Browsing by Author "J. Balasubramaniam"

Now showing 1 - 7 of 7

Chitosan Based Periodontal Pocket Inserts - Formulation, In vitro and Preliminary Clinical Evaluation
(2004) J. Balasubramaniam; M. Thilek Kumar; Romi Barat; J.K. Pandit; Neelam Mittal
The present paper concerns the in vitro and clinical evaluation of chitosan based periodontal inserts of ciprofloxacin hydrochloride (CPH). The effects of polymer concentration, plasticizer, drug loading and type and concentration of cross-linking agents (formaldehyde and glutaraldehyde) on CPH release were studied. The release of CPH followed a Q vs t1/2 profile. An increase in the plasticizer concentration (propylene glycol and glycerol) and drug loading resulted in a higher rate of CPH release, but the type of plasticizer did not show any significant effect on drug release, whereas retardation was observed with an increase in polymer concentration and cross-linking. Clinical evaluations of the inserts were carried out in patients suffering from periodontitis with an average pocket depth of > 5 mm. Significant improvements were observed in various clinical indices as: Peridontal Index (PI), Bleeding Index (BI), Periodontal Disease Index (PDI), Shick-Ash Modification of Plaque Criteria (SAPC) and Gingival Index (GI) and microbial parameters (% of G (+)and G (-) bacteria and Total Bacterial Count - TBC) at the device inserted site, thus affirming the therapeutic value of the inserts in the treatment of periodontal pocket formation.
Gellan-based scleral implants of indomethacin: In vitro and in vivo evaluation
(2004) J. Balasubramaniam; M. Thilek Kumar; J.K. Pandit; Shri Kant
Film-type scleral implants of indomethacin with gellan gum were prepared by solvent casting and evaluated for uniformities of thickness, weight, drug content, and surface pH. The effect of plasticizers like glycerol, propylene glycol (PG), and polyethylene glycol 200, and 400 on the void volume of free gellan films (placebo) was calculated from the water content of the films. The drug release from the prepared implants was determined using a static dissolution set-up developed and optimized in our laboratory. Based on the results of the void volume and initial drug release studies, glycerol and PG were selected as the plasticizers for the gellan-based implants. The morphology of the drug-free films (containing 10% and 40% of PG) and the drug-loaded films (before and after dissolution and crosslinked) was studied using scanning electron microscopy. Further, the effect of plasticizer concentration, gellan concentration, effect of crosslinking technique, and duration of crosslinking using calcium chloride on in vitro drug release characteristics were evaluated. Selected batches of the implants were subjected to pharmacodynamic studies, after scleral placement, in uveitis-induced (intravitreal injection of bovine serum albumin 50 μg/ml) rabbit eyes. The release of indomethacin from the prepared implants followed matrix diffusion kinetics with diffusion co-efficient (n) values ranging between 0.358 to 0.708 and seemed to depend on both gellan and plasticizer concentration. Surface crosslinking with 10% calcium chloride for 8 hr retarded drug release (1.42 times less than noncrosslinked implant) and was optimum. The pharmacodynamic studies showed a marked improvement in the various clinical parameters (congestion, keratitis, flare, clot, aqueous cells, and synechias) in the implanted eye compared with the control eye in the rabbits. The scleral implants survived up to 3 weeks in vivo.
In Vitro and In Vivo Characterization of Scleral Implant of Indomethacin: Role of Plasticizer and Cross-Linking Time
(Taylor and Francis Inc., 2003) M. Thilek Kumar; C. Rajeswari; J. Balasubramaniam; J.K. Pandit; S. Kant
Film-type scleral implants of indomethacin using sodium alginate and PEG 400 and 600 (3, 5, 8, and 10% w/w w.r.t. sodium alginate) as plasticizers were fabricated by solvent casting. The prepared implants were cross-linked by treatment with calcium chloride 10, 20, and 30% w/v solution, for periods between 1 to 24 hr. Uniformity of thickness, weight, and drug content and surface pH of the implants were evaluated. The influence of plasticizer type/concentration and crosslinking time/concentration of calcium chloride on indomethacin release was studied on a static dissolution setup developed by us. Selected batches of the implants were subjected to pharmacodynamic studies, after scleral placement, in uveitis-induced (intravitreal injection of bovine serum albumin 50 μg/ml) rabbit eyes. The release of indomethacin from the implants was influenced by the concentration and nature of plasticizers used. Chemical cross-linking with calcium chloride was successful in retarding the drug release. The pharmacodynamic studies showed a marked improvement in the various clinical parameters (congestion, keratitis, flare, clot, aqueous cells, and synechias) in the implanted eye when compared with the control eye in the rabbits. The implants survived for 2 weeks in vivo.
In vitro microbiological evaluation of polyvinyl alcohol-based ocular inserts of ciprofloxacin hydrochloride
(Medknow Publications and Media Pvt. Ltd, 2006) J. Balasubramaniam; A. Srinatha; J.K. Pandit; Gopal Nath
Soluble inserts of ciprofloxacin hydrochloride using high and low molecular weight polyvinyl alcohol alone and in various combinations were fabricated by a casting technique. The in vitro drug release from the prepared inserts was studied using a continuous flow-through model, developed in our laboratory. The antimicrobial efficacies of the prepared inserts against common ocular pathogens, viz., Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853, were evaluated using a modified in vitro microbiological model. Ciprofloxacin hydrochloride release from the inserts followed matrix diffusion kinetics showing an anomalous release mechanism (erosion-controlled) based on the calculated release exponent (n) values. Drug release increased with an increase in the proportion of high molecular weight polyvinyl alcohol in the inserts. The in vitro microbiological model demonstrated the effectiveness of the inserts against the two microorganisms. Further, the results of the in vitro release studies correlated well with that of the antimicrobial studies.
Newer approaches for optimal bioavailability of ocularly delivered drugs: Review
(2011) K. Kesavan; J. Balasubramaniam; S. Kant; P.N. Singh; J.K. Pandit
Eye diseases can cause discomfort and anxiety in patients, with the ultimate fear of loss of vision and facial disfigurement. Many regions of the eye are relatively inaccessible to systemically administered drugs and, as a result, topical drug delivery remains the preferred route in most cases. Drugs may be delivered to treat the precorneal region for conjunctivitis and blepharitis, or to provide intraocular diseases such as glaucoma, uveitis, and cytomegalovirus retinitis. Most of the ophthalmic formulation strategies aim at maximizing ocular drug permeability through prolongation of the drug residence time in the cornea and conjunctival sac, as well as minimizing precorneal drug loss. The conventional topical ocular drug delivery systems show drawbacks such as increased precorneal elimination and high variability in efficacy. Attempts have been made to overcome these problems and enhance ocular bioavailability by the development of newer drug delivery systems. This review is concerned with classification, recent findings and applications and biocompatibility of newer drug delivery systems for the treatment of ocular diseases. © 2011 Bentham Science Publishers Ltd.
Niridazole biodegradable inserts for local long-term treatment of periodontitis: Possible new life for an orphan drug
(2006) Romi Barat; A. Srinatha; J. Pandit; D. Ridhurkar; J. Balasubramaniam; Neelam Mittal; Deena Mishra
Periodontal pocket inserts of niridazole (NZ) made with Resomer® (grades RG 503H and RG858, designated as RH and RG, respectively) were studied. Various formulation variables were evaluated to obtain a biodegradable delivery systems showing device degradation and drug depletion parallel to each other in vitro. Drug release from the prepared inserts was evaluated using a static dissolution setup (for 1 month). Incorporation of 3 parts of RG in 1 part of RH inserts caused a 50% decrease in the initial release rate. The RH-NZ inserts showed a spurt in release around the 10th day of the study, which coincided with the decrease in device weight, suggesting onset of device degradation. Pilot-scale clinical trials in 12 patients indicated improvements in clinical indices from the baseline values. The average pocket depth was reduced significantly (α = 0.05) from 6.34 ± 1.86 mm at baseline to 5.94 ± 0.28 mm after 28 days of treatment. Copyright © Informa Healthcare.
pH-induced in situ gelling systems of indomethacin for sustained ocular delivery
(2005) M. Thilek Kumar; D. Bharathi; J. Balasubramaniam; S. Kant; J.K. Pandit
The low bioavailability and ocular residence time exhibited by the topical conventional liquid opht halmic formulations because of spillage by overflow, dilution of drug by tear turn over, nasolacrimal drainage and systemic absorption may be overcome by the use of in situ forming systems that are instilled as liquid drops into the cul-de-sac of the eye, where they transform into a gel or semisolid phase. The present work describes the formulation and evaluation of an opthalmic delivery system of an antiinflammatory drug, indomethacin for the treatment of uveitis based on the concept of pH induced in situ gelation. The carbopol solutions which are acidic and less viscous, transform into stiff gels upon increase in pH of eyes as the gelling agents and its combination with hydroxypropylmethylcellulose-K15M, a well known ocular viscosity enhancing agent. The enhanced therapeutic efficacy and sustained release of indomethacin over 8 hour period in vitro make them an excellent candidate for in situ gelling ocular delivery systems.