ABSTRACT
In the field of oral drug delivery system, a gastroretentive system is gaining popularity day by day. Numerous of research work and extensive literature are published in past few years on gastroretentive drug delivery system. It is the one of the best and appropriate approaches for increasing the residence time of drug in the stomach and diffuses drug slowly in the sustained manner which helps in the site-specific delivery of the drug as well also increases the bioavailability at site-specific of delivery. This helps in many challenges associated with conventional oral drug delivery system. Different ways are used for approaching gastroretention viz. swelling and expandable system, high-density system, magnetic system, bioadhesive system and buoyant system with or without gas generating agents. During data mining well in vitro characterization and in vivo characterization including gamma scintigraphic and MRI techniques are well established and reported. But, still, today in vivo characterization technique is major challenging for the researcher due to its limitation. The documented literature explains the use of animal models like beagle dogs, rabbits and human subjects for in vivo evaluation parameter but it leads to increase in variation that抯 why this delivery system is limited in the market. This paper contains the latest literature compilation and various techniques used for gastroretention with its pros and cons. This review paper helps the researcher to take an overview of basics of gastroretentive drug delivery system and helps in understanding the basics of the system.
ABSTRACT
In the present experimental investigation an attempt has been made to assess the utility of Crushed Puffed Rice (CPR)-High Molecular Weight Chitosan (HMWCH)-Hydroxypropyl Methylcellulose K15M (HPMC K15M) as a polymeric carrier for the sustained stomach delivery of Piroxicam (PRX). A total of nine formulations were prepared by using 3 (2) Taguchi factorial design, physically blending drug and polymer(s) followed by encapsulation into hard gelatin capsules size 1. The prepared capsules were evaluated for various performance such as weight variation, drug contents, in vitro buoyancy and drug release in 0.1 M HCl. The effect of drug loading on in vitro performance of the formulations was also determined. Crushed puffed rice (CPR) remained buoyant for up to average time span of 06 hr as an unwetted irregular mass in 0.1 M HCl. However, when combined with HMWCH or HPMC K15M or HPMC K15M + HMWCH a low -density cylindrical raft type hydrogel was formed which remained buoyant for up to 12 hr and released up to 99% drug in a sustained manner from 8 to 12 hr following zero order release kinetics. It was also observed that drug release from drug + CPR matrices followed Fickian mechanism. Combination of CPR + HMWCH or HMWCH + HPMC K15M also follows Fickian mechanism. Obtained data from the research work suggests that CPR in combination with HMWCH or HPMC K15M or HPMC has sufficient potential to be used as a carrier for stomach specific delivery of gastric irritant drug like PRX
ABSTRACT
The purpose of investigation is to find out the potential of Medium Molecular Weight Chitosan (MMWCH) loaded with Lincomycin Hydrochloride (LNC) having pKa 7.6 and log p value 0.20 for treatment of periodontitis and gingivitis, prepared by using solvent casting technology in form of intra pocket dental film. Four sets of formulation were prepared and each set comprises of four formulations each. The formulations were evaluated for drug content uniformity, weight uniformity, thickness of patch, surface pH, moisture loss, swelling index, water vapor transmission rate, static in vitro release studies using diffusion cell, ex vivo flux study using diffusion cell by help of excised gum lining of goat, release kinetics and Akaike Information Criteria; goodness of fit (AIC) value determination. Excipient drug interaction was carried out by using Fourier Transform Infrared spectroscopy (FTIR), and by Thermo gravimetric Analysis (TGA)/Differential thermal analysis (DTA)/Derivative thermo gravimetric analysis (DTG) and this suggests that there is no drug excipient interaction occurs. The drug release studies show the sustained release without any burst effect for consecutive 5 days. Formulation R1, R2, R7, R8, R9, R10, R13 and R14 and follows the zero order release pattern and formulation R3, R4, R5, R6, R11, R12, R15 and R16 follows the Higuchi model because they have lower AIC value and higher r2 value. Formulation ER17, ER18, ER19 and ER20 is having the average flux of 1.0, 1.48, 1.35 and 1.45 mg/cm2 hr-1 respectively, and when compared statistically student’s paired t-test these all formulations are significantly different from each other.