Release in vitro is one of the indexes for quality control of solid dosage forms. It is not only the important indexes for evaluation of bioequivalence, also the important parameter of formulation optimization, study of the stability and quality control within producing of sustained or controlled release dosage forms. The review is the study on index for formulation optimization of sustained or controlled released dosege forms in China since 1999, including the application of similarity factor and deviation.
Chemistry, Pharmaceutical ; Delayed-Action Preparations ; standards ; Dosage Forms ; standards ; Drug Stability ; Quality Control

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

OBJECTIVETo optimize the formulation and preparation process of sinomenine liposomes.

METHODMethod of aether injection and mixture uniform design were adopted to determine the formulation of sinomenine liposomes is the proportion of phospholipids, cholesterol and Vitamin E with the index of entrapment efficiency. And the single-factor test was used to study the preparation process of the liposomes, including the volume of buffer solution, the preparation temperature and the ultrasonic time.

RESULTThe optimized formulation was that the ratio of sinomenine : phospholipids : cholesterol : vitamin E mass ratio was 8.92 : 60.35 : 28.81 : 1.91. The volume of buffer solution was 50 mL x g(-1) membrane, the preparation temperature was 50 degrees C, and the ultrasonic time was 20 min.

CONCLUSIONSatisfactory shape and entrapment efficiency of the liposomes can be obtained by the optimized formulation and preparation process.

Chemistry, Pharmaceutical ; Cholesterol ; Dosage Forms ; Drug Carriers ; Drug Compounding ; economics ; methods ; Drug Delivery Systems ; Drug Stability ; Liposomes ; Morphinans ; pharmacokinetics ; Particle Size ; Phospholipids ; Technology, Pharmaceutical

To investigate the delivery mechanism of micro-porous osmotic pump tablets ( MPOP), taking tramadol hydrochloride ( TR) as the model drug, tramadol hydrochloride micro-porous osmotic pump tablets (TR MPOP) were prepared with compressible starch as diluent, cellulose acetate as coating material, polyethylene glycol 400 as pore-forming agents. The equilibrium solubility and osmolality of TR were determined. The effects of fillers in tablet cores, coating levels, and osmotic pressures of release media on expansion behavior of preparations were described. The influences of the category, osmolality, and pH value of release media, release methods, and release conditions on release curves of tablets were evaluated. Based on several models, the delivery pattern of TR MPOP was fitted. The equilibrium solubility in water and osmolality of TR were (775.8 +/- 17.7) g x L(-1) and 4.036 Osmol x kg(-1), respectively. During the drug-release period, it was observed that the tablets expanded markedly in response to the expansion characteristics of compressible starch and the osmotic pressure difference across the membrane. When osmotic pressure of release media increased, the significant change of the equilibrium solubility of TR was not found, but the release rates of TR MPOP decreased significantly. The delivery rate was not influenced by the pH of release mediums, dissolution methods and paddle stirring rates. The drug release profile conformed to the model of zero order in 8 h. The pore-forming agents were dissolved in release medium, which caused micro-pores. The expansion of tablets made the size of micropores bigger, and then the drug-releasing pores were obtained. It was proved that the drivers of drug delivering from TR MPOP were mainly the difference of osmotic pressure, and secondly the difference of solubility. TR MPOP were the controlled-release preparation.
Analgesics, Opioid ; administration & dosage ; chemistry ; Cellulose ; analogs & derivatives ; chemistry ; Delayed-Action Preparations ; Drug Carriers ; Drug Delivery Systems ; methods ; Drug Stability ; Osmosis ; Osmotic Pressure ; Polyethylene Glycols ; chemistry ; Porosity ; Solubility ; Starch ; chemistry ; Tablets, Enteric-Coated ; Technology, Pharmaceutical ; methods ; Tramadol ; administration & dosage ; chemistry ; pharmacokinetics

Introduction on the factors influence dosage that is equivalent in effectiveness between animals. They comprised drug metabolism, minimum concentration have with effect in serum, the effective time, cellular respiration, organic weight rate comparison with body weight, heat production, cytochrom C, volume of kidney and body surface.
Dosage Forms ; Animal Experimentation

Sustained release dosage forms belong to new forms with innovative bioavailability, in which drug was released in tailored design. If physicians haven't a firm grasp on nature, composition of dosage form and give incorrect instruction for use, model of release dosage of drug will be changed, and drug is not only less effective but also harmful. Author introduced technical rules of preparing sustained release drugs, sustained release dosage forms and pathways of administration
Pharmaceutical Preparations ; Dosage Forms

PURPOSE: It has been reported in several for factors on the drug compliance of patients, number of drug being taken, symptom, and pharmaceutical dosage form. However, Studies of drug compliance by dosing methodologies of tamsulosin, finasteride combination therapy and symptom relief for benign prostatic hyperplasia has not been performed. Therefore, we studied for symptom and differences in medication adherence in method of administration of tamsulosin, finasteride combination therapy. MATERIALS AND METHODS: The groups were consisted in need of combination therapy of tamsulosin, finasteride on benign prostatic hyperplasia, one had packaged both drugs together (Group A, n=30) and the other were individually packaged both agents (Group B, n=30). International Prostatic Symptom Score (IPSS) were checked on first, 4weeks, and 8weeks. The evaluation was carried out of medicine compliance by checking the number of drugs 4weeks-interval. which was every 4weeks during 8weeks. RESULTS: The properties other than the PSA in both groups, there was no statistically significant differences between patients. In first 4weeks, drug compliance of each Group A and B had tamsulosin 82.6%, 93.3% (p=0.033), finasteride 80.1%, 93.3% (p=0.042), and last 4weeks tamsulosin 80.6%, 93.7% (p=0.013), finasteride 79.5%, 93.7% (p=0.002) were checked. Group C, D had 81.4%, 96.4% (p=0.021) on 4weeks, 80.6%, 97.2% (p=0.011) on 8weeks. CONCLUSIONS: For co-administration of finasteride and tamsulosin are required in patients with benign prostatic hyperplasia, in order to enhance drug compliance, both tablets have to prescript together in one package to be taken at one time is useful.
Compliance ; Dosage Forms ; Finasteride* ; Humans ; Medication Adherence* ; Prostatic Hyperplasia* ; Tablets

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

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

Dosage Forms ; Drug Carriers ; Drug Delivery Systems ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Nanotechnology