Rakesh Pahwa

Ciprofloxacin: review on developments in synthetic, analytical, and medicinal aspects

In the current practices of antiinfective therapy, ciprofloxacin is a very popular fluoroquinolone having a broad spectrum of activity and diverse therapeutic prospects. The reasons for its wide use include multiresistant pathogens susceptible only to ciprofloxacin. The available clinical evidence suggests the potentially enhanced efficacy of this drug in the treatment of various community acquired and nosocomial infections, e.g. respiratory tract, urinary tract, and skin infections and sexually transmitted diseases. As compared to other agents of its class, the pharmacokinetic profile of ciprofloxacin demonstrates equivalent or greater bioavailability, higher plasma concentrations, and increased tissue penetration, as reflected in the greater volume of distribution. Various molecular modifications of this drug have been made to further improve its characteristics. Several methods of analytical determination of ciprofloxacin and its metabolites in biological fluids employing various techniques have been reported. The present article is focused on the synthetic development, pharmacotherapeutic, and analytical evaluation vistas of ciprofloxacin.

Chitosan-based gastroretentive floating drug delivery technology: an updated review

Introduction: Gastroretentive floating drug delivery systems have emerged as efficient approaches for enhancing the bioavailability and controlled delivery of various therapeutic agents. Significant advancements exploiting chitosan have been made worldwide, in order to investigate these systems according to patient requirements, both in terms of therapeutic efficacy as well as patient compliance. Such systems precisely control the release rate of the target drug to a specific site, which facilitates an enormous impact on health care. Areas covered: Different novel strategies have been undertaken for the development of various gastric floating dosage forms utilizing chitosan as a promising excipient. The present paper is an earnest attempt to provide new insights on various physicochemical and biological characteristics of chitosan, along with its potential applications in a wide array of biomedical approaches. Numerous and significant research findings in the vistas of chitosan-based gastroretentive floating drug delivery technology are also discussed. Expert opinion: Chitosan has been considered as a unique and efficacious agent possessing a myriad spectrum of desired characteristics. It is emphasized that recent scientific advancements in the use of this excipient as a carrier will yield new generation gastroretentive drug delivery systems, with better pharmacotherapeutic interventions. Further studies are required to unveil the hidden beneficial properties of chitosan and its derivatives, to obtain newer delivery systems which may hold tremendous prospects in the near future.

Synthesis and evaluation of novel prodrugs of naproxen

A series of novel prodrugs of naproxen has been synthesized. Naproxen (1) was reacted with thionyl chloride to yield acid chloride (2) which was further reacted with glucose to form the glucosyl naproxen (3). Tetra-acetate of glucosyl naproxen was prepared and finally reacted with different amino acids to yield the title compounds. These compounds were evaluated for analgesic, anti-inflammatory activities, and for possible GI toxicity. Compound 5b depicted most potent analgesic activity with percentage inhibition of 98.15%. Compound 5a was found to be most potent anti-inflammatory agent with 76% inhibition. Compound 5n was second most active analgesic (92.26%) and anti-inflammatory (73%) agent. In vitro hydrolysis pattern of synthesized prodrugs was studied in phosphate buffer of pH 7.4 and acetate buffers of pH 3.0, 4.0, and 5.0, respectively. Selected compounds were evaluated for their ulcerogenic potential and all the tested derivatives were significantly less irritating to gastric mucosa than the parent drug.

Recent Advances in Gastric Floating Drug Delivery Technology: A Review

Gastric floating drug delivery systems have been an avenue of considerable interest in terms of their immense potential for better pharmacotherapeutic interventions along with site-specific absorption. These buoyant systems significantly enhance the bioavailability and controlled delivery of several drug molecules. Scientific investigators have also carried out substantial research endeavours worldwide in order to design a more systematic and intellectual floating systems. The present manuscript is an attempt to highlight numerous recent advancements in the design of gastric floating drug delivery systems along with various available commercial preparations. Salient applications, characterization aspects and future perspectives of these multifarious systems have also been addressed.

Recent Advances and Patent Perspectives in Gastroretentive Technology

Gastroretentive drug delivery technology has emerged as an efficient approach for enhancing the bioavailability and controlled delivery of various therapeutic molecules. Myriad of patents issued in the vistas of gastroretentive technology have inspired scientific community worldwide to develop more innovative strategies for the fabrication of drug delivery devices which can be retained in stomach for a controlled period of time. The present paper describes various recent efforts and technological advancements of gastroretentive drug delivery systems along with potential advantages and available marketed preparations. Numerous significant patents concerning gastroretentive drug delivery devices are also highlighted.

Insight into Prodrugs of Quinolones and Fluoroquinolones

Quinolones and fluoroquinolones are principal weapons against variety of bacterial infections and exert their antibacterial potential by interfering the activities of bacterial enzymes. As these agents are associated with some limitations, an important approach to overcome these major constraints is to prepare covalent derivatives, i.e. prodrugs. Prodrug design has been employed to improve the limitations of these drugs such as less aqueous solubility, poor absorption and distribution, toxicity, disagreeable taste, poor lipophilicity etc and for improving their pharmacological profile. This paper highlights the utility of various prodrug strategies in optimizing the therapeutic index of these antibacterial agents and their recent patents. Some of their prodrugs being utilized at preclinical and clinical levels have also been discussed. Hence, this paper has been prepared to present the significant findings of various research papers that would be helpful in motivating scientific researchers to forward the research in direction of utilization of prodrugs in clinical therapy.

Naproxen: An Update on Physicochemical, Analytical and Pharmacological Aspects

Naproxen is a propionic acid derivative related to the arylacetic acid group. This drug is one of the most popular non-steroidal anti-inflammatory agents. It is a non-selective cyclooxygenase inhibitor and is advocated for use in painful and inflammatory rheumatic and non-rheumatic conditions. In low risk patients, naproxen and ibuprofen may be the first choice agents because they are effective, well tolerated and inexpensive. Naproxen is rapidly and completely absorbed from the gastrointestinal tract with an in vivo bioavailability of 95% and elimination half-life is 12 to 17 h. It has a volume of distribution of 0.16 L/Kg and at therapeutic levels, it is more than 99% albumin-bound. Although introduced long back, several efforts have been done to develop its prodrugs and analytical procedures. The current article describes chemistry, pharmacology, pharmacokinetics, adverse effects, interactions and contraindications of naproxen. A special emphasis is laid on the review of recent literature of various prodrugs synthesized and analytical methods developed for determination of naproxen in pharmaceutical preparations.