In-vitro and in-vivo performance of locally manufactured glimepiride tablet generics compared to the innovator (Amaryl®) tablets

Both physicians and patients in Egypt often express concern as to the clinical efficacy of locally manufactured glimepiride tablet generics whenever adequate control of blood sugar is not achieved with these products. The present study addresses this issue. The pharmaceutical quality of four glimepiride 3 mg tablet generics purchased in Egypt from local pharmacies was assessed relative to the innovator product (Amaryl^®), 3 mg tablets. Uniformity of Content, dissolution rate, disintegration time and hardness were determined. Products were subjected to a 6-month stability study under stress condition (40 °c/75%RH). The same brands were evaluated in vivo in a clinical study conducted in the Main Alexandria University Hospital involving 100 patients (20 patients per brand including innovator). Patients recruited were newly diagnosed type II diabetics. Glimepiride tablets were used as a monotherapy. Fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1C) were measured over a period of 3 months. The results indicated differences (p ≤ .05) in the in vitro and in vivo performance of the tested products; innovator and tested generics substitution was not evident. The stability study indicated that the tablets were prone to deterioration in their physical characteristics, particularly dissolution profiles, upon storage of blisters in a hot humid climate. In vitro/in vivo correlations were investigated seeking to identify an in vitro test to serve as a performance indicator for glimepiride tablets in the post-marketing period. The similarity factor (f₂) of the dissolution data proved to be a good indicator of in vivo performance of the tablets.

Real-Time Analysis of Tenofovir Release Kinetics Using Quantitative Phosphorus (31P) Nuclear Magnetic Resonance Spectroscopy

The dialysis method is classically used for drug separation before analysis, but does not provide direct and real-time drug quantification and has limitations affecting the dialysis rate. In this study, a phosphorus nuclear magnetic resonance (³¹P-qNMR) method is developed for the real-time quantification of therapeutic molecules in vitro. The release kinetics of model drug, tenofovir (anti-HIV microbicide), was analyzed in vaginal fluid simulant (VFS), seminal fluid simulant (SFS), and human plasma (HP) from chitosan nanofibers (size ∼100-200 nm) using the NMR (direct) method and compared with dialysis/UV-Vis (indirect) method. The assay was linear in VFS/SFS (0.20-5.0 mM), HP (0.30-5.0 mM of drug concentration range) and specific no drug ³¹P-qNMR chemical shift [∼15 ppm] interference with formulation/media components. Limit of detection values were 0.075/0.10/0.20 mM, whereas limit of quantification values were 0.20/0.20/0.30 mM in VFS/SFS/HP, respectively. The method was robust, precise (%RSE <2%), and accurate (%mean recovery 90%-110%). After 12 h, ∼77%/72%/70% wt/wt of tenofovir release was observed with direct, compared to ∼47%/52%/52% wt/wt by indirect method in VFS/SFS/HP, respectively. Approximately 20% decrease in %drug release observed with dialysis method suggested an interference with drug transport process due to the dialysis membrane and the Gibbs-Donnan effect. Overall, ³¹P-qNMR provides more accurate, real-time, and direct drug quantification for effective in vitro-in vivo correlation.

Key Considerations in Designing Oral Drug Delivery Systems for Dogs

The present review discusses the pharmaceutical impact of the anatomy and physiology of the canine gastrointestinal tract to provide a comprehensive guide to the theories and challenges associated with the development of oral drug delivery systems for dogs. Novel pharmaceutical technologies applied to veterinary drugs are discussed indicating the advantages and benefits for animals. There are currently immense research and development efforts being funneled into novel canine health products. Such products are being used to overcome limitations of drugs that display site-dependent absorption or possess poor biopharmaceutical properties. Techniques that are employed to increase bioavailability of the Biopharmaceutics Classification System class II drugs are discussed in this article. Furthermore, an overview of palatable oral formulations for dog care is provided as an approach to easy administration. In vitro and in vivo evaluation and correlation of oral drug formulations in dogs are also addressed. This article assesses the outlook of canine oral drug development recognizing substantial growth forecasts of the dog care market.

Bad Science: Cause and Consequence

Scientific progress is dependent on accumulation of quality data with appropriate data analysis. Unfortunately, there are a troubling number of accounts describing an inability to replicate published work. Some explanations are lack of access to proprietary reagents and equipment, or lack of expertise and know how. However, it is clear that there are many publications that are fatally flawed, and it is difficult to ascertain which ones they are, but there are clues. Many articles are improperly controlled, resulting in false-positive or -negative results. Reagents and procedures are used without verifying their specificity. There is also confirmation bias, a tendency to seek and find conclusions that we like, which is exacerbated by faithful acceptance by readers of the publication record without assessment of merit. These and other issues have slowed progress, resulted in waste of scarce funds, and even put patients at risk when clinical decisions are made according to flawed data. Solving these and related problems requires recognition of the problem and better training. We also need to take personal responsibility for not only our own work, but also for the accuracy of information in the scientific domain.