rate of hydration, fall in viscosity on storage, susceptibility to microbial degradation, and turbidity in aqueous dispersion. Many of these drawbacks can be overcome by using guar derivatives. Guar derivatives upon contact with water hydrate to form hydrogels for controlled-release mechanism and show stimuli-responsive changes in their structural network, and hence, the drug release. The present investigation aims at screening guar derivative (hydroxyl propyl guar) during preformulation stage by spectral (FTIR spectroscopy), thermal (differential scanning calorimetry (DSC)), isothermal (HPLC technique), and rheological characterization for the development of stable in situ ophthalmic dosage using linezolid as the model drug.

The objective of the present study was to develop fast-dissolving tablets (FDTs) of glipizide, a sulfonylurea antidiabetic drug. The husk of Plantago ovata and pregelatinized husk of P. ovata were used as disintegrating agents. Microcrystalline cellulose was used as binder and starch (soluble) was used as bulk-forming agent. The powder blends were evaluated for angle of repose, compressibility index and Hausner ratio. The results of angle of repose, compressibility index (%) and Hausner ratio ranged from 24.23±0.57 to 29.34±0.78, 15.76±0.82 to 20.12±1.25 and 1.18±0.011 to 1.25±0.019, respectively. The tablet blends were converted into tablets by using direct compression method. The tablets were evaluated for disintegration test, hardness test, friability test, drug entrapment efficiency, content uniformity tests and drug release study. Formulations, which contained pregelatinized husk of P. ovata as a superdisintegrant, showed faster disintegration, higher percentage friability and lesser hardness than formulations containing husk of P. ovata as a superdisintegrant. Drug entrapment efficiency was found to be uniform among different batches of the tablets and ranged from 97.53±0.52 to 99.72±0.45. The results of content uniformity test of all the batches were found in the official range. The batches containing husk of P. ovata as a superdisintegrant released 15%-27% of glipizide per minute and those containing pregelatinized husk of P. ovata as a superdisintegrant released more than 95% of the drug within a minute. These results revealed that pregelatinized husk of P. ovata can be used as a superdisintegrant for obtaining FDTs.

Modified-release multiple unit dosage form (MRMUD) of desloratadine and pseudoephedrine hydrochloride with different release profiles were prepared. The MRMUD system consists of the immediate-release pellets containing desloratadine and sustained release pellets containing pseudoephedrine hydrochloride. The immediate and sustained release pellets were prepared by solution layering technique. A 3 ² full-factorial design was employed to optimize the sustained release formulation where in polymer ratio (Ethyl cellulose : hydroxyl propyl methyl cellulose) (X1) and % polymer coating (X2) were taken as independent variables and amount of drug release, in 0.1N HCl (Y1), after 10 haves (Y2) were taken as the dependent variables. Optimization studies were carried out using the Design Expert Software. Formulations were evaluated for in vitro release studies, the release data were evaluated by the model dependent (curve fitting) method using the PCP Disso software. The in vitro drug release followed Hixson-Crowell model and the drug release mechanism was found to be anomalous or non-fickian type. It was found that proper combination of ethyl cellulose and hydroxy propyl methyl cellulose polymer, % polymer coating and process parameters could provide sustained release of pseudoephedrine hydrochloride for a period of 12 haves.

The aim of this study was to prepare tamoxifen citrate (TC)-loaded cylindrical and strip-shaped polymeric subdermal implants. The implant was based on poly(ε-caprolactone), a low-melting, biodegradable and biocompatible polymer. Polyethylene glycol (PEG 4000) was used to enhance solubility and release of the drug in the phosphate buffer saline pH 7.4. Implants were prepared by a standardized melt manufacturing method. The prepared implants were evaluated for their physicochemical parameters and drug content in implants by UV spectrophotometric method. PCL-based implants were characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry, X-ray diffraction studies (XRD) and scanning electron microscopy (SEM). DSC studies showed that the TC in the implants was in the amorphous state. In vitro drug release studies were performed in methanol:phosphate-buffered saline (pH 7.4) at 37±2°C by using horizontal water bath shaker. Stability study was carried out for 90 days, there was no significant change in drug content and other parameters of the PCL-based formulations.

Stomach-specific floating tablet of metronidazole based on the buoyancy and bioadhesion concept was prepared with a purpose to retain the drug in stomach for longer duration and helps in releasing the drug in the antrum region of gastric mucosa, a safe heaven for Helicobacter pylori. This research work systematically studied the effects of various polymeric blends of bioadhesive polymers namely chitosan and carbopol 971P with low density polymer- methocel K100LV on the desired in vitro drug release profile in the stomach, buoyancy, swelling index, and mucoadhesion of tablet formulation. Chitosan and carbopol 971P concentration significantly influence the in vitro drug release and bioadhesion strength. An increase in buoyancy was observed with increase in Methocel K100LV concentration in the polymeric blend. The increase in buoyancy and drug release was obtained in the presence of microcrystalline cellulose, sodium bicarbonate, and sodium citrate. The optimum formulation provides desired high drug concentration (~35%) during 1 hour and sustained release up to 12 hours, following the Higuchi model. The mechanism of release of metronidazole from the floating bioadhesive tablets was anomalous diffusion transport. The studies indicated successful formulation of gastroretentive compressed tablet with excellent controlled release, mucoadhesion, and hydrodynamic balance.

The main objective of the present study was to prepare paclitaxel (PTX)-loaded poly(sebacic acid-co-ricinoleic ester anhydride) (poly (SA-RA) 70:30 w/w)-based nanoparticles (NPs). PTX- Poly (SA-RA) NPs were prepared by solvent displacement technique. The prepared formulations were characterized in terms of particle size and distribution, surface morphology using Malvern laser analyzer, scanning electron microscope (SEM). Drug physical and chemical state were determined by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) and differential scanning calorimetry. The particles obtained were spherical in shape with a smooth surface and mean particle size in the range of 443-436 nm. The entrapped PTX within the polymer matrix was in the form of amorphous state.

The purpose of the present research is to investigate systematically the tablettability and drug release properties of ethyl cellulose (EC) in compact form. A total of nine batches of compacts containing metformin hydrochloride (MTF) as model drug and ECs with varying viscosity grades (7, 10, and 100 cps) at 10, 20 and 30% w/w contents were prepared. Profound effect of viscosity grades and content of EC on compression behavior of granules and drug release from compacted matrices was observed. An increase in EC 7 cps content resulted improvement in tensile strength and compactibility. However, compression susceptibility gets inversely affected. EC 7 cps has shown MTF release, which is extended upto 10 hours (t _90% ), attributed to high interparticulate interactions. Similar trend was observed with both EC 10 cps (t _90% ; upto 13 hours) and 100 cps (t _90% ; upto 10 hours). Surprising results were observed for matrices of EC 10 cps at 20% w/w, which showed moderate compactibility and tensile strength, but extended the MTF release for maximum time among all compact formulations (t _90% ; 13 hours; peppas model). These results show the use of EC 10 cps in formulations desired for extended drug release at its optimum content. Matrices containing EC 100 cps have shown better compressibility and compactibility among all batches. The anomalous behavior of high viscosity EC (at 20% w/w content) matrices releasing drug in shorter time (t _90% , 8 hours; zero order) can be ascribed to poor matrixing of MTF in EC network due to high molecular weight of EC 100 cps.

The aim of this study was to develop controlled release mucoadhesive microspheres of amoxicillin trihydrate for the treatment of peptic ulcer disease caused by Helicobacter pylori (H. pylori). Microspheres were prepared by solvent evaporation technique using carbopol 974P, hydroxypropyl methyl cellulose K4M (HPMC K4M) and Eudragit RS 100. The prepared microspheres were subjected to evaluation for particle size, incorporation efficiency, in vitro mucoadhesion and in vitro drug release characteristics. Absence of drug-polymer interaction was confirmed using differential scanning calorimetry analysis and fourier transform infrared spectrophotometry. The prepared microspheres showed a strong mucoadhesive property. The polymer concentration influenced the in vitro drug release significantly in 0.1N HCl. The particle sizes of systems ranged between 123±8.35 μm and 524±11.54 μm. Percent drug entrapment and release profiles of amoxicillin trihydrate in 0.1 N HCl were determined using high-performance liquid chromatography. The percentage drug entrapment and percentage yield of formulations were about 56.71±1.66% to 88.32±0.65% and 39.20±1.62% to 92.40±1.32%, respectively. The stability of the drugs was assessed in 0.1 N HCl. The results further substantiated that mucoadhesive microspheres improved the gastric stability of amoxicillin trihydrate (due to entrapment within the microsphere). From the above results, it was concluded that the mucoadhesive microspheres of amoxicillin trihydrate has feasibility for eradicating H. pylori from the stomach more effectively because of the prolonged gastrointestinal residence time and controlled release of drug from the formulation.