Improving the safety efficacy ratio of existing drugs is a current challenge to be addressed rather than the development of novel drugs which involve much expense and time. The efficacy of drugs is affected by a number of factors such as their low aqueous solubility, unequal absorption along the gastrointestinal (GI) tract, risk of degradation in the acidic milieu of the stomach, low permeation of the drugs in the upper GI tract, systematic side effects, etc. This review aims to enlighten readers on the role of pH sensitive hydrogels in drug delivery, their mechanism of action, swelling, and drug release as a function of pH change along the GI tract. The basis for the selection of materials, their structural features, physical and chemical properties, the presence of ionic pendant groups, and the influence of their pKa and pKb values on the ionization, consequent swelling, and targeted drug release are also highlighted.

https://www.mdpi.com/2073-4360/9/4/137/pdf

pH Sensitive Hydrogels in Drug Delivery: Brief History, Properties, Swelling, and Release Mechanism, Material Selection and Applications

Renin and angiotensin

Chitosan/o-carboxymethyl chitosan nanoparticles for efficient and safe oral anticancer drug delivery: in vitro and in vivo evaluation.

The implications of recent advances in carboxymethyl chitosan based targeted drug delivery and tissue engineering applications.

Loading of anthocyanins on chitosan nanoparticles influences anthocyanin degradation in gastrointestinal fluids and stability in a beverage

Mucoadhesion is topic of current interest in the design of drug delivery system. Mucoadhesive microsphere exhibit a prolonged residence time at the site of application and facilitate an intimate contact with the underlying absorption surface and thus contribute to improved or better therapeutic performance of drug. Mucoadhesive drug delivery systems promises several advantages that arise from localization at a given target site, prolonged residence time at the site of drug absorption and an intensified contact with the mucosa increasing the drug concentration gradient. Hence, uptake and consequently bioavailability of the drug is increased and frequency of dosing reduced with the result that patient compliance is improved. In recent years such Mucoadhesive microspheres have been developed for oral, buccal, nasal, ocular, rectal and vaginal for either systemic or local effects. The principles underlying the development of Mucoadhesive microsphere and research work carried out on these systems are reviewed here.

Different methods of formulation and evaluation of mucoadhesive microsphere

pH sensitive polyelectrolyte complex of O-carboxymethyl chitosan and poly (acrylic acid) cross-linked with calcium for sustained delivery of acid susceptible drugs.

Novel sustained release drug delivery system: a review

Background: Most of floating systems have an inbuilt limitation of high variability in the gastric retention time, invariably affecting the bioavailability of drug. An oral sustained release system is formulated to increase gastric residence time by a different way like floating.Aim: The objective of present investigation was to prepare hollow microspheres of Rosiglitazone Maleate in order to increase its bioavailability and reduce the dose frequency.Method: Hollow microspheres of Rosiglitazone Maleate were prepared by O/W emulsion-solvent diffusion technique using biodegradable anionic acrylic resin as a polymer. A mixture of dichloromethane and ethanol (1:1) used as solvent system for drug and polymer with water containing polyvinyl alcohol and salt as external aqueous phase.Result: Entrapment efficiency of drug was increased upto 89.71% as a result of salting out effect. The morphology of Eudragit S100 based microspheres in comparison to Ethyl cellulose and hydroxy propyl methyl cellulose (HPMC) was fo...

Biodegradable anionic acrylic resin based hollow microspheres of moderately water soluble drug Rosiglitazone Maleate: preparation and in vitro characterization

The goal of all Pharmaceutical industry is to make a good quality product and for this it is necessary to allow In-Process Quality Control (IPQC) Approaches. In-process quality control tests are done before the manufacturing process is completed. The function of in-process controls is to monitor and if necessary, adaptation of the manufacturing process to achieve the required specification. This may incorporate control of equipment and environment too. In-process materials should be tested for their physical parameters and its quality attributes which are later approved or rejected by the quality control department. The reason of IPQC is to deliver a cumulative finished product by avoiding or eliminating mistakes at every stage in production. The objective of this study is the comparison of In-process quality control test of India Pharmacopoeia, British Pharmacopoeia and the United state Pharmacopoeia. It was observed from various studies that quality control tests for tablet and capsule listed in different pharmacopoeias   have slight similarities and differences

/pdf/comparative-study-of-in-process-and-finished-products-3giymvupfl.pdf

Nayan A Gujarathi

Papers

Different methods of formulation and evaluation of mucoadhesive microsphere

pH sensitive polyelectrolyte complex of O-carboxymethyl chitosan and poly (acrylic acid) cross-linked with calcium for sustained delivery of acid susceptible drugs.

Novel sustained release drug delivery system: a review

Biodegradable anionic acrylic resin based hollow microspheres of moderately water soluble drug Rosiglitazone Maleate: preparation and in vitro characterization

Comparative study of In-process and finished products quality control test for tablet and capsules according to pharmacopoeias