Preparation and evaluation of tamsulosin hydrochloride sustained-release pellets modified by two-layered membrane techniques

A Review on Enteric Coated Pellets Composed of Core Pellets Prepared by Extrusion-Spheronization

Enteric coated dosage form bypasses the stomach and releases the drug into the small intestine. Advantages of enteric coated pellets in comparison with enteric coated tablets are a) Pellets provide rapid onset of action and faster drug release due to the smaller size than tablets and b) Pellets exhibit less residence time of acid-labile drugs in the stomach compared to tablets. Dosage form coat can be damaged by longer resistance time in the stomach. The present review summarizes the current state of enteric coated pellets where core pellets are prepared by extrusion-spheronization technique and the enteric coating is applied in a fluidized bed processor. Two approaches are involved in the preparation of core pellets. In the first approach, a mixture of drug and excipient(s)/co-processed excipient is passed through extruders to prepare core pellets. In the second approach, excipient core pellets are prepared by extrusion technique and the drug is layered onto it before the enteric coating. The excipients present in the core pellets decide immediate or extended release of drug in the intestine. The coprocessed excipient pellets provide less batch variability and provide a platform for layering of many drugs before enteric coating. Some patents included enteric coating pellets [CN105456223 (A), CN105596310 (A), CN105616371 (A), CN105663095 (A), CN101611766B, CN106511862 (A), CN106668018 (A), CN106727381 (A), CN106924222 (A), TW200624127 (A), US 2017/0165248A1, US 2017/0224720A1] are discussed.

Preparation and stability investigation of tamsulosin hydrochloride sustained release pellets containing acrylic resin polymers with two different techniques

The objective of this study was to prepare tamsulosin hydrochloride-sustained release (TSH-SR) pellets which showed good release stability with frame-controlled method. TSH was added to Eudragit^®NE30D and Eudragit^®L30D-55 polymers to form drug-loaded inner core. Afterwards, enteric Eudragit^®L30D-55 polymer was modified on the surface of it to the final product. Dissolution studies showed that TSH-SR pellets were more stable during the coating process, different curing temperatures and storage conditions compared with TSH pellets produced by film-controlled technique. Appearances and glass transition temperatures (Tgs) of free films and surface morphologies observed by scanning electron microscopy (SEM) of blank sustained release pellets prepared by different ratios of Eudragit^®NE30D and Eudragit^®L30D-55 further indicated that temperature and relative humidity (RH) were the key factors when Eudragit^®NE30D blended with Eudragit^®L30D-55 were applied to sustained/controlled release preparations. In addition, SEM identified the surface morphologies of TSH-SR pellets before and after dissolution, which showed intact surface structure and great correlation with release curve respectively.

Preparation and evaluation of duloxetine hydrochloride enteric-coated pellets with different enteric polymers

The main purpose of the present study was to prepare duloxetine hydrochloride (DXH) enteric-coated pellets using different enteric polymers. Three layers (drug-loaded layer, barrier layer, and enteric-coated layer) were applied to the inert core pellets, successively. The optimal formulation was manufactured by employing suspension layering method in fluidized bed processor (FBP) with varieties of enteric polymers like Aqoat^® AS-LF, Eudragit^® L30D55 and HPMCP-HP55. The prepared pellets were measured for physical characterization and the in vitro dissolution profile. Scanning electron microscopy (SEM) was conducted to observe the morphology of pellets, and different kinetic models were applied to analyze the release mechanism of Cymbalta^® and home-made pellets. The coating weight gain of enteric-coated layer containing Eudragit^® L30D55, Aqoat^® AS-LF and HP-55 were determined to be 35%, 26% and 24%, respectively. The similarity factors (f₂) of self-made capsules with above polymers and commercially available capsules (Cymbalta^®) were above 50 in the dissolution medium of pH 6.8 phosphate buffer solution (PBS). SEM figures showed the smooth surfaces of self-prepared pellets using Eudragit^® L30D55 and Aqoat^® AS-LF, whereas rough surface was found in the HP-55 pellets at day 0, and an impurity was appearing in the condition of 40 °C/75% relative humidity for 1 month. In conclusion, the pellets prepared by utilizing Eudragit^® L30D55 and Aqoat^® AS-LF were the optimal preparations based on the dissolution profile and stability.