• Macromolecular Research
• /
• v.11 no.4
• /
• pp.207-223
• /
• 2003

For last five years, we are developing the novel local drug delivery devices using biodegradable polymers, especially polylactide (PLA) and poly(D,L-lactide-co-glycolide) (PLGA) due to its relatively good biocompatibility, easily controlled biodegradability, good processability and only FDA approved synthetic degradable polymers. The relationship between various kinds of drug [water soluble small molecule drugs: gentamicin sulfate (GS), fentanyl citrate (FC), BCNU, azidothymidine (AZT), pamidronate (ADP), $1,25(OH)_2$ vitamin $D_3$, water insoluble small molecule drugs: fentanyl, ipriflavone (IP) and nifedipine, and water soluble large peptide molecule drug: nerve growth factor (NGF), and Japanese encephalitis virus (JEV)], different types of geometrical devices [microspheres (MSs), microcapsule, nanoparticle, wafers, pellet, beads, multiple-layered beads, implants, fiber, scaffolds, and films], and pharmacological activity are proposed and discussed for the application of pharmaceutics and tissue engineering. Also, local drug delivery devices proposed in this work are introduced in view of preparation method, drug release behavior, biocompatibility, pharmacological effect, and animal studies. In conclusion, we can control the drug release profiles varying with the preparation, formulation and geometrical parameters. Moreover, any types of drug were successfully applicable to achieve linear sustained release from short period ($1{\sim}3$ days) to long period (over 2 months). It is very important to design a suitable formulation for the wanting period of bioactive molecules loaded in biodegradable polymers for the local delivery of drug. The drug release is affected by many factors such as hydrophilicity of drug, electric charge of drug, drug loading amount, polymer molecular weight, the monomer composition, the size of implants, the applied fabrication techniques, and so on. It is well known that the commercialization of new drug needs a lot of cost of money (average: over 10 million US dollar per one drug) and time (average: above 9 years) whereas the development of DDS and high effective generic drug might be need relatively low investment with a short time period. Also, one core technology of DDS can be applicable to many drugs for the market needs. From these reasons, the DDS research on potent generic drugs might be suitable for less risk and high return.

• YAKHAK HOEJI
• /
• v.51 no.6
• /
• pp.440-446
• /
• 2007

Arcabose is a competitive inhibitor of the intestinal ${\alpha}$-glucosidases and reduces the postprandial digestion and absorption of carbohydrate and disaccharides. Due to its negligible oral absorption, measuring drug concentration in the plasma is impractical. Thus, the common pharmacokinetic study is not available to determine the bioequivalence of the generic acarbose preparations. The aim of this study is the establishment of pharmacodynamic assessment method for the bioequivalence test of the generic acarbose preparations. Placebo-controlled cross-over ($3{\times}3$) clinical study was conducted in 23 healthy volunteers. Volunteers received a single oral dose of placebo, reference drug ($Glucoby^{(R)}$ 100 mg, Lot # D043) or test drug ($Glucoby^{(R)}$ 100 mg, Lot # E005) just before breakfast, then blood samples for evaluation of serum glucose and insulin levels were taken during for 4 hours. $C_{max},\;AUC_{0-2},\;AUC_{0-4},\;{\Delta}C_{max},\;{\Delta}AUC_{0-2}\;and\;{\Delta}AUC_{0-4}$ of the postprandial plasma glucose level significantly decreased when a single dose of acarbose 100 mg preparations was administered. However, any significant difference was not detected between the groups taken the reference drug and the test drug. These results proposed that the pharmacodynamic protocols of this study is suitable to use for bioequivalence test of acarbose preparations. On the basis of the results of this study and the data of literature on this subject, the standard protocols of bioequivalence study of acarbose preparation are proposed.

• Korean Journal of Clinical Pharmacy
• /
• v.16 no.2
• /
• pp.147-154
• /
• 2006

Drugs are often taken together with meals and there are numerous opportunity for food-drug interaction to occure. Food-drug interactions and their clinical consequences are very complex indeed. The composition of the meal, and the volume of fluid that is ingested often are decisive factors in food-drug interactions. Various formulations of a specific drug may behave differently. Solutions and suspensions seem to be less susceptible and enteric-coated preparations are more susceptible, to food interactions than are other dosage forms but exceptions to this rule do exist. Furthermore, generic and environmental factors, disease and other drugs cause considerable inter- and intraindividual variation in food-drug interactions. Also, eating habits are dissimilar in different parts of the world, and diets often vary greatly from day to day. The taking of drugs together with meals offers some obvious benefits. It may help to reduce gastrointestinal irritation and compliance is improved. On the other hand, in some cases food interferes seriously with drug absorption. The purpose of this review is to clarify the complexity of food-drug interactions, and to discuss interactions that may be of clinical importance.

• Journal of Korean Institute of Industrial Engineers
• /
• v.39 no.5
• /
• pp.403-411
• /
• 2013

The quality of the products/processes has been improved remarkably since robust design (RD) methodology is applied into the practice manufacturing processes. A model building method based on the dual responses methods for multiple and time oriented responses on a drug development process is employed in this paper instead of the previous methods that handle the static nature of data and single response. Subsequently, the optimal solutions of a multiple and time series RD problem are obtained by using the proposed augmented weighted Tchebycheff method that has a significant flexibility on assigning weights. Finally, a pharmaceutical case study associated with a generic drug development process is conducted in order to illustrate the efficient optimal solutions from the proposed model.

• The Korean Society of Law and Medicine
• /
• v.22 no.1
• /
• pp.91-124
• /
• 2021

In May 2019, the Ministry of Food and Drug Safety revised the "Pharmaceutical Determination and Adjustment Criteria" with the content of differentially calculating the price of generic drugs according to the registration of the drug substance and meeting the requirements for their own bioequivalence test. According to this revised rule, if their own bioequivalence test is not conducted, even the generic drugs that have already been approved would be lowered in price. I wondered whether this system was introduced with sufficient public legal considerations regarding its legislative purposes and means. Therefore, I reviewed the contents of the revised notice based on whether or not it is valid to determine and adjust the price of generic drugs in terms of the legitimacy of legislative purposes and the proportionality principle after introducing the history and background of the rule. First, I raised a question as to whether the purpose of preventing the overrun of generic drugs is indeed legitimate in terms of the legitimacy of the purpose. In order for the revised notice of "reduction of drug prices when the test requirements are not met," to meet the conformity principle, the premise that it is difficult to recognize safety and effectiveness through consignment (joint) bioequivalence test or that these tests are insufficient in safety and efficacy verification than their own test must be established. Nevertheless, it seems that suffficient review has not been carried out. In order to achieve the purpose of securing safety and effectiveness, the focus should be on 'reinforcement of the standards for bioequivalence test and the management of the bioequivalence test itself' rather than whether it is a their own test or a consignment (joint) test. Third, it is contrary to the necessity and substantiality principle that strict standards are uniformly applied to the products that can be considered to have been sufficiently verified for safety and effectiveness after a considerable period of time has passed after the product approval. In many cases, revised administrative legislations quickly enacted and amended in the state of lack of legal review or consensus, while the regulatory effects resulting from it are quite direct and specific to the regulated person. In this respect, I emphasized that the administrative legislative process also requires substantial review and prior control of the regulatory purposes and means, and that the participation of stakeholders in the legislative procedure is to be strengthened.

• The Journal of Asian Finance, Economics and Business
• /
• v.5 no.2
• /
• pp.105-118
• /
• 2018

Generic medicine (GM), which is an alternative drug product for branded medicine (BM), is used less in Japan than in other OECD countries. Therefore, we investigate why the medical consumers of Japan avoid the use of GMs even though the efficacy and safety of the medicines have already been proven. We theorize that effectiveness or risk of GMs are related to the consumer attitude toward GMs is affected by the behavioral approach/activation system (BAS) which promotes actions to reach the desired state, and the behavioral inhibition system (BIS) which suppresses behaviors to avoid negative outcomes. To see which of the BAS and BIS dimensions are related to GM usage, we surveyed 374 Japanese consumers and found that Quality, Efficacy, Safety, & Cost-effectiveness with the BAS, and Functional Risk, Financial Risk, Social Risk, Physical Risk, Psychological Risk, & Time Risk with the BIS had a significant effect on consumer attitude to GMs. These results are important in that they 1), confirm the role of BAS/BIS in attitudes to GMs, 2), provide guidelines when marketing GMs, 3), help governments promote the use of GMs as a cost-saving measure, and 4), guide future surveys regarding consumer attitudes to GMs.

• Journal of Pharmaceutical Investigation
• /
• v.35 no.6
• /
• pp.471-481
• /
• 2005

In Korea, generic drug and bioequivalence test are the hot issues since a new medical system of separation of dispensary from medical practice was started in 2000. The KFDA(Korea FDA) had revised several times ${\ulcorner}Guidance\;for\;bioequivalence\;test{\lrcorner}$. In vitro dissolution test has been extensively used as a quality control tool for solid oral dosage forms. In an effort to minimize unnecessary human testing, in vitro/in vivo correlations (IVIVC) between in vitro dissolution and in vivo bioavailability are increasingly becoming an integral part on extended release drug product development. The recently published US guidance, ${\ulcorner}Extended\;release\;oral\;dosage\;forms\;:\;development,\;evaluation,\;and\;application\;of\;in\;vitro/in\;vivo\;correlations{\lrcorner}$ will be helpful for us to make our own guideline.

• Communications for Statistical Applications and Methods
• /
• v.5 no.2
• /
• pp.491-501
• /
• 1998

Motivated by bioequivalence studies which involve comparisons of pharmaceutically equivalent dosage forms, we propose a more general decision rule for showing equivalence simultaneously between multiple means and a control mean. Namely, this testing procedure is concerned with the situation in that one must make decisions as to the bioequivalence of an original drug product and several generic formulations of that drug. This general test is developed by considering a spherical confidence region, which is a direct extension of the usual t-based confidence interval rule formally approved by the U.S. Food and Drug Administration. We characterize the test by the probability of rejection curves and assess its performance via Monte-Carlo simulation. Since the manufacturer's main concern is the proper choice of sample sizes, we provide optimal sample sizes from the Monte-Carlo simulation results. We also consider an application of the generalized equivalence test to a repeated measures design.

• The Korean Journal of Applied Statistics
• /
• v.24 no.3
• /
• pp.495-503
• /
• 2011

When a patent of an innovative (brand-name) small-molecule drug expires, generic copies of the innovative drug may be marketed if their therapeutic equivalence to the innovative drug has been shown. The small-molecule drugs are considered therapeutically equivalent and can be used interchangeably if two drugs are shown to be pharmaceutically equivalent with identical active substance and bioequivalent with comparable pharmacokinetics in a crossover clinical trial. However, the therapeutic equivalence paradigm cannot be applied to biosimilars since the active ingredients of biosimilars are huge molecules with complex and heterogeneous structures, and these molecules are difficult to replicate in every detail. The European Medicine Agency(EMEA) has introduced a regulatory biosimilar pathway which mandates clinical trials to show therapeutic equivalence. In this paper, we discuss statistical considerations in the design and analysis of biosimilar cancer clinical trials.

• Communications for Statistical Applications and Methods
• /
• v.27 no.6
• /
• pp.641-647
• /
• 2020

The 2 × 3 crossover design, a modified version of the 3 × 3 crossover design, is considered to compare the bioavailability of two generic candidates with a reference drug. The 2 × 3 crossover design is more economically favorable due to decrease in the number of sequences, rather than conducting a 3×3 crossover trial or two separate 2 × 2 crossover trials. However, when using a higher-order crossover trial, the risk of drop-outs and withdrawals of subjects increases, so the suitable statistical inferences for missing data is needed. The bioequivalence model of a of 2×3 crossover trial with missing data is defined and the statistical procedures of assessing bioequivalence is proposed. An illustrated example of the 2 × 3 trial with missing data is also presented with discussion.