Design and evaluation of an extended-release matrix tablet formulation; the combination of hypromellose acetate succinate and hydroxypropylcellulose

The purpose of this study was to develop an extended-release(ER) matrix tablet that shows robust dissolution properties able to account for the variability of pH and mechanical stress in the GI tract using a combination of enteric polymer and hydrophilic polymer. Hypromellose acetate succinate(HPMCAS) and hydroxypropylcellulose(HPC) were selected as ER polymers for the ER matrix tablet(HPMCAS/HPC ER matrix tablet). Oxycodone hydrochloride was employed as a model drug. Dissolution properties of the HPMCAS/HPC ER matrix tablets were evaluated and were not affected by the pH of the test medium or paddle rotating speed.In a USP apparatus 3(bio-relevant dissolution method), dissolution profiles of the HPMCAS/HPC ER matrix tablets containing oxycodone hydrochloride were similar to that of the reference product(OxyC ontin). Moreover, in vivo performance after oral administration of the HPMCAS/HPC ER matrix tablets to humans was simulated by GastroP lus based on dissolution profiles from the USP apparatus 3. The plasma concentration-time profile simulated was similar to that of the reference product. These results suggest that the combination of HPMCAS and HPC shows a robust dissolution profile against pH and paddle rotating speed and indicates the appropriate extended-release profile in humans.

Influence of solvent mixtures on HPMCAS-celecoxib microparticles prepared by electrospraying

Hypromellose acetate succinate(HPMCAS) microparticles containing the poorly-water soluble drug celecoxib(CEL) were prepared by electrospraying intended for oral drug delivery. Various solvent mixtures with different solubility for CEL and HPMCAS were used to induce changes in the polymer structural conformation of the microparticles. The performance of the prepared microparticles was evaluated by studying the solid state from, particle size and morphology, radial drug distribution and drug release. CEL was amorphous in all electrosprayed HPMCAS microparticles. The particle size and morphology was dependent on the solubility of HPMCAS in the solvent mixture used with poorer solvents resulting in smaller microparticles with rougher appearance. The CEL distribution on the particles surface was relatively homogeneous and similar for all microparticles. Drug release from the microparticles was observed at a higher rate depending on the solubility of HPMCAS in the solvent used for electrospraying, and in all cases an at least 4-fold higher rate was observed compared with the crystalline drug. Drug precipitation from the supersaturated solution was inhibited by HPMCAS for all microparticles based on its parachute effect while crystalline CEL did not reach supersaturation. This study demonstrated that electrospraying can be used to produce microparticles with tailored properties for pharmaceutical application by adjusting solvent selection.

Hydroxy Propyl Methyl Cellulose： Different Aspects in Drug Delivery

Among the various research works going on nowadays, designing of controlled release dosage form is of great importance. For the development of suitable controlled release dosage form, a proper matrix needs to be formed from which the drug release generally occur by polymer swelling, polymer erosion, drug dissolution/diffusion mechanism. HPMC （hydroxy propyl methyl cellulose）, also known as hypromellose, is one of the best known cellulosic polymers used in the development of controlled released drug delivery. It is available in various grades. Cellulosic polymers are ingredients that contain units linked together which help to retain water. Due to its high water absorptive capacity, it acts as an excellent hydrophilic gel forming polymer. HPMC generally hydrates on the outer surface to form a gelatinous layer which is critical to prevent wetting and rapid drug release from the matrices. If the drug is sparingly soluble in the system, the release of drug from the system is slow and helps in formulation of controlled release dosage form. In the ophthalmic dosage form, HPMC is used as a matrix that swells and expands after absorbing water and expand the thickness of the tear film.

Research on the Influence of HPMC Release the Bupropion Hydrochloride Sustained Release Tablets

Objective Study of bupropion hydrochloride gel matrix sustained release tablet and the preparation method, test the skeleton material of hydroxypropyl methyl cellulose influencing drug release for evaluation, explore the preparation of sustained release tablets of optimization method. Method With hydroxypropyl methyl cellulose as skeleton material, according to the different prescription preparation of bupmpion hydrochloride sustained release tablets. Different HPMC viscosity, Consumption, particle size, compression pressure and slurry rotational speed and other factors, analysis the influence on drug release rate.Through the release of test evaluation of sustained release effect, and the preliminary study on the drug release characteristic. With hydroxypropyl methyl cellulose （ HPMC ） as skeleton material, with citric acid citrate as a porogenic agent, direct powder tabletting method of bupropion hydrochloride sustained release tablets; by using single factor and orthogonal experiment method to investigate HPMC different viscosity, different Consumption, different particle size, different compression pressure, different pulp rotational speed and other factors on the release of delivery rate. Result Select HPMC-K100M for bupropion hydrochloride sustained release tablets of the skeleton materials; reinforcing materials of high viscosity HPMC K100M and main drug quality ratio of 1： 1; HPMC particle diameter of 125p m, make use of these conditions to preparation of bupropion hydrochloride sustained release tablets for optimal prescription conditions. Conclusion bupropion hydroehloride sustained release tablets on the drug release rate is mainly affected by HPMC viscosity and dosage effect. Along with the tablet of HPMC viscosity increased, the drug is released slowly. HPMC viscosity, dosage on the drug release rate has significant influence.