K. Jayaram Kumar

Isolation and physicochemical characterization of sustained releasing starches from Dioscorea of Jharkhand

Starches were isolated from varieties of Dioscorea (Da1, Da2) grown in Jharkhand state of India and it was characterized in terms of moisture, ash, amylose content, bulk density, tapped density, true density, porosity, Carrs index, Hausners ratio, swelling power, solubility, water holding capacity, paste clarity. Morphological, thermal and IR spectroscopic studies were also done to characterize the isolated starch. The shape and size of starch granules were round/oval to ellipsoid and 5-10μm. There were considerable differences in powder characteristics, amylose content, ash values, and water holding capacity, swelling and solubility power. Starch from variety Da2 showed high enthalpy of gelatinization temperature as compared to variety Da1. Peaks in FTIR spectra of both starches revealed its carbohydrate nature. In vitro studies revealed that both the starches from Da1 and Da2 can be used in developing sustained release formulations. The result showed that starches from both Dioscorea can be used in pharmaceutical industries as excipients with minimal modifications.

Different approaches of katira gum formulations for colon targeting.

The objective of the study is to compare the different formulations prepared by using gum, grafted gum and hydrogel of katira as a carrier for colon-specific drug delivery using in vitro methods with and without enzymes. Katira gum is naturally occurring polysaccharides containing mainly l-rhamnose and d-galactose sugar unit and small percent of d-galactouronic acid. Compared to grafted gum and hydrogel, all proportions of katira gum protect the drug from being released completely in the physiological environment of the stomach and small intestine. In vitro release studies in enzymes (Pectinex Ultra SP-L having galactouronidase activity) have demonstrated the susceptibility of katira gum to the colonic bacterial enzyme (galactouronidase activity from Pectinex Ultra SP-L) with a consequent drug release. It illustrates that katira gum, a natural polysaccharide may be suitable as a carrier for colon targeting.

Studies on water soluble polysaccharides from Pithecellobium dulce (Roxb.) Benth. seeds

In this existing experimental work, water soluble PDP polysaccharides were secluded from Pithecellobium dulce (Roxb.) Benth. seeds. The physicochemical properties were analyzed in terms of swelling power, solubility, pH and water holding capacity. Micromeretic studies proved the polysaccharide may be used a potential pharmaceutical adjuvant. The polysaccharide was characterized by FT-IR, SEM, TGA and NMR techniques. Methylation analysis confirmed that the polysaccharide is composed of Arabinose (Araf) units. The chemical shifts of anomeric proton region were found in the region of 4.4-5.5ppm. Thermogravimetric analysis showed that PDP polysaccharide was thermally stable. The in vitro antioxidant capacities of the polysaccharide were investigated in terms of scavenging of hydroxyl radicals, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radicals, hydrogen peroxide (H2O2) and reducing power assay. The polysaccharide fractions showed activity in a concentration dependent manner which was comparable to the standard, ascorbic acid.

Isolation and release characteristics of starch from the rhizome of Indian Palo

The objective of the present study was to isolate and evaluate the morphological, physicochemical and drug release properties of starch from the rhizome of Indian Palo (Curcuma angustifolia Roxb.). Morphological study revealed that the shape of the isolated starch varied from oval to elliptical. Isolated starch showed high water-holding capacity. Mineral content and Ash value were found to be very low. Amylose content was found to be 12.12 ± 0.01%. FTIR data confirmed polysaccharide nature of the starch. Swelling and solubility was found to be increase with an increase in the temperature. Initially, paste clarity was high, and gradually it decreased with the increase of storage time. TGA showed that the starch is thermally stable up to 250 °C. In-vitro release study revealed that the starch retarded the release of drug in the acidic pH of the stomach; therefore, it can be used as an excipient in a sustained-release formulation.

Synthesis, characterization and evaluation of release retardant modified starches of Lagenaria siceraria seeds.

Starch isolated from under-utilized seeds of five different cultivars of Lagenaria siceraria (Mol.) standley (Cucurbitaceae) was carboxymethylated. The influence of the degree of substitution (DS) on physicochemical properties and drug release properties of starches was studied. The physicochemical profiles of the derivatives were assessed by means of FT-IR, XRD, SEM, elemental analysis, reaction efficiency, water binding capacity, swelling power, powder characteristics and visual estimation. The highest values of the DS obtained when the carboxymethylation was performed at 45 °C for 4h. Scanning electron microscopy (SEM) showed that after carboxymethylation, the granular appearance of the native starch was distorted. The new bands at 1576.87 cm(-1) and 1423.81 cm(-1) in Fourier transform infrared (FT-IR) indicated that the starch granules were substituted. Wide-angle X-ray diffractometry revealed that crystallinity was reduced significantly after carboxymethylation. Powder studies revealed that these starches possess potential for pharmaceutical applications. The matrix tablets were found to release the drug by Korsmeyer and Peppas kinetics. The carboxymethylated starches with high DS can be used as a drug release retardant in sustained release formulations, as the drug dissolution rate of native starches was significantly lower than the modified starches.

Physicochemical and release kinetics of natural and retrograded starch of Indian palmyrah shoots.

Starch was isolated from the shoots of Indian palmyrah (Borassus flabellifer L.) and it was subjected to the process of retrogradation. The influence of retrogradation on morphological, physicochemical and drug release properties was studied. Retrogradation of native starch changed its morphology from oval, elliptical to crystalline rods. Due to retrogradation there is an increase in amylose content and better hydration capacity, swelling and solubility power. The micromeritic properties of native and retrograded starch uncover its usage as excipients in tablet manufacturing. The retrograded starch showed better powder characteristics to that of native starch. The characteristic peaks for d-glucopyranosyl ring confirms the carbohydrate nature of starch. The TGA data reveals that the retrograded starch shows less bound water to that of native starch during the first decomposition step. In-vitro release study reveals that the retrograded starch attained a better release retardant property and was best explained by Hixson-Crowell model. The result showed that retrograded starches can be used for the preparation of sustained release tablets.

Isolation and partial characterization of delayed releasing starches of Colocasia species from Jharkhand, India.

There is an increasing interest in starch manufactured from edible tubers for controlled delivery of drug. Starches of different cultivars of Colocasia from Jharkhand, North Eastern State of India, were isolated and their morphological, physicochemical, structural properties were studied. The yield of starches was estimated in the range of 6.46-13.75%. All the isolated starches revealed their irregular shape with a diameter of 5-10 μm. There was considerable variation in amylose content, swelling and solubility power, water hydration capacity. FTIR spectra confirmed their carbohydrate nature. Powder studies revealed that these starches possess potential for pharmaceutical industries. In vitro release data revealed the delayed release of all tablets made by using Colocasia starches at pH 6.8 and 7.4 when compared with maize starch. Delayed release of all starches showed there is a great potential to be used these starches as pharmaceutical excipient in sustained release dosage form with minimum modification.

Effect of carboxymethylation on physicochemical and release characteristics of Indian Palo starch

Limited application of native starch has created the interest in the modification of starch to extend its asset for pharmaceutical application. An effort has been made to study the influence of carboxymethylation on morphological, physicochemical and drug release properties of wild Indian Palo (Curcuma angustifolia) starch. Carboxymethyl starches of different degree of substitution (0.046-0.256) were prepared using varying amount of monochloroacetic acid. The characteristic peaks at around 1600cm(-1) confirmed the carboxymethylation of starch. Morphological studies showed that porous structure formed on the surface of the starch granules and degree of deformity was found to be increased with the increment in the degree of substitution. Amylose content was decreased with the increase in degree of substitution. The TGA data showed that the carboxymethyl starches were thermally stable. Swelling and solubility power was found to be improved with the increase in the temperature. Micromeritic properties of carboxymethyl starches proved its usefulness as excipients in tablet manufacturing. Release profile of paracetamol was found to be decreased with the increase in the degree of substitution, and this proves the suitability of carboxymethyl Indian Palo starch in sustained-release tablets.

Physicochemical properties and release characteristics of starches from seeds of Indian Shahi Litchi

Many conventional sources of starches are from staple foods. Non-conventional and cheap sources of starch are being explored. Starch was isolated from Shahi Litchi seeds using two extraction media; acidic (citric acid 0.3%, w/w; LC) and alkaline (NaOH 0.5%, w/w; LN). Each starch was investigated for various properties such as structural, morphological and functional. The percentage yield of LN and LC was 11% and 12.6%, respectively. Morphological properties of both starches show same structural makeup, but compound granules were in LN starch. Moisture content, amylose content was found to be higher LC starch than in LN starch, which indicates that extraction media affects the properties of starch. FTIR confirmed the carbohydrate nature of the both isolated starches. TGA data of both starches reveal slight difference in stability with temperature. In vitro release of both starches shows the release up to 58.95±0.04% and 67.184±0.07% in 5h for LN and LC, respectively, that indicates that these starches can be used in delayed drug delivery and targeting drugs to the colon.

Physicochemical and release properties of carboxymethylated starches of Dioscorea from Jharkhand

Increasing demand and considerable attention to the non-conventional sources of starches leads to explore new sources. Starches of Dioscorea (Da1 and Da2) from Jharkhand, North Eastern region of India have been studied for its physicochemical properties. An attempt has been made to study the carboxymethylated derivatives of starches from two varieties of Dioscorea of this region. Different concentration of monochloroacetate was used to study the effect of degree of substitution (DS) on the physicochemical properties of starches. A considerable effect of DS was noticed on the ash content, amylose content, water-holding capacity, swelling and solubility power of carboxymethylated derivatives. Morphological studies showed the increase in the deformation of structure of the starch granule with an increase in the degree of substitution. FTIR confirmed the carboxymethylation reaction. TGA data of carboxymethylated starches revealed the stability to the temperature. Micromeritics of starch powder and granules showed the value which makes these starches to be utilized as an excipient. With the increase in DS, the % release of drug was found to be decreased. This further makes the carboxymethyl derivatives of Dioscorea a good source to be used as an excipient for sustained release formulations.