Bioadhesive HPMC Gel Containing Gelatin Nanoparticles for Intravaginal Delivery of Tenofovir.

The aim of the present study is to formulate tenofovir loaded gelatin nanoparticles by two step desolvation method for targeted release of drug by varying the concentration of polymer and cross-linking agent. Entrapment efficiency for all the formulations was found to be within 67.32 ± 1.24 % to 92.11 ± 1.13 %. Average particle size of different tenofovir loaded gelatin nanoparticle formulations was found within the range of 294.9 - 445.3 nm. In-vitro drug release study for glutaraldehyde cross linked gelatin nanoparticles were found between 67.09 % ± 1.423 – 82.41 % ± 1.874 after 8 h of dissolution. F5 (850 mg gelatin, 0.2 ml glutaraldehyde) was considered as the best formulation based on the entrapment efficiency and drug release from nanoparticle core. Kinetics study was performed for all the formulations and best fit model for drug release was determined depending on R squared values. HPMC K15M was used as a bioadhesive polymer as well as a gelling agent. Three different gel formulations were prepared by varying concentration of HPMC K15M and incorporated with the best formulation, F5. Membrane permeation and bio-adhesion study revealed F5B gel (5% HPMC K15M) as an optimum formulation with suitable bioadhesive strength and membrane permeability.

Formulation and In-Vitro Characterization of Acyclovir Floating Matrix Tablets: A Factorial Design Study.

The objective of present study was to develop controlled release floating matrix tablets of Acyclovir using combination of release retarding polymers: hydroxypropyl methylcellulose (HPMC K15M CR) and polyethylene oxide (Polyox WSR 303) for treatment of herpes infections using direct compression technique. The influence of type of polymer and its concentration on the drug release from prepared floating tablets was investigated using a 32 factorial design. Independent variables selected were concentration of Polyox WSR 303 (X1) and HPMC K15M CR (X2) while dependent variables were percentage cumulative drug release at 3, 9 and 12 h (Q3, Q9, and Q12). Analysis of variance (ANOVA) and multiple regression analysis showed significant effect on Q3, Q9, and Q12. Formulations also contained sodium bicarbonate (NaHCO3) and anhydrous citric acid as floating agent, polyvinyl pyrrolidone (PVP K30) as dry binder and microcrystalline cellulose (MCC, Avicel PH 102) as diluent. The floating tablets were evaluated for their floating lag time (FLT), floating duration, hardness, friability, weight variation, and in-vitro drug release, dissolution efficiency and accelerated stability study. F2 with Polyox WSR 303 (50 mg) and HPMC K15M CR (15 mg) gave best results. Stability study revealed optimized formulation F2 to remain stable. A controlled release floating matrix tablet of Acyclovir was successfully prepared by using Polyox WSR 303 and HPMC K15M CR.

Formulation and characterization of a novel pH-triggered in-situ gelling ocular system containing Gatifloxacin.

The present research work deals with the formulation and evaluation of in-situ gelling system based on sol-to-gel transition for ophthalmic delivery of an antibacterial agent gatifloxacin, to overcome the problems of poor bioavaila-bility and therapeutic response exhibited by conventional formulations based a sol-to-gel transition in the cul-de-sac upon instillation. Carbopol 940 was used as the gelling agent in combination with HPMC and HPMC K15M which acted as a viscosity enhancing agent. The prepared formulations were evaluated for pH, clarity, drug content, gelling capacity, bioadhesive strength and in-vitro drug release. In-vitro drug release data of optimized formulation (F12) was treated according to Zero, First, Korsmeyer Peppas and Higuchi kinetics to access the mechanism of drug release. The clarity, pH, viscosity and drug content of the developed formulations were found in range 6.0-6.8, 10-570cps, 82-98% respectively. The gel provided sustained drug release over an 8 hour period. The developed formulation can be used as an in-situ gelling vehicle to enhance ocular bioavailability and the reduction in the frequency of instillation thereby resulting in better patient compliance.

Programmed delivery of verapamil hydrochloride from tablet in a capsule device

The aim of the present work was to develop a programmed drug delivery system which would be able to release the drug after 6 h of lag time by use of hydrophilic polymers. The capsule body was made impermeable by use of formaldehyde vapor treatment, while the cap was untreated. The capsule was filled with two layered tablets (tablet-in-capsule), followed by a sodium bicarbonate:citric acid mixture (SBCM) and lactose as bulking agent. Sodium alginate, chitosan, HPMC K15 and chitosan:sodium alginate complex (CSAC) were used as the rate modulating layer. Through combined use of HPMC K15 and adjusting the ratio of CSAC, the desired lag time of 6 h was obtained. The effect of the bulking agents on the lag time were also studied and it was found that the lag time was decreased with higher amounts of lactose, and delayed dissolution and decreased lag time was observed at higher amount of effervescent mixture.

O objetivo do presente trabalho foi desenvolver sistema de liberação programada de cloridrato de verapamil capaz de liberação imediata do fármaco após 6 h de intervalo de tempo usando polímeros hidrofílicos. O corpo da cápsula foi impermeabilizado por tratamento de vapor de formaldeído, enquanto a tampa não foi submetida ao tratamento. Dois comprimidos foram inseridos na cápsula (comprimidos em cápsula) seguido de mistura de bicarbonato de sódio: ácido cítrico e lactose, utilizados como excipientes. O alginato de sódio, a quitosana, o HPMC K15 e o complexo quitosana:alginato de sódio foram utilizados para modular a razão de liberação do fármaco. A combinação entre o HPMC K15 e o ajuste da proporção do complexo quitosana:alginato de sódio permitiu a liberação do fármaco após 6 h. O efeito dos excipientes na liberação do fármaco foi também avaliado. Verificou-se que o tempo de latência foi reduzido na presença de maior quantidade de lactose, enquanto o menor tempo foi observado empregando maior concentração da mistura efervescente.

Formulation and characterization of a novel pH-triggered in-situ gelling ocular system containing Gatifloxacin.

The present research work deals with the formulation and evaluation of in-situ gelling system based on sol-to-gel transition for ophthalmic delivery of an antibacterial agent gatifloxacin, to overcome the problems of poor bioavaila-bility and therapeutic response exhibited by conventional formulations based a sol-to-gel transition in the cul-de-sac upon instillation. Carbopol 940 was used as the gelling agent in combination with HPMC and HPMC K15M which acted as a viscosity enhancing agent. The prepared formulations were evaluated for pH, clarity, drug content, gelling capacity, bioadhesive strength and in-vitro drug release. In-vitro drug release data of optimized formulation (F12) was treated according to Zero, First, Korsmeyer Peppas and Higuchi kinetics to access the mechanism of drug release. The clarity, pH, viscosity and drug content of the developed formulations were found in range 6.0-6.8, 10-570cps, 82-98% respectively. The gel provided sustained drug release over an 8 hour period. The developed formulation can be used as an in-situ gelling vehicle to enhance ocular bioavailability and the reduction in the frequency of instillation thereby resulting in better patient compliance.