The most common instability problem of gelatin capsules arises from negative impact of extremes of temperature and especially atmospheric relative humidity on the mechanical integrity of the capsule shells with adverse effect extended even to the fill material. Moreover, choice of fill materials is highly restricted either due to their specific chemical structure, physical state or hygroscopicity. Additional reports of unpredictable disintegration and dissolution of filled hard gelatin capsules in experimental studies have prompted the search for a better alternative capsule shell material. The present review aims to provide an overview on the physicochemical, pharmaceutical and biopharmaceutical properties of hydroxypropyl methylcellulose (HPMC) as capsule shell material and perform comparative evaluation of HPMC and gelatin in terms of in vitro/in vivo performance and storage stability. HPMC capsule provides a highly flexible and widely acceptable platform capable of solving numerous challenges currently facing the pharmaceutical and nutraceutical industries and expands the possibilities for selection of different types of fill materials. The current topic introduces a new section on influence of various factors on in vitro dissolution of HPMC capsules. Delayed in vitro disintegration/dissolution of HPMC capsules in aqueous medium does not produce any negative effect in vivo. However, advancements in the processes of production and filling of HPMC capsule shells and detailed studies on effects of various parameters on their in vitro/in vivo dissolution would establish their supremacy over hard gelatin capsules in future.

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Marine environment with rich biodiversity offer unlimited choice for novel biopolymers. Sulfated polysaccharides isolated from marine algae and bacteria constitute an important group in the marinederived biomolecules and biopolymers. They possess unique structural features which can be exploited to their fullest potential in the development of new therapeutic molecules, design of nanocarriers and stimuli-responsive drug delivery systems, development of anti-aging and moisturizing creams and as molecular probes in diagnosis of cancers and cardiovascular diseases. The aim of the present review is to highlight the sources, characteristics and applications of sulfated polysaccharides and exopolysaccharides isolated from marine algae, cyanobacteria, extremophilic and halophilic bacteria. Detailed description of physicochemical properties and versatile applications of ulvan, fucoidan, galactofucan sulfate, laminarin, mauran, cyanobacterial exopolysaccharides and other lesser known exopolysaccharides of marine bacterial origin has been provided. In a nutshell, it can be concluded that sustainable exploitation of the renewable, diverse library of these unique and novel sulfated polysaccharides will unravel newer possibilities in future and will enrich the existing arsenal of biopolymers.

Topical hydrogel preparations are applied on skin to obtain local or systemic action. NSAID's are non-steroidal drugs having excellent anti-inflammatory and analgesic activity but it produces GIT ulceration when used orally. To overcome that problem with oral formulations, many NSAID's are preferred to be administered by topical route. The present investigation is aimed to formulate the hydrogel of Diclofenac potassium with different ratio of Carbopol of different grades along with guar gum for application over the skin. Fourier transform Infrared (FT-IR) spectrophotometer has been used to notice drug -polymer interaction. After getting satisfactory combinations of polymers, hydrogel formulations of Diclofenac potassium were subjected to different physicochemical studies. Evaluation tests for visual appearance, pH, viscosity, spreadability, swelling index etc. were found satisfactory. To investigate the drug permeation kinetics and permeability coefficient from the goat abdominal skin, pieces of goat skin were fixed on the Franz diffusion cell, in a way that the upper surface of abdominal skin faced the donor chamber. The experiment was carried out with 2 gm of the drug loaded hydrogel spreaded on the skin surface at 32 o C in phosphate buffer pH-5.8. A distinct correlation between % swelling index and permeability coefficient of the formulations through goat abdominal skin has been observed. With increase in % swelling index over a period of 8 h the permeability coefficient decreased. It indicates that swelling of hydrogel forms a sticky, gelatinous mass that retards the permeation of Diclofenac potassium through goat abdominal skin. There are significant co relations between viscosity of hydrogel, % swelling index and permeation coefficient. It has been found that with increase in viscosity, permeability coefficient increased whereas permeability coefficient of drug decreased with increase in % swelling index of the formulations.

Objective: The objective of the present investigation was to develop olive and soybean oil-based oleogels with Span 40 and/or Tween 80 (as gelator and/or surfactant) and determine the critical gelator concentration (CGC), characterise and compare the rheological, thermal properties and drug release profile of the gels formed for topical delivery. Methods: Olive and soybean oil-based Span 40 and Span 40/Tween 80 oleogel formulations were prepared by solid fiber mechanism and subjected to organoleptic evaluation, FT-IR spectroscopy, thermal analysis, rheological study, kinetic modeling of gelation and drug release. Results: The critical gelator (Span 40) concentration was found to be lower for olive oil (12% w/v) and depend on the type of oil. Tween 80 reduced CGC of soybean oleogels only. Soybean oil-based oleogel containing 18% w/v Span 40 was found to form more flexible, less viscous and thermally less stable formulation with better release of paracetamol as evident from lower melt flow index, Tg value, lower β and higher α value compared to olive oil-based oleogel with 12% w/v Span 40 (CGC). Surfactant addition can be assumed to modify the microarchitecture of the oleogels to a great extent to produce more flexible and thermally stable gels with even better drug release profile. Span-Tween based soybean oleogel formed a gel-matrix whereas matrix in olive oil-based oleogels containing Span only became slightly flexible to release the drug in zero-order fashion on the addition of surfactant cogelator. Conclusion: Nature of oil exerts profound influence on the rheological, thermal and release profile of oleogels containing Span 40 as gelator and/or Tween 80 as surfactant cogelator.

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Sulfated polysaccharides extracted from marine algae and bacteria constitute an important class of biomacromolecules as they are characterized by biocompatibility, biodegradability and low immunogenicity. Recent advances in bionanotechnology are attributed to identification of marine sulfated polysaccharides of unique composition and functional properties. Promising results obtained so far justify the need for additional research in the study of absorption, distribution, metabolism and elimination (ADME) of these novel biopolymer-based nanomaterials in human body after administration by oral or parenteral route for therapeutic or diagnostic purpose. In vitro enzymatic degradation pathways should be investigated in order to yield commercially valuable oligomers. The goal of the present review is to enlighten on the ADME, cytotoxicity and in vitro enzymatic degradation of three marine sulfated polysaccharides, fucoidan, ulvan and mauran, obtained from brown seaweeds or macroalgae in the class of Phaeophyceae, members of Ulvales (green algae) and halophilic bacteria, respectively. They are presently being exploited in fabrication of nanoplatforms with novel applications in the field of controlled drug delivery, tissue regeneration scaffolds, cancer therapy, and bioimaging. However, significant research still needs to be carried out to characterize ADME of mauran and to improve production of the biopolymers on a large scale in order to find out clinically relevant solutions to establish these sulfated polysachharide-based nanotools as novel bionanotechnology strategies in future.

Plant pectin constitutes an important class of naturally occurring polysaccharides and are widely distributed in various fruits and vegetables consumed on a regular basis. These biomolecules are reported to exhibit a vast array of biological activities including effects on digestive system, chemopreventive effect in colon cancer, regulation of blood cholesterol level and immune-potentiating effects. However, variation in spectrum of activity and efficacy occurs due to different sources of pectin and also different methods of extraction. Pectin modification by pH treatment, change in temperature or enzymatic modification methods can ensure derivatives with variable but defined degrees of esterification, customized physicochemical properties and improved pharmacological and therapeutic profile, mainly in cancer prevention and management. Pharmaceutical utility of plant pectin is attributed to the unique rheological behavior and gelling properties in aqueous medium and have been successfully employed in development of colon specific sustained release drug delivery systems and edible pectin films with stabilizing effect on entrapped labile molecules. The goal of the review article is to focus on the therapeutic and pharmaceutical benefits of native and modified pectin. Although, several milestones towards understanding the process of pectin modification have been established, most of the data generated till date are obtained from in vitro studies or on commercial varieties of modified pectin. Complete characterization of structure-activity relationships of modified pectin, wellplanned in vivo investigations and optimization of pectin-based scaffolds for controlled and targeted drug delivery in oncotherapy are yet to be ascertained for enhancing the marketing potential of these renewable plant-derived biopolymers.