Development and Comprehensive Characteristics of Thermosensitive Liquid Suppositories of Metoprolol Based on Poly(lactide-co-glycolide) Nanoparticles.

Thermosensitive liquid suppositories (LSs) carrying the model antihypertensive drug metoprolol tartrate (MT) were developed and evaluated. The fundamental purpose of this work was to produce, for the first time, liquid MT suppositories based on biodegradable nanoparticles and optimize their rheological and mechanical properties for prospective rectal administration. The nanoparticle system was based on a biodegradable copolymer synthesized by ring opening polymerization (ROP) of glycolide (GL) and L,L-lactide (LLA). Biodegradable nanoparticles loaded with the model drug were produced by the o/o method at the first stage of the investigation. Depending on the concentration of the drug in the sample, from 66 to 91% of MT was released over 12 h, according to first-order kinetics. Then, thermosensitive LSs with MT-loaded biodegradable nanoparticles were obtained by a cold method and their mechanical and rheological properties were evaluated. To adjust the thermogelling and mucoadhesive properties for rectal administration, the amounts of major formulation components such as poloxamers (P407, P188), Tween 80, hydroxypropylcellulose (HPC), polyvinylpyrrolidone (PVP), and sodium alginate were optimized. The in vitro release results revealed that more than 80% of the MT was released after 12 h, following also first-order kinetics. It was discovered that the diffusion process was dominant. The drug release profile was mainly governed by the rheological and mechanical properties of the developed formulation. Such a novel, thermosensitive formulation might be an effective alternative to hypertension treatment, particularly for unconscious patients, patients with mental illnesses, geriatric patients, and children.

Current state of the polymeric delivery systems of fluoroquinolones - A review.

Recently, growing interest in polymers (natural and synthetic) as drug carriers in controlled release formulations and drug targeting systems that may improve the efficacy of treatment and reduce the side effects of a drug therapy, has been observed. Special attention has been paid to improving the effectiveness of antibiotics, which constitute a very important, often life-saving group of drugs. In this paper, we review polymers as macromolecular carriers of fluoroquinolones, a group of antibiotics with a broad spectrum of activity. We consider both physical intermixtures and chemical conjugates, although we discuss in greater depth the latter type of coupling, in which covalent bonds between drug molecules and polymers occur.

Determination of tropicamide and its major impurity in raw material by the HPLC-DAD analysis and identification of this impurity using the off-line HPLC-FT-IR coupling.

This study presents TLC, HPLC-DAD and HPLC-FT-IR analyses concerning the detection, identification and determination of organic impurities of commercial tropicamide ((R,S)-N-ethyl-3-hydroxy-2-phenyl-N-(4-pyridylmethyl)propanamide) as a medical substance designed for the production of eye drops. In the examined samples from several random production batches, only one impurity (defined by Ph. Eur. 6th Ed.) was discovered in the amount sufficient for the quantitative analysis. On the basis of comparison of retention times, UV and IR spectra of the impurity and its synthesized standard, this impurity was identified as apotropicamide (N-ethyl-2-phenyl-N-(4-pyridylmethyl)prop-2-enamide). For the chemical identification of organic compounds occurring in the tropicamide samples, an off-line coupling of HPLC with FT-IR was used. The structure of a standard of apotropicamide was confirmed by (1)H NMR and (13)C NMR analysis. Validation of the HPLC-DAD method of determination both tropicamide and apotropicamide in the tropicamide medical substance was performed. This method is suitable for use in the quality control of tropicamide during its production.