A formulation of pellet containing ibuprofen was carried out using Avicel, lactose as exipients. The obtained pellets were coated with EC to prolong the drug release. An ibuprofen sustained release capsule was prepared by filling coated pellet into the capsule shell.
Ibuprofen ; Delayed-Action Preparations

Study on the influence of appropriate sustained-release excipients on the release of propranolol hydrochloride from experimental sustained-release tablet. Hydroxyl propyl methyl cellulose and Avicel PH 101 could protect the release of propranolol hydrochloride from sustained-release tablet. Establish the coating with 2 types of polymers HPMC and Eudragit L100. Test the degree of dissolution during 12 hours and compare to the reference tablet. The release of propranolol hydrochloride from sustained release tablet prepared by the formula 20th was similar to that of reference tablet, the coefficient of f2=64.54. At the same time, the quantitative method of serum propranolol was established, in order to assess the in vivo ability of products
Propranolol ; Delayed-Action Preparations

We investigated the single- and multiple dose pharmacokinetics of a new controlled-release formulation (Orfil retard enteric coated tablet) of valproic acid in comparison with those of the plain tablet as a reference. Twelve healthy volunteers were given each formulation of 300 mg in the single-dose study. In the steady-state multiple-dose study, twelve epileptic patients received 1200 mg/day of the reference drug (300 mg 9 AM, 300 mg 3 PM, 600 mg 9 PM) and the test formulation (600 mg 9 AM, 600 mg 9 PM) with at least one week interval in cross-over manner. The AUC values of the test controlled release formulation were 91.7% (95% confidence interval: 78.4-100.4%) of the reference drug in the single-dose study and 98.2% (95% confidence interval: 86.2%-109.9%) in the steady-state study. The AUC's of the two formulations were not significantly different by ANOVA test. The Cmax and Tmax values of the test formulation were significantly different from the values of the reference in single-(Tmax: 158.4%, Cmax: 52.5% of the reference) and multiple-dose study (Tmax: 153.5% of the reference). The MRT values of the test formulation were also significantly greater (129.4% of the reference) in the single-dose study. Regarding the controlled-release characteristics of the test formulation, fluctuation index and percentage fluctuation of the twice a day dosage regimen of the test formulation were comparable with those of the thrice a day dosage regimen of the conventional tablet. Area deviation was even smaller in the test regimen of the controlled release formulation.(ABSTRACT TRUNCATED AT 250 WORDS)
Administration, Oral ; Adult ; Biological Availability ; Delayed-Action Preparations ; Epilepsy/blood/*drug therapy ; Humans ; Male ; Tablets ; Tablets, Enteric-Coated ; Valproic Acid/*pharmacokinetics

AIMTo prepare a new oral colon-specific delivery formulation and to investigate the release profile in vitro and the colon-specific delivery property in vivo in dogs.

METHODSSodium 4-aminosalicylic acid was selected as the model drug. The combination of Eudragit RL30D and RS30D were used as sustained-release film, and Eudragit FS30D used as enteric film, which was expected to release drug depending on pH and time. The release profile of tablets was studied in three phosphate buffers with the pH 6.5, 7.0 or 7.4 for 12 h after a simulated gastric presoak for 2 h in 0.1 mol x L(-1) HCl. The tablets were radiolabelled with 99mTc to make their release times and positions in the gastrointestinal tract be followed using a gamma camera.

RESULTSFor the in vitro study, there was no drug released in 0.1 mol x L(-1) HCl for 2 h, and release occurred slowly when pH was above 6.5. Drug was released faster while pH was higher. For the in vivo study, the coated tablets remained intact in the upper gastrointestinal tract, and drug release began after the colonic arrival. The uncoated tablets, however, disintegrated in the stomach of the dogs rapidly.

CONCLUSIONThe coating could protect the drug until the tablets reached the ascending colon, where drug was released slowly for over 10 h.

Acrylic Resins ; chemistry ; Administration, Oral ; Aminosalicylic Acid ; administration & dosage ; chemistry ; pharmacokinetics ; Animals ; Antitubercular Agents ; administration & dosage ; chemistry ; pharmacokinetics ; Colon ; metabolism ; Delayed-Action Preparations ; Dogs ; Drug Delivery Systems ; Hydrogen-Ion Concentration ; Male ; Tablets, Enteric-Coated

Antipsychotic medications are important for the successful management of schizophrenia. Continuous treatment with medication is superior in relapse prevention and non-adherence to antipsychotic medication is associated with a poor clinical outcome. Long-acting injectable antipsychotics (LAIs) that can guarantee adherence to a treatment regimen could be a useful treatment option. With the introduction of second-generation atypical antipsychotics-long acting injection (SGA-LAI), the risks for extrapyramidal adverse events are decreased. The indications for SGA-LAI have been extended from chronic, stabilized patients to acute psychotic patients. Some studies investigated the use of LAI in first-episode schizophrenia patients and raised the possibility of prescribing LAI as a treatment option. However, there is still limited research using LAI in first-episode schizophrenia. More well-designed, randomized, controlled clinical trials using SGA-LAIs in first episode schizophrenia are needed. Additionally, studies on side effects of SGA-LAI in long-term use are required prior to recommending LAI for patients with first episode schizophrenia.
Antipsychotic Agents ; Delayed-Action Preparations ; Humans ; Recurrence ; Schizophrenia

OBJECTIVETo prepare sustained-release pellets of active components from Ligusticun chuanxiong by coating in the fluid-bed.

METHODThe fast-release pellets were prepared by the extrusion-spheronization process. The coating formulation was optimized with the release of ferulic acid as criteria. The micromeritic properties and drug dissolution behaviors of the prepared pellets were evaluated.

RESULTThe pellets presented perfect sphericity. The obviously sustained-release effects were shown in 12 h. The coating weight gain was the major factor impacting drug release.

CONCLUSIONThe coating pellets show the obviously sustained-release effects.

Coumaric Acids ; analysis ; Delayed-Action Preparations ; Ligusticum ; chemistry ; Technology, Pharmaceutical

OBJECTIVETo develop a best chitosan film for using as a drug sustained-release system through the evaluation of the sustained-release property, degradation property, and cytotoxicity to osteoblast.

METHODSOrthogonal experiments were designed to determine the best combination of chitosan film preparations. Drug release rate was determined with Coomassie brilliant blue G250. In a separate study, chitosan films were placed into the test tubes with buffer solution and 10(7) U/L lysozyme. The degradation rate was calculated. Osteoblasts derived from fetal rat calvarial were cultured on chitosan films. Cell proliferation was tested by methyl thiazolyl tetrazolium (MTT) assay. The relative growth rate was calculated and the cytotoxicity was graded.

RESULTSThe best processing condition was 1% acetic acid, chitosan concentration of 2 mg/mL, 6% sodium tripolyphosphate (STPP) concentration, and cross-linking time of one hour. The resulting chitosan film released 33.13% of bovine serum albumin (BSA) within 8 d, 36.73% of BSA within four weeks and the cytotoxicity grade was 0 or 1.

CONCLUSIONThis chitosan film possesses good sustained release property, and a good degradation rate.

Animals ; Chitosan ; Delayed-Action Preparations ; Polyphosphates ; Rats ; Serum Albumin, Bovine

OBJECTIVEThe aim of this study was to prepare Pingyangmycin Albumin Microspheres (PYM-AMS) for arteriovenous malformations treatment.

METHODSPYM-AMS was prepared at 140 degrees C by the method of emulsification-heat solidification and its characteristics were evaluated, such as morphosis, particle size, drug loading (DL%), encapsulation efficiency (EE%), stability and drug sustained-releasing in vitro. After being packaged, PYM-AMS were sterilized with 13.7 kGy of 60Co. Small samples of PYM-AMS were packaged in small bottles and stored at 3 - 5 degrees C, 15 - 25 degrees C, 37 degrees C for 3 months, then checked the change of morphology, DL, EE and the release rate.

RESULTSThe surface of particles was smooth and integrated. The average diameter of PYM-AMS particles was 139.422 microm and 80% was in the range of 56 - 251 microm. The mean DL% and EE% were 26.47% and 84.3%, respectively. PYM released fast in 5 h, but then released slowly. 88.65% drugs were released in 24 h, and t50 was 1.5 h. There was no obvious change of the morphology, DL,EE and the release rate of PYM-AMS stored at 3 - 5 degrees C 15 - 25 degrees C, 37 degrees C for 3 months.

CONCLUSIONPYM-AMS prepared in this study had sustained-release effect, high drug loading and high stability. Albumin is a good carrier of PYM embolization agent.

Albumins ; Bleomycin ; analogs & derivatives ; Delayed-Action Preparations ; Microspheres ; Particle Size

This study pharmacokinetically examined the lovastatin sustained-release tablet and sustained-release capsule in Beagle dogs. An reversed-phase HPLC method was established for the determination of lovastatin in Beagle dog plasma. Pharmacokinetic findings were compared among three preparation(lovastatin sustained-release tablet, Tp; sustained-release capsule, TJ and conventional capsule). Our results showed that the pharmacokinetic parameters in 6 dogs after single-dose oral administration of three perparations were calculated. Tmax, Cmax and MRT revealed significant difference (P<0.05). Relative bioavailability was 111.5 +/- 16.9% (Tp) and 110.4% +/- 9.6% (Tj). The pharmacokinetic parameters in the 6 dogs after multiple-dose oral administration of three perparations, Tmax, Cmax MRT and DF had significant difference (P < 0.05); Cav, Cmin and AUC0-24 h displayed no significant difference (P>0.05). It is concluded that the lovastatin sustained-release tablet and sustained-release capsule are able to maintain a sustained-release for 24 h.
Anticholesteremic Agents/*pharmacokinetics ; Capsules ; Delayed-Action Preparations ; Lovastatin/*pharmacokinetics ; Tablets

The application of intraocular drug delivery is usually limited due to special anatomical and physiological barriers, and the elimination mechanisms in the eye. Organic nano-drug delivery carriers exhibit excellent adhesion, permeability, targeted modification and controlled release abilities to overcome the obstacles and improve the efficiency of drug delivery and bioavailability. Solid lipid nanoparticles can entrap the active components in the lipid structure to improve the stability of drugs and reduce the production cost. Liposomes can transport hydrophobic or hydrophilic molecules, including small molecules, proteins and nucleic acids. Compared with linear macromolecules, dendrimers have a regular structure and well-defined molecular mass and size, which can precisely control the molecular shape and functional groups. Degradable polymer materials endow nano-delivery systems a variety of size, potential, morphology and other characteristics, which enable controlled release of drugs and are easy to modify with a variety of ligands and functional molecules. Organic biomimetic nanocarriers are highly optimized through evolution of natural particles, showing better biocompatibility and lower toxicity. In this article, we summarize the advantages of organic nanocarriers in overcoming multiple barriers and improving the bioavailability of drugs, and highlight the latest research progresses on the application of organic nanocarriers for treatment of ocular diseases.
Drug Carriers ; Delayed-Action Preparations ; Drug Delivery Systems ; Nanoparticles/chemistry*